1 /*
2  * copyright (c) 2001 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVCODEC_AVCODEC_H
22 #define AVCODEC_AVCODEC_H
23 
24 /**
25  * @file
26  * @ingroup libavc
27  * Libavcodec external API header
28  */
29 
30 #include <errno.h>
31 #include "libavutil/samplefmt.h"
32 #include "libavutil/attributes.h"
33 #include "libavutil/avutil.h"
34 #include "libavutil/buffer.h"
35 #include "libavutil/cpu.h"
36 #include "libavutil/channel_layout.h"
37 #include "libavutil/dict.h"
38 #include "libavutil/frame.h"
39 #include "libavutil/log.h"
40 #include "libavutil/pixfmt.h"
41 #include "libavutil/rational.h"
42 
43 #include "version.h"
44 
45 /**
46  * @defgroup libavc Encoding/Decoding Library
47  * @{
48  *
49  * @defgroup lavc_decoding Decoding
50  * @{
51  * @}
52  *
53  * @defgroup lavc_encoding Encoding
54  * @{
55  * @}
56  *
57  * @defgroup lavc_codec Codecs
58  * @{
59  * @defgroup lavc_codec_native Native Codecs
60  * @{
61  * @}
62  * @defgroup lavc_codec_wrappers External library wrappers
63  * @{
64  * @}
65  * @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
66  * @{
67  * @}
68  * @}
69  * @defgroup lavc_internal Internal
70  * @{
71  * @}
72  * @}
73  *
74  */
75 
76 /**
77  * @defgroup lavc_core Core functions/structures.
78  * @ingroup libavc
79  *
80  * Basic definitions, functions for querying libavcodec capabilities,
81  * allocating core structures, etc.
82  * @{
83  */
84 
85 
86 /**
87  * Identify the syntax and semantics of the bitstream.
88  * The principle is roughly:
89  * Two decoders with the same ID can decode the same streams.
90  * Two encoders with the same ID can encode compatible streams.
91  * There may be slight deviations from the principle due to implementation
92  * details.
93  *
94  * If you add a codec ID to this list, add it so that
95  * 1. no value of a existing codec ID changes (that would break ABI),
96  * 2. it is as close as possible to similar codecs
97  *
98  * After adding new codec IDs, do not forget to add an entry to the codec
99  * descriptor list and bump libavcodec minor version.
100  */
101 enum AVCodecID {
102     AV_CODEC_ID_NONE,
103 
104     /* video codecs */
105     AV_CODEC_ID_MPEG1VIDEO,
106     AV_CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
107 #if FF_API_XVMC
108     AV_CODEC_ID_MPEG2VIDEO_XVMC,
109 #endif /* FF_API_XVMC */
110     AV_CODEC_ID_H261,
111     AV_CODEC_ID_H263,
112     AV_CODEC_ID_RV10,
113     AV_CODEC_ID_RV20,
114     AV_CODEC_ID_MJPEG,
115     AV_CODEC_ID_MJPEGB,
116     AV_CODEC_ID_LJPEG,
117     AV_CODEC_ID_SP5X,
118     AV_CODEC_ID_JPEGLS,
119     AV_CODEC_ID_MPEG4,
120     AV_CODEC_ID_RAWVIDEO,
121     AV_CODEC_ID_MSMPEG4V1,
122     AV_CODEC_ID_MSMPEG4V2,
123     AV_CODEC_ID_MSMPEG4V3,
124     AV_CODEC_ID_WMV1,
125     AV_CODEC_ID_WMV2,
126     AV_CODEC_ID_H263P,
127     AV_CODEC_ID_H263I,
128     AV_CODEC_ID_FLV1,
129     AV_CODEC_ID_SVQ1,
130     AV_CODEC_ID_SVQ3,
131     AV_CODEC_ID_DVVIDEO,
132     AV_CODEC_ID_HUFFYUV,
133     AV_CODEC_ID_CYUV,
134     AV_CODEC_ID_H264,
135     AV_CODEC_ID_INDEO3,
136     AV_CODEC_ID_VP3,
137     AV_CODEC_ID_THEORA,
138     AV_CODEC_ID_ASV1,
139     AV_CODEC_ID_ASV2,
140     AV_CODEC_ID_FFV1,
141     AV_CODEC_ID_4XM,
142     AV_CODEC_ID_VCR1,
143     AV_CODEC_ID_CLJR,
144     AV_CODEC_ID_MDEC,
145     AV_CODEC_ID_ROQ,
146     AV_CODEC_ID_INTERPLAY_VIDEO,
147     AV_CODEC_ID_XAN_WC3,
148     AV_CODEC_ID_XAN_WC4,
149     AV_CODEC_ID_RPZA,
150     AV_CODEC_ID_CINEPAK,
151     AV_CODEC_ID_WS_VQA,
152     AV_CODEC_ID_MSRLE,
153     AV_CODEC_ID_MSVIDEO1,
154     AV_CODEC_ID_IDCIN,
155     AV_CODEC_ID_8BPS,
156     AV_CODEC_ID_SMC,
157     AV_CODEC_ID_FLIC,
158     AV_CODEC_ID_TRUEMOTION1,
159     AV_CODEC_ID_VMDVIDEO,
160     AV_CODEC_ID_MSZH,
161     AV_CODEC_ID_ZLIB,
162     AV_CODEC_ID_QTRLE,
163     AV_CODEC_ID_TSCC,
164     AV_CODEC_ID_ULTI,
165     AV_CODEC_ID_QDRAW,
166     AV_CODEC_ID_VIXL,
167     AV_CODEC_ID_QPEG,
168     AV_CODEC_ID_PNG,
169     AV_CODEC_ID_PPM,
170     AV_CODEC_ID_PBM,
171     AV_CODEC_ID_PGM,
172     AV_CODEC_ID_PGMYUV,
173     AV_CODEC_ID_PAM,
174     AV_CODEC_ID_FFVHUFF,
175     AV_CODEC_ID_RV30,
176     AV_CODEC_ID_RV40,
177     AV_CODEC_ID_VC1,
178     AV_CODEC_ID_WMV3,
179     AV_CODEC_ID_LOCO,
180     AV_CODEC_ID_WNV1,
181     AV_CODEC_ID_AASC,
182     AV_CODEC_ID_INDEO2,
183     AV_CODEC_ID_FRAPS,
184     AV_CODEC_ID_TRUEMOTION2,
185     AV_CODEC_ID_BMP,
186     AV_CODEC_ID_CSCD,
187     AV_CODEC_ID_MMVIDEO,
188     AV_CODEC_ID_ZMBV,
189     AV_CODEC_ID_AVS,
190     AV_CODEC_ID_SMACKVIDEO,
191     AV_CODEC_ID_NUV,
192     AV_CODEC_ID_KMVC,
193     AV_CODEC_ID_FLASHSV,
194     AV_CODEC_ID_CAVS,
195     AV_CODEC_ID_JPEG2000,
196     AV_CODEC_ID_VMNC,
197     AV_CODEC_ID_VP5,
198     AV_CODEC_ID_VP6,
199     AV_CODEC_ID_VP6F,
200     AV_CODEC_ID_TARGA,
201     AV_CODEC_ID_DSICINVIDEO,
202     AV_CODEC_ID_TIERTEXSEQVIDEO,
203     AV_CODEC_ID_TIFF,
204     AV_CODEC_ID_GIF,
205     AV_CODEC_ID_DXA,
206     AV_CODEC_ID_DNXHD,
207     AV_CODEC_ID_THP,
208     AV_CODEC_ID_SGI,
209     AV_CODEC_ID_C93,
210     AV_CODEC_ID_BETHSOFTVID,
211     AV_CODEC_ID_PTX,
212     AV_CODEC_ID_TXD,
213     AV_CODEC_ID_VP6A,
214     AV_CODEC_ID_AMV,
215     AV_CODEC_ID_VB,
216     AV_CODEC_ID_PCX,
217     AV_CODEC_ID_SUNRAST,
218     AV_CODEC_ID_INDEO4,
219     AV_CODEC_ID_INDEO5,
220     AV_CODEC_ID_MIMIC,
221     AV_CODEC_ID_RL2,
222     AV_CODEC_ID_ESCAPE124,
223     AV_CODEC_ID_DIRAC,
224     AV_CODEC_ID_BFI,
225     AV_CODEC_ID_CMV,
226     AV_CODEC_ID_MOTIONPIXELS,
227     AV_CODEC_ID_TGV,
228     AV_CODEC_ID_TGQ,
229     AV_CODEC_ID_TQI,
230     AV_CODEC_ID_AURA,
231     AV_CODEC_ID_AURA2,
232     AV_CODEC_ID_V210X,
233     AV_CODEC_ID_TMV,
234     AV_CODEC_ID_V210,
235     AV_CODEC_ID_DPX,
236     AV_CODEC_ID_MAD,
237     AV_CODEC_ID_FRWU,
238     AV_CODEC_ID_FLASHSV2,
239     AV_CODEC_ID_CDGRAPHICS,
240     AV_CODEC_ID_R210,
241     AV_CODEC_ID_ANM,
242     AV_CODEC_ID_BINKVIDEO,
243     AV_CODEC_ID_IFF_ILBM,
244 #define AV_CODEC_ID_IFF_BYTERUN1 AV_CODEC_ID_IFF_ILBM
245     AV_CODEC_ID_KGV1,
246     AV_CODEC_ID_YOP,
247     AV_CODEC_ID_VP8,
248     AV_CODEC_ID_PICTOR,
249     AV_CODEC_ID_ANSI,
250     AV_CODEC_ID_A64_MULTI,
251     AV_CODEC_ID_A64_MULTI5,
252     AV_CODEC_ID_R10K,
253     AV_CODEC_ID_MXPEG,
254     AV_CODEC_ID_LAGARITH,
255     AV_CODEC_ID_PRORES,
256     AV_CODEC_ID_JV,
257     AV_CODEC_ID_DFA,
258     AV_CODEC_ID_WMV3IMAGE,
259     AV_CODEC_ID_VC1IMAGE,
260     AV_CODEC_ID_UTVIDEO,
261     AV_CODEC_ID_BMV_VIDEO,
262     AV_CODEC_ID_VBLE,
263     AV_CODEC_ID_DXTORY,
264     AV_CODEC_ID_V410,
265     AV_CODEC_ID_XWD,
266     AV_CODEC_ID_CDXL,
267     AV_CODEC_ID_XBM,
268     AV_CODEC_ID_ZEROCODEC,
269     AV_CODEC_ID_MSS1,
270     AV_CODEC_ID_MSA1,
271     AV_CODEC_ID_TSCC2,
272     AV_CODEC_ID_MTS2,
273     AV_CODEC_ID_CLLC,
274     AV_CODEC_ID_MSS2,
275     AV_CODEC_ID_VP9,
276     AV_CODEC_ID_AIC,
277     AV_CODEC_ID_ESCAPE130,
278     AV_CODEC_ID_G2M,
279     AV_CODEC_ID_WEBP,
280     AV_CODEC_ID_HNM4_VIDEO,
281     AV_CODEC_ID_HEVC,
282 #define AV_CODEC_ID_H265 AV_CODEC_ID_HEVC
283     AV_CODEC_ID_FIC,
284     AV_CODEC_ID_ALIAS_PIX,
285     AV_CODEC_ID_BRENDER_PIX,
286     AV_CODEC_ID_PAF_VIDEO,
287     AV_CODEC_ID_EXR,
288     AV_CODEC_ID_VP7,
289     AV_CODEC_ID_SANM,
290     AV_CODEC_ID_SGIRLE,
291     AV_CODEC_ID_MVC1,
292     AV_CODEC_ID_MVC2,
293     AV_CODEC_ID_HQX,
294     AV_CODEC_ID_TDSC,
295     AV_CODEC_ID_HQ_HQA,
296     AV_CODEC_ID_HAP,
297     AV_CODEC_ID_DDS,
298     AV_CODEC_ID_DXV,
299     AV_CODEC_ID_SCREENPRESSO,
300     AV_CODEC_ID_RSCC,
301 
302     AV_CODEC_ID_Y41P = 0x8000,
303     AV_CODEC_ID_AVRP,
304     AV_CODEC_ID_012V,
305     AV_CODEC_ID_AVUI,
306     AV_CODEC_ID_AYUV,
307     AV_CODEC_ID_TARGA_Y216,
308     AV_CODEC_ID_V308,
309     AV_CODEC_ID_V408,
310     AV_CODEC_ID_YUV4,
311     AV_CODEC_ID_AVRN,
312     AV_CODEC_ID_CPIA,
313     AV_CODEC_ID_XFACE,
314     AV_CODEC_ID_SNOW,
315     AV_CODEC_ID_SMVJPEG,
316     AV_CODEC_ID_APNG,
317     AV_CODEC_ID_DAALA,
318 
319     /* various PCM "codecs" */
320     AV_CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs
321     AV_CODEC_ID_PCM_S16LE = 0x10000,
322     AV_CODEC_ID_PCM_S16BE,
323     AV_CODEC_ID_PCM_U16LE,
324     AV_CODEC_ID_PCM_U16BE,
325     AV_CODEC_ID_PCM_S8,
326     AV_CODEC_ID_PCM_U8,
327     AV_CODEC_ID_PCM_MULAW,
328     AV_CODEC_ID_PCM_ALAW,
329     AV_CODEC_ID_PCM_S32LE,
330     AV_CODEC_ID_PCM_S32BE,
331     AV_CODEC_ID_PCM_U32LE,
332     AV_CODEC_ID_PCM_U32BE,
333     AV_CODEC_ID_PCM_S24LE,
334     AV_CODEC_ID_PCM_S24BE,
335     AV_CODEC_ID_PCM_U24LE,
336     AV_CODEC_ID_PCM_U24BE,
337     AV_CODEC_ID_PCM_S24DAUD,
338     AV_CODEC_ID_PCM_ZORK,
339     AV_CODEC_ID_PCM_S16LE_PLANAR,
340     AV_CODEC_ID_PCM_DVD,
341     AV_CODEC_ID_PCM_F32BE,
342     AV_CODEC_ID_PCM_F32LE,
343     AV_CODEC_ID_PCM_F64BE,
344     AV_CODEC_ID_PCM_F64LE,
345     AV_CODEC_ID_PCM_BLURAY,
346     AV_CODEC_ID_PCM_LXF,
347     AV_CODEC_ID_S302M,
348     AV_CODEC_ID_PCM_S8_PLANAR,
349     AV_CODEC_ID_PCM_S24LE_PLANAR,
350     AV_CODEC_ID_PCM_S32LE_PLANAR,
351     AV_CODEC_ID_PCM_S16BE_PLANAR,
352     /* new PCM "codecs" should be added right below this line starting with
353      * an explicit value of for example 0x10800
354      */
355 
356     /* various ADPCM codecs */
357     AV_CODEC_ID_ADPCM_IMA_QT = 0x11000,
358     AV_CODEC_ID_ADPCM_IMA_WAV,
359     AV_CODEC_ID_ADPCM_IMA_DK3,
360     AV_CODEC_ID_ADPCM_IMA_DK4,
361     AV_CODEC_ID_ADPCM_IMA_WS,
362     AV_CODEC_ID_ADPCM_IMA_SMJPEG,
363     AV_CODEC_ID_ADPCM_MS,
364     AV_CODEC_ID_ADPCM_4XM,
365     AV_CODEC_ID_ADPCM_XA,
366     AV_CODEC_ID_ADPCM_ADX,
367     AV_CODEC_ID_ADPCM_EA,
368     AV_CODEC_ID_ADPCM_G726,
369     AV_CODEC_ID_ADPCM_CT,
370     AV_CODEC_ID_ADPCM_SWF,
371     AV_CODEC_ID_ADPCM_YAMAHA,
372     AV_CODEC_ID_ADPCM_SBPRO_4,
373     AV_CODEC_ID_ADPCM_SBPRO_3,
374     AV_CODEC_ID_ADPCM_SBPRO_2,
375     AV_CODEC_ID_ADPCM_THP,
376     AV_CODEC_ID_ADPCM_IMA_AMV,
377     AV_CODEC_ID_ADPCM_EA_R1,
378     AV_CODEC_ID_ADPCM_EA_R3,
379     AV_CODEC_ID_ADPCM_EA_R2,
380     AV_CODEC_ID_ADPCM_IMA_EA_SEAD,
381     AV_CODEC_ID_ADPCM_IMA_EA_EACS,
382     AV_CODEC_ID_ADPCM_EA_XAS,
383     AV_CODEC_ID_ADPCM_EA_MAXIS_XA,
384     AV_CODEC_ID_ADPCM_IMA_ISS,
385     AV_CODEC_ID_ADPCM_G722,
386     AV_CODEC_ID_ADPCM_IMA_APC,
387     AV_CODEC_ID_ADPCM_VIMA,
388 #if FF_API_VIMA_DECODER
389     AV_CODEC_ID_VIMA = AV_CODEC_ID_ADPCM_VIMA,
390 #endif
391 
392     AV_CODEC_ID_ADPCM_AFC = 0x11800,
393     AV_CODEC_ID_ADPCM_IMA_OKI,
394     AV_CODEC_ID_ADPCM_DTK,
395     AV_CODEC_ID_ADPCM_IMA_RAD,
396     AV_CODEC_ID_ADPCM_G726LE,
397     AV_CODEC_ID_ADPCM_THP_LE,
398     AV_CODEC_ID_ADPCM_PSX,
399     AV_CODEC_ID_ADPCM_AICA,
400 
401     /* AMR */
402     AV_CODEC_ID_AMR_NB = 0x12000,
403     AV_CODEC_ID_AMR_WB,
404 
405     /* RealAudio codecs*/
406     AV_CODEC_ID_RA_144 = 0x13000,
407     AV_CODEC_ID_RA_288,
408 
409     /* various DPCM codecs */
410     AV_CODEC_ID_ROQ_DPCM = 0x14000,
411     AV_CODEC_ID_INTERPLAY_DPCM,
412     AV_CODEC_ID_XAN_DPCM,
413     AV_CODEC_ID_SOL_DPCM,
414 
415     AV_CODEC_ID_SDX2_DPCM = 0x14800,
416 
417     /* audio codecs */
418     AV_CODEC_ID_MP2 = 0x15000,
419     AV_CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
420     AV_CODEC_ID_AAC,
421     AV_CODEC_ID_AC3,
422     AV_CODEC_ID_DTS,
423     AV_CODEC_ID_VORBIS,
424     AV_CODEC_ID_DVAUDIO,
425     AV_CODEC_ID_WMAV1,
426     AV_CODEC_ID_WMAV2,
427     AV_CODEC_ID_MACE3,
428     AV_CODEC_ID_MACE6,
429     AV_CODEC_ID_VMDAUDIO,
430     AV_CODEC_ID_FLAC,
431     AV_CODEC_ID_MP3ADU,
432     AV_CODEC_ID_MP3ON4,
433     AV_CODEC_ID_SHORTEN,
434     AV_CODEC_ID_ALAC,
435     AV_CODEC_ID_WESTWOOD_SND1,
436     AV_CODEC_ID_GSM, ///< as in Berlin toast format
437     AV_CODEC_ID_QDM2,
438     AV_CODEC_ID_COOK,
439     AV_CODEC_ID_TRUESPEECH,
440     AV_CODEC_ID_TTA,
441     AV_CODEC_ID_SMACKAUDIO,
442     AV_CODEC_ID_QCELP,
443     AV_CODEC_ID_WAVPACK,
444     AV_CODEC_ID_DSICINAUDIO,
445     AV_CODEC_ID_IMC,
446     AV_CODEC_ID_MUSEPACK7,
447     AV_CODEC_ID_MLP,
448     AV_CODEC_ID_GSM_MS, /* as found in WAV */
449     AV_CODEC_ID_ATRAC3,
450 #if FF_API_VOXWARE
451     AV_CODEC_ID_VOXWARE,
452 #endif
453     AV_CODEC_ID_APE,
454     AV_CODEC_ID_NELLYMOSER,
455     AV_CODEC_ID_MUSEPACK8,
456     AV_CODEC_ID_SPEEX,
457     AV_CODEC_ID_WMAVOICE,
458     AV_CODEC_ID_WMAPRO,
459     AV_CODEC_ID_WMALOSSLESS,
460     AV_CODEC_ID_ATRAC3P,
461     AV_CODEC_ID_EAC3,
462     AV_CODEC_ID_SIPR,
463     AV_CODEC_ID_MP1,
464     AV_CODEC_ID_TWINVQ,
465     AV_CODEC_ID_TRUEHD,
466     AV_CODEC_ID_MP4ALS,
467     AV_CODEC_ID_ATRAC1,
468     AV_CODEC_ID_BINKAUDIO_RDFT,
469     AV_CODEC_ID_BINKAUDIO_DCT,
470     AV_CODEC_ID_AAC_LATM,
471     AV_CODEC_ID_QDMC,
472     AV_CODEC_ID_CELT,
473     AV_CODEC_ID_G723_1,
474     AV_CODEC_ID_G729,
475     AV_CODEC_ID_8SVX_EXP,
476     AV_CODEC_ID_8SVX_FIB,
477     AV_CODEC_ID_BMV_AUDIO,
478     AV_CODEC_ID_RALF,
479     AV_CODEC_ID_IAC,
480     AV_CODEC_ID_ILBC,
481     AV_CODEC_ID_OPUS,
482     AV_CODEC_ID_COMFORT_NOISE,
483     AV_CODEC_ID_TAK,
484     AV_CODEC_ID_METASOUND,
485     AV_CODEC_ID_PAF_AUDIO,
486     AV_CODEC_ID_ON2AVC,
487     AV_CODEC_ID_DSS_SP,
488 
489     AV_CODEC_ID_FFWAVESYNTH = 0x15800,
490     AV_CODEC_ID_SONIC,
491     AV_CODEC_ID_SONIC_LS,
492     AV_CODEC_ID_EVRC,
493     AV_CODEC_ID_SMV,
494     AV_CODEC_ID_DSD_LSBF,
495     AV_CODEC_ID_DSD_MSBF,
496     AV_CODEC_ID_DSD_LSBF_PLANAR,
497     AV_CODEC_ID_DSD_MSBF_PLANAR,
498     AV_CODEC_ID_4GV,
499     AV_CODEC_ID_INTERPLAY_ACM,
500     AV_CODEC_ID_XMA1,
501     AV_CODEC_ID_XMA2,
502 
503     /* subtitle codecs */
504     AV_CODEC_ID_FIRST_SUBTITLE = 0x17000,          ///< A dummy ID pointing at the start of subtitle codecs.
505     AV_CODEC_ID_DVD_SUBTITLE = 0x17000,
506     AV_CODEC_ID_DVB_SUBTITLE,
507     AV_CODEC_ID_TEXT,  ///< raw UTF-8 text
508     AV_CODEC_ID_XSUB,
509     AV_CODEC_ID_SSA,
510     AV_CODEC_ID_MOV_TEXT,
511     AV_CODEC_ID_HDMV_PGS_SUBTITLE,
512     AV_CODEC_ID_DVB_TELETEXT,
513     AV_CODEC_ID_SRT,
514 
515     AV_CODEC_ID_MICRODVD   = 0x17800,
516     AV_CODEC_ID_EIA_608,
517     AV_CODEC_ID_JACOSUB,
518     AV_CODEC_ID_SAMI,
519     AV_CODEC_ID_REALTEXT,
520     AV_CODEC_ID_STL,
521     AV_CODEC_ID_SUBVIEWER1,
522     AV_CODEC_ID_SUBVIEWER,
523     AV_CODEC_ID_SUBRIP,
524     AV_CODEC_ID_WEBVTT,
525     AV_CODEC_ID_MPL2,
526     AV_CODEC_ID_VPLAYER,
527     AV_CODEC_ID_PJS,
528     AV_CODEC_ID_ASS,
529     AV_CODEC_ID_HDMV_TEXT_SUBTITLE,
530 
531     /* other specific kind of codecs (generally used for attachments) */
532     AV_CODEC_ID_FIRST_UNKNOWN = 0x18000,           ///< A dummy ID pointing at the start of various fake codecs.
533     AV_CODEC_ID_TTF = 0x18000,
534 
535     AV_CODEC_ID_BINTEXT    = 0x18800,
536     AV_CODEC_ID_XBIN,
537     AV_CODEC_ID_IDF,
538     AV_CODEC_ID_OTF,
539     AV_CODEC_ID_SMPTE_KLV,
540     AV_CODEC_ID_DVD_NAV,
541     AV_CODEC_ID_TIMED_ID3,
542     AV_CODEC_ID_BIN_DATA,
543 
544 
545     AV_CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like AV_CODEC_ID_NONE) but lavf should attempt to identify it
546 
547     AV_CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
548                                 * stream (only used by libavformat) */
549     AV_CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
550                                 * stream (only used by libavformat) */
551     AV_CODEC_ID_FFMETADATA = 0x21000,   ///< Dummy codec for streams containing only metadata information.
552     AV_CODEC_ID_WRAPPED_AVFRAME = 0x21001, ///< Passthrough codec, AVFrames wrapped in AVPacket
553 };
554 
555 /**
556  * This struct describes the properties of a single codec described by an
557  * AVCodecID.
558  * @see avcodec_descriptor_get()
559  */
560 typedef struct AVCodecDescriptor {
561     enum AVCodecID     id;
562     enum AVMediaType type;
563     /**
564      * Name of the codec described by this descriptor. It is non-empty and
565      * unique for each codec descriptor. It should contain alphanumeric
566      * characters and '_' only.
567      */
568     const char      *name;
569     /**
570      * A more descriptive name for this codec. May be NULL.
