1 /*
2  * Copyright (c) 2006 Paul Richards <paul.richards@gmail.com>
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 /**
22  * @file
23  * @brief Theora encoder using libtheora.
24  * @author Paul Richards <paul.richards@gmail.com>
25  *
26  * A lot of this is copy / paste from other output codecs in
27  * libavcodec or pure guesswork (or both).
28  *
29  * I have used t_ prefixes on variables which are libtheora types
30  * and o_ prefixes on variables which are libogg types.
31  */
32 
33 /* FFmpeg includes */
34 #include "libavutil/common.h"
35 #include "libavutil/intreadwrite.h"
36 #include "libavutil/pixdesc.h"
37 #include "libavutil/log.h"
38 #include "libavutil/base64.h"
39 #include "avcodec.h"
40 #include "internal.h"
41 
42 /* libtheora includes */
43 #include <theora/theoraenc.h>
44 
45 typedef struct TheoraContext {
46     th_enc_ctx *t_state;
47     uint8_t    *stats;
48     int         stats_size;
49     int         stats_offset;
50     int         uv_hshift;
51     int         uv_vshift;
52     int         keyframe_mask;
53 } TheoraContext;
54 
55 /** Concatenate an ogg_packet into the extradata. */
concatenate_packet(unsigned int * offset,AVCodecContext * avc_context,const ogg_packet * packet)56 static int concatenate_packet(unsigned int* offset,
57                               AVCodecContext* avc_context,
58                               const ogg_packet* packet)
59 {
60     const char* message = NULL;
61     int newsize = avc_context->extradata_size + 2 + packet->bytes;
62     int err = AVERROR_INVALIDDATA;
63 
64     if (packet->bytes < 0) {
65         message = "ogg_packet has negative size";
66     } else if (packet->bytes > 0xffff) {
67         message = "ogg_packet is larger than 65535 bytes";
68     } else if (newsize < avc_context->extradata_size) {
69         message = "extradata_size would overflow";
70     } else {
71         if ((err = av_reallocp(&avc_context->extradata, newsize)) < 0) {
72             avc_context->extradata_size = 0;
73             message = "av_realloc failed";
74         }
75     }
76     if (message) {
77         av_log(avc_context, AV_LOG_ERROR, "concatenate_packet failed: %s\n", message);
78         return err;
79     }
80 
81     avc_context->extradata_size = newsize;
82     AV_WB16(avc_context->extradata + (*offset), packet->bytes);
83     *offset += 2;
84     memcpy(avc_context->extradata + (*offset), packet->packet, packet->bytes);
85     (*offset) += packet->bytes;
86     return 0;
87 }
88 
get_stats(AVCodecContext * avctx,int eos)89 static int get_stats(AVCodecContext *avctx, int eos)
90 {
91 #ifdef TH_ENCCTL_2PASS_OUT
92     TheoraContext *h = avctx->priv_data;
93     uint8_t *buf;
94     int bytes;
95 
96     bytes = th_encode_ctl(h->t_state, TH_ENCCTL_2PASS_OUT, &buf, sizeof(buf));
97     if (bytes < 0) {
98         av_log(avctx, AV_LOG_ERROR, "Error getting first pass stats\n");
99         return AVERROR_EXTERNAL;
100     }
101     if (!eos) {
102         void *tmp = av_fast_realloc(h->stats, &h->stats_size,
103                                    h->stats_offset + bytes);
104         if (!tmp)
105             return AVERROR(ENOMEM);
106         h->stats = tmp;
107         memcpy(h->stats + h->stats_offset, buf, bytes);
108         h->stats_offset += bytes;
109     } else {
110         int b64_size = AV_BASE64_SIZE(h->stats_offset);
111         // libtheora generates a summary header at the end
112         memcpy(h->stats, buf, bytes);
113         avctx->stats_out = av_malloc(b64_size);
114         if (!avctx->stats_out)
115             return AVERROR(ENOMEM);
116         av_base64_encode(avctx->stats_out, b64_size, h->stats, h->stats_offset);
117     }
118     return 0;
119 #else
120     av_log(avctx, AV_LOG_ERROR, "libtheora too old to support 2pass\n");
121     return AVERROR(ENOSUP);
122 #endif
123 }
124 
125 // libtheora won't read the entire buffer we give it at once, so we have to
126 // repeatedly submit it...