571      */
572     const char *long_name;
573     /**
574      * Codec properties, a combination of AV_CODEC_PROP_* flags.
575      */
576     int             props;
577     /**
578      * MIME type(s) associated with the codec.
579      * May be NULL; if not, a NULL-terminated array of MIME types.
580      * The first item is always non-NULL and is the preferred MIME type.
581      */
582     const char *const *mime_types;
583     /**
584      * If non-NULL, an array of profiles recognized for this codec.
585      * Terminated with FF_PROFILE_UNKNOWN.
586      */
587     const struct AVProfile *profiles;
588 } AVCodecDescriptor;
589 
590 /**
591  * Codec uses only intra compression.
592  * Video codecs only.
593  */
594 #define AV_CODEC_PROP_INTRA_ONLY    (1 << 0)
595 /**
596  * Codec supports lossy compression. Audio and video codecs only.
597  * @note a codec may support both lossy and lossless
598  * compression modes
599  */
600 #define AV_CODEC_PROP_LOSSY         (1 << 1)
601 /**
602  * Codec supports lossless compression. Audio and video codecs only.
603  */
604 #define AV_CODEC_PROP_LOSSLESS      (1 << 2)
605 /**
606  * Codec supports frame reordering. That is, the coded order (the order in which
607  * the encoded packets are output by the encoders / stored / input to the
608  * decoders) may be different from the presentation order of the corresponding
609  * frames.
610  *
611  * For codecs that do not have this property set, PTS and DTS should always be
612  * equal.
613  */
614 #define AV_CODEC_PROP_REORDER       (1 << 3)
615 /**
616  * Subtitle codec is bitmap based
617  * Decoded AVSubtitle data can be read from the AVSubtitleRect->pict field.
618  */
619 #define AV_CODEC_PROP_BITMAP_SUB    (1 << 16)
620 /**
621  * Subtitle codec is text based.
622  * Decoded AVSubtitle data can be read from the AVSubtitleRect->ass field.
623  */
624 #define AV_CODEC_PROP_TEXT_SUB      (1 << 17)
625 
626 /**
627  * @ingroup lavc_decoding
628  * Required number of additionally allocated bytes at the end of the input bitstream for decoding.
629  * This is mainly needed because some optimized bitstream readers read
630  * 32 or 64 bit at once and could read over the end.<br>
631  * Note: If the first 23 bits of the additional bytes are not 0, then damaged
632  * MPEG bitstreams could cause overread and segfault.
633  */
634 #define AV_INPUT_BUFFER_PADDING_SIZE 32
635 
636 /**
637  * @ingroup lavc_encoding
638  * minimum encoding buffer size
639  * Used to avoid some checks during header writing.
640  */
641 #define AV_INPUT_BUFFER_MIN_SIZE 16384
642 
643 #if FF_API_WITHOUT_PREFIX
644 /**
645  * @deprecated use AV_INPUT_BUFFER_PADDING_SIZE instead
646  */
647 #define FF_INPUT_BUFFER_PADDING_SIZE 32
648 
649 /**
650  * @deprecated use AV_INPUT_BUFFER_MIN_SIZE instead
651  */
652 #define FF_MIN_BUFFER_SIZE 16384
653 #endif /* FF_API_WITHOUT_PREFIX */
654 
655 /**
656  * @ingroup lavc_encoding
657  * motion estimation type.
658  * @deprecated use codec private option instead
659  */
660 #if FF_API_MOTION_EST
661 enum Motion_Est_ID {
662     ME_ZERO = 1,    ///< no search, that is use 0,0 vector whenever one is needed
663     ME_FULL,
664     ME_LOG,
665     ME_PHODS,
666     ME_EPZS,        ///< enhanced predictive zonal search
667     ME_X1,          ///< reserved for experiments
668     ME_HEX,         ///< hexagon based search
669     ME_UMH,         ///< uneven multi-hexagon search
670     ME_TESA,        ///< transformed exhaustive search algorithm
671     ME_ITER=50,     ///< iterative search
672 };
673 #endif
674 
675 /**
676  * @ingroup lavc_decoding
677  */
678 enum AVDiscard{
679     /* We leave some space between them for extensions (drop some
680      * keyframes for intra-only or drop just some bidir frames). */
681     AVDISCARD_NONE    =-16, ///< discard nothing
682     AVDISCARD_DEFAULT =  0, ///< discard useless packets like 0 size packets in avi
683     AVDISCARD_NONREF  =  8, ///< discard all non reference
684     AVDISCARD_BIDIR   = 16, ///< discard all bidirectional frames
685     AVDISCARD_NONINTRA= 24, ///< discard all non intra frames
686     AVDISCARD_NONKEY  = 32, ///< discard all frames except keyframes
687     AVDISCARD_ALL     = 48, ///< discard all
688 };
689 
690 enum AVAudioServiceType {
691     AV_AUDIO_SERVICE_TYPE_MAIN              = 0,
692     AV_AUDIO_SERVICE_TYPE_EFFECTS           = 1,
693     AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED = 2,
694     AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED  = 3,
695     AV_AUDIO_SERVICE_TYPE_DIALOGUE          = 4,
696     AV_AUDIO_SERVICE_TYPE_COMMENTARY        = 5,
697     AV_AUDIO_SERVICE_TYPE_EMERGENCY         = 6,
698     AV_AUDIO_SERVICE_TYPE_VOICE_OVER        = 7,
699     AV_AUDIO_SERVICE_TYPE_KARAOKE           = 8,
700     AV_AUDIO_SERVICE_TYPE_NB                   , ///< Not part of ABI
701 };
702 
703 /**
704  * @ingroup lavc_encoding
705  */
706 typedef struct RcOverride{
707     int start_frame;
708     int end_frame;
709     int qscale; // If this is 0 then quality_factor will be used instead.
710     float quality_factor;
711 } RcOverride;
712 
713 #if FF_API_MAX_BFRAMES
714 /**
715  * @deprecated there is no libavcodec-wide limit on the number of B-frames
716  */
717 #define FF_MAX_B_FRAMES 16
718 #endif
719 
720 /* encoding support
721    These flags can be passed in AVCodecContext.flags before initialization.
722    Note: Not everything is supported yet.
723 */
724 
725 /**
726  * Allow decoders to produce frames with data planes that are not aligned
727  * to CPU requirements (e.g. due to cropping).
728  */
729 #define AV_CODEC_FLAG_UNALIGNED       (1 <<  0)
730 /**
731  * Use fixed qscale.
732  */
733 #define AV_CODEC_FLAG_QSCALE          (1 <<  1)
734 /**
735  * 4 MV per MB allowed / advanced prediction for H.263.
736  */
737 #define AV_CODEC_FLAG_4MV             (1 <<  2)
738 /**
739  * Output even those frames that might be corrupted.
740  */
741 #define AV_CODEC_FLAG_OUTPUT_CORRUPT  (1 <<  3)
742 /**
743  * Use qpel MC.
744  */
745 #define AV_CODEC_FLAG_QPEL            (1 <<  4)
746 /**
747  * Use internal 2pass ratecontrol in first pass mode.
748  */
749 #define AV_CODEC_FLAG_PASS1           (1 <<  9)
750 /**
751  * Use internal 2pass ratecontrol in second pass mode.
752  */
753 #define AV_CODEC_FLAG_PASS2           (1 << 10)
754 /**
755  * loop filter.
756  */
757 #define AV_CODEC_FLAG_LOOP_FILTER     (1 << 11)
758 /**
759  * Only decode/encode grayscale.
760  */
761 #define AV_CODEC_FLAG_GRAY            (1 << 13)
762 /**
763  * error[?] variables will be set during encoding.
764  */
765 #define AV_CODEC_FLAG_PSNR            (1 << 15)
766 /**
767  * Input bitstream might be truncated at a random location
768  * instead of only at frame boundaries.
769  */
770 #define AV_CODEC_FLAG_TRUNCATED       (1 << 16)
771 /**
772  * Use interlaced DCT.
773  */
774 #define AV_CODEC_FLAG_INTERLACED_DCT  (1 << 18)
775 /**
776  * Force low delay.
777  */
778 #define AV_CODEC_FLAG_LOW_DELAY       (1 << 19)
779 /**
780  * Place global headers in extradata instead of every keyframe.
781  */
782 #define AV_CODEC_FLAG_GLOBAL_HEADER   (1 << 22)
783 /**
784  * Use only bitexact stuff (except (I)DCT).
785  */
786 #define AV_CODEC_FLAG_BITEXACT        (1 << 23)
787 /* Fx : Flag for h263+ extra options */
788 /**
789  * H.263 advanced intra coding / MPEG-4 AC prediction
790  */
791 #define AV_CODEC_FLAG_AC_PRED         (1 << 24)
792 /**
793  * interlaced motion estimation
794  */
795 #define AV_CODEC_FLAG_INTERLACED_ME   (1 << 29)
796 #define AV_CODEC_FLAG_CLOSED_GOP      (1U << 31)
797 
798 /**
799  * Allow non spec compliant speedup tricks.
800  */
801 #define AV_CODEC_FLAG2_FAST           (1 <<  0)
802 /**
803  * Skip bitstream encoding.
804  */
805 #define AV_CODEC_FLAG2_NO_OUTPUT      (1 <<  2)
806 /**
807  * Place global headers at every keyframe instead of in extradata.
808  */
809 #define AV_CODEC_FLAG2_LOCAL_HEADER   (1 <<  3)
810 
811 /**
812  * timecode is in drop frame format. DEPRECATED!!!!
813  */
814 #define AV_CODEC_FLAG2_DROP_FRAME_TIMECODE (1 << 13)
815 
816 /**
817  * Input bitstream might be truncated at a packet boundaries
818  * instead of only at frame boundaries.
819  */
820 #define AV_CODEC_FLAG2_CHUNKS         (1 << 15)
821 /**
822  * Discard cropping information from SPS.
823  */
824 #define AV_CODEC_FLAG2_IGNORE_CROP    (1 << 16)
825 
826 /**
827  * Show all frames before the first keyframe
828  */
829 #define AV_CODEC_FLAG2_SHOW_ALL       (1 << 22)
830 /**
831  * Export motion vectors through frame side data
832  */
833 #define AV_CODEC_FLAG2_EXPORT_MVS     (1 << 28)
834 /**
835  * Do not skip samples and export skip information as frame side data
836  */
837 #define AV_CODEC_FLAG2_SKIP_MANUAL    (1 << 29)
838 
839 /* Unsupported options :
840  *              Syntax Arithmetic coding (SAC)
841  *              Reference Picture Selection
842  *              Independent Segment Decoding */
843 /* /Fx */
844 /* codec capabilities */
845 
846 /**
847  * Decoder can use draw_horiz_band callback.
848  */
849 #define AV_CODEC_CAP_DRAW_HORIZ_BAND     (1 <<  0)
850 /**
851  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
852  * If not set, it might not use get_buffer() at all or use operations that
853  * assume the buffer was allocated by avcodec_default_get_buffer.
854  */
855 #define AV_CODEC_CAP_DR1                 (1 <<  1)
856 #define AV_CODEC_CAP_TRUNCATED           (1 <<  3)
857 /**
858  * Encoder or decoder requires flushing with NULL input at the end in order to
859  * give the complete and correct output.
860  *
861  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
862  *       with NULL data. The user can still send NULL data to the public encode
863  *       or decode function, but libavcodec will not pass it along to the codec
864  *       unless this flag is set.
865  *
866  * Decoders:
867  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
868  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
869  * returns frames.
870  *
871  * Encoders:
872  * The encoder needs to be fed with NULL data at the end of encoding until the
873  * encoder no longer returns data.
874  *
875  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
876  *       flag also means that the encoder must set the pts and duration for
877  *       each output packet. If this flag is not set, the pts and duration will
878  *       be determined by libavcodec from the input frame.
879  */
880 #define AV_CODEC_CAP_DELAY               (1 <<  5)
881 /**
882  * Codec can be fed a final frame with a smaller size.
883  * This can be used to prevent truncation of the last audio samples.
884  */
885 #define AV_CODEC_CAP_SMALL_LAST_FRAME    (1 <<  6)
886 
887 #if FF_API_CAP_VDPAU
888 /**
889  * Codec can export data for HW decoding (VDPAU).
890  */
891 #define AV_CODEC_CAP_HWACCEL_VDPAU       (1 <<  7)
892 #endif
893 
894 /**
895  * Codec can output multiple frames per AVPacket
896  * Normally demuxers return one frame at a time, demuxers which do not do
897  * are connected to a parser to split what they return into proper frames.
898  * This flag is reserved to the very rare category of codecs which have a
899  * bitstream that cannot be split into frames without timeconsuming
900  * operations like full decoding. Demuxers carring such bitstreams thus
901  * may return multiple frames in a packet. This has many disadvantages like
902  * prohibiting stream copy in many cases thus it should only be considered
903  * as a last resort.
904  */
905 #define AV_CODEC_CAP_SUBFRAMES           (1 <<  8)
906 /**
907  * Codec is experimental and is thus avoided in favor of non experimental
908  * encoders
909  */
910 #define AV_CODEC_CAP_EXPERIMENTAL        (1 <<  9)
911 /**
912  * Codec should fill in channel configuration and samplerate instead of container
913  */
914 #define AV_CODEC_CAP_CHANNEL_CONF        (1 << 10)
915 /**
916  * Codec supports frame-level multithreading.
917  */
918 #define AV_CODEC_CAP_FRAME_THREADS       (1 << 12)
919 /**
920  * Codec supports slice-based (or partition-based) multithreading.
921  */
922 #define AV_CODEC_CAP_SLICE_THREADS       (1 << 13)
923 /**
924  * Codec supports changed parameters at any point.
925  */
926 #define AV_CODEC_CAP_PARAM_CHANGE        (1 << 14)
927 /**
928  * Codec supports avctx->thread_count == 0 (auto).
929  */
930 #define AV_CODEC_CAP_AUTO_THREADS        (1 << 15)
931 /**
932  * Audio encoder supports receiving a different number of samples in each call.
933  */
934 #define AV_CODEC_CAP_VARIABLE_FRAME_SIZE (1 << 16)
935 /**
936  * Codec is intra only.
937  */
938 #define AV_CODEC_CAP_INTRA_ONLY       0x40000000
939 /**
940  * Codec is lossless.
941  */
942 #define AV_CODEC_CAP_LOSSLESS         0x80000000
943 
944 
945 #if FF_API_WITHOUT_PREFIX
946 /**
947  * Allow decoders to produce frames with data planes that are not aligned
948  * to CPU requirements (e.g. due to cropping).
949  */
950 #define CODEC_FLAG_UNALIGNED AV_CODEC_FLAG_UNALIGNED
951 #define CODEC_FLAG_QSCALE AV_CODEC_FLAG_QSCALE
952 #define CODEC_FLAG_4MV    AV_CODEC_FLAG_4MV
953 #define CODEC_FLAG_OUTPUT_CORRUPT AV_CODEC_FLAG_OUTPUT_CORRUPT
954 #define CODEC_FLAG_QPEL   AV_CODEC_FLAG_QPEL
955 #if FF_API_GMC
956 /**
957  * @deprecated use the "gmc" private option of the libxvid encoder
958  */
959 #define CODEC_FLAG_GMC    0x0020  ///< Use GMC.
960 #endif
961 #if FF_API_MV0
962 /**
963  * @deprecated use the flag "mv0" in the "mpv_flags" private option of the
964  * mpegvideo encoders
965  */
966 #define CODEC_FLAG_MV0    0x0040
967 #endif
968 #if FF_API_INPUT_PRESERVED
969 /**
970  * @deprecated passing reference-counted frames to the encoders replaces this
971  * flag
972  */
973 #define CODEC_FLAG_INPUT_PRESERVED 0x0100
974 #endif
975 #define CODEC_FLAG_PASS1           AV_CODEC_FLAG_PASS1
976 #define CODEC_FLAG_PASS2           AV_CODEC_FLAG_PASS2
977 #define CODEC_FLAG_GRAY            AV_CODEC_FLAG_GRAY
978 #if FF_API_EMU_EDGE
979 /**
980  * @deprecated edges are not used/required anymore. I.e. this flag is now always
981  * set.
982  */
983 #define CODEC_FLAG_EMU_EDGE        0x4000
984 #endif
985 #define CODEC_FLAG_PSNR            AV_CODEC_FLAG_PSNR
986 #define CODEC_FLAG_TRUNCATED       AV_CODEC_FLAG_TRUNCATED
987 
988 #if FF_API_NORMALIZE_AQP
989 /**
990  * @deprecated use the flag "naq" in the "mpv_flags" private option of the
991  * mpegvideo encoders
992  */
993 #define CODEC_FLAG_NORMALIZE_AQP  0x00020000
994 #endif
995 #define CODEC_FLAG_INTERLACED_DCT AV_CODEC_FLAG_INTERLACED_DCT
996 #define CODEC_FLAG_LOW_DELAY      AV_CODEC_FLAG_LOW_DELAY
997 #define CODEC_FLAG_GLOBAL_HEADER  AV_CODEC_FLAG_GLOBAL_HEADER
998 #define CODEC_FLAG_BITEXACT       AV_CODEC_FLAG_BITEXACT
999 #define CODEC_FLAG_AC_PRED        AV_CODEC_FLAG_AC_PRED
1000 #define CODEC_FLAG_LOOP_FILTER    AV_CODEC_FLAG_LOOP_FILTER
1001 #define CODEC_FLAG_INTERLACED_ME  AV_CODEC_FLAG_INTERLACED_ME
1002 #define CODEC_FLAG_CLOSED_GOP     AV_CODEC_FLAG_CLOSED_GOP
1003 #define CODEC_FLAG2_FAST          AV_CODEC_FLAG2_FAST
1004 #define CODEC_FLAG2_NO_OUTPUT     AV_CODEC_FLAG2_NO_OUTPUT
1005 #define CODEC_FLAG2_LOCAL_HEADER  AV_CODEC_FLAG2_LOCAL_HEADER
1006 #define CODEC_FLAG2_DROP_FRAME_TIMECODE AV_CODEC_FLAG2_DROP_FRAME_TIMECODE
1007 #define CODEC_FLAG2_IGNORE_CROP   AV_CODEC_FLAG2_IGNORE_CROP
1008 
1009 #define CODEC_FLAG2_CHUNKS        AV_CODEC_FLAG2_CHUNKS
1010 #define CODEC_FLAG2_SHOW_ALL      AV_CODEC_FLAG2_SHOW_ALL
1011 #define CODEC_FLAG2_EXPORT_MVS    AV_CODEC_FLAG2_EXPORT_MVS
1012 #define CODEC_FLAG2_SKIP_MANUAL   AV_CODEC_FLAG2_SKIP_MANUAL
1013 
1014 /* Unsupported options :
1015  *              Syntax Arithmetic coding (SAC)
1016  *              Reference Picture Selection
1017  *              Independent Segment Decoding */
1018 /* /Fx */
1019 /* codec capabilities */
1020 
1021 #define CODEC_CAP_DRAW_HORIZ_BAND AV_CODEC_CAP_DRAW_HORIZ_BAND ///< Decoder can use draw_horiz_band callback.
1022 /**
1023  * Codec uses get_buffer() for allocating buffers and supports custom allocators.
1024  * If not set, it might not use get_buffer() at all or use operations that
1025  * assume the buffer was allocated by avcodec_default_get_buffer.
1026  */
1027 #define CODEC_CAP_DR1             AV_CODEC_CAP_DR1
1028 #define CODEC_CAP_TRUNCATED       AV_CODEC_CAP_TRUNCATED
1029 #if FF_API_XVMC
1030 /* Codec can export data for HW decoding. This flag indicates that
1031  * the codec would call get_format() with list that might contain HW accelerated
1032  * pixel formats (XvMC, VDPAU, VAAPI, etc). The application can pick any of them
1033  * including raw image format.
1034  * The application can use the passed context to determine bitstream version,
1035  * chroma format, resolution etc.
1036  */
1037 #define CODEC_CAP_HWACCEL         0x0010
1038 #endif /* FF_API_XVMC */
1039 /**
1040  * Encoder or decoder requires flushing with NULL input at the end in order to
1041  * give the complete and correct output.
1042  *
1043  * NOTE: If this flag is not set, the codec is guaranteed to never be fed with
1044  *       with NULL data. The user can still send NULL data to the public encode
1045  *       or decode function, but libavcodec will not pass it along to the codec
1046  *       unless this flag is set.
1047  *
1048  * Decoders:
1049  * The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
1050  * avpkt->size=0 at the end to get the delayed data until the decoder no longer
1051  * returns frames.
1052  *
1053  * Encoders:
1054  * The encoder needs to be fed with NULL data at the end of encoding until the
1055  * encoder no longer returns data.
1056  *
1057  * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
1058  *       flag also means that the encoder must set the pts and duration for
1059  *       each output packet. If this flag is not set, the pts and duration will
1060  *       be determined by libavcodec from the input frame.
1061  */
1062 #define CODEC_CAP_DELAY           AV_CODEC_CAP_DELAY
1063 /**
1064  * Codec can be fed a final frame with a smaller size.
1065  * This can be used to prevent truncation of the last audio samples.
1066  */
1067 #define CODEC_CAP_SMALL_LAST_FRAME AV_CODEC_CAP_SMALL_LAST_FRAME
1068 #if FF_API_CAP_VDPAU
1069 /**
1070  * Codec can export data for HW decoding (VDPAU).
1071  */
1072 #define CODEC_CAP_HWACCEL_VDPAU    AV_CODEC_CAP_HWACCEL_VDPAU
1073 #endif
1074 /**
1075  * Codec can output multiple frames per AVPacket
1076  * Normally demuxers return one frame at a time, demuxers which do not do
1077  * are connected to a parser to split what they return into proper frames.
1078  * This flag is reserved to the very rare category of codecs which have a
1079  * bitstream that cannot be split into frames without timeconsuming
1080  * operations like full decoding. Demuxers carring such bitstreams thus
1081  * may return multiple frames in a packet. This has many disadvantages like
1082  * prohibiting stream copy in many cases thus it should only be considered
1083  * as a last resort.
1084  */
1085 #define CODEC_CAP_SUBFRAMES        AV_CODEC_CAP_SUBFRAMES
1086 /**
1087  * Codec is experimental and is thus avoided in favor of non experimental
1088  * encoders
1089  */
1090 #define CODEC_CAP_EXPERIMENTAL     AV_CODEC_CAP_EXPERIMENTAL
1091 /**
1092  * Codec should fill in channel configuration and samplerate instead of container
1093  */
1094 #define CODEC_CAP_CHANNEL_CONF     AV_CODEC_CAP_CHANNEL_CONF
1095 #if FF_API_NEG_LINESIZES
1096 /**
1097  * @deprecated no codecs use this capability
1098  */
1099 #define CODEC_CAP_NEG_LINESIZES    0x0800
1100 #endif
1101 /**
1102  * Codec supports frame-level multithreading.
1103  */
1104 #define CODEC_CAP_FRAME_THREADS    AV_CODEC_CAP_FRAME_THREADS
1105 /**
1106  * Codec supports slice-based (or partition-based) multithreading.
1107  */
1108 #define CODEC_CAP_SLICE_THREADS    AV_CODEC_CAP_SLICE_THREADS
1109 /**
1110  * Codec supports changed parameters at any point.
1111  */
1112 #define CODEC_CAP_PARAM_CHANGE     AV_CODEC_CAP_PARAM_CHANGE
1113 /**
1114  * Codec supports avctx->thread_count == 0 (auto).
1115  */
1116 #define CODEC_CAP_AUTO_THREADS     AV_CODEC_CAP_AUTO_THREADS
1117 /**
1118  * Audio encoder supports receiving a different number of samples in each call.
1119  */
1120 #define CODEC_CAP_VARIABLE_FRAME_SIZE AV_CODEC_CAP_VARIABLE_FRAME_SIZE
1121 /**
1122  * Codec is intra only.
1123  */
1124 #define CODEC_CAP_INTRA_ONLY       AV_CODEC_CAP_INTRA_ONLY
1125 /**
1126  * Codec is lossless.
1127  */
1128 #define CODEC_CAP_LOSSLESS         AV_CODEC_CAP_LOSSLESS
1129 
1130 /**
1131  * HWAccel is experimental and is thus avoided in favor of non experimental
1132  * codecs
1133  */
1134 #define HWACCEL_CODEC_CAP_EXPERIMENTAL     0x0200
1135 #endif /* FF_API_WITHOUT_PREFIX */
1136 
1137 #if FF_API_MB_TYPE
1138 //The following defines may change, don't expect compatibility if you use them.
1139 #define MB_TYPE_INTRA4x4   0x0001
1140 #define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
1141 #define MB_TYPE_INTRA_PCM  0x0004 //FIXME H.264-specific
1142 #define MB_TYPE_16x16      0x0008
1143 #define MB_TYPE_16x8       0x0010
1144 #define MB_TYPE_8x16       0x0020
1145 #define MB_TYPE_8x8        0x0040
1146 #define MB_TYPE_INTERLACED 0x0080
1147 #define MB_TYPE_DIRECT2    0x0100 //FIXME
1148 #define MB_TYPE_ACPRED     0x0200
1149 #define MB_TYPE_GMC        0x0400
1150 #define MB_TYPE_SKIP       0x0800
1151 #define MB_TYPE_P0L0       0x1000
1152 #define MB_TYPE_P1L0       0x2000
1153 #define MB_TYPE_P0L1       0x4000
1154 #define MB_TYPE_P1L1       0x8000
1155 #define MB_TYPE_L0         (MB_TYPE_P0L0 | MB_TYPE_P1L0)
1156 #define MB_TYPE_L1         (MB_TYPE_P0L1 | MB_TYPE_P1L1)
1157 #define MB_TYPE_L0L1       (MB_TYPE_L0   | MB_TYPE_L1)
1158 #define MB_TYPE_QUANT      0x00010000
1159 #define MB_TYPE_CBP        0x00020000
1160 //Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)
1161 #endif
1162 
1163 /**
1164  * Pan Scan area.
1165  * This specifies the area which should be displayed.
1166  * Note there may be multiple such areas for one frame.
1167  */
1168 typedef struct AVPanScan{
1169     /**
1170      * id
1171      * - encoding: Set by user.
1172      * - decoding: Set by libavcodec.
1173      */
1174     int id;
1175 
1176     /**
1177      * width and height in 1/16 pel
1178      * - encoding: Set by user.
1179      * - decoding: Set by libavcodec.
1180      */
1181     int width;
1182     int height;
1183 
1184     /**
1185      * position of the top left corner in 1/16 pel for up to 3 fields/frames
1186      * - encoding: Set by user.
1187      * - decoding: Set by libavcodec.
1188      */
1189     int16_t position[3][2];
1190 }AVPanScan;
1191 
1192 /**
1193  * This structure describes the bitrate properties of an encoded bitstream. It
1194  * roughly corresponds to a subset the VBV parameters for MPEG-2 or HRD
1195  * parameters for H.264/HEVC.
1196  */
1197 typedef struct AVCPBProperties {
1198     /**
1199      * Maximum bitrate of the stream, in bits per second.
1200      * Zero if unknown or unspecified.
1201      */
1202     int max_bitrate;
1203     /**
1204      * Minimum bitrate of the stream, in bits per second.
1205      * Zero if unknown or unspecified.
1206      */
1207     int min_bitrate;
1208     /**
1209      * Average bitrate of the stream, in bits per second.
1210      * Zero if unknown or unspecified.
1211      */
1212     int avg_bitrate;
1213 
1214     /**
1215      * The size of the buffer to which the ratecontrol is applied, in bits.
1216      * Zero if unknown or unspecified.
1217      */
1218     int buffer_size;
1219 
1220     /**
1221      * The delay between the time the packet this structure is associated with
1222      * is received and the time when it should be decoded, in periods of a 27MHz
1223      * clock.
1224      *
1225      * UINT64_MAX when unknown or unspecified.
1226      */
1227     uint64_t vbv_delay;
1228 } AVCPBProperties;
1229 
1230 #if FF_API_QSCALE_TYPE
1231 #define FF_QSCALE_TYPE_MPEG1 0
1232 #define FF_QSCALE_TYPE_MPEG2 1
1233 #define FF_QSCALE_TYPE_H264  2
1234 #define FF_QSCALE_TYPE_VP56  3
1235 #endif
1236 
1237 /**
1238  * The decoder will keep a reference to the frame and may reuse it later.
1239  */
1240 #define AV_GET_BUFFER_FLAG_REF (1 << 0)
1241 
1242 /**
1243  * @defgroup lavc_packet AVPacket
1244  *
1245  * Types and functions for working with AVPacket.
1246  * @{
1247  */
1248 enum AVPacketSideDataType {
1249     AV_PKT_DATA_PALETTE,
1250     AV_PKT_DATA_NEW_EXTRADATA,
1251 
1252     /**
1253      * An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
1254      * @code
1255      * u32le param_flags
1256      * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
1257      *     s32le channel_count
1258      * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
1259      *     u64le channel_layout
1260      * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
1261      *     s32le sample_rate
1262      * if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
1263      *     s32le width
1264      *     s32le height
1265      * @endcode
1266      */
1267     AV_PKT_DATA_PARAM_CHANGE,
1268 
1269     /**
1270      * An AV_PKT_DATA_H263_MB_INFO side data packet contains a number of
1271      * structures with info about macroblocks relevant to splitting the
1272      * packet into smaller packets on macroblock edges (e.g. as for RFC 2190).
1273      * That is, it does not necessarily contain info about all macroblocks,
1274      * as long as the distance between macroblocks in the info is smaller
1275      * than the target payload size.
1276      * Each MB info structure is 12 bytes, and is laid out as follows:
1277      * @code
1278      * u32le bit offset from the start of the packet
1279      * u8    current quantizer at the start of the macroblock
1280      * u8    GOB number
1281      * u16le macroblock address within the GOB
1282      * u8    horizontal MV predictor
1283      * u8    vertical MV predictor
1284      * u8    horizontal MV predictor for block number 3
1285      * u8    vertical MV predictor for block number 3
1286      * @endcode
1287      */
1288     AV_PKT_DATA_H263_MB_INFO,
1289 
1290     /**
1291      * This side data should be associated with an audio stream and contains
1292      * ReplayGain information in form of the AVReplayGain struct.
1293      */
1294     AV_PKT_DATA_REPLAYGAIN,
1295 
1296     /**
1297      * This side data contains a 3x3 transformation matrix describing an affine
1298      * transformation that needs to be applied to the decoded video frames for
1299      * correct presentation.
1300      *
1301      * See libavutil/display.h for a detailed description of the data.
1302      */
1303     AV_PKT_DATA_DISPLAYMATRIX,
1304 
1305     /**
1306      * This side data should be associated with a video stream and contains
1307      * Stereoscopic 3D information in form of the AVStereo3D struct.
1308      */
1309     AV_PKT_DATA_STEREO3D,
1310 
1311     /**
1312      * This side data should be associated with an audio stream and corresponds
1313      * to enum AVAudioServiceType.
1314      */
1315     AV_PKT_DATA_AUDIO_SERVICE_TYPE,
1316 
1317     /**
1318      * This side data contains quality related information from the encoder.
1319      * @code
1320      * u32le quality factor of the compressed frame. Allowed range is between 1 (good) and FF_LAMBDA_MAX (bad).
1321      * u8    picture type
1322      * u8    error count
1323      * u16   reserved
1324      * u64le[error count] sum of squared differences between encoder in and output
1325      * @endcode
1326      */
1327     AV_PKT_DATA_QUALITY_STATS,
1328 
1329     /**
1330      * This side data contains an integer value representing the stream index
1331      * of a "fallback" track.  A fallback track indicates an alternate
1332      * track to use when the current track can not be decoded for some reason.
1333      * e.g. no decoder available for codec.
1334      */
1335     AV_PKT_DATA_FALLBACK_TRACK,
1336 
1337     /**
1338      * This side data corresponds to the AVCPBProperties struct.
1339      */
1340     AV_PKT_DATA_CPB_PROPERTIES,
1341 
1342     /**
1343      * Recommmends skipping the specified number of samples
1344      * @code
1345      * u32le number of samples to skip from start of this packet
1346      * u32le number of samples to skip from end of this packet
1347      * u8    reason for start skip
1348      * u8    reason for end   skip (0=padding silence, 1=convergence)
1349      * @endcode
1350      */
1351     AV_PKT_DATA_SKIP_SAMPLES=70,
1352 
1353     /**
1354      * An AV_PKT_DATA_JP_DUALMONO side data packet indicates that
1355      * the packet may contain "dual mono" audio specific to Japanese DTV
1356      * and if it is true, recommends only the selected channel to be used.
1357      * @code
1358      * u8    selected channels (0=mail/left, 1=sub/right, 2=both)
1359      * @endcode
1360      */
1361     AV_PKT_DATA_JP_DUALMONO,
1362 
1363     /**
1364      * A list of zero terminated key/value strings. There is no end marker for
1365      * the list, so it is required to rely on the side data size to stop.
1366      */
1367     AV_PKT_DATA_STRINGS_METADATA,
1368 
1369     /**
1370      * Subtitle event position
1371      * @code
1372      * u32le x1
1373      * u32le y1
1374      * u32le x2
1375      * u32le y2
1376      * @endcode
1377      */
1378     AV_PKT_DATA_SUBTITLE_POSITION,
1379 
1380     /**
1381      * Data found in BlockAdditional element of matroska container. There is
1382      * no end marker for the data, so it is required to rely on the side data
1383      * size to recognize the end. 8 byte id (as found in BlockAddId) followed
1384      * by data.
1385      */
1386     AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,
1387 
1388     /**
1389      * The optional first identifier line of a WebVTT cue.
1390      */
1391     AV_PKT_DATA_WEBVTT_IDENTIFIER,
1392 
1393     /**
1394      * The optional settings (rendering instructions) that immediately
1395      * follow the timestamp specifier of a WebVTT cue.
1396      */
1397     AV_PKT_DATA_WEBVTT_SETTINGS,
1398 
1399     /**
1400      * A list of zero terminated key/value strings. There is no end marker for
1401      * the list, so it is required to rely on the side data size to stop. This
1402      * side data includes updated metadata which appeared in the stream.
1403      */
1404     AV_PKT_DATA_METADATA_UPDATE,
1405 };
1406 
1407 #define AV_PKT_DATA_QUALITY_FACTOR AV_PKT_DATA_QUALITY_STATS //DEPRECATED
1408 
1409 typedef struct AVPacketSideData {
1410     uint8_t *data;
1411     int      size;
1412     enum AVPacketSideDataType type;
1413 } AVPacketSideData;
1414 
1415 /**
1416  * This structure stores compressed data. It is typically exported by demuxers
1417  * and then passed as input to decoders, or received as output from encoders and
1418  * then passed to muxers.
1419  *
1420  * For video, it should typically contain one compressed frame. For audio it may
1421  * contain several compressed frames. Encoders are allowed to output empty
1422  * packets, with no compressed data, containing only side data
1423  * (e.g. to update some stream parameters at the end of encoding).
1424  *
1425  * AVPacket is one of the few structs in FFmpeg, whose size is a part of public
1426  * ABI. Thus it may be allocated on stack and no new fields can be added to it
1427  * without libavcodec and libavformat major bump.
1428  *
1429  * The semantics of data ownership depends on the buf field.
1430  * If it is set, the packet data is dynamically allocated and is
1431  * valid indefinitely until a call to av_packet_unref() reduces the
1432  * reference count to 0.
1433  *
1434  * If the buf field is not set av_packet_ref() would make a copy instead
1435  * of increasing the reference count.
1436  *
1437  * The side data is always allocated with av_malloc(), copied by
1438  * av_packet_ref() and freed by av_packet_unref().
1439  *
1440  * @see av_packet_ref
1441  * @see av_packet_unref
1442  */
1443 typedef struct AVPacket {
1444     /**
1445      * A reference to the reference-counted buffer where the packet data is
1446      * stored.
1447      * May be NULL, then the packet data is not reference-counted.
1448      */
1449     AVBufferRef *buf;
1450     /**
1451      * Presentation timestamp in AVStream->time_base units; the time at which
1452      * the decompressed packet will be presented to the user.
1453      * Can be AV_NOPTS_VALUE if it is not stored in the file.
1454      * pts MUST be larger or equal to dts as presentation cannot happen before
1455      * decompression, unless one wants to view hex dumps. Some formats misuse
1456      * the terms dts and pts/cts to mean something different. Such timestamps
1457      * must be converted to true pts/dts before they are stored in AVPacket.
1458      */
1459     int64_t pts;
1460     /**
1461      * Decompression timestamp in AVStream->time_base units; the time at which
1462      * the packet is decompressed.
1463      * Can be AV_NOPTS_VALUE if it is not stored in the file.
1464      */
1465     int64_t dts;
1466     uint8_t *data;
1467     int   size;
1468     int   stream_index;
1469     /**
1470      * A combination of AV_PKT_FLAG values
1471      */
1472     int   flags;
1473     /**
1474      * Additional packet data that can be provided by the container.
1475      * Packet can contain several types of side information.
1476      */
1477     AVPacketSideData *side_data;
1478     int side_data_elems;
1479 
1480     /**
1481      * Duration of this packet in AVStream->time_base units, 0 if unknown.
1482      * Equals next_pts - this_pts in presentation order.
1483      */
1484     int64_t duration;
1485 
1486     int64_t pos;                            ///< byte position in stream, -1 if unknown
1487 
1488 #if FF_API_CONVERGENCE_DURATION
1489     /**
1490      * @deprecated Same as the duration field, but as int64_t. This was required
1491      * for Matroska subtitles, whose duration values could overflow when the
1492      * duration field was still an int.
1493      */
1494     attribute_deprecated
1495     int64_t convergence_duration;
1496 #endif
1497 } AVPacket;
1498 #define AV_PKT_FLAG_KEY     0x0001 ///< The packet contains a keyframe
1499 #define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted
1500 
1501 enum AVSideDataParamChangeFlags {
1502     AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT  = 0x0001,
1503     AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT = 0x0002,
1504     AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE    = 0x0004,
1505     AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS     = 0x0008,
1506 };
1507 /**
1508  * @}
1509  */
1510 
1511 struct AVCodecInternal;
1512 
1513 enum AVFieldOrder {
1514     AV_FIELD_UNKNOWN,
1515     AV_FIELD_PROGRESSIVE,
1516     AV_FIELD_TT,          //< Top coded_first, top displayed first
1517     AV_FIELD_BB,          //< Bottom coded first, bottom displayed first
1518     AV_FIELD_TB,          //< Top coded first, bottom displayed first
1519     AV_FIELD_BT,          //< Bottom coded first, top displayed first
1520 };
1521 
1522 /**
1523  * main external API structure.
1524  * New fields can be added to the end with minor version bumps.
1525  * Removal, reordering and changes to existing fields require a major
1526  * version bump.
1527  * Please use AVOptions (av_opt* / av_set/get*()) to access these fields from user
1528  * applications.
1529  * sizeof(AVCodecContext) must not be used outside libav*.
1530  */
1531 typedef struct AVCodecContext {
1532     /**
1533      * information on struct for av_log
1534      * - set by avcodec_alloc_context3
1535      */
1536     const AVClass *av_class;
1537     int log_level_offset;
1538 
1539     enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
1540     const struct AVCodec  *codec;
1541 #if FF_API_CODEC_NAME
1542     /**
1543      * @deprecated this field is not used for anything in libavcodec
1544      */
1545     attribute_deprecated
1546     char             codec_name[32];
1547 #endif
1548     enum AVCodecID     codec_id; /* see AV_CODEC_ID_xxx */
1549 
1550     /**
1551      * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
1552      * This is used to work around some encoder bugs.
1553      * A demuxer should set this to what is stored in the field used to identify the codec.
1554      * If there are multiple such fields in a container then the demuxer should choose the one
1555      * which maximizes the information about the used codec.
1556      * If the codec tag field in a container is larger than 32 bits then the demuxer should
1557      * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
1558      * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
1559      * first.
1560      * - encoding: Set by user, if not then the default based on codec_id will be used.
1561      * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
1562      */
1563     unsigned int codec_tag;
1564 
1565 #if FF_API_STREAM_CODEC_TAG
1566     /**
1567      * @deprecated this field is unused
1568      */
1569     attribute_deprecated
1570     unsigned int stream_codec_tag;
1571 #endif
1572 
1573     void *priv_data;
1574 
1575     /**
1576      * Private context used for internal data.
1577      *
1578      * Unlike priv_data, this is not codec-specific. It is used in general
1579      * libavcodec functions.
1580      */
1581     struct AVCodecInternal *internal;
1582 
1583     /**
1584      * Private data of the user, can be used to carry app specific stuff.
1585      * - encoding: Set by user.
1586      * - decoding: Set by user.
1587      */
1588     void *opaque;
1589 
1590     /**
1591      * the average bitrate
1592      * - encoding: Set by user; unused for constant quantizer encoding.
1593      * - decoding: Set by user, may be overwritten by libavcodec
1594      *             if this info is available in the stream
1595      */
1596     int64_t bit_rate;
1597 
1598     /**
1599      * number of bits the bitstream is allowed to diverge from the reference.
1600      *           the reference can be CBR (for CBR pass1) or VBR (for pass2)
1601      * - encoding: Set by user; unused for constant quantizer encoding.
1602      * - decoding: unused
1603      */
1604     int bit_rate_tolerance;
1605 
1606     /**
1607      * Global quality for codecs which cannot change it per frame.
1608      * This should be proportional to MPEG-1/2/4 qscale.
1609      * - encoding: Set by user.
1610      * - decoding: unused
1611      */
1612     int global_quality;
1613 
1614     /**
1615      * - encoding: Set by user.
1616      * - decoding: unused
1617      */
1618     int compression_level;
1619 #define FF_COMPRESSION_DEFAULT -1
1620 
1621     /**
1622      * AV_CODEC_FLAG_*.
1623      * - encoding: Set by user.
1624      * - decoding: Set by user.
1625      */
1626     int flags;
1627 
1628     /**
1629      * AV_CODEC_FLAG2_*
1630      * - encoding: Set by user.
1631      * - decoding: Set by user.
1632      */
1633     int flags2;
1634 
1635     /**
1636      * some codecs need / can use extradata like Huffman tables.
1637      * mjpeg: Huffman tables
1638      * rv10: additional flags
1639      * mpeg4: global headers (they can be in the bitstream or here)
1640      * The allocated memory should be AV_INPUT_BUFFER_PADDING_SIZE bytes larger
1641      * than extradata_size to avoid problems if it is read with the bitstream reader.
1642      * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
1643      * - encoding: Set/allocated/freed by libavcodec.
1644      * - decoding: Set/allocated/freed by user.
1645      */
1646     uint8_t *extradata;
1647     int extradata_size;
1648 
1649     /**
1650      * This is the fundamental unit of time (in seconds) in terms
1651      * of which frame timestamps are represented. For fixed-fps content,
1652      * timebase should be 1/framerate and timestamp increments should be
1653      * identically 1.
1654      * This often, but not always is the inverse of the frame rate or field rate
1655      * for video.
1656      * - encoding: MUST be set by user.
1657      * - decoding: the use of this field for decoding is deprecated.
1658      *             Use framerate instead.
1659      */
1660     AVRational time_base;
1661 
1662     /**
1663      * For some codecs, the time base is closer to the field rate than the frame rate.
1664      * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
1665      * if no telecine is used ...
1666      *
1667      * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
1668      */
1669     int ticks_per_frame;
1670 
1671     /**
1672      * Codec delay.
1673      *
1674      * Encoding: Number of frames delay there will be from the encoder input to
1675      *           the decoder output. (we assume the decoder matches the spec)
1676      * Decoding: Number of frames delay in addition to what a standard decoder
1677      *           as specified in the spec would produce.
1678      *
1679      * Video:
1680      *   Number of frames the decoded output will be delayed relative to the
1681      *   encoded input.
1682      *
1683      * Audio:
1684      *   For encoding, this field is unused (see initial_padding).
1685      *
1686      *   For decoding, this is the number of samples the decoder needs to
1687      *   output before the decoder's output is valid. When seeking, you should
1688      *   start decoding this many samples prior to your desired seek point.
1689      *
1690      * - encoding: Set by libavcodec.
1691      * - decoding: Set by libavcodec.
1692      */
1693     int delay;
1694 
1695 
1696     /* video only */
1697     /**
1698      * picture width / height.
1699      *
1700      * @note Those fields may not match the values of the last
1701      * AVFrame outputted by avcodec_decode_video2 due frame
1702      * reordering.
1703      *
1704      * - encoding: MUST be set by user.
1705      * - decoding: May be set by the user before opening the decoder if known e.g.
1706      *             from the container. Some decoders will require the dimensions
1707      *             to be set by the caller. During decoding, the decoder may
1708      *             overwrite those values as required while parsing the data.
1709      */
1710     int width, height;
1711 
1712     /**
1713      * Bitstream width / height, may be different from width/height e.g. when
1714      * the decoded frame is cropped before being output or lowres is enabled.
1715      *
1716      * @note Those field may not match the value of the last
1717      * AVFrame outputted by avcodec_decode_video2 due frame
1718      * reordering.
1719      *
1720      * - encoding: unused
1721      * - decoding: May be set by the user before opening the decoder if known
1722      *             e.g. from the container. During decoding, the decoder may
1723      *             overwrite those values as required while parsing the data.
1724      */
1725     int coded_width, coded_height;
1726 
1727 #if FF_API_ASPECT_EXTENDED
1728 #define FF_ASPECT_EXTENDED 15
1729 #endif
1730 
1731     /**
1732      * the number of pictures in a group of pictures, or 0 for intra_only
1733      * - encoding: Set by user.
1734      * - decoding: unused
1735      */
1736     int gop_size;
1737 
1738     /**
1739      * Pixel format, see AV_PIX_FMT_xxx.
1740      * May be set by the demuxer if known from headers.
1741      * May be overridden by the decoder if it knows better.
1742      *
1743      * @note This field may not match the value of the last
1744      * AVFrame outputted by avcodec_decode_video2 due frame
1745      * reordering.
1746      *
1747      * - encoding: Set by user.
1748      * - decoding: Set by user if known, overridden by libavcodec while
1749      *             parsing the data.
1750      */
1751     enum AVPixelFormat pix_fmt;
1752 
1753 #if FF_API_MOTION_EST
1754     /**
1755      * This option does nothing
1756      * @deprecated use codec private options instead
1757      */
1758     attribute_deprecated int me_method;
1759 #endif
1760 
1761     /**
1762      * If non NULL, 'draw_horiz_band' is called by the libavcodec
1763      * decoder to draw a horizontal band. It improves cache usage. Not
1764      * all codecs can do that. You must check the codec capabilities
1765      * beforehand.
1766      * When multithreading is used, it may be called from multiple threads
1767      * at the same time; threads might draw different parts of the same AVFrame,
1768      * or multiple AVFrames, and there is no guarantee that slices will be drawn
1769      * in order.
1770      * The function is also used by hardware acceleration APIs.
1771      * It is called at least once during frame decoding to pass
1772      * the data needed for hardware render.
1773      * In that mode instead of pixel data, AVFrame points to
1774      * a structure specific to the acceleration API. The application
1775      * reads the structure and can change some fields to indicate progress
1776      * or mark state.
1777      * - encoding: unused
1778      * - decoding: Set by user.
1779      * @param height the height of the slice
1780      * @param y the y position of the slice
1781      * @param type 1->top field, 2->bottom field, 3->frame
1782      * @param offset offset into the AVFrame.data from which the slice should be read
1783      */
1784     void (*draw_horiz_band)(struct AVCodecContext *s,
1785                             const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
1786                             int y, int type, int height);
1787 
1788     /**
1789      * callback to negotiate the pixelFormat
1790      * @param fmt is the list of formats which are supported by the codec,
1791      * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
1792      * The first is always the native one.
1793      * @note The callback may be called again immediately if initialization for
1794      * the selected (hardware-accelerated) pixel format failed.
1795      * @warning Behavior is undefined if the callback returns a value not
1796      * in the fmt list of formats.
1797      * @return the chosen format
1798      * - encoding: unused
1799      * - decoding: Set by user, if not set the native format will be chosen.
1800      */
1801     enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
1802 
1803     /**
1804      * maximum number of B-frames between non-B-frames
1805      * Note: The output will be delayed by max_b_frames+1 relative to the input.
1806      * - encoding: Set by user.
1807      * - decoding: unused
1808      */
1809     int max_b_frames;
1810 
1811     /**
1812      * qscale factor between IP and B-frames
1813      * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
1814      * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1815      * - encoding: Set by user.
1816      * - decoding: unused
1817      */
1818     float b_quant_factor;
1819 
1820 #if FF_API_RC_STRATEGY
1821     /** @deprecated use codec private option instead */
1822     attribute_deprecated int rc_strategy;
1823 #define FF_RC_STRATEGY_XVID 1
1824 #endif
1825 
1826     int b_frame_strategy;
1827 
1828     /**
1829      * qscale offset between IP and B-frames
1830      * - encoding: Set by user.
1831      * - decoding: unused
1832      */
1833     float b_quant_offset;
1834 
1835     /**
1836      * Size of the frame reordering buffer in the decoder.
1837      * For MPEG-2 it is 1 IPB or 0 low delay IP.
1838      * - encoding: Set by libavcodec.
1839      * - decoding: Set by libavcodec.
1840      */
1841     int has_b_frames;
1842 
1843     /**
1844      * 0-> h263 quant 1-> mpeg quant
1845      * - encoding: Set by user.
1846      * - decoding: unused
1847      */
1848     int mpeg_quant;
1849 
1850     /**
1851      * qscale factor between P and I-frames
1852      * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
1853      * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
1854      * - encoding: Set by user.
1855      * - decoding: unused
1856      */
1857     float i_quant_factor;
1858 
1859     /**
1860      * qscale offset between P and I-frames
1861      * - encoding: Set by user.
1862      * - decoding: unused
1863      */
1864     float i_quant_offset;
1865 
1866     /**
1867      * luminance masking (0-> disabled)
1868      * - encoding: Set by user.
1869      * - decoding: unused
1870      */
1871     float lumi_masking;
1872 
1873     /**
1874      * temporary complexity masking (0-> disabled)
1875      * - encoding: Set by user.
1876      * - decoding: unused
1877      */
1878     float temporal_cplx_masking;
1879 
1880     /**
1881      * spatial complexity masking (0-> disabled)
1882      * - encoding: Set by user.
1883      * - decoding: unused
1884      */
1885     float spatial_cplx_masking;
1886 
1887     /**
1888      * p block masking (0-> disabled)
1889      * - encoding: Set by user.
1890      * - decoding: unused
1891      */
1892     float p_masking;
1893 
1894     /**
1895      * darkness masking (0-> disabled)
1896      * - encoding: Set by user.
1897      * - decoding: unused
1898      */
1899     float dark_masking;
1900 
1901     /**
1902      * slice count
1903      * - encoding: Set by libavcodec.
1904      * - decoding: Set by user (or 0).
1905      */
1906     int slice_count;
1907     /**
1908      * prediction method (needed for huffyuv)
1909      * - encoding: Set by user.
1910      * - decoding: unused
1911      */
1912      int prediction_method;
1913 #define FF_PRED_LEFT   0
1914 #define FF_PRED_PLANE  1
1915 #define FF_PRED_MEDIAN 2
1916 
1917     /**
1918      * slice offsets in the frame in bytes
1919      * - encoding: Set/allocated by libavcodec.
1920      * - decoding: Set/allocated by user (or NULL).
1921      */
1922     int *slice_offset;
1923 
1924     /**
1925      * sample aspect ratio (0 if unknown)
1926      * That is the width of a pixel divided by the height of the pixel.
1927      * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
1928      * - encoding: Set by user.
1929      * - decoding: Set by libavcodec.
1930      */
1931     AVRational sample_aspect_ratio;
1932 
1933     /**
1934      * motion estimation comparison function
1935      * - encoding: Set by user.
1936      * - decoding: unused
1937      */
1938     int me_cmp;
1939     /**
1940      * subpixel motion estimation comparison function
1941      * - encoding: Set by user.
1942      * - decoding: unused
1943      */
1944     int me_sub_cmp;
1945     /**
1946      * macroblock comparison function (not supported yet)
1947      * - encoding: Set by user.
1948      * - decoding: unused
1949      */
1950     int mb_cmp;
1951     /**
1952      * interlaced DCT comparison function
1953      * - encoding: Set by user.
1954      * - decoding: unused
1955      */
1956     int ildct_cmp;
1957 #define FF_CMP_SAD    0
1958 #define FF_CMP_SSE    1
1959 #define FF_CMP_SATD   2
1960 #define FF_CMP_DCT    3
1961 #define FF_CMP_PSNR   4
1962 #define FF_CMP_BIT    5
1963 #define FF_CMP_RD     6
1964 #define FF_CMP_ZERO   7
1965 #define FF_CMP_VSAD   8
1966 #define FF_CMP_VSSE   9
1967 #define FF_CMP_NSSE   10
1968 #define FF_CMP_W53    11
1969 #define FF_CMP_W97    12
1970 #define FF_CMP_DCTMAX 13
1971 #define FF_CMP_DCT264 14
1972 #define FF_CMP_CHROMA 256
1973 
1974     /**
1975      * ME diamond size & shape
1976      * - encoding: Set by user.
1977      * - decoding: unused
1978      */
1979     int dia_size;
1980 
1981     /**
1982      * amount of previous MV predictors (2a+1 x 2a+1 square)
1983      * - encoding: Set by user.
1984      * - decoding: unused
1985      */
1986     int last_predictor_count;
1987 
1988     /**
1989      * prepass for motion estimation
1990      * - encoding: Set by user.
1991      * - decoding: unused
1992      */
1993     int pre_me;
1994 
1995     /**
1996      * motion estimation prepass comparison function
1997      * - encoding: Set by user.
1998      * - decoding: unused
1999      */
2000     int me_pre_cmp;
2001 
2002     /**
2003      * ME prepass diamond size & shape
2004      * - encoding: Set by user.
2005      * - decoding: unused
2006      */
2007     int pre_dia_size;
2008 
2009     /**
2010      * subpel ME quality
2011      * - encoding: Set by user.
2012      * - decoding: unused
2013      */
2014     int me_subpel_quality;
2015 
2016 #if FF_API_AFD
2017     /**
2018      * DTG active format information (additional aspect ratio
2019      * information only used in DVB MPEG-2 transport streams)
2020      * 0 if not set.
2021      *
2022      * - encoding: unused
2023      * - decoding: Set by decoder.
2024      * @deprecated Deprecated in favor of AVSideData
2025      */
2026     attribute_deprecated int dtg_active_format;
2027 #define FF_DTG_AFD_SAME         8
2028 #define FF_DTG_AFD_4_3          9
2029 #define FF_DTG_AFD_16_9         10
2030 #define FF_DTG_AFD_14_9         11
2031 #define FF_DTG_AFD_4_3_SP_14_9  13
2032 #define FF_DTG_AFD_16_9_SP_14_9 14
2033 #define FF_DTG_AFD_SP_4_3       15
2034 #endif /* FF_API_AFD */
2035 
2036     /**
2037      * maximum motion estimation search range in subpel units
2038      * If 0 then no limit.
2039      *
2040      * - encoding: Set by user.
2041      * - decoding: unused
2042      */
2043     int me_range;
2044 
2045 #if FF_API_QUANT_BIAS
2046     /**
2047      * @deprecated use encoder private option instead
2048      */
2049     attribute_deprecated int intra_quant_bias;
2050 #define FF_DEFAULT_QUANT_BIAS 999999
2051 
2052     /**
2053      * @deprecated use encoder private option instead
2054      */
2055     attribute_deprecated int inter_quant_bias;
2056 #endif
2057 
2058     /**
2059      * slice flags
2060      * - encoding: unused
2061      * - decoding: Set by user.
2062      */
2063     int slice_flags;
2064 #define SLICE_FLAG_CODED_ORDER    0x0001 ///< draw_horiz_band() is called in coded order instead of display
2065 #define SLICE_FLAG_ALLOW_FIELD    0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
2066 #define SLICE_FLAG_ALLOW_PLANE    0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)
2067 
2068 #if FF_API_XVMC
2069     /**
2070      * XVideo Motion Acceleration
2071      * - encoding: forbidden
2072      * - decoding: set by decoder
2073      * @deprecated XvMC doesn't need it anymore.
2074      */
2075     attribute_deprecated int xvmc_acceleration;
2076 #endif /* FF_API_XVMC */
2077 
2078     /**
2079      * macroblock decision mode
2080      * - encoding: Set by user.
2081      * - decoding: unused
2082      */
2083     int mb_decision;
2084 #define FF_MB_DECISION_SIMPLE 0        ///< uses mb_cmp
2085 #define FF_MB_DECISION_BITS   1        ///< chooses the one which needs the fewest bits
2086 #define FF_MB_DECISION_RD     2        ///< rate distortion
2087 
2088     /**
2089      * custom intra quantization matrix
2090      * - encoding: Set by user, can be NULL.
2091      * - decoding: Set by libavcodec.
2092      */
2093     uint16_t *intra_matrix;
2094 
2095     /**
2096      * custom inter quantization matrix
2097      * - encoding: Set by user, can be NULL.
2098      * - decoding: Set by libavcodec.
2099      */
2100     uint16_t *inter_matrix;
2101 
2102     /**
2103      * scene change detection threshold
2104      * 0 is default, larger means fewer detected scene changes.
2105      * - encoding: Set by user.
2106      * - decoding: unused
2107      */
2108     int scenechange_threshold;
2109 
2110     /**
2111      * noise reduction strength
2112      * - encoding: Set by user.
2113      * - decoding: unused
2114      */
2115     int noise_reduction;
2116 
2117 #if FF_API_MPV_OPT
2118     /**
2119      * @deprecated this field is unused
2120      */
2121     attribute_deprecated
2122     int me_threshold;
2123 
2124     /**
2125      * @deprecated this field is unused
2126      */
2127     attribute_deprecated
2128     int mb_threshold;
2129 #endif
2130 
2131     /**
2132      * precision of the intra DC coefficient - 8
2133      * - encoding: Set by user.
2134      * - decoding: Set by libavcodec
2135      */
2136     int intra_dc_precision;
2137 
2138     /**
2139      * Number of macroblock rows at the top which are skipped.
2140      * - encoding: unused
2141      * - decoding: Set by user.
2142      */
2143     int skip_top;
2144 
2145     /**
2146      * Number of macroblock rows at the bottom which are skipped.
2147      * - encoding: unused
2148      * - decoding: Set by user.
2149      */
2150     int skip_bottom;
2151 
2152 #if FF_API_MPV_OPT
2153     /**
2154      * @deprecated use encoder private options instead
2155      */
2156     attribute_deprecated
2157     float border_masking;
2158 #endif
2159 
2160     /**
2161      * minimum MB lagrange multipler
2162      * - encoding: Set by user.
2163      * - decoding: unused
2164      */
2165     int mb_lmin;
2166 
2167     /**
2168      * maximum MB lagrange multipler
2169      * - encoding: Set by user.
2170      * - decoding: unused
2171      */
2172     int mb_lmax;
2173 
2174     /**
2175      *
2176      * - encoding: Set by user.
2177      * - decoding: unused
2178      */
2179     int me_penalty_compensation;
2180 
2181     /**
2182      *
2183      * - encoding: Set by user.
2184      * - decoding: unused
2185      */
2186     int bidir_refine;
2187 
2188     /**
2189      *
2190      * - encoding: Set by user.
2191      * - decoding: unused
2192      */
2193     int brd_scale;
2194 
2195     /**
2196      * minimum GOP size
2197      * - encoding: Set by user.
2198      * - decoding: unused
2199      */
2200     int keyint_min;
2201 
2202     /**
2203      * number of reference frames
2204      * - encoding: Set by user.
2205      * - decoding: Set by lavc.
2206      */
2207     int refs;
2208 
2209     /**
2210      * chroma qp offset from luma
2211      * - encoding: Set by user.
2212      * - decoding: unused
2213      */
2214     int chromaoffset;
2215 
2216 #if FF_API_UNUSED_MEMBERS
2217     /**
2218      * Multiplied by qscale for each frame and added to scene_change_score.
2219      * - encoding: Set by user.
2220      * - decoding: unused
2221      */
2222     attribute_deprecated int scenechange_factor;
2223 #endif
2224 
2225     /**
2226      *
2227      * Note: Value depends upon the compare function used for fullpel ME.
2228      * - encoding: Set by user.
2229      * - decoding: unused
2230      */
2231     int mv0_threshold;
2232 
2233     /**
2234      * Adjust sensitivity of b_frame_strategy 1.
2235      * - encoding: Set by user.
2236      * - decoding: unused
2237      */
2238     int b_sensitivity;
2239 
2240     /**
2241      * Chromaticity coordinates of the source primaries.
2242      * - encoding: Set by user
2243      * - decoding: Set by libavcodec
2244      */
2245     enum AVColorPrimaries color_primaries;
2246 
2247     /**
2248      * Color Transfer Characteristic.
2249      * - encoding: Set by user
2250      * - decoding: Set by libavcodec
2251      */
2252     enum AVColorTransferCharacteristic color_trc;
2253 
2254     /**
2255      * YUV colorspace type.
2256      * - encoding: Set by user
2257      * - decoding: Set by libavcodec
2258      */
2259     enum AVColorSpace colorspace;
2260 
2261     /**
2262      * MPEG vs JPEG YUV range.
2263      * - encoding: Set by user
2264      * - decoding: Set by libavcodec
2265      */
2266     enum AVColorRange color_range;
2267 
2268     /**
2269      * This defines the location of chroma samples.
2270      * - encoding: Set by user
2271      * - decoding: Set by libavcodec
2272      */
2273     enum AVChromaLocation chroma_sample_location;
2274 
2275     /**
2276      * Number of slices.
2277      * Indicates number of picture subdivisions. Used for parallelized
2278      * decoding.
2279      * - encoding: Set by user
2280      * - decoding: unused
2281      */
2282     int slices;
2283 
2284     /** Field order
2285      * - encoding: set by libavcodec
2286      * - decoding: Set by user.
2287      */
2288     enum AVFieldOrder field_order;
2289 
2290     /* audio only */
2291     int sample_rate; ///< samples per second
2292     int channels;    ///< number of audio channels
2293 
2294     /**
2295      * audio sample format
2296      * - encoding: Set by user.
2297      * - decoding: Set by libavcodec.
2298      */
2299     enum AVSampleFormat sample_fmt;  ///< sample format
2300 
2301     /* The following data should not be initialized. */
2302     /**
2303      * Number of samples per channel in an audio frame.
2304      *
2305      * - encoding: set by libavcodec in avcodec_open2(). Each submitted frame
2306      *   except the last must contain exactly frame_size samples per channel.
2307      *   May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the
2308      *   frame size is not restricted.
2309      * - decoding: may be set by some decoders to indicate constant frame size
2310      */
2311     int frame_size;
2312 
2313     /**
2314      * Frame counter, set by libavcodec.
2315      *
2316      * - decoding: total number of frames returned from the decoder so far.
2317      * - encoding: total number of frames passed to the encoder so far.
2318      *
2319      *   @note the counter is not incremented if encoding/decoding resulted in
2320      *   an error.
2321      */
2322     int frame_number;
2323 
2324     /**
2325      * number of bytes per packet if constant and known or 0
2326      * Used by some WAV based audio codecs.
2327      */
2328     int block_align;
2329 
2330     /**
2331      * Audio cutoff bandwidth (0 means "automatic")
2332      * - encoding: Set by user.
2333      * - decoding: unused
2334      */
2335     int cutoff;
2336 
2337     /**
2338      * Audio channel layout.
2339      * - encoding: set by user.
2340      * - decoding: set by user, may be overwritten by libavcodec.
2341      */
2342     uint64_t channel_layout;
2343 
2344     /**
2345      * Request decoder to use this channel layout if it can (0 for default)
2346      * - encoding: unused
2347      * - decoding: Set by user.
2348      */
2349     uint64_t request_channel_layout;
2350 
2351     /**
2352      * Type of service that the audio stream conveys.
2353      * - encoding: Set by user.
2354      * - decoding: Set by libavcodec.
2355      */
2356     enum AVAudioServiceType audio_service_type;
2357 
2358     /**
2359      * desired sample format
2360      * - encoding: Not used.
2361      * - decoding: Set by user.
2362      * Decoder will decode to this format if it can.
2363      */
2364     enum AVSampleFormat request_sample_fmt;
2365 
2366     /**
2367      * This callback is called at the beginning of each frame to get data
2368      * buffer(s) for it. There may be one contiguous buffer for all the data or
2369      * there may be a buffer per each data plane or anything in between. What
2370      * this means is, you may set however many entries in buf[] you feel necessary.
2371      * Each buffer must be reference-counted using the AVBuffer API (see description
2372      * of buf[] below).
2373      *
2374      * The following fields will be set in the frame before this callback is
2375      * called:
2376      * - format
2377      * - width, height (video only)
2378      * - sample_rate, channel_layout, nb_samples (audio only)
2379      * Their values may differ from the corresponding values in
2380      * AVCodecContext. This callback must use the frame values, not the codec
2381      * context values, to calculate the required buffer size.
2382      *
2383      * This callback must fill the following fields in the frame:
2384      * - data[]
2385      * - linesize[]
2386      * - extended_data:
2387      *   * if the data is planar audio with more than 8 channels, then this
2388      *     callback must allocate and fill extended_data to contain all pointers
2389      *     to all data planes. data[] must hold as many pointers as it can.
2390      *     extended_data must be allocated with av_malloc() and will be freed in
2391      *     av_frame_unref().
2392      *   * otherwise exended_data must point to data
2393      * - buf[] must contain one or more pointers to AVBufferRef structures. Each of
2394      *   the frame's data and extended_data pointers must be contained in these. That
2395      *   is, one AVBufferRef for each allocated chunk of memory, not necessarily one
2396      *   AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(),
2397      *   and av_buffer_ref().
2398      * - extended_buf and nb_extended_buf must be allocated with av_malloc() by
2399      *   this callback and filled with the extra buffers if there are more
2400      *   buffers than buf[] can hold. extended_buf will be freed in
2401      *   av_frame_unref().
2402      *
2403      * If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call
2404      * avcodec_default_get_buffer2() instead of providing buffers allocated by
2405      * some other means.
2406      *
2407      * Each data plane must be aligned to the maximum required by the target
2408      * CPU.
2409      *
2410      * @see avcodec_default_get_buffer2()
2411      *
2412      * Video:
2413      *
2414      * If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused
2415      * (read and/or written to if it is writable) later by libavcodec.
2416      *
2417      * avcodec_align_dimensions2() should be used to find the required width and
2418      * height, as they normally need to be rounded up to the next multiple of 16.
2419      *
2420      * Some decoders do not support linesizes changing between frames.
2421      *
2422      * If frame multithreading is used and thread_safe_callbacks is set,
2423      * this callback may be called from a different thread, but not from more
2424      * than one at once. Does not need to be reentrant.
2425      *
2426      * @see avcodec_align_dimensions2()
2427      *
2428      * Audio:
2429      *
2430      * Decoders request a buffer of a particular size by setting
2431      * AVFrame.nb_samples prior to calling get_buffer2(). The decoder may,
2432      * however, utilize only part of the buffer by setting AVFrame.nb_samples
2433      * to a smaller value in the output frame.
2434      *
2435      * As a convenience, av_samples_get_buffer_size() and
2436      * av_samples_fill_arrays() in libavutil may be used by custom get_buffer2()
2437      * functions to find the required data size and to fill data pointers and
2438      * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
2439      * since all planes must be the same size.
2440      *
2441      * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
2442      *
2443      * - encoding: unused
2444      * - decoding: Set by libavcodec, user can override.
2445      */
2446     int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);
2447 
2448     /**
2449      * If non-zero, the decoded audio and video frames returned from
2450      * avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted
2451      * and are valid indefinitely. The caller must free them with
2452      * av_frame_unref() when they are not needed anymore.
2453      * Otherwise, the decoded frames must not be freed by the caller and are
2454      * only valid until the next decode call.
2455      *
2456      * - encoding: unused
2457      * - decoding: set by the caller before avcodec_open2().
2458      */
2459     int refcounted_frames;
2460 
2461     /* - encoding parameters */
2462     float qcompress;  ///< amount of qscale change between easy & hard scenes (0.0-1.0)
2463     float qblur;      ///< amount of qscale smoothing over time (0.0-1.0)
2464 
2465     /**
2466      * minimum quantizer
2467      * - encoding: Set by user.
2468      * - decoding: unused
2469      */
2470     int qmin;
2471 
2472     /**
2473      * maximum quantizer
2474      * - encoding: Set by user.
2475      * - decoding: unused
2476      */
2477     int qmax;
2478 
2479     /**
2480      * maximum quantizer difference between frames
2481      * - encoding: Set by user.
2482      * - decoding: unused
2483      */
2484     int max_qdiff;
2485 
2486 #if FF_API_MPV_OPT
2487     /**
2488      * @deprecated use encoder private options instead
2489      */
2490     attribute_deprecated
2491     float rc_qsquish;
2492 
2493     attribute_deprecated
2494     float rc_qmod_amp;
2495     attribute_deprecated
2496     int rc_qmod_freq;
2497 #endif
2498 
2499     /**
2500      * decoder bitstream buffer size
2501      * - encoding: Set by user.
2502      * - decoding: unused
2503      */
2504     int rc_buffer_size;
2505 
2506     /**
2507      * ratecontrol override, see RcOverride
2508      * - encoding: Allocated/set/freed by user.
2509      * - decoding: unused
2510      */
2511     int rc_override_count;
2512     RcOverride *rc_override;
2513 
2514 #if FF_API_MPV_OPT
2515     /**
2516      * @deprecated use encoder private options instead
2517      */
2518     attribute_deprecated
2519     const char *rc_eq;
2520 #endif
2521 
2522     /**
2523      * maximum bitrate
2524      * - encoding: Set by user.
2525      * - decoding: Set by user, may be overwritten by libavcodec.
2526      */
2527     int64_t rc_max_rate;
2528 
2529     /**
2530      * minimum bitrate
2531      * - encoding: Set by user.
2532      * - decoding: unused
2533      */
2534     int64_t rc_min_rate;
2535 
2536 #if FF_API_MPV_OPT
2537     /**
2538      * @deprecated use encoder private options instead
2539      */
2540     attribute_deprecated
2541     float rc_buffer_aggressivity;
2542 
2543     attribute_deprecated
2544     float rc_initial_cplx;
2545 #endif
2546 
2547     /**
2548      * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
2549      * - encoding: Set by user.
2550      * - decoding: unused.
2551      */
2552     float rc_max_available_vbv_use;
2553 
2554     /**
2555      * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
2556      * - encoding: Set by user.
2557      * - decoding: unused.
2558      */
2559     float rc_min_vbv_overflow_use;
2560 
2561     /**
2562      * Number of bits which should be loaded into the rc buffer before decoding starts.
2563      * - encoding: Set by user.
2564      * - decoding: unused
2565      */
2566     int rc_initial_buffer_occupancy;
2567 
2568 #if FF_API_CODER_TYPE
2569 #define FF_CODER_TYPE_VLC       0
2570 #define FF_CODER_TYPE_AC        1
2571 #define FF_CODER_TYPE_RAW       2
2572 #define FF_CODER_TYPE_RLE       3
2573 #if FF_API_UNUSED_MEMBERS
2574 #define FF_CODER_TYPE_DEFLATE   4
2575 #endif /* FF_API_UNUSED_MEMBERS */
2576     /**
2577      * @deprecated use encoder private options instead
2578      */
2579     attribute_deprecated
2580     int coder_type;
2581 #endif /* FF_API_CODER_TYPE */
2582 
2583     /**
2584      * context model
2585      * - encoding: Set by user.
2586      * - decoding: unused
2587      */
2588     int context_model;
2589 
2590 #if FF_API_MPV_OPT
2591     /**
2592      * @deprecated use encoder private options instead
2593      */
2594     attribute_deprecated
2595     int lmin;
2596 
2597     /**
2598      * @deprecated use encoder private options instead
2599      */
2600     attribute_deprecated
2601     int lmax;
2602 #endif
2603 
2604     /**
2605      * frame skip threshold
2606      * - encoding: Set by user.
2607      * - decoding: unused
2608      */
2609     int frame_skip_threshold;
2610 
2611     /**
2612      * frame skip factor
2613      * - encoding: Set by user.
2614      * - decoding: unused
2615      */
2616     int frame_skip_factor;
2617 
2618     /**
2619      * frame skip exponent
2620      * - encoding: Set by user.
2621      * - decoding: unused
2622      */
2623     int frame_skip_exp;
2624 
2625     /**
2626      * frame skip comparison function
2627      * - encoding: Set by user.
2628      * - decoding: unused
2629      */
2630     int frame_skip_cmp;
2631 
2632     /**
2633      * trellis RD quantization
2634      * - encoding: Set by user.
2635      * - decoding: unused
2636      */
2637     int trellis;
2638 
2639     /**
2640      * - encoding: Set by user.
2641      * - decoding: unused
2642      */
2643     int min_prediction_order;
2644 
2645     /**
2646      * - encoding: Set by user.
2647      * - decoding: unused
2648      */
2649     int max_prediction_order;
2650 
2651     /**
2652      * GOP timecode frame start number
2653      * - encoding: Set by user, in non drop frame format
2654      * - decoding: Set by libavcodec (timecode in the 25 bits format, -1 if unset)
2655      */
2656     int64_t timecode_frame_start;
2657 
2658 #if FF_API_RTP_CALLBACK
2659     /**
2660      * @deprecated unused
2661      */
2662     /* The RTP callback: This function is called    */
2663     /* every time the encoder has a packet to send. */
2664     /* It depends on the encoder if the data starts */
2665     /* with a Start Code (it should). H.263 does.   */
2666     /* mb_nb contains the number of macroblocks     */
2667     /* encoded in the RTP payload.                  */
2668     attribute_deprecated
2669     void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);
2670 #endif
2671 
2672     int rtp_payload_size;   /* The size of the RTP payload: the coder will  */
2673                             /* do its best to deliver a chunk with size     */
2674                             /* below rtp_payload_size, the chunk will start */
2675                             /* with a start code on some codecs like H.263. */
2676                             /* This doesn't take account of any particular  */
2677                             /* headers inside the transmitted RTP payload.  */
2678 
2679 #if FF_API_STAT_BITS
2680     /* statistics, used for 2-pass encoding */
2681     attribute_deprecated
2682     int mv_bits;
2683     attribute_deprecated
2684     int header_bits;
2685     attribute_deprecated
2686     int i_tex_bits;
2687     attribute_deprecated
2688     int p_tex_bits;
2689     attribute_deprecated
2690     int i_count;
2691     attribute_deprecated
2692     int p_count;
2693     attribute_deprecated
2694     int skip_count;
2695     attribute_deprecated
2696     int misc_bits;
2697 
2698     /** @deprecated this field is unused */
2699     attribute_deprecated
2700     int frame_bits;
2701 #endif
2702 
2703     /**
2704      * pass1 encoding statistics output buffer
2705      * - encoding: Set by libavcodec.
2706      * - decoding: unused
2707      */
2708     char *stats_out;
2709 
2710     /**
2711      * pass2 encoding statistics input buffer
2712      * Concatenated stuff from stats_out of pass1 should be placed here.
2713      * - encoding: Allocated/set/freed by user.
2714      * - decoding: unused
2715      */
2716     char *stats_in;
2717 
2718     /**
2719      * Work around bugs in encoders which sometimes cannot be detected automatically.
2720      * - encoding: Set by user
2721      * - decoding: Set by user
2722      */
2723     int workaround_bugs;
2724 #define FF_BUG_AUTODETECT       1  ///< autodetection
2725 #if FF_API_OLD_MSMPEG4
2726 #define FF_BUG_OLD_MSMPEG4      2
2727 #endif
2728 #define FF_BUG_XVID_ILACE       4
2729 #define FF_BUG_UMP4             8
2730 #define FF_BUG_NO_PADDING       16
2731 #define FF_BUG_AMV              32
2732 #if FF_API_AC_VLC
2733 #define FF_BUG_AC_VLC           0  ///< Will be removed, libavcodec can now handle these non-compliant files by default.
2734 #endif
2735 #define FF_BUG_QPEL_CHROMA      64
2736 #define FF_BUG_STD_QPEL         128
2737 #define FF_BUG_QPEL_CHROMA2     256
2738 #define FF_BUG_DIRECT_BLOCKSIZE 512
2739 #define FF_BUG_EDGE             1024
2740 #define FF_BUG_HPEL_CHROMA      2048
2741 #define FF_BUG_DC_CLIP          4096
2742 #define FF_BUG_MS               8192 ///< Work around various bugs in Microsoft's broken decoders.
2743 #define FF_BUG_TRUNCATED       16384
2744 
2745     /**
2746      * strictly follow the standard (MPEG4, ...).
2747      * - encoding: Set by user.
2748      * - decoding: Set by user.
2749      * Setting this to STRICT or higher means the encoder and decoder will
2750      * generally do stupid things, whereas setting it to unofficial or lower
2751      * will mean the encoder might produce output that is not supported by all
2752      * spec-compliant decoders. Decoders don't differentiate between normal,
2753      * unofficial and experimental (that is, they always try to decode things
2754      * when they can) unless they are explicitly asked to behave stupidly
2755      * (=strictly conform to the specs)
2756      */
2757     int strict_std_compliance;
2758 #define FF_COMPLIANCE_VERY_STRICT   2 ///< Strictly conform to an older more strict version of the spec or reference software.
2759 #define FF_COMPLIANCE_STRICT        1 ///< Strictly conform to all the things in the spec no matter what consequences.
2760 #define FF_COMPLIANCE_NORMAL        0
2761 #define FF_COMPLIANCE_UNOFFICIAL   -1 ///< Allow unofficial extensions
2762 #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.
2763 
2764     /**
2765      * error concealment flags
2766      * - encoding: unused
2767      * - decoding: Set by user.
2768      */
2769     int error_concealment;
2770 #define FF_EC_GUESS_MVS   1
2771 #define FF_EC_DEBLOCK     2
2772 #define FF_EC_FAVOR_INTER 256
2773 
2774     /**
2775      * debug
2776      * - encoding: Set by user.
2777      * - decoding: Set by user.
2778      */
2779     int debug;
2780 #define FF_DEBUG_PICT_INFO   1
2781 #define FF_DEBUG_RC          2
2782 #define FF_DEBUG_BITSTREAM   4
2783 #define FF_DEBUG_MB_TYPE     8
2784 #define FF_DEBUG_QP          16
2785 #if FF_API_DEBUG_MV
2786 /**
2787  * @deprecated this option does nothing
2788  */
2789 #define FF_DEBUG_MV          32
2790 #endif
2791 #define FF_DEBUG_DCT_COEFF   0x00000040
2792 #define FF_DEBUG_SKIP        0x00000080
2793 #define FF_DEBUG_STARTCODE   0x00000100
2794 #if FF_API_UNUSED_MEMBERS
2795 #define FF_DEBUG_PTS         0x00000200
2796 #endif /* FF_API_UNUSED_MEMBERS */
2797 #define FF_DEBUG_ER          0x00000400
2798 #define FF_DEBUG_MMCO        0x00000800
2799 #define FF_DEBUG_BUGS        0x00001000
2800 #if FF_API_DEBUG_MV
2801 #define FF_DEBUG_VIS_QP      0x00002000 ///< only access through AVOptions from outside libavcodec
2802 #define FF_DEBUG_VIS_MB_TYPE 0x00004000 ///< only access through AVOptions from outside libavcodec
2803 #endif
2804 #define FF_DEBUG_BUFFERS     0x00008000
2805 #define FF_DEBUG_THREADS     0x00010000
2806 #define FF_DEBUG_GREEN_MD    0x00800000
2807 #define FF_DEBUG_NOMC        0x01000000
2808 
2809 #if FF_API_DEBUG_MV
2810     /**
2811      * debug
2812      * Code outside libavcodec should access this field using AVOptions
2813      * - encoding: Set by user.
2814      * - decoding: Set by user.
2815      */
2816     int debug_mv;
2817 #define FF_DEBUG_VIS_MV_P_FOR  0x00000001 //visualize forward predicted MVs of P frames
2818 #define FF_DEBUG_VIS_MV_B_FOR  0x00000002 //visualize forward predicted MVs of B frames
2819 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
2820 #endif
2821 
2822     /**
2823      * Error recognition; may misdetect some more or less valid parts as errors.
2824      * - encoding: unused
2825      * - decoding: Set by user.
2826      */
2827     int err_recognition;
2828 
2829 /**
2830  * Verify checksums embedded in the bitstream (could be of either encoded or
2831  * decoded data, depending on the codec) and print an error message on mismatch.
2832  * If AV_EF_EXPLODE is also set, a mismatching checksum will result in the
2833  * decoder returning an error.
2834  */
2835 #define AV_EF_CRCCHECK  (1<<0)
2836 #define AV_EF_BITSTREAM (1<<1)          ///< detect bitstream specification deviations
2837 #define AV_EF_BUFFER    (1<<2)          ///< detect improper bitstream length
2838 #define AV_EF_EXPLODE   (1<<3)          ///< abort decoding on minor error detection
2839 
2840 #define AV_EF_IGNORE_ERR (1<<15)        ///< ignore errors and continue
2841 #define AV_EF_CAREFUL    (1<<16)        ///< consider things that violate the spec, are fast to calculate and have not been seen in the wild as errors
2842 #define AV_EF_COMPLIANT  (1<<17)        ///< consider all spec non compliances as errors
2843 #define AV_EF_AGGRESSIVE (1<<18)        ///< consider things that a sane encoder should not do as an error
2844 
2845 
2846     /**
2847      * opaque 64bit number (generally a PTS) that will be reordered and
2848      * output in AVFrame.reordered_opaque
2849      * - encoding: unused
2850      * - decoding: Set by user.
2851      */
2852     int64_t reordered_opaque;
2853 
2854     /**
2855      * Hardware accelerator in use
2856      * - encoding: unused.
2857      * - decoding: Set by libavcodec
2858      */
2859     struct AVHWAccel *hwaccel;
2860 
2861     /**
2862      * Hardware accelerator context.
2863      * For some hardware accelerators, a global context needs to be
2864      * provided by the user. In that case, this holds display-dependent
2865      * data FFmpeg cannot instantiate itself. Please refer to the
2866      * FFmpeg HW accelerator documentation to know how to fill this
2867      * is. e.g. for VA API, this is a struct vaapi_context.
2868      * - encoding: unused
2869      * - decoding: Set by user
2870      */
2871     void *hwaccel_context;
2872 
2873     /**
2874      * error
2875      * - encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR.
2876      * - decoding: unused
2877      */
2878     uint64_t error[AV_NUM_DATA_POINTERS];
2879 
2880     /**
2881      * DCT algorithm, see FF_DCT_* below
2882      * - encoding: Set by user.
2883      * - decoding: unused
2884      */
2885     int dct_algo;
2886 #define FF_DCT_AUTO    0
2887 #define FF_DCT_FASTINT 1
2888 #define FF_DCT_INT     2
2889 #define FF_DCT_MMX     3
2890 #define FF_DCT_ALTIVEC 5
2891 #define FF_DCT_FAAN    6
2892 
2893     /**
2894      * IDCT algorithm, see FF_IDCT_* below.
2895      * - encoding: Set by user.
2896      * - decoding: Set by user.
2897      */
2898     int idct_algo;
2899 #define FF_IDCT_AUTO          0
2900 #define FF_IDCT_INT           1
2901 #define FF_IDCT_SIMPLE        2
2902 #define FF_IDCT_SIMPLEMMX     3
2903 #define FF_IDCT_ARM           7
2904 #define FF_IDCT_ALTIVEC       8
2905 #if FF_API_ARCH_SH4
2906 #define FF_IDCT_SH4           9
2907 #endif
2908 #define FF_IDCT_SIMPLEARM     10
2909 #if FF_API_UNUSED_MEMBERS
2910 #define FF_IDCT_IPP           13
2911 #endif /* FF_API_UNUSED_MEMBERS */
2912 #define FF_IDCT_XVID          14
2913 #if FF_API_IDCT_XVIDMMX
2914 #define FF_IDCT_XVIDMMX       14
2915 #endif /* FF_API_IDCT_XVIDMMX */
2916 #define FF_IDCT_SIMPLEARMV5TE 16
2917 #define FF_IDCT_SIMPLEARMV6   17
2918 #if FF_API_ARCH_SPARC
2919 #define FF_IDCT_SIMPLEVIS     18
2920 #endif
2921 #define FF_IDCT_FAAN          20
2922 #define FF_IDCT_SIMPLENEON    22
2923 #if FF_API_ARCH_ALPHA
2924 #define FF_IDCT_SIMPLEALPHA   23
2925 #endif
2926 #define FF_IDCT_SIMPLEAUTO    128
2927 
2928     /**
2929      * bits per sample/pixel from the demuxer (needed for huffyuv).
2930      * - encoding: Set by libavcodec.
2931      * - decoding: Set by user.
2932      */
2933      int bits_per_coded_sample;
2934 
2935     /**
2936      * Bits per sample/pixel of internal libavcodec pixel/sample format.
2937      * - encoding: set by user.
2938      * - decoding: set by libavcodec.
2939      */
2940     int bits_per_raw_sample;
2941 
2942 #if FF_API_LOWRES
2943     /**
2944      * low resolution decoding, 1-> 1/2 size, 2->1/4 size
2945      * - encoding: unused
2946      * - decoding: Set by user.
2947      * Code outside libavcodec should access this field using:
2948      * av_codec_{get,set}_lowres(avctx)
2949      */
2950      int lowres;
2951 #endif
2952 
2953 #if FF_API_CODED_FRAME
2954     /**
2955      * the picture in the bitstream
2956      * - encoding: Set by libavcodec.
2957      * - decoding: unused
2958      *
2959      * @deprecated use the quality factor packet side data instead
2960      */
2961     attribute_deprecated AVFrame *coded_frame;
2962 #endif
2963 
2964     /**
2965      * thread count
2966      * is used to decide how many independent tasks should be passed to execute()
2967      * - encoding: Set by user.
2968      * - decoding: Set by user.
2969      */
2970     int thread_count;
2971 
2972     /**
2973      * Which multithreading methods to use.
2974      * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
2975      * so clients which cannot provide future frames should not use it.
2976      *
2977      * - encoding: Set by user, otherwise the default is used.
2978      * - decoding: Set by user, otherwise the default is used.
2979      */
2980     int thread_type;
2981 #define FF_THREAD_FRAME   1 ///< Decode more than one frame at once
2982 #define FF_THREAD_SLICE   2 ///< Decode more than one part of a single frame at once
2983 
2984     /**
2985      * Which multithreading methods are in use by the codec.
2986      * - encoding: Set by libavcodec.
2987      * - decoding: Set by libavcodec.
2988      */
2989     int active_thread_type;
2990 
2991     /**
2992      * Set by the client if its custom get_buffer() callback can be called
2993      * synchronously from another thread, which allows faster multithreaded decoding.
2994      * draw_horiz_band() will be called from other threads regardless of this setting.
2995      * Ignored if the default get_buffer() is used.
2996      * - encoding: Set by user.
2997      * - decoding: Set by user.
2998      */
2999     int thread_safe_callbacks;
3000 
3001     /**
3002      * The codec may call this to execute several independent things.
3003      * It will return only after finishing all tasks.
3004      * The user may replace this with some multithreaded implementation,
3005      * the default implementation will execute the parts serially.
3006      * @param count the number of things to execute
3007      * - encoding: Set by libavcodec, user can override.
3008      * - decoding: Set by libavcodec, user can override.
3009      */
3010     int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);
3011 
3012     /**
3013      * The codec may call this to execute several independent things.
3014      * It will return only after finishing all tasks.
3015      * The user may replace this with some multithreaded implementation,
3016      * the default implementation will execute the parts serially.
3017      * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
3018      * @param c context passed also to func
3019      * @param count the number of things to execute
3020      * @param arg2 argument passed unchanged to func
3021      * @param ret return values of executed functions, must have space for "count" values. May be NULL.
3022      * @param func function that will be called count times, with jobnr from 0 to count-1.
3023      *             threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
3024      *             two instances of func executing at the same time will have the same threadnr.
3025      * @return always 0 currently, but code should handle a future improvement where when any call to func
3026      *         returns < 0 no further calls to func may be done and < 0 is returned.
3027      * - encoding: Set by libavcodec, user can override.
3028      * - decoding: Set by libavcodec, user can override.
3029      */
3030     int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);
3031 
3032     /**
3033      * noise vs. sse weight for the nsse comparison function
3034      * - encoding: Set by user.
3035      * - decoding: unused
3036      */
3037      int nsse_weight;
3038 
3039     /**
3040      * profile
3041      * - encoding: Set by user.
3042      * - decoding: Set by libavcodec.
3043      */
3044      int profile;
3045 #define FF_PROFILE_UNKNOWN -99
3046 #define FF_PROFILE_RESERVED -100
3047 
3048 #define FF_PROFILE_AAC_MAIN 0
3049 #define FF_PROFILE_AAC_LOW  1
3050 #define FF_PROFILE_AAC_SSR  2
3051 #define FF_PROFILE_AAC_LTP  3
3052 #define FF_PROFILE_AAC_HE   4
3053 #define FF_PROFILE_AAC_HE_V2 28
3054 #define FF_PROFILE_AAC_LD   22
3055 #define FF_PROFILE_AAC_ELD  38
3056 #define FF_PROFILE_MPEG2_AAC_LOW 128
3057 #define FF_PROFILE_MPEG2_AAC_HE  131
3058 
3059 #define FF_PROFILE_DTS         20
3060 #define FF_PROFILE_DTS_ES      30
3061 #define FF_PROFILE_DTS_96_24   40
3062 #define FF_PROFILE_DTS_HD_HRA  50
3063 #define FF_PROFILE_DTS_HD_MA   60
3064 #define FF_PROFILE_DTS_EXPRESS 70
3065 
3066 #define FF_PROFILE_MPEG2_422    0
3067 #define FF_PROFILE_MPEG2_HIGH   1
3068 #define FF_PROFILE_MPEG2_SS     2
3069 #define FF_PROFILE_MPEG2_SNR_SCALABLE  3
3070 #define FF_PROFILE_MPEG2_MAIN   4
3071 #define FF_PROFILE_MPEG2_SIMPLE 5
3072 
3073 #define FF_PROFILE_H264_CONSTRAINED  (1<<9)  // 8+1; constraint_set1_flag
3074 #define FF_PROFILE_H264_INTRA        (1<<11) // 8+3; constraint_set3_flag
3075 
3076 #define FF_PROFILE_H264_BASELINE             66
3077 #define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
3078 #define FF_PROFILE_H264_MAIN                 77
3079 #define FF_PROFILE_H264_EXTENDED             88
3080 #define FF_PROFILE_H264_HIGH                 100
3081 #define FF_PROFILE_H264_HIGH_10              110
3082 #define FF_PROFILE_H264_HIGH_10_INTRA        (110|FF_PROFILE_H264_INTRA)
3083 #define FF_PROFILE_H264_HIGH_422             122
3084 #define FF_PROFILE_H264_HIGH_422_INTRA       (122|FF_PROFILE_H264_INTRA)
3085 #define FF_PROFILE_H264_HIGH_444             144
3086 #define FF_PROFILE_H264_HIGH_444_PREDICTIVE  244
3087 #define FF_PROFILE_H264_HIGH_444_INTRA       (244|FF_PROFILE_H264_INTRA)
3088 #define FF_PROFILE_H264_CAVLC_444            44
3089 
3090 #define FF_PROFILE_VC1_SIMPLE   0
3091 #define FF_PROFILE_VC1_MAIN     1
3092 #define FF_PROFILE_VC1_COMPLEX  2
3093 #define FF_PROFILE_VC1_ADVANCED 3
3094 
3095 #define FF_PROFILE_MPEG4_SIMPLE                     0
3096 #define FF_PROFILE_MPEG4_SIMPLE_SCALABLE            1
3097 #define FF_PROFILE_MPEG4_CORE                       2
3098 #define FF_PROFILE_MPEG4_MAIN                       3
3099 #define FF_PROFILE_MPEG4_N_BIT                      4
3100 #define FF_PROFILE_MPEG4_SCALABLE_TEXTURE           5
3101 #define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION      6
3102 #define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE     7
3103 #define FF_PROFILE_MPEG4_HYBRID                     8
3104 #define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME         9
3105 #define FF_PROFILE_MPEG4_CORE_SCALABLE             10
3106 #define FF_PROFILE_MPEG4_ADVANCED_CODING           11
3107 #define FF_PROFILE_MPEG4_ADVANCED_CORE             12
3108 #define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
3109 #define FF_PROFILE_MPEG4_SIMPLE_STUDIO             14
3110 #define FF_PROFILE_MPEG4_ADVANCED_SIMPLE           15
3111 
3112 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_0   0
3113 #define FF_PROFILE_JPEG2000_CSTREAM_RESTRICTION_1   1
3114 #define FF_PROFILE_JPEG2000_CSTREAM_NO_RESTRICTION  2
3115 #define FF_PROFILE_JPEG2000_DCINEMA_2K              3
3116 #define FF_PROFILE_JPEG2000_DCINEMA_4K              4
3117 
3118 #define FF_PROFILE_VP9_0                            0
3119 #define FF_PROFILE_VP9_1                            1
3120 #define FF_PROFILE_VP9_2                            2
3121 #define FF_PROFILE_VP9_3                            3
3122 
3123 #define FF_PROFILE_HEVC_MAIN                        1
3124 #define FF_PROFILE_HEVC_MAIN_10                     2
3125 #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE          3
3126 #define FF_PROFILE_HEVC_REXT                        4
3127 
3128     /**
3129      * level
3130      * - encoding: Set by user.
3131      * - decoding: Set by libavcodec.
3132      */
3133      int level;
3134 #define FF_LEVEL_UNKNOWN -99
3135 
3136     /**
3137      * Skip loop filtering for selected frames.
3138      * - encoding: unused
3139      * - decoding: Set by user.
3140      */
3141     enum AVDiscard skip_loop_filter;
3142 
3143     /**
3144      * Skip IDCT/dequantization for selected frames.
3145      * - encoding: unused
3146      * - decoding: Set by user.
3147      */
3148     enum AVDiscard skip_idct;
3149 
3150     /**
3151      * Skip decoding for selected frames.
3152      * - encoding: unused
3153      * - decoding: Set by user.
3154      */
3155     enum AVDiscard skip_frame;
3156 
3157     /**
3158      * Header containing style information for text subtitles.
3159      * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
3160      * [Script Info] and [V4+ Styles] section, plus the [Events] line and
3161      * the Format line following. It shouldn't include any Dialogue line.
3162      * - encoding: Set/allocated/freed by user (before avcodec_open2())
3163      * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
3164      */
3165     uint8_t *subtitle_header;
3166     int subtitle_header_size;
3167 
3168 #if FF_API_ERROR_RATE
3169     /**
3170      * @deprecated use the 'error_rate' private AVOption of the mpegvideo
3171      * encoders
3172      */
3173     attribute_deprecated
3174     int error_rate;
3175 #endif
3176 
3177 #if FF_API_VBV_DELAY
3178     /**
3179      * VBV delay coded in the last frame (in periods of a 27 MHz clock).
3180      * Used for compliant TS muxing.
3181      * - encoding: Set by libavcodec.
3182      * - decoding: unused.
3183      * @deprecated this value is now exported as a part of
3184      * AV_PKT_DATA_CPB_PROPERTIES packet side data
3185      */
3186     attribute_deprecated
3187     uint64_t vbv_delay;
3188 #endif
3189 
3190 #if FF_API_SIDEDATA_ONLY_PKT
3191     /**
3192      * Encoding only and set by default. Allow encoders to output packets
3193      * that do not contain any encoded data, only side data.
3194      *
3195      * Some encoders need to output such packets, e.g. to update some stream
3196      * parameters at the end of encoding.
3197      *
3198      * @deprecated this field disables the default behaviour and
3199      *             it is kept only for compatibility.
3200      */
3201     attribute_deprecated
3202     int side_data_only_packets;
3203 #endif
3204 
3205     /**
3206      * Audio only. The number of "priming" samples (padding) inserted by the
3207      * encoder at the beginning of the audio. I.e. this number of leading
3208      * decoded samples must be discarded by the caller to get the original audio
3209      * without leading padding.
3210      *
3211      * - decoding: unused
3212      * - encoding: Set by libavcodec. The timestamps on the output packets are
3213      *             adjusted by the encoder so that they always refer to the
3214      *             first sample of the data actually contained in the packet,
3215      *             including any added padding.  E.g. if the timebase is
3216      *             1/samplerate and the timestamp of the first input sample is
3217      *             0, the timestamp of the first output packet will be
3218      *             -initial_padding.
3219      */
3220     int initial_padding;
3221 
3222     /**
3223      * - decoding: For codecs that store a framerate value in the compressed
3224      *             bitstream, the decoder may export it here. { 0, 1} when
3225      *             unknown.
3226      * - encoding: unused
3227      */
3228     AVRational framerate;
3229 
3230     /**
3231      * Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.
3232      * - encoding: unused.
3233      * - decoding: Set by libavcodec before calling get_format()
3234      */
3235     enum AVPixelFormat sw_pix_fmt;
3236 
3237     /**
3238      * Timebase in which pkt_dts/pts and AVPacket.dts/pts are.
3239      * Code outside libavcodec should access this field using:
3240      * av_codec_{get,set}_pkt_timebase(avctx)
3241      * - encoding unused.
3242      * - decoding set by user.
3243      */
3244     AVRational pkt_timebase;
3245 
3246     /**
3247      * AVCodecDescriptor
3248      * Code outside libavcodec should access this field using:
3249      * av_codec_{get,set}_codec_descriptor(avctx)
3250      * - encoding: unused.
3251      * - decoding: set by libavcodec.
3252      */
3253     const AVCodecDescriptor *codec_descriptor;
3254 
3255 #if !FF_API_LOWRES
3256     /**
3257      * low resolution decoding, 1-> 1/2 size, 2->1/4 size
3258      * - encoding: unused
3259      * - decoding: Set by user.
3260      * Code outside libavcodec should access this field using:
3261      * av_codec_{get,set}_lowres(avctx)
3262      */
3263      int lowres;
3264 #endif
3265 
3266     /**
3267      * Current statistics for PTS correction.
3268      * - decoding: maintained and used by libavcodec, not intended to be used by user apps
3269      * - encoding: unused
3270      */
3271     int64_t pts_correction_num_faulty_pts; /// Number of incorrect PTS values so far
3272     int64_t pts_correction_num_faulty_dts; /// Number of incorrect DTS values so far
3273     int64_t pts_correction_last_pts;       /// PTS of the last frame
3274     int64_t pts_correction_last_dts;       /// DTS of the last frame
3275 
3276     /**
3277      * Character encoding of the input subtitles file.
3278      * - decoding: set by user
3279      * - encoding: unused
3280      */
3281     char *sub_charenc;
3282 
3283     /**
3284      * Subtitles character encoding mode. Formats or codecs might be adjusting
3285      * this setting (if they are doing the conversion themselves for instance).
3286      * - decoding: set by libavcodec
3287      * - encoding: unused
3288      */
3289     int sub_charenc_mode;
3290 #define FF_SUB_CHARENC_MODE_DO_NOTHING  -1  ///< do nothing (demuxer outputs a stream supposed to be already in UTF-8, or the codec is bitmap for instance)
3291 #define FF_SUB_CHARENC_MODE_AUTOMATIC    0  ///< libavcodec will select the mode itself
3292 #define FF_SUB_CHARENC_MODE_PRE_DECODER  1  ///< the AVPacket data needs to be recoded to UTF-8 before being fed to the decoder, requires iconv
3293 
3294     /**
3295      * Skip processing alpha if supported by codec.
3296      * Note that if the format uses pre-multiplied alpha (common with VP6,
3297      * and recommended due to better video quality/compression)
3298      * the image will look as if alpha-blended onto a black background.
3299      * However for formats that do not use pre-multiplied alpha
3300      * there might be serious artefacts (though e.g. libswscale currently
3301      * assumes pre-multiplied alpha anyway).
3302      * Code outside libavcodec should access this field using AVOptions
3303      *
3304      * - decoding: set by user
3305      * - encoding: unused
3306      */
3307     int skip_alpha;
3308 
3309     /**
3310      * Number of samples to skip after a discontinuity
3311      * - decoding: unused
3312      * - encoding: set by libavcodec
3313      */
3314     int seek_preroll;
3315 
3316 #if !FF_API_DEBUG_MV
3317     /**
3318      * debug motion vectors
3319      * Code outside libavcodec should access this field using AVOptions
3320      * - encoding: Set by user.
3321      * - decoding: Set by user.
3322      */
3323     int debug_mv;
3324 #define FF_DEBUG_VIS_MV_P_FOR  0x00000001 //visualize forward predicted MVs of P frames
3325 #define FF_DEBUG_VIS_MV_B_FOR  0x00000002 //visualize forward predicted MVs of B frames
3326 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
3327 #endif
3328 
3329     /**
3330      * custom intra quantization matrix
3331      * Code outside libavcodec should access this field using av_codec_g/set_chroma_intra_matrix()
3332      * - encoding: Set by user, can be NULL.
3333      * - decoding: unused.
3334      */
3335     uint16_t *chroma_intra_matrix;
3336 
3337     /**
3338      * dump format separator.
3339      * can be ", " or "\n      " or anything else
3340      * Code outside libavcodec should access this field using AVOptions
3341      * (NO direct access).
3342      * - encoding: Set by user.
3343      * - decoding: Set by user.
3344      */
3345     uint8_t *dump_separator;
3346 
3347     /**
3348      * ',' separated list of allowed decoders.
3349      * If NULL then all are allowed
3350      * - encoding: unused
3351      * - decoding: set by user through AVOPtions (NO direct access)
3352      */
3353     char *codec_whitelist;
3354 
3355     /*
3356      * Properties of the stream that gets decoded
3357      * To be accessed through av_codec_get_properties() (NO direct access)
3358      * - encoding: unused
3359      * - decoding: set by libavcodec
3360      */
3361     unsigned properties;
3362 #define FF_CODEC_PROPERTY_LOSSLESS        0x00000001
3363 #define FF_CODEC_PROPERTY_CLOSED_CAPTIONS 0x00000002
3364 
3365     /**
3366      * Additional data associated with the entire coded stream.
3367      *
3368      * - decoding: unused
3369      * - encoding: may be set by libavcodec after avcodec_open2().
3370      */
3371     AVPacketSideData *coded_side_data;
3372     int            nb_coded_side_data;
3373 
3374 } AVCodecContext;
3375 
3376 AVRational av_codec_get_pkt_timebase         (const AVCodecContext *avctx);
3377 void       av_codec_set_pkt_timebase         (AVCodecContext *avctx, AVRational val);
3378 
3379 const AVCodecDescriptor *av_codec_get_codec_descriptor(const AVCodecContext *avctx);
3380 void                     av_codec_set_codec_descriptor(AVCodecContext *avctx, const AVCodecDescriptor *desc);
3381 
3382 unsigned av_codec_get_codec_properties(const AVCodecContext *avctx);
3383 
3384 int  av_codec_get_lowres(const AVCodecContext *avctx);
3385 void av_codec_set_lowres(AVCodecContext *avctx, int val);
3386 
3387 int  av_codec_get_seek_preroll(const AVCodecContext *avctx);
3388 void av_codec_set_seek_preroll(AVCodecContext *avctx, int val);
3389 
3390 uint16_t *av_codec_get_chroma_intra_matrix(const AVCodecContext *avctx);
3391 void av_codec_set_chroma_intra_matrix(AVCodecContext *avctx, uint16_t *val);
3392 
3393 /**
3394  * AVProfile.
3395  */
3396 typedef struct AVProfile {
3397     int profile;
3398     const char *name; ///< short name for the profile
3399 } AVProfile;
3400 
3401 typedef struct AVCodecDefault AVCodecDefault;
3402 
3403 struct AVSubtitle;
3404 
3405 /**
3406  * AVCodec.
3407  */
3408 typedef struct AVCodec {
3409     /**
3410      * Name of the codec implementation.
3411      * The name is globally unique among encoders and among decoders (but an
3412      * encoder and a decoder can share the same name).
3413      * This is the primary way to find a codec from the user perspective.
3414      */
3415     const char *name;
3416     /**
3417      * Descriptive name for the codec, meant to be more human readable than name.
3418      * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
3419      */
3420     const char *long_name;
3421     enum AVMediaType type;
3422     enum AVCodecID id;
3423     /**
3424      * Codec capabilities.
3425      * see AV_CODEC_CAP_*
3426      */
3427     int capabilities;
3428     const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
3429     const enum AVPixelFormat *pix_fmts;     ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
3430     const int *supported_samplerates;       ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
3431     const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
3432     const uint64_t *channel_layouts;         ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
3433     uint8_t max_lowres;                     ///< maximum value for lowres supported by the decoder, no direct access, use av_codec_get_max_lowres()
3434     const AVClass *priv_class;              ///< AVClass for the private context
3435     const AVProfile *profiles;              ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
3436 
3437     /*****************************************************************
3438      * No fields below this line are part of the public API. They
3439      * may not be used outside of libavcodec and can be changed and
3440      * removed at will.
3441      * New public fields should be added right above.
3442      *****************************************************************
3443      */
3444     int priv_data_size;
3445     struct AVCodec *next;
3446     /**
3447      * @name Frame-level threading support functions
3448      * @{
3449      */
3450     /**
3451      * If defined, called on thread contexts when they are created.
3452      * If the codec allocates writable tables in init(), re-allocate them here.
3453      * priv_data will be set to a copy of the original.
3454      */
3455     int (*init_thread_copy)(AVCodecContext *);
3456     /**
3457      * Copy necessary context variables from a previous thread context to the current one.
3458      * If not defined, the next thread will start automatically; otherwise, the codec
3459      * must call ff_thread_finish_setup().
3460      *
3461      * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
3462      */
3463     int (*update_thread_context)(AVCodecContext *dst, const AVCodecContext *src);
3464     /** @} */
3465 
3466     /**
3467      * Private codec-specific defaults.
3468      */
3469     const AVCodecDefault *defaults;
3470 
3471     /**
3472      * Initialize codec static data, called from avcodec_register().
3473      */
3474     void (*init_static_data)(struct AVCodec *codec);
3475 
3476     int (*init)(AVCodecContext *);
3477     int (*encode_sub)(AVCodecContext *, uint8_t *buf, int buf_size,
3478                       const struct AVSubtitle *sub);
3479     /**
3480      * Encode data to an AVPacket.
3481      *
3482      * @param      avctx          codec context
3483      * @param      avpkt          output AVPacket (may contain a user-provided buffer)
3484      * @param[in]  frame          AVFrame containing the raw data to be encoded
3485      * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
3486      *                            non-empty packet was returned in avpkt.
3487      * @return 0 on success, negative error code on failure
3488      */
3489     int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
3490                    int *got_packet_ptr);
3491     int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
3492     int (*close)(AVCodecContext *);
3493     /**
3494      * Flush buffers.
3495      * Will be called when seeking
3496      */
3497     void (*flush)(AVCodecContext *);
3498     /**
3499      * Internal codec capabilities.
3500      * See FF_CODEC_CAP_* in internal.h
3501      */
3502     int caps_internal;
3503 } AVCodec;
3504 
3505 int av_codec_get_max_lowres(const AVCodec *codec);
3506 
3507 struct MpegEncContext;
3508 
3509 /**
3510  * @defgroup lavc_hwaccel AVHWAccel
3511  * @{
3512  */
3513 typedef struct AVHWAccel {
3514     /**
3515      * Name of the hardware accelerated codec.
3516      * The name is globally unique among encoders and among decoders (but an
3517      * encoder and a decoder can share the same name).
3518      */
3519     const char *name;
3520 
3521     /**
3522      * Type of codec implemented by the hardware accelerator.
3523      *
3524      * See AVMEDIA_TYPE_xxx
3525      */
3526     enum AVMediaType type;
3527 
3528     /**
3529      * Codec implemented by the hardware accelerator.
3530      *
3531      * See AV_CODEC_ID_xxx
3532      */
3533     enum AVCodecID id;
3534 
3535     /**
3536      * Supported pixel format.
3537      *
3538      * Only hardware accelerated formats are supported here.
3539      */
3540     enum AVPixelFormat pix_fmt;
3541 
3542     /**
3543      * Hardware accelerated codec capabilities.
3544      * see HWACCEL_CODEC_CAP_*
3545      */
3546     int capabilities;
3547 
3548     /*****************************************************************
3549      * No fields below this line are part of the public API. They
3550      * may not be used outside of libavcodec and can be changed and
3551      * removed at will.
3552      * New public fields should be added right above.
3553      *****************************************************************
3554      */
3555     struct AVHWAccel *next;
3556 
3557     /**
3558      * Allocate a custom buffer
3559      */
3560     int (*alloc_frame)(AVCodecContext *avctx, AVFrame *frame);
3561 
3562     /**
3563      * Called at the beginning of each frame or field picture.
3564      *
3565      * Meaningful frame information (codec specific) is guaranteed to
3566      * be parsed at this point. This function is mandatory.
3567      *
3568      * Note that buf can be NULL along with buf_size set to 0.
3569      * Otherwise, this means the whole frame is available at this point.
3570      *
3571      * @param avctx the codec context
3572      * @param buf the frame data buffer base
3573      * @param buf_size the size of the frame in bytes
3574      * @return zero if successful, a negative value otherwise
3575      */
3576     int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3577 
3578     /**
3579      * Callback for each slice.
3580      *
3581      * Meaningful slice information (codec specific) is guaranteed to
3582      * be parsed at this point. This function is mandatory.
3583      * The only exception is XvMC, that works on MB level.
3584      *
3585      * @param avctx the codec context
3586      * @param buf the slice data buffer base
3587      * @param buf_size the size of the slice in bytes
3588      * @return zero if successful, a negative value otherwise
3589      */
3590     int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);
3591 
3592     /**
3593      * Called at the end of each frame or field picture.
3594      *
3595      * The whole picture is parsed at this point and can now be sent
3596      * to the hardware accelerator. This function is mandatory.
3597      *
3598      * @param avctx the codec context
3599      * @return zero if successful, a negative value otherwise
3600      */
3601     int (*end_frame)(AVCodecContext *avctx);
3602 
3603     /**
3604      * Size of per-frame hardware accelerator private data.
3605      *
3606      * Private data is allocated with av_mallocz() before
3607      * AVCodecContext.get_buffer() and deallocated after
3608      * AVCodecContext.release_buffer().
3609      */
3610     int frame_priv_data_size;
3611 
3612     /**
3613      * Called for every Macroblock in a slice.
3614      *
3615      * XvMC uses it to replace the ff_mpv_decode_mb().
3616      * Instead of decoding to raw picture, MB parameters are
3617      * stored in an array provided by the video driver.
3618      *
3619      * @param s the mpeg context
3620      */
3621     void (*decode_mb)(struct MpegEncContext *s);
3622 
3623     /**
3624      * Initialize the hwaccel private data.
3625      *
3626      * This will be called from ff_get_format(), after hwaccel and
3627      * hwaccel_context are set and the hwaccel private data in AVCodecInternal
3628      * is allocated.
3629      */
3630     int (*init)(AVCodecContext *avctx);
3631 
3632     /**
3633      * Uninitialize the hwaccel private data.
3634      *
3635      * This will be called from get_format() or avcodec_close(), after hwaccel
3636      * and hwaccel_context are already uninitialized.
3637      */
3638     int (*uninit)(AVCodecContext *avctx);
3639 
3640     /**
3641      * Size of the private data to allocate in
3642      * AVCodecInternal.hwaccel_priv_data.
3643      */
3644     int priv_data_size;
3645 } AVHWAccel;
3646 
3647 /**
3648  * Hardware acceleration should be used for decoding even if the codec level
3649  * used is unknown or higher than the maximum supported level reported by the
3650  * hardware driver.
3651  *
3652  * It's generally a good idea to pass this flag unless you have a specific
3653  * reason not to, as hardware tends to under-report supported levels.
3654  */
3655 #define AV_HWACCEL_FLAG_IGNORE_LEVEL (1 << 0)
3656 
3657 /**
3658  * Hardware acceleration can output YUV pixel formats with a different chroma
3659  * sampling than 4:2:0 and/or other than 8 bits per component.
3660  */
3661 #define AV_HWACCEL_FLAG_ALLOW_HIGH_DEPTH (1 << 1)
3662 
3663 /**
3664  * @}
3665  */
3666 
3667 #if FF_API_AVPICTURE
3668 /**
3669  * @defgroup lavc_picture AVPicture
3670  *
3671  * Functions for working with AVPicture
3672  * @{
3673  */
3674 
3675 /**
3676  * Picture data structure.
3677  *
3678  * Up to four components can be stored into it, the last component is
3679  * alpha.
3680  * @deprecated use AVFrame or imgutils functions instead
3681  */
3682 typedef struct AVPicture {
3683     attribute_deprecated
3684     uint8_t *data[AV_NUM_DATA_POINTERS];    ///< pointers to the image data planes
3685     attribute_deprecated
3686     int linesize[AV_NUM_DATA_POINTERS];     ///< number of bytes per line
3687 } AVPicture;
3688 
3689 /**
3690  * @}
3691  */
3692 #endif
3693 
3694 enum AVSubtitleType {
3695     SUBTITLE_NONE,
3696 
3697     SUBTITLE_BITMAP,                ///< A bitmap, pict will be set
3698 
3699     /**
3700      * Plain text, the text field must be set by the decoder and is
3701      * authoritative. ass and pict fields may contain approximations.
3702      */
3703     SUBTITLE_TEXT,
3704 
3705     /**
3706      * Formatted text, the ass field must be set by the decoder and is
3707      * authoritative. pict and text fields may contain approximations.
3708      */
3709     SUBTITLE_ASS,
3710 };
3711 
3712 #define AV_SUBTITLE_FLAG_FORCED 0x00000001
3713 
3714 typedef struct AVSubtitleRect {
3715     int x;         ///< top left corner  of pict, undefined when pict is not set
3716     int y;         ///< top left corner  of pict, undefined when pict is not set
3717     int w;         ///< width            of pict, undefined when pict is not set
3718     int h;         ///< height           of pict, undefined when pict is not set
3719     int nb_colors; ///< number of colors in pict, undefined when pict is not set
3720 
3721 #if FF_API_AVPICTURE
3722     /**
3723      * @deprecated unused
3724      */
3725     attribute_deprecated
3726     AVPicture pict;
3727 #endif
3728     /**
3729      * data+linesize for the bitmap of this subtitle.
3730      * Can be set for text/ass as well once they are rendered.
3731      */
3732     uint8_t *data[4];
3733     int linesize[4];
3734 
3735     enum AVSubtitleType type;
3736 
3737     char *text;                     ///< 0 terminated plain UTF-8 text
3738 
3739     /**
3740      * 0 terminated ASS/SSA compatible event line.
3741      * The presentation of this is unaffected by the other values in this
3742      * struct.
3743      */
3744     char *ass;
3745 
3746     int flags;
3747 } AVSubtitleRect;
3748 
3749 typedef struct AVSubtitle {
3750     uint16_t format; /* 0 = graphics */
3751     uint32_t start_display_time; /* relative to packet pts, in ms */
3752     uint32_t end_display_time; /* relative to packet pts, in ms */
3753     unsigned num_rects;
3754     AVSubtitleRect **rects;
3755     int64_t pts;    ///< Same as packet pts, in AV_TIME_BASE
3756 } AVSubtitle;
3757 
3758 /**
3759  * If c is NULL, returns the first registered codec,
3760  * if c is non-NULL, returns the next registered codec after c,
3761  * or NULL if c is the last one.
3762  */
3763 AVCodec *av_codec_next(const AVCodec *c);
3764 
3765 /**
3766  * Return the LIBAVCODEC_VERSION_INT constant.
3767  */
3768 unsigned avcodec_version(void);
3769 
3770 /**
3771  * Return the libavcodec build-time configuration.
3772  */
3773 const char *avcodec_configuration(void);
3774 
3775 /**
3776  * Return the libavcodec license.
3777  */
3778 const char *avcodec_license(void);
3779 
3780 /**
3781  * Register the codec codec and initialize libavcodec.
3782  *
3783  * @warning either this function or avcodec_register_all() must be called
3784  * before any other libavcodec functions.
3785  *
3786  * @see avcodec_register_all()
3787  */
3788 void avcodec_register(AVCodec *codec);
3789 
3790 /**
3791  * Register all the codecs, parsers and bitstream filters which were enabled at
3792  * configuration time. If you do not call this function you can select exactly
3793  * which formats you want to support, by using the individual registration
3794  * functions.
3795  *
3796  * @see avcodec_register
3797  * @see av_register_codec_parser
3798  * @see av_register_bitstream_filter
3799  */
3800 void avcodec_register_all(void);
3801 
3802 /**
3803  * Allocate an AVCodecContext and set its fields to default values. The
3804  * resulting struct should be freed with avcodec_free_context().
3805  *
3806  * @param codec if non-NULL, allocate private data and initialize defaults
3807  *              for the given codec. It is illegal to then call avcodec_open2()
3808  *              with a different codec.
3809  *              If NULL, then the codec-specific defaults won't be initialized,
3810  *              which may result in suboptimal default settings (this is
3811  *              important mainly for encoders, e.g. libx264).
3812  *
3813  * @return An AVCodecContext filled with default values or NULL on failure.
3814  * @see avcodec_get_context_defaults
3815  */
3816 AVCodecContext *avcodec_alloc_context3(const AVCodec *codec);
3817 
3818 /**
3819  * Free the codec context and everything associated with it and write NULL to
3820  * the provided pointer.
3821  */
3822 void avcodec_free_context(AVCodecContext **avctx);
3823 
3824 /**
3825  * Set the fields of the given AVCodecContext to default values corresponding
3826  * to the given codec (defaults may be codec-dependent).
3827  *
3828  * Do not call this function if a non-NULL codec has been passed
3829  * to avcodec_alloc_context3() that allocated this AVCodecContext.
3830  * If codec is non-NULL, it is illegal to call avcodec_open2() with a
3831  * different codec on this AVCodecContext.
3832  */
3833 int avcodec_get_context_defaults3(AVCodecContext *s, const AVCodec *codec);
3834 
3835 /**
3836  * Get the AVClass for AVCodecContext. It can be used in combination with
3837  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3838  *
3839  * @see av_opt_find().
3840  */
3841 const AVClass *avcodec_get_class(void);
3842 
3843 /**
3844  * Get the AVClass for AVFrame. It can be used in combination with
3845  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3846  *
3847  * @see av_opt_find().
3848  */
3849 const AVClass *avcodec_get_frame_class(void);
3850 
3851 /**
3852  * Get the AVClass for AVSubtitleRect. It can be used in combination with
3853  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
3854  *
3855  * @see av_opt_find().
3856  */
3857 const AVClass *avcodec_get_subtitle_rect_class(void);
3858 
3859 /**
3860  * Copy the settings of the source AVCodecContext into the destination
3861  * AVCodecContext. The resulting destination codec context will be
3862  * unopened, i.e. you are required to call avcodec_open2() before you
3863  * can use this AVCodecContext to decode/encode video/audio data.
3864  *
3865  * @param dest target codec context, should be initialized with
3866  *             avcodec_alloc_context3(NULL), but otherwise uninitialized
3867  * @param src source codec context
3868  * @return AVERROR() on error (e.g. memory allocation error), 0 on success
3869  */
3870 int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src);
3871 
3872 /**
3873  * Initialize the AVCodecContext to use the given AVCodec. Prior to using this
3874  * function the context has to be allocated with avcodec_alloc_context3().
3875  *
3876  * The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
3877  * avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
3878  * retrieving a codec.
3879  *
3880  * @warning This function is not thread safe!
3881  *
3882  * @note Always call this function before using decoding routines (such as
3883  * @ref avcodec_decode_video2()).
3884  *
3885  * @code
3886  * avcodec_register_all();
3887  * av_dict_set(&opts, "b", "2.5M", 0);
3888  * codec = avcodec_find_decoder(AV_CODEC_ID_H264);
3889  * if (!codec)
3890  *     exit(1);
3891  *
3892  * context = avcodec_alloc_context3(codec);
3893  *
3894  * if (avcodec_open2(context, codec, opts) < 0)
3895  *     exit(1);
3896  * @endcode
3897  *
3898  * @param avctx The context to initialize.
3899  * @param codec The codec to open this context for. If a non-NULL codec has been
3900  *              previously passed to avcodec_alloc_context3() or
3901  *              avcodec_get_context_defaults3() for this context, then this
3902  *              parameter MUST be either NULL or equal to the previously passed
3903  *              codec.
3904  * @param options A dictionary filled with AVCodecContext and codec-private options.
3905  *                On return this object will be filled with options that were not found.
3906  *
3907  * @return zero on success, a negative value on error
3908  * @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
3909  *      av_dict_set(), av_opt_find().
3910  */
3911 int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options);
3912 
3913 /**
3914  * Close a given AVCodecContext and free all the data associated with it
3915  * (but not the AVCodecContext itself).
3916  *
3917  * Calling this function on an AVCodecContext that hasn't been opened will free
3918  * the codec-specific data allocated in avcodec_alloc_context3() /
3919  * avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
3920  * do nothing.
3921  */
3922 int avcodec_close(AVCodecContext *avctx);
3923 
3924 /**
3925  * Free all allocated data in the given subtitle struct.
3926  *
3927  * @param sub AVSubtitle to free.
3928  */
3929 void avsubtitle_free(AVSubtitle *sub);
3930 
3931 /**
3932  * @}
3933  */
3934 
3935 /**
3936  * @addtogroup lavc_packet
3937  * @{
3938  */
3939 
3940 /**
3941  * Allocate an AVPacket and set its fields to default values.  The resulting
3942  * struct must be freed using av_packet_free().
3943  *
3944  * @return An AVPacket filled with default values or NULL on failure.
3945  *
3946  * @note this only allocates the AVPacket itself, not the data buffers. Those
3947  * must be allocated through other means such as av_new_packet.
3948  *
3949  * @see av_new_packet
3950  */
3951 AVPacket *av_packet_alloc(void);
3952 
3953 /**
3954  * Create a new packet that references the same data as src.
3955  *
3956  * This is a shortcut for av_packet_alloc()+av_packet_ref().
3957  *
3958  * @return newly created AVPacket on success, NULL on error.
3959  *
3960  * @see av_packet_alloc
3961  * @see av_packet_ref
3962  */
3963 AVPacket *av_packet_clone(AVPacket *src);
3964 
3965 /**
3966  * Free the packet, if the packet is reference counted, it will be
3967  * unreferenced first.
3968  *
3969  * @param packet packet to be freed. The pointer will be set to NULL.
3970  * @note passing NULL is a no-op.
3971  */
3972 void av_packet_free(AVPacket **pkt);
3973 
3974 /**
3975  * Initialize optional fields of a packet with default values.
3976  *
3977  * Note, this does not touch the data and size members, which have to be
3978  * initialized separately.
3979  *
3980  * @param pkt packet
3981  */
3982 void av_init_packet(AVPacket *pkt);
3983 
3984 /**
3985  * Allocate the payload of a packet and initialize its fields with
3986  * default values.
3987  *
3988  * @param pkt packet
3989  * @param size wanted payload size
3990  * @return 0 if OK, AVERROR_xxx otherwise
3991  */
3992 int av_new_packet(AVPacket *pkt, int size);
3993 
3994 /**
3995  * Reduce packet size, correctly zeroing padding
3996  *
3997  * @param pkt packet
3998  * @param size new size
3999  */
4000 void av_shrink_packet(AVPacket *pkt, int size);
4001 
4002 /**
4003  * Increase packet size, correctly zeroing padding
4004  *
4005  * @param pkt packet
4006  * @param grow_by number of bytes by which to increase the size of the packet
4007  */
4008 int av_grow_packet(AVPacket *pkt, int grow_by);
4009 
4010 /**
4011  * Initialize a reference-counted packet from av_malloc()ed data.
4012  *
4013  * @param pkt packet to be initialized. This function will set the data, size,
4014  *        buf and destruct fields, all others are left untouched.
4015  * @param data Data allocated by av_malloc() to be used as packet data. If this
4016  *        function returns successfully, the data is owned by the underlying AVBuffer.
4017  *        The caller may not access the data through other means.
4018  * @param size size of data in bytes, without the padding. I.e. the full buffer
4019  *        size is assumed to be size + AV_INPUT_BUFFER_PADDING_SIZE.
4020  *
4021  * @return 0 on success, a negative AVERROR on error
4022  */
4023 int av_packet_from_data(AVPacket *pkt, uint8_t *data, int size);
4024 
4025 #if FF_API_AVPACKET_OLD_API
4026 /**
4027  * @warning This is a hack - the packet memory allocation stuff is broken. The
4028  * packet is allocated if it was not really allocated.
4029  *
4030  * @deprecated Use av_packet_ref
4031  */
4032 attribute_deprecated
4033 int av_dup_packet(AVPacket *pkt);
4034 /**
4035  * Copy packet, including contents
4036  *
4037  * @return 0 on success, negative AVERROR on fail
4038  */
4039 int av_copy_packet(AVPacket *dst, const AVPacket *src);
4040 
4041 /**
4042  * Copy packet side data
4043  *
4044  * @return 0 on success, negative AVERROR on fail
4045  */
4046 int av_copy_packet_side_data(AVPacket *dst, const AVPacket *src);
4047 
4048 /**
4049  * Free a packet.
4050  *
4051  * @deprecated Use av_packet_unref
4052  *
4053  * @param pkt packet to free
4054  */
4055 attribute_deprecated
4056 void av_free_packet(AVPacket *pkt);
4057 #endif
4058 /**
4059  * Allocate new information of a packet.
4060  *
4061  * @param pkt packet
4062  * @param type side information type
4063  * @param size side information size
4064  * @return pointer to fresh allocated data or NULL otherwise
4065  */
4066 uint8_t* av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
4067                                  int size);
4068 
4069 /**
4070  * Wrap an existing array as a packet side data.
4071  *
4072  * @param pkt packet
4073  * @param type side information type
4074  * @param data the side data array. It must be allocated with the av_malloc()
4075  *             family of functions. The ownership of the data is transferred to
4076  *             pkt.
4077  * @param size side information size
4078  * @return a non-negative number on success, a negative AVERROR code on
4079  *         failure. On failure, the packet is unchanged and the data remains
4080  *         owned by the caller.
4081  */
4082 int av_packet_add_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
4083                             uint8_t *data, size_t size);
4084 
4085 /**
4086  * Shrink the already allocated side data buffer
4087  *
4088  * @param pkt packet
4089  * @param type side information type
4090  * @param size new side information size
4091  * @return 0 on success, < 0 on failure
4092  */
4093 int av_packet_shrink_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
4094                                int size);
4095 
4096 /**
4097  * Get side information from packet.
4098  *
4099  * @param pkt packet
4100  * @param type desired side information type
4101  * @param size pointer for side information size to store (optional)
4102  * @return pointer to data if present or NULL otherwise
4103  */
4104 uint8_t* av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
4105                                  int *size);
4106 
4107 int av_packet_merge_side_data(AVPacket *pkt);
4108 
4109 int av_packet_split_side_data(AVPacket *pkt);
4110 
4111 const char *av_packet_side_data_name(enum AVPacketSideDataType type);
4112 
4113 /**
4114  * Pack a dictionary for use in side_data.
4115  *
4116  * @param dict The dictionary to pack.
4117  * @param size pointer to store the size of the returned data
4118  * @return pointer to data if successful, NULL otherwise
4119  */
4120 uint8_t *av_packet_pack_dictionary(AVDictionary *dict, int *size);
4121 /**
4122  * Unpack a dictionary from side_data.
4123  *
4124  * @param data data from side_data
4125  * @param size size of the data
4126  * @param dict the metadata storage dictionary
4127  * @return 0 on success, < 0 on failure
4128  */
4129 int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **dict);
4130 
4131 
4132 /**
4133  * Convenience function to free all the side data stored.
4134  * All the other fields stay untouched.
4135  *
4136  * @param pkt packet
4137  */
4138 void av_packet_free_side_data(AVPacket *pkt);
4139 
4140 /**
4141  * Setup a new reference to the data described by a given packet
4142  *
4143  * If src is reference-counted, setup dst as a new reference to the
4144  * buffer in src. Otherwise allocate a new buffer in dst and copy the
4145  * data from src into it.
4146  *
4147  * All the other fields are copied from src.
4148  *
4149  * @see av_packet_unref
4150  *
4151  * @param dst Destination packet
4152  * @param src Source packet
4153  *
4154  * @return 0 on success, a negative AVERROR on error.
4155  */
4156 int av_packet_ref(AVPacket *dst, const AVPacket *src);
4157 
4158 /**
4159  * Wipe the packet.
4160  *
4161  * Unreference the buffer referenced by the packet and reset the
4162  * remaining packet fields to their default values.
4163  *
4164  * @param pkt The packet to be unreferenced.
4165  */
4166 void av_packet_unref(AVPacket *pkt);
4167 
4168 /**
4169  * Move every field in src to dst and reset src.
4170  *
4171  * @see av_packet_unref
4172  *
4173  * @param src Source packet, will be reset
4174  * @param dst Destination packet
4175  */
4176 void av_packet_move_ref(AVPacket *dst, AVPacket *src);
4177 
4178 /**
4179  * Copy only "properties" fields from src to dst.
4180  *
4181  * Properties for the purpose of this function are all the fields
4182  * beside those related to the packet data (buf, data, size)
4183  *
4184  * @param dst Destination packet
4185  * @param src Source packet
4186  *
4187  * @return 0 on success AVERROR on failure.
4188  *
4189  */
4190 int av_packet_copy_props(AVPacket *dst, const AVPacket *src);
4191 
4192 /**
4193  * Convert valid timing fields (timestamps / durations) in a packet from one
4194  * timebase to another. Timestamps with unknown values (AV_NOPTS_VALUE) will be
4195  * ignored.
4196  *
4197  * @param pkt packet on which the conversion will be performed
4198  * @param tb_src source timebase, in which the timing fields in pkt are
4199  *               expressed
4200  * @param tb_dst destination timebase, to which the timing fields will be
4201  *               converted
4202  */
4203 void av_packet_rescale_ts(AVPacket *pkt, AVRational tb_src, AVRational tb_dst);
4204 
4205 /**
4206  * @}
4207  */
4208 
4209 /**
4210  * @addtogroup lavc_decoding
4211  * @{
4212  */
4213 
4214 /**
4215  * Find a registered decoder with a matching codec ID.
4216  *
4217  * @param id AVCodecID of the requested decoder
4218  * @return A decoder if one was found, NULL otherwise.
4219  */
4220 AVCodec *avcodec_find_decoder(enum AVCodecID id);
4221 
4222 /**
4223  * Find a registered decoder with the specified name.
4224  *
4225  * @param name name of the requested decoder
4226  * @return A decoder if one was found, NULL otherwise.
4227  */
4228 AVCodec *avcodec_find_decoder_by_name(const char *name);
4229 
4230 /**
4231  * The default callback for AVCodecContext.get_buffer2(). It is made public so
4232  * it can be called by custom get_buffer2() implementations for decoders without
4233  * AV_CODEC_CAP_DR1 set.
4234  */
4235 int avcodec_default_get_buffer2(AVCodecContext *s, AVFrame *frame, int flags);
4236 
4237 #if FF_API_EMU_EDGE
4238 /**
4239  * Return the amount of padding in pixels which the get_buffer callback must
4240  * provide around the edge of the image for codecs which do not have the
4241  * CODEC_FLAG_EMU_EDGE flag.
4242  *
4243  * @return Required padding in pixels.
4244  *
4245  * @deprecated CODEC_FLAG_EMU_EDGE is deprecated, so this function is no longer
4246  * needed
4247  */
4248 attribute_deprecated
4249 unsigned avcodec_get_edge_width(void);
4250 #endif
4251 
4252 /**
4253  * Modify width and height values so that they will result in a memory
4254  * buffer that is acceptable for the codec if you do not use any horizontal
4255  * padding.
4256  *
4257  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4258  */
4259 void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height);
4260 
4261 /**
4262  * Modify width and height values so that they will result in a memory
4263  * buffer that is acceptable for the codec if you also ensure that all
4264  * line sizes are a multiple of the respective linesize_align[i].
4265  *
4266  * May only be used if a codec with AV_CODEC_CAP_DR1 has been opened.
4267  */
4268 void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height,
4269                                int linesize_align[AV_NUM_DATA_POINTERS]);
4270 
4271 /**
4272  * Converts AVChromaLocation to swscale x/y chroma position.
4273  *
4274  * The positions represent the chroma (0,0) position in a coordinates system
4275  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4276  *
4277  * @param xpos  horizontal chroma sample position
4278  * @param ypos  vertical   chroma sample position
4279  */
4280 int avcodec_enum_to_chroma_pos(int *xpos, int *ypos, enum AVChromaLocation pos);
4281 
4282 /**
4283  * Converts swscale x/y chroma position to AVChromaLocation.
4284  *
4285  * The positions represent the chroma (0,0) position in a coordinates system
4286  * with luma (0,0) representing the origin and luma(1,1) representing 256,256
4287  *
4288  * @param xpos  horizontal chroma sample position
4289  * @param ypos  vertical   chroma sample position
4290  */
4291 enum AVChromaLocation avcodec_chroma_pos_to_enum(int xpos, int ypos);
4292 
4293 /**
4294  * Decode the audio frame of size avpkt->size from avpkt->data into frame.
4295  *
4296  * Some decoders may support multiple frames in a single AVPacket. Such
4297  * decoders would then just decode the first frame and the return value would be
4298  * less than the packet size. In this case, avcodec_decode_audio4 has to be
4299  * called again with an AVPacket containing the remaining data in order to
4300  * decode the second frame, etc...  Even if no frames are returned, the packet
4301  * needs to be fed to the decoder with remaining data until it is completely
4302  * consumed or an error occurs.
4303  *
4304  * Some decoders (those marked with AV_CODEC_CAP_DELAY) have a delay between input
4305  * and output. This means that for some packets they will not immediately
4306  * produce decoded output and need to be flushed at the end of decoding to get
4307  * all the decoded data. Flushing is done by calling this function with packets
4308  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4309  * returning samples. It is safe to flush even those decoders that are not
4310  * marked with AV_CODEC_CAP_DELAY, then no samples will be returned.
4311  *
4312  * @warning The input buffer, avpkt->data must be AV_INPUT_BUFFER_PADDING_SIZE
4313  *          larger than the actual read bytes because some optimized bitstream
4314  *          readers read 32 or 64 bits at once and could read over the end.
4315  *
4316  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4317  * before packets may be fed to the decoder.
4318  *
4319  * @param      avctx the codec context
4320  * @param[out] frame The AVFrame in which to store decoded audio samples.
4321  *                   The decoder will allocate a buffer for the decoded frame by
4322  *                   calling the AVCodecContext.get_buffer2() callback.
4323  *                   When AVCodecContext.refcounted_frames is set to 1, the frame is
4324  *                   reference counted and the returned reference belongs to the
4325  *                   caller. The caller must release the frame using av_frame_unref()
4326  *                   when the frame is no longer needed. The caller may safely write
4327  *                   to the frame if av_frame_is_writable() returns 1.
4328  *                   When AVCodecContext.refcounted_frames is set to 0, the returned
4329  *                   reference belongs to the decoder and is valid only until the
4330  *                   next call to this function or until closing or flushing the
4331  *                   decoder. The caller may not write to it.
4332  * @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
4333  *                           non-zero. Note that this field being set to zero
4334  *                           does not mean that an error has occurred. For
4335  *                           decoders with AV_CODEC_CAP_DELAY set, no given decode
4336  *                           call is guaranteed to produce a frame.
4337  * @param[in]  avpkt The input AVPacket containing the input buffer.
4338  *                   At least avpkt->data and avpkt->size should be set. Some
4339  *                   decoders might also require additional fields to be set.
4340  * @return A negative error code is returned if an error occurred during
4341  *         decoding, otherwise the number of bytes consumed from the input
4342  *         AVPacket is returned.
4343  */
4344 int avcodec_decode_audio4(AVCodecContext *avctx, AVFrame *frame,
4345                           int *got_frame_ptr, const AVPacket *avpkt);
4346 
4347 /**
4348  * Decode the video frame of size avpkt->size from avpkt->data into picture.
4349  * Some decoders may support multiple frames in a single AVPacket, such
4350  * decoders would then just decode the first frame.
4351  *
4352  * @warning The input buffer must be AV_INPUT_BUFFER_PADDING_SIZE larger than
4353  * the actual read bytes because some optimized bitstream readers read 32 or 64
4354  * bits at once and could read over the end.
4355  *
4356  * @warning The end of the input buffer buf should be set to 0 to ensure that
4357  * no overreading happens for damaged MPEG streams.
4358  *
4359  * @note Codecs which have the AV_CODEC_CAP_DELAY capability set have a delay
4360  * between input and output, these need to be fed with avpkt->data=NULL,
4361  * avpkt->size=0 at the end to return the remaining frames.
4362  *
4363  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4364  * before packets may be fed to the decoder.
4365  *
4366  * @param avctx the codec context
4367  * @param[out] picture The AVFrame in which the decoded video frame will be stored.
4368  *             Use av_frame_alloc() to get an AVFrame. The codec will
4369  *             allocate memory for the actual bitmap by calling the
4370  *             AVCodecContext.get_buffer2() callback.
4371  *             When AVCodecContext.refcounted_frames is set to 1, the frame is
4372  *             reference counted and the returned reference belongs to the
4373  *             caller. The caller must release the frame using av_frame_unref()
4374  *             when the frame is no longer needed. The caller may safely write
4375  *             to the frame if av_frame_is_writable() returns 1.
4376  *             When AVCodecContext.refcounted_frames is set to 0, the returned
4377  *             reference belongs to the decoder and is valid only until the
4378  *             next call to this function or until closing or flushing the
4379  *             decoder. The caller may not write to it.
4380  *
4381  * @param[in] avpkt The input AVPacket containing the input buffer.
4382  *            You can create such packet with av_init_packet() and by then setting
4383  *            data and size, some decoders might in addition need other fields like
4384  *            flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
4385  *            fields possible.
4386  * @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
4387  * @return On error a negative value is returned, otherwise the number of bytes
4388  * used or zero if no frame could be decompressed.
4389  */
4390 int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
4391                          int *got_picture_ptr,
4392                          const AVPacket *avpkt);
4393 
4394 /**
4395  * Decode a subtitle message.
4396  * Return a negative value on error, otherwise return the number of bytes used.
4397  * If no subtitle could be decompressed, got_sub_ptr is zero.
4398  * Otherwise, the subtitle is stored in *sub.
4399  * Note that AV_CODEC_CAP_DR1 is not available for subtitle codecs. This is for
4400  * simplicity, because the performance difference is expect to be negligible
4401  * and reusing a get_buffer written for video codecs would probably perform badly
4402  * due to a potentially very different allocation pattern.
4403  *
4404  * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
4405  * and output. This means that for some packets they will not immediately
4406  * produce decoded output and need to be flushed at the end of decoding to get
4407  * all the decoded data. Flushing is done by calling this function with packets
4408  * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
4409  * returning subtitles. It is safe to flush even those decoders that are not
4410  * marked with CODEC_CAP_DELAY, then no subtitles will be returned.
4411  *
4412  * @note The AVCodecContext MUST have been opened with @ref avcodec_open2()
4413  * before packets may be fed to the decoder.
4414  *
4415  * @param avctx the codec context
4416  * @param[out] sub The Preallocated AVSubtitle in which the decoded subtitle will be stored,
4417  *                 must be freed with avsubtitle_free if *got_sub_ptr is set.
4418  * @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
4419  * @param[in] avpkt The input AVPacket containing the input buffer.
4420  */
4421 int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub,
4422                             int *got_sub_ptr,
4423                             AVPacket *avpkt);
4424 
4425 /**
4426  * @defgroup lavc_parsing Frame parsing
4427  * @{
4428  */
4429 
4430 enum AVPictureStructure {
4431     AV_PICTURE_STRUCTURE_UNKNOWN,      //< unknown
4432     AV_PICTURE_STRUCTURE_TOP_FIELD,    //< coded as top field
4433     AV_PICTURE_STRUCTURE_BOTTOM_FIELD, //< coded as bottom field
4434     AV_PICTURE_STRUCTURE_FRAME,        //< coded as frame
4435 };
4436 
4437 typedef struct AVCodecParserContext {
4438     void *priv_data;
4439     struct AVCodecParser *parser;
4440     int64_t frame_offset; /* offset of the current frame */
4441     int64_t cur_offset; /* current offset
4442                            (incremented by each av_parser_parse()) */
4443     int64_t next_frame_offset; /* offset of the next frame */
4444     /* video info */
4445     int pict_type; /* XXX: Put it back in AVCodecContext. */
4446     /**
4447      * This field is used for proper frame duration computation in lavf.
4448      * It signals, how much longer the frame duration of the current frame
4449      * is compared to normal frame duration.
4450      *
4451      * frame_duration = (1 + repeat_pict) * time_base
4452      *
4453      * It is used by codecs like H.264 to display telecined material.
4454      */
4455     int repeat_pict; /* XXX: Put it back in AVCodecContext. */
4456     int64_t pts;     /* pts of the current frame */
4457     int64_t dts;     /* dts of the current frame */
4458 
4459     /* private data */
4460     int64_t last_pts;
4461     int64_t last_dts;
4462     int fetch_timestamp;
4463 
4464 #define AV_PARSER_PTS_NB 4
4465     int cur_frame_start_index;
4466     int64_t cur_frame_offset[AV_PARSER_PTS_NB];
4467     int64_t cur_frame_pts[AV_PARSER_PTS_NB];
4468     int64_t cur_frame_dts[AV_PARSER_PTS_NB];
4469 
4470     int flags;
4471 #define PARSER_FLAG_COMPLETE_FRAMES           0x0001
4472 #define PARSER_FLAG_ONCE                      0x0002
4473 /// Set if the parser has a valid file offset
4474 #define PARSER_FLAG_FETCHED_OFFSET            0x0004
4475 #define PARSER_FLAG_USE_CODEC_TS              0x1000
4476 
4477     int64_t offset;      ///< byte offset from starting packet start
4478     int64_t cur_frame_end[AV_PARSER_PTS_NB];
4479 
4480     /**
4481      * Set by parser to 1 for key frames and 0 for non-key frames.
4482      * It is initialized to -1, so if the parser doesn't set this flag,
4483      * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
4484      * will be used.
4485      */
4486     int key_frame;
4487 
4488 #if FF_API_CONVERGENCE_DURATION
4489     /**
4490      * @deprecated unused
4491      */
4492     attribute_deprecated
4493     int64_t convergence_duration;
4494 #endif
4495 
4496     // Timestamp generation support:
4497     /**
4498      * Synchronization point for start of timestamp generation.
4499      *
4500      * Set to >0 for sync point, 0 for no sync point and <0 for undefined
4501      * (default).
4502      *
4503      * For example, this corresponds to presence of H.264 buffering period
4504      * SEI message.
4505      */
4506     int dts_sync_point;
4507 
4508     /**
4509      * Offset of the current timestamp against last timestamp sync point in
4510      * units of AVCodecContext.time_base.
4511      *
4512      * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4513      * contain a valid timestamp offset.
4514      *
4515      * Note that the timestamp of sync point has usually a nonzero
4516      * dts_ref_dts_delta, which refers to the previous sync point. Offset of
4517      * the next frame after timestamp sync point will be usually 1.
4518      *
4519      * For example, this corresponds to H.264 cpb_removal_delay.
4520      */
4521     int dts_ref_dts_delta;
4522 
4523     /**
4524      * Presentation delay of current frame in units of AVCodecContext.time_base.
4525      *
4526      * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
4527      * contain valid non-negative timestamp delta (presentation time of a frame
4528      * must not lie in the past).
4529      *
4530      * This delay represents the difference between decoding and presentation
4531      * time of the frame.
4532      *
4533      * For example, this corresponds to H.264 dpb_output_delay.
4534      */
4535     int pts_dts_delta;
4536 
4537     /**
4538      * Position of the packet in file.
4539      *
4540      * Analogous to cur_frame_pts/dts
4541      */
4542     int64_t cur_frame_pos[AV_PARSER_PTS_NB];
4543 
4544     /**
4545      * Byte position of currently parsed frame in stream.
4546      */
4547     int64_t pos;
4548 
4549     /**
4550      * Previous frame byte position.
4551      */
4552     int64_t last_pos;
4553 
4554     /**
4555      * Duration of the current frame.
4556      * For audio, this is in units of 1 / AVCodecContext.sample_rate.
4557      * For all other types, this is in units of AVCodecContext.time_base.
4558      */
4559     int duration;
4560 
4561     enum AVFieldOrder field_order;
4562 
4563     /**
4564      * Indicate whether a picture is coded as a frame, top field or bottom field.
4565      *
4566      * For example, H.264 field_pic_flag equal to 0 corresponds to
4567      * AV_PICTURE_STRUCTURE_FRAME. An H.264 picture with field_pic_flag
4568      * equal to 1 and bottom_field_flag equal to 0 corresponds to
4569      * AV_PICTURE_STRUCTURE_TOP_FIELD.
4570      */
4571     enum AVPictureStructure picture_structure;
4572 
4573     /**
4574      * Picture number incremented in presentation or output order.
4575      * This field may be reinitialized at the first picture of a new sequence.
4576      *
4577      * For example, this corresponds to H.264 PicOrderCnt.
4578      */
4579     int output_picture_number;
4580 
4581     /**
4582      * Dimensions of the decoded video intended for presentation.
4583      */
4584     int width;
4585     int height;
4586 
4587     /**
4588      * Dimensions of the coded video.
4589      */
4590     int coded_width;
4591     int coded_height;
4592 
4593     /**
4594      * The format of the coded data, corresponds to enum AVPixelFormat for video
4595      * and for enum AVSampleFormat for audio.
4596      *
4597      * Note that a decoder can have considerable freedom in how exactly it
4598      * decodes the data, so the format reported here might be different from the
4599      * one returned by a decoder.
4600      */
4601     int format;
4602 } AVCodecParserContext;
4603 
4604 typedef struct AVCodecParser {
4605     int codec_ids[5]; /* several codec IDs are permitted */
4606     int priv_data_size;
4607     int (*parser_init)(AVCodecParserContext *s);
4608     /* This callback never returns an error, a negative value means that
4609      * the frame start was in a previous packet. */
4610     int (*parser_parse)(AVCodecParserContext *s,
4611                         AVCodecContext *avctx,
4612                         const uint8_t **poutbuf, int *poutbuf_size,
4613                         const uint8_t *buf, int buf_size);
4614     void (*parser_close)(AVCodecParserContext *s);
4615     int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
4616     struct AVCodecParser *next;
4617 } AVCodecParser;
4618 
4619 AVCodecParser *av_parser_next(const AVCodecParser *c);
4620 
4621 void av_register_codec_parser(AVCodecParser *parser);
4622 AVCodecParserContext *av_parser_init(int codec_id);
4623 
4624 /**
4625  * Parse a packet.
4626  *
4627  * @param s             parser context.
4628  * @param avctx         codec context.
4629  * @param poutbuf       set to pointer to parsed buffer or NULL if not yet finished.
4630  * @param poutbuf_size  set to size of parsed buffer or zero if not yet finished.
4631  * @param buf           input buffer.
4632  * @param buf_size      input length, to signal EOF, this should be 0 (so that the last frame can be output).
4633  * @param pts           input presentation timestamp.
4634  * @param dts           input decoding timestamp.
4635  * @param pos           input byte position in stream.
4636  * @return the number of bytes of the input bitstream used.
4637  *
4638  * Example:
4639  * @code
4640  *   while(in_len){
4641  *       len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
4642  *                                        in_data, in_len,
4643  *                                        pts, dts, pos);
4644  *       in_data += len;
4645  *       in_len  -= len;
4646  *
4647  *       if(size)
4648  *          decode_frame(data, size);
4649  *   }
4650  * @endcode
4651  */
4652 int av_parser_parse2(AVCodecParserContext *s,
4653                      AVCodecContext *avctx,
4654                      uint8_t **poutbuf, int *poutbuf_size,
4655                      const uint8_t *buf, int buf_size,
4656                      int64_t pts, int64_t dts,
4657                      int64_t pos);
4658 
4659 /**
4660  * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
4661  * @deprecated use AVBitStreamFilter
4662  */
4663 int av_parser_change(AVCodecParserContext *s,
4664                      AVCodecContext *avctx,
4665                      uint8_t **poutbuf, int *poutbuf_size,
4666                      const uint8_t *buf, int buf_size, int keyframe);
4667 void av_parser_close(AVCodecParserContext *s);
4668 
4669 /**
4670  * @}
4671  * @}
4672  */
4673 
4674 /**
4675  * @addtogroup lavc_encoding
4676  * @{
4677  */
4678 
4679 /**
4680  * Find a registered encoder with a matching codec ID.
4681  *
4682  * @param id AVCodecID of the requested encoder
4683  * @return An encoder if one was found, NULL otherwise.
4684  */
4685 AVCodec *avcodec_find_encoder(enum AVCodecID id);
4686 
4687 /**
4688  * Find a registered encoder with the specified name.
4689  *
4690  * @param name name of the requested encoder
4691  * @return An encoder if one was found, NULL otherwise.
4692  */
4693 AVCodec *avcodec_find_encoder_by_name(const char *name);
4694 
4695 /**
4696  * Encode a frame of audio.
4697  *
4698  * Takes input samples from frame and writes the next output packet, if
4699  * available, to avpkt. The output packet does not necessarily contain data for
4700  * the most recent frame, as encoders can delay, split, and combine input frames
4701  * internally as needed.
4702  *
4703  * @param avctx     codec context
4704  * @param avpkt     output AVPacket.
4705  *                  The user can supply an output buffer by setting
4706  *                  avpkt->data and avpkt->size prior to calling the
4707  *                  function, but if the size of the user-provided data is not
4708  *                  large enough, encoding will fail. If avpkt->data and
4709  *                  avpkt->size are set, avpkt->destruct must also be set. All
4710  *                  other AVPacket fields will be reset by the encoder using
4711  *                  av_init_packet(). If avpkt->data is NULL, the encoder will
4712  *                  allocate it. The encoder will set avpkt->size to the size
4713  *                  of the output packet.
4714  *
4715  *                  If this function fails or produces no output, avpkt will be
4716  *                  freed using av_packet_unref().
4717  * @param[in] frame AVFrame containing the raw audio data to be encoded.
4718  *                  May be NULL when flushing an encoder that has the
4719  *                  AV_CODEC_CAP_DELAY capability set.
4720  *                  If AV_CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
4721  *                  can have any number of samples.
4722  *                  If it is not set, frame->nb_samples must be equal to
4723  *                  avctx->frame_size for all frames except the last.
4724  *                  The final frame may be smaller than avctx->frame_size.
4725  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4726  *                            output packet is non-empty, and to 0 if it is
4727  *                            empty. If the function returns an error, the
4728  *                            packet can be assumed to be invalid, and the
4729  *                            value of got_packet_ptr is undefined and should
4730  *                            not be used.
4731  * @return          0 on success, negative error code on failure
4732  */
4733 int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
4734                           const AVFrame *frame, int *got_packet_ptr);
4735 
4736 /**
4737  * Encode a frame of video.
4738  *
4739  * Takes input raw video data from frame and writes the next output packet, if
4740  * available, to avpkt. The output packet does not necessarily contain data for
4741  * the most recent frame, as encoders can delay and reorder input frames
4742  * internally as needed.
4743  *
4744  * @param avctx     codec context
4745  * @param avpkt     output AVPacket.
4746  *                  The user can supply an output buffer by setting
4747  *                  avpkt->data and avpkt->size prior to calling the
4748  *                  function, but if the size of the user-provided data is not
4749  *                  large enough, encoding will fail. All other AVPacket fields
4750  *                  will be reset by the encoder using av_init_packet(). If
4751  *                  avpkt->data is NULL, the encoder will allocate it.
4752  *                  The encoder will set avpkt->size to the size of the
4753  *                  output packet. The returned data (if any) belongs to the
4754  *                  caller, he is responsible for freeing it.
4755  *
4756  *                  If this function fails or produces no output, avpkt will be
4757  *                  freed using av_packet_unref().
4758  * @param[in] frame AVFrame containing the raw video data to be encoded.
4759  *                  May be NULL when flushing an encoder that has the
4760  *                  AV_CODEC_CAP_DELAY capability set.
4761  * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
4762  *                            output packet is non-empty, and to 0 if it is
4763  *                            empty. If the function returns an error, the
4764  *                            packet can be assumed to be invalid, and the
4765  *                            value of got_packet_ptr is undefined and should
4766  *                            not be used.
4767  * @return          0 on success, negative error code on failure
4768  */
4769 int avcodec_encode_video2(AVCodecContext *avctx, AVPacket *avpkt,
4770                           const AVFrame *frame, int *got_packet_ptr);
4771 
4772 int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
4773                             const AVSubtitle *sub);
4774 
4775 
4776 /**
4777  * @}
4778  */
4779 
4780 #if FF_API_AVCODEC_RESAMPLE
4781 /**
4782  * @defgroup lavc_resample Audio resampling
4783  * @ingroup libavc
4784  * @deprecated use libswresample instead
4785  *
4786  * @{
4787  */
4788 struct ReSampleContext;
4789 struct AVResampleContext;
4790 
4791 typedef struct ReSampleContext ReSampleContext;
4792 
4793 /**
4794  *  Initialize audio resampling context.
4795  *
4796  * @param output_channels  number of output channels
4797  * @param input_channels   number of input channels
4798  * @param output_rate      output sample rate
4799  * @param input_rate       input sample rate
4800  * @param sample_fmt_out   requested output sample format
4801  * @param sample_fmt_in    input sample format
4802  * @param filter_length    length of each FIR filter in the filterbank relative to the cutoff frequency
4803  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4804  * @param linear           if 1 then the used FIR filter will be linearly interpolated
4805                            between the 2 closest, if 0 the closest will be used
4806  * @param cutoff           cutoff frequency, 1.0 corresponds to half the output sampling rate
4807  * @return allocated ReSampleContext, NULL if error occurred
4808  */
4809 attribute_deprecated
4810 ReSampleContext *av_audio_resample_init(int output_channels, int input_channels,
4811                                         int output_rate, int input_rate,
4812                                         enum AVSampleFormat sample_fmt_out,
4813                                         enum AVSampleFormat sample_fmt_in,
4814                                         int filter_length, int log2_phase_count,
4815                                         int linear, double cutoff);
4816 
4817 attribute_deprecated
4818 int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);
4819 
4820 /**
4821  * Free resample context.
4822  *
4823  * @param s a non-NULL pointer to a resample context previously
4824  *          created with av_audio_resample_init()
4825  */
4826 attribute_deprecated
4827 void audio_resample_close(ReSampleContext *s);
4828 
4829 
4830 /**
4831  * Initialize an audio resampler.
4832  * Note, if either rate is not an integer then simply scale both rates up so they are.
4833  * @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
4834  * @param log2_phase_count log2 of the number of entries in the polyphase filterbank
4835  * @param linear If 1 then the used FIR filter will be linearly interpolated
4836                  between the 2 closest, if 0 the closest will be used
4837  * @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
4838  */
4839 attribute_deprecated
4840 struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);
4841 
4842 /**
4843  * Resample an array of samples using a previously configured context.
4844  * @param src an array of unconsumed samples
4845  * @param consumed the number of samples of src which have been consumed are returned here
4846  * @param src_size the number of unconsumed samples available
4847  * @param dst_size the amount of space in samples available in dst
4848  * @param update_ctx If this is 0 then the context will not be modified, that way several channels can be resampled with the same context.
4849  * @return the number of samples written in dst or -1 if an error occurred
4850  */
4851 attribute_deprecated
4852 int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);
4853 
4854 
4855 /**
4856  * Compensate samplerate/timestamp drift. The compensation is done by changing
4857  * the resampler parameters, so no audible clicks or similar distortions occur
4858  * @param compensation_distance distance in output samples over which the compensation should be performed
4859  * @param sample_delta number of output samples which should be output less
4860  *
4861  * example: av_resample_compensate(c, 10, 500)
4862  * here instead of 510 samples only 500 samples would be output
4863  *
4864  * note, due to rounding the actual compensation might be slightly different,
4865  * especially if the compensation_distance is large and the in_rate used during init is small
4866  */
4867 attribute_deprecated
4868 void av_resample_compensate(struct AVResampleContext *c, int sample_delta, int compensation_distance);
4869 attribute_deprecated
4870 void av_resample_close(struct AVResampleContext *c);
4871 
4872 /**
4873  * @}
4874  */
4875 #endif
4876 
4877 #if FF_API_AVPICTURE
4878 /**
4879  * @addtogroup lavc_picture
4880  * @{
4881  */
4882 
4883 /**
4884  * @deprecated unused
4885  */
4886 attribute_deprecated
4887 int avpicture_alloc(AVPicture *picture, enum AVPixelFormat pix_fmt, int width, int height);
4888 
4889 /**
4890  * @deprecated unused
4891  */
4892 attribute_deprecated
4893 void avpicture_free(AVPicture *picture);
4894 
4895 /**
4896  * @deprecated use av_image_fill_arrays() instead.
4897  */
4898 attribute_deprecated
4899 int avpicture_fill(AVPicture *picture, const uint8_t *ptr,
4900                    enum AVPixelFormat pix_fmt, int width, int height);
4901 
4902 /**
4903  * @deprecated use av_image_copy_to_buffer() instead.
4904  */
4905 attribute_deprecated
4906 int avpicture_layout(const AVPicture *src, enum AVPixelFormat pix_fmt,
4907                      int width, int height,
4908                      unsigned char *dest, int dest_size);
4909 
4910 /**
4911  * @deprecated use av_image_get_buffer_size() instead.
4912  */
4913 attribute_deprecated
4914 int avpicture_get_size(enum AVPixelFormat pix_fmt, int width, int height);
4915 
4916 /**
4917  * @deprecated av_image_copy() instead.
4918  */
4919 attribute_deprecated
4920 void av_picture_copy(AVPicture *dst, const AVPicture *src,
4921                      enum AVPixelFormat pix_fmt, int width, int height);
4922 
4923 /**
4924  * @deprecated unused
4925  */
4926 attribute_deprecated
4927 int av_picture_crop(AVPicture *dst, const AVPicture *src,
4928                     enum AVPixelFormat pix_fmt, int top_band, int left_band);
4929 
4930 /**
4931  * @deprecated unused
4932  */
4933 attribute_deprecated
4934 int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, enum AVPixelFormat pix_fmt,
4935             int padtop, int padbottom, int padleft, int padright, int *color);
4936 
4937 /**
4938  * @}
4939  */
4940 #endif
4941 
4942 /**
4943  * @defgroup lavc_misc Utility functions
4944  * @ingroup libavc
4945  *
4946  * Miscellaneous utility functions related to both encoding and decoding
4947  * (or neither).
4948  * @{
4949  */
4950 
4951 /**
4952  * @defgroup lavc_misc_pixfmt Pixel formats
4953  *
4954  * Functions for working with pixel formats.
4955  * @{
4956  */
4957 
4958 /**
4959  * Utility function to access log2_chroma_w log2_chroma_h from
4960  * the pixel format AVPixFmtDescriptor.
4961  *
4962  * This function asserts that pix_fmt is valid. See av_pix_fmt_get_chroma_sub_sample
4963  * for one that returns a failure code and continues in case of invalid
4964  * pix_fmts.
4965  *
4966  * @param[in]  pix_fmt the pixel format
4967  * @param[out] h_shift store log2_chroma_w
4968  * @param[out] v_shift store log2_chroma_h
4969  *
4970  * @see av_pix_fmt_get_chroma_sub_sample
4971  */
4972 
4973 void avcodec_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift);
4974 
4975 /**
4976  * Return a value representing the fourCC code associated to the
4977  * pixel format pix_fmt, or 0 if no associated fourCC code can be
4978  * found.
4979  */
4980 unsigned int avcodec_pix_fmt_to_codec_tag(enum AVPixelFormat pix_fmt);
4981 
4982 /**
4983  * @deprecated see av_get_pix_fmt_loss()
4984  */
4985 int avcodec_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt, enum AVPixelFormat src_pix_fmt,
4986                              int has_alpha);
4987 
4988 /**
4989  * Find the best pixel format to convert to given a certain source pixel
4990  * format.  When converting from one pixel format to another, information loss
4991  * may occur.  For example, when converting from RGB24 to GRAY, the color
4992  * information will be lost. Similarly, other losses occur when converting from
4993  * some formats to other formats. avcodec_find_best_pix_fmt_of_2() searches which of
4994  * the given pixel formats should be used to suffer the least amount of loss.
4995  * The pixel formats from which it chooses one, are determined by the
4996  * pix_fmt_list parameter.
4997  *
4998  *
4999  * @param[in] pix_fmt_list AV_PIX_FMT_NONE terminated array of pixel formats to choose from
5000  * @param[in] src_pix_fmt source pixel format
5001  * @param[in] has_alpha Whether the source pixel format alpha channel is used.
5002  * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
5003  * @return The best pixel format to convert to or -1 if none was found.
5004  */
5005 enum AVPixelFormat avcodec_find_best_pix_fmt_of_list(const enum AVPixelFormat *pix_fmt_list,
5006                                             enum AVPixelFormat src_pix_fmt,
5007                                             int has_alpha, int *loss_ptr);
5008 
5009 /**
5010  * @deprecated see av_find_best_pix_fmt_of_2()
5011  */
5012 enum AVPixelFormat avcodec_find_best_pix_fmt_of_2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
5013                                             enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
5014 
5015 attribute_deprecated
5016 #if AV_HAVE_INCOMPATIBLE_LIBAV_ABI
5017 enum AVPixelFormat avcodec_find_best_pix_fmt2(const enum AVPixelFormat *pix_fmt_list,
5018                                               enum AVPixelFormat src_pix_fmt,
5019                                               int has_alpha, int *loss_ptr);
5020 #else
5021 enum AVPixelFormat avcodec_find_best_pix_fmt2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
5022                                             enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
5023 #endif
5024 
5025 
5026 enum AVPixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
5027 
5028 /**
5029  * @}
5030  */
5031 
5032 #if FF_API_SET_DIMENSIONS
5033 /**
5034  * @deprecated this function is not supposed to be used from outside of lavc
5035  */
5036 attribute_deprecated
5037 void avcodec_set_dimensions(AVCodecContext *s, int width, int height);
5038 #endif
5039 
5040 /**
5041  * Put a string representing the codec tag codec_tag in buf.
5042  *
5043  * @param buf       buffer to place codec tag in
5044  * @param buf_size size in bytes of buf
5045  * @param codec_tag codec tag to assign
5046  * @return the length of the string that would have been generated if
5047  * enough space had been available, excluding the trailing null
5048  */
5049 size_t av_get_codec_tag_string(char *buf, size_t buf_size, unsigned int codec_tag);
5050 
5051 void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
5052 
5053 /**
5054  * Return a name for the specified profile, if available.
5055  *
5056  * @param codec the codec that is searched for the given profile
5057  * @param profile the profile value for which a name is requested
5058  * @return A name for the profile if found, NULL otherwise.
5059  */
5060 const char *av_get_profile_name(const AVCodec *codec, int profile);
5061 
5062 /**
5063  * Return a name for the specified profile, if available.
5064  *
5065  * @param codec_id the ID of the codec to which the requested profile belongs
5066  * @param profile the profile value for which a name is requested
5067  * @return A name for the profile if found, NULL otherwise.
5068  *
5069  * @note unlike av_get_profile_name(), which searches a list of profiles
5070  *       supported by a specific decoder or encoder implementation, this
5071  *       function searches the list of profiles from the AVCodecDescriptor
5072  */
5073 const char *avcodec_profile_name(enum AVCodecID codec_id, int profile);
5074 
5075 int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
5076 int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
5077 //FIXME func typedef
5078 
5079 /**
5080  * Fill AVFrame audio data and linesize pointers.
5081  *
5082  * The buffer buf must be a preallocated buffer with a size big enough
5083  * to contain the specified samples amount. The filled AVFrame data
5084  * pointers will point to this buffer.
5085  *
5086  * AVFrame extended_data channel pointers are allocated if necessary for
5087  * planar audio.
5088  *
5089  * @param frame       the AVFrame
5090  *                    frame->nb_samples must be set prior to calling the
5091  *                    function. This function fills in frame->data,
5092  *                    frame->extended_data, frame->linesize[0].
5093  * @param nb_channels channel count
5094  * @param sample_fmt  sample format
5095  * @param buf         buffer to use for frame data
5096  * @param buf_size    size of buffer
5097  * @param align       plane size sample alignment (0 = default)
5098  * @return            >=0 on success, negative error code on failure
5099  * @todo return the size in bytes required to store the samples in
5100  * case of success, at the next libavutil bump
5101  */
5102 int avcodec_fill_audio_frame(AVFrame *frame, int nb_channels,
5103                              enum AVSampleFormat sample_fmt, const uint8_t *buf,
5104                              int buf_size, int align);
5105 
5106 /**
5107  * Reset the internal decoder state / flush internal buffers. Should be called
5108  * e.g. when seeking or when switching to a different stream.
5109  *
5110  * @note when refcounted frames are not used (i.e. avctx->refcounted_frames is 0),
5111  * this invalidates the frames previously returned from the decoder. When
5112  * refcounted frames are used, the decoder just releases any references it might
5113  * keep internally, but the caller's reference remains valid.
5114  */
5115 void avcodec_flush_buffers(AVCodecContext *avctx);
5116 
5117 /**
5118  * Return codec bits per sample.
5119  *
5120  * @param[in] codec_id the codec
5121  * @return Number of bits per sample or zero if unknown for the given codec.
5122  */
5123 int av_get_bits_per_sample(enum AVCodecID codec_id);
5124 
5125 /**
5126  * Return the PCM codec associated with a sample format.
5127  * @param be  endianness, 0 for little, 1 for big,
5128  *            -1 (or anything else) for native
5129  * @return  AV_CODEC_ID_PCM_* or AV_CODEC_ID_NONE
5130  */
5131 enum AVCodecID av_get_pcm_codec(enum AVSampleFormat fmt, int be);
5132 
5133 /**
5134  * Return codec bits per sample.
5135  * Only return non-zero if the bits per sample is exactly correct, not an
5136  * approximation.
5137  *
5138  * @param[in] codec_id the codec
5139  * @return Number of bits per sample or zero if unknown for the given codec.
5140  */
5141 int av_get_exact_bits_per_sample(enum AVCodecID codec_id);
5142 
5143 /**
5144  * Return audio frame duration.
5145  *
5146  * @param avctx        codec context
5147  * @param frame_bytes  size of the frame, or 0 if unknown
5148  * @return             frame duration, in samples, if known. 0 if not able to
5149  *                     determine.
5150  */
5151 int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes);
5152 
5153 
5154 typedef struct AVBitStreamFilterContext {
5155     void *priv_data;
5156     struct AVBitStreamFilter *filter;
5157     AVCodecParserContext *parser;
5158     struct AVBitStreamFilterContext *next;
5159     /**
5160      * Internal default arguments, used if NULL is passed to av_bitstream_filter_filter().
5161      * Not for access by library users.
5162      */
5163     char *args;
5164 } AVBitStreamFilterContext;
5165 
5166 
5167 typedef struct AVBitStreamFilter {
5168     const char *name;
5169     int priv_data_size;
5170     int (*filter)(AVBitStreamFilterContext *bsfc,
5171                   AVCodecContext *avctx, const char *args,
5172                   uint8_t **poutbuf, int *poutbuf_size,
5173                   const uint8_t *buf, int buf_size, int keyframe);
5174     void (*close)(AVBitStreamFilterContext *bsfc);
5175     struct AVBitStreamFilter *next;
5176 } AVBitStreamFilter;
5177 
5178 /**
5179  * Register a bitstream filter.
5180  *
5181  * The filter will be accessible to the application code through
5182  * av_bitstream_filter_next() or can be directly initialized with
5183  * av_bitstream_filter_init().
5184  *
5185  * @see avcodec_register_all()
5186  */
5187 void av_register_bitstream_filter(AVBitStreamFilter *bsf);
5188 
5189 /**
5190  * Create and initialize a bitstream filter context given a bitstream
5191  * filter name.
5192  *
5193  * The returned context must be freed with av_bitstream_filter_close().
5194  *
5195  * @param name    the name of the bitstream filter
5196  * @return a bitstream filter context if a matching filter was found
5197  * and successfully initialized, NULL otherwise
5198  */
5199 AVBitStreamFilterContext *av_bitstream_filter_init(const char *name);
5200 
5201 /**
5202  * Filter bitstream.
5203  *
5204  * This function filters the buffer buf with size buf_size, and places the
5205  * filtered buffer in the buffer pointed to by poutbuf.
5206  *
5207  * The output buffer must be freed by the caller.
5208  *
5209  * @param bsfc            bitstream filter context created by av_bitstream_filter_init()
5210  * @param avctx           AVCodecContext accessed by the filter, may be NULL.
5211  *                        If specified, this must point to the encoder context of the
5212  *                        output stream the packet is sent to.
5213  * @param args            arguments which specify the filter configuration, may be NULL
5214  * @param poutbuf         pointer which is updated to point to the filtered buffer
5215  * @param poutbuf_size    pointer which is updated to the filtered buffer size in bytes
5216  * @param buf             buffer containing the data to filter
5217  * @param buf_size        size in bytes of buf
5218  * @param keyframe        set to non-zero if the buffer to filter corresponds to a key-frame packet data
5219  * @return >= 0 in case of success, or a negative error code in case of failure
5220  *
5221  * If the return value is positive, an output buffer is allocated and
5222  * is available in *poutbuf, and is distinct from the input buffer.
5223  *
5224  * If the return value is 0, the output buffer is not allocated and
5225  * should be considered identical to the input buffer, or in case
5226  * *poutbuf was set it points to the input buffer (not necessarily to
5227  * its starting address).
5228  */
5229 int av_bitstream_filter_filter(AVBitStreamFilterContext *bsfc,
5230                                AVCodecContext *avctx, const char *args,
5231                                uint8_t **poutbuf, int *poutbuf_size,
5232                                const uint8_t *buf, int buf_size, int keyframe);
5233 
5234 /**
5235  * Release bitstream filter context.
5236  *
5237  * @param bsf the bitstream filter context created with
5238  * av_bitstream_filter_init(), can be NULL
5239  */
5240 void av_bitstream_filter_close(AVBitStreamFilterContext *bsf);
5241 
5242 /**
5243  * If f is NULL, return the first registered bitstream filter,
5244  * if f is non-NULL, return the next registered bitstream filter
5245  * after f, or NULL if f is the last one.
5246  *
5247  * This function can be used to iterate over all registered bitstream
5248  * filters.
5249  */
5250 AVBitStreamFilter *av_bitstream_filter_next(const AVBitStreamFilter *f);
5251 
5252 /* memory */
5253 
5254 /**
5255  * Same behaviour av_fast_malloc but the buffer has additional
5256  * AV_INPUT_BUFFER_PADDING_SIZE at the end which will always be 0.
5257  *
5258  * In addition the whole buffer will initially and after resizes
5259  * be 0-initialized so that no uninitialized data will ever appear.
5260  */
5261 void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size);
5262 
5263 /**
5264  * Same behaviour av_fast_padded_malloc except that buffer will always
5265  * be 0-initialized after call.
5266  */
5267 void av_fast_padded_mallocz(void *ptr, unsigned int *size, size_t min_size);
5268 
5269 /**
5270  * Encode extradata length to a buffer. Used by xiph codecs.
5271  *
5272  * @param s buffer to write to; must be at least (v/255+1) bytes long
5273  * @param v size of extradata in bytes
5274  * @return number of bytes written to the buffer.
5275  */
5276 unsigned int av_xiphlacing(unsigned char *s, unsigned int v);
5277 
5278 #if FF_API_MISSING_SAMPLE
5279 /**
5280  * Log a generic warning message about a missing feature. This function is
5281  * intended to be used internally by FFmpeg (libavcodec, libavformat, etc.)
5282  * only, and would normally not be used by applications.
5283  * @param[in] avc a pointer to an arbitrary struct of which the first field is
5284  * a pointer to an AVClass struct
5285  * @param[in] feature string containing the name of the missing feature
5286  * @param[in] want_sample indicates if samples are wanted which exhibit this feature.
5287  * If want_sample is non-zero, additional verbage will be added to the log
5288  * message which tells the user how to report samples to the development
5289  * mailing list.
5290  * @deprecated Use avpriv_report_missing_feature() instead.
5291  */
5292 attribute_deprecated
5293 void av_log_missing_feature(void *avc, const char *feature, int want_sample);
5294 
5295 /**
5296  * Log a generic warning message asking for a sample. This function is
5297  * intended to be used internally by FFmpeg (libavcodec, libavformat, etc.)
5298  * only, and would normally not be used by applications.
5299  * @param[in] avc a pointer to an arbitrary struct of which the first field is
5300  * a pointer to an AVClass struct
5301  * @param[in] msg string containing an optional message, or NULL if no message
5302  * @deprecated Use avpriv_request_sample() instead.
5303  */
5304 attribute_deprecated
5305 void av_log_ask_for_sample(void *avc, const char *msg, ...) av_printf_format(2, 3);
5306 #endif /* FF_API_MISSING_SAMPLE */
5307 
5308 /**
5309  * Register the hardware accelerator hwaccel.
5310  */
5311 void av_register_hwaccel(AVHWAccel *hwaccel);
5312 
5313 /**
5314  * If hwaccel is NULL, returns the first registered hardware accelerator,
5315  * if hwaccel is non-NULL, returns the next registered hardware accelerator
5316  * after hwaccel, or NULL if hwaccel is the last one.
5317  */
5318 AVHWAccel *av_hwaccel_next(const AVHWAccel *hwaccel);
5319 
5320 
5321 /**
5322  * Lock operation used by lockmgr
5323  */
5324 enum AVLockOp {
5325   AV_LOCK_CREATE,  ///< Create a mutex
5326   AV_LOCK_OBTAIN,  ///< Lock the mutex
5327   AV_LOCK_RELEASE, ///< Unlock the mutex
5328   AV_LOCK_DESTROY, ///< Free mutex resources
5329 };
5330 
5331 /**
5332  * Register a user provided lock manager supporting the operations
5333  * specified by AVLockOp. The "mutex" argument to the function points
5334  * to a (void *) where the lockmgr should store/get a pointer to a user
5335  * allocated mutex. It is NULL upon AV_LOCK_CREATE and equal to the
5336  * value left by the last call for all other ops. If the lock manager is
5337  * unable to perform the op then it should leave the mutex in the same
5338  * state as when it was called and return a non-zero value. However,
5339  * when called with AV_LOCK_DESTROY the mutex will always be assumed to
5340  * have been successfully destroyed. If av_lockmgr_register succeeds
5341  * it will return a non-negative value, if it fails it will return a
5342  * negative value and destroy all mutex and unregister all callbacks.
5343  * av_lockmgr_register is not thread-safe, it must be called from a
5344  * single thread before any calls which make use of locking are used.
5345  *
5346  * @param cb User defined callback. av_lockmgr_register invokes calls
5347  *           to this callback and the previously registered callback.
5348  *           The callback will be used to create more than one mutex
5349  *           each of which must be backed by its own underlying locking
5350  *           mechanism (i.e. do not use a single static object to
5351  *           implement your lock manager). If cb is set to NULL the
5352  *           lockmgr will be unregistered.
5353  */
5354 int av_lockmgr_register(int (*cb)(void **mutex, enum AVLockOp op));
5355 
5356 /**
5357  * Get the type of the given codec.
5358  */
5359 enum AVMediaType avcodec_get_type(enum AVCodecID codec_id);
5360 
5361 /**
5362  * Get the name of a codec.
5363  * @return  a static string identifying the codec; never NULL
5364  */
5365 const char *avcodec_get_name(enum AVCodecID id);
5366 
5367 /**
5368  * @return a positive value if s is open (i.e. avcodec_open2() was called on it
5369  * with no corresponding avcodec_close()), 0 otherwise.
5370  */
5371 int avcodec_is_open(AVCodecContext *s);
5372 
5373 /**
5374  * @return a non-zero number if codec is an encoder, zero otherwise
5375  */
5376 int av_codec_is_encoder(const AVCodec *codec);
5377 
5378 /**
5379  * @return a non-zero number if codec is a decoder, zero otherwise
5380  */
5381 int av_codec_is_decoder(const AVCodec *codec);
5382 
5383 /**
5384  * @return descriptor for given codec ID or NULL if no descriptor exists.
5385  */
5386 const AVCodecDescriptor *avcodec_descriptor_get(enum AVCodecID id);
5387 
5388 /**
5389  * Iterate over all codec descriptors known to libavcodec.
5390  *
5391  * @param prev previous descriptor. NULL to get the first descriptor.
5392  *
5393  * @return next descriptor or NULL after the last descriptor
5394  */
5395 const AVCodecDescriptor *avcodec_descriptor_next(const AVCodecDescriptor *prev);
5396 
5397 /**
5398  * @return codec descriptor with the given name or NULL if no such descriptor
5399  *         exists.
5400  */
5401 const AVCodecDescriptor *avcodec_descriptor_get_by_name(const char *name);
5402 
5403 /**
5404  * Allocate a CPB properties structure and initialize its fields to default
5405  * values.
5406  *
5407  * @param size if non-NULL, the size of the allocated struct will be written
5408  *             here. This is useful for embedding it in side data.
5409  *
5410  * @return the newly allocated struct or NULL on failure
5411  */
5412 AVCPBProperties *av_cpb_properties_alloc(size_t *size);
5413 
5414 /**
5415  * @}
5416  */
5417 
5418 #endif /* AVCODEC_AVCODEC_H */
5419