submit_stats(AVCodecContext * avctx)127 static int submit_stats(AVCodecContext *avctx)
128 {
129 #ifdef TH_ENCCTL_2PASS_IN
130     TheoraContext *h = avctx->priv_data;
131     int bytes;
132     if (!h->stats) {
133         if (!avctx->stats_in) {
134             av_log(avctx, AV_LOG_ERROR, "No statsfile for second pass\n");
135             return AVERROR(EINVAL);
136         }
137         h->stats_size = strlen(avctx->stats_in) * 3/4;
138         h->stats      = av_malloc(h->stats_size);
139         if (!h->stats) {
140             h->stats_size = 0;
141             return AVERROR(ENOMEM);
142         }
143         h->stats_size = av_base64_decode(h->stats, avctx->stats_in, h->stats_size);
144     }
145     while (h->stats_size - h->stats_offset > 0) {
146         bytes = th_encode_ctl(h->t_state, TH_ENCCTL_2PASS_IN,
147                               h->stats + h->stats_offset,
148                               h->stats_size - h->stats_offset);
149         if (bytes < 0) {
150             av_log(avctx, AV_LOG_ERROR, "Error submitting stats\n");
151             return AVERROR_EXTERNAL;
152         }
153         if (!bytes)
154             return 0;
155         h->stats_offset += bytes;
156     }
157     return 0;
158 #else
159     av_log(avctx, AV_LOG_ERROR, "libtheora too old to support 2pass\n");
160     return AVERROR(ENOSUP);
161 #endif
162 }
163 
encode_init(AVCodecContext * avc_context)164 static av_cold int encode_init(AVCodecContext* avc_context)
165 {
166     th_info t_info;
167     th_comment t_comment;
168     ogg_packet o_packet;
169     unsigned int offset;
170     TheoraContext *h = avc_context->priv_data;
171     uint32_t gop_size = avc_context->gop_size;
172     int ret;
173 
174     /* Set up the theora_info struct */
175     th_info_init(&t_info);
176     t_info.frame_width  = FFALIGN(avc_context->width,  16);
177     t_info.frame_height = FFALIGN(avc_context->height, 16);
178     t_info.pic_width    = avc_context->width;
179     t_info.pic_height   = avc_context->height;
180     t_info.pic_x        = 0;
181     t_info.pic_y        = 0;
182     /* Swap numerator and denominator as time_base in AVCodecContext gives the
183      * time period between frames, but theora_info needs the framerate.  */
184     t_info.fps_numerator   = avc_context->time_base.den;
185     t_info.fps_denominator = avc_context->time_base.num;
186     if (avc_context->sample_aspect_ratio.num) {
187         t_info.aspect_numerator   = avc_context->sample_aspect_ratio.num;
188         t_info.aspect_denominator = avc_context->sample_aspect_ratio.den;
189     } else {
190         t_info.aspect_numerator   = 1;
191         t_info.aspect_denominator = 1;
192     }
193 
194     if (avc_context->color_primaries == AVCOL_PRI_BT470M)
195         t_info.colorspace = TH_CS_ITU_REC_470M;
196     else if (avc_context->color_primaries == AVCOL_PRI_BT470BG)
197         t_info.colorspace = TH_CS_ITU_REC_470BG;
198     else
199         t_info.colorspace = TH_CS_UNSPECIFIED;
200 
201     if (avc_context->pix_fmt == AV_PIX_FMT_YUV420P)
202         t_info.pixel_fmt = TH_PF_420;
203     else if (avc_context->pix_fmt == AV_PIX_FMT_YUV422P)
204         t_info.pixel_fmt = TH_PF_422;
205     else if (avc_context->pix_fmt == AV_PIX_FMT_YUV444P)
206         t_info.pixel_fmt = TH_PF_444;
207     else {
208         av_log(avc_context, AV_LOG_ERROR, "Unsupported pix_fmt\n");
209         return AVERROR(EINVAL);
210     }
211     ret = av_pix_fmt_get_chroma_sub_sample(avc_context->pix_fmt, &h->uv_hshift, &h->uv_vshift);
212     if (ret)
213         return ret;
214 
215     if (avc_context->flags & AV_CODEC_FLAG_QSCALE) {
216         /* Clip global_quality in QP units to the [0 - 10] range
217            to be consistent with the libvorbis implementation.
218            Theora accepts a quality parameter which is an int value in
219            the [0 - 63] range.
220         */
221         t_info.quality        = av_clipf(avc_context->global_quality / (float)FF_QP2LAMBDA, 0, 10) * 6.3;
222         t_info.target_bitrate = 0;
223     } else {
224         t_info.target_bitrate = avc_context->bit_rate;
225         t_info.quality        = 0;
226     }
227 
228     /* Now initialise libtheora */
229     h->t_state = th_encode_alloc(&t_info);
230     if (!h->t_state) {
231         av_log(avc_context, AV_LOG_ERROR, "theora_encode_init failed\n");
232         return AVERROR_EXTERNAL;
233     }
234 
235     h->keyframe_mask = (1 << t_info.keyframe_granule_shift) - 1;
236     /* Clear up theora_info struct */
237     th_info_clear(&t_info);
238 
239     if (th_encode_ctl(h->t_state, TH_ENCCTL_SET_KEYFRAME_FREQUENCY_FORCE,
240                       &gop_size, sizeof(gop_size))) {
241         av_log(avc_context, AV_LOG_ERROR, "Error setting GOP size\n");
242         return AVERROR_EXTERNAL;
243     }
244 
245     // need to enable 2 pass (via TH_ENCCTL_2PASS_) before encoding headers
246     if (avc_context->flags & AV_CODEC_FLAG_PASS1) {
247         if ((ret = get_stats(avc_context, 0)) < 0)
248             return ret;
249     } else if (avc_context->flags & AV_CODEC_FLAG_PASS2) {
250         if ((ret = submit_stats(avc_context)) < 0)
251             return ret;
252     }
253 
254     /*
255         Output first header packet consisting of theora
256         header, comment, and tables.
257 
258         Each one is prefixed with a 16-bit size, then they
259         are concatenated together into libavcodec's extradata.
260     */
261     offset = 0;
262 
263     /* Headers */
264     th_comment_init(&t_comment);
265 
266     while (th_encode_flushheader(h->t_state, &t_comment, &o_packet))
267         if ((ret = concatenate_packet(&offset, avc_context, &o_packet)) < 0)
268             return ret;
269 
270     th_comment_clear(&t_comment);
271 
272     return 0;
273 }
274 
encode_frame(AVCodecContext * avc_context,AVPacket * pkt,const AVFrame * frame,int * got_packet)275 static int encode_frame(AVCodecContext* avc_context, AVPacket *pkt,
276                         const AVFrame *frame, int *got_packet)
277 {
278     th_ycbcr_buffer t_yuv_buffer;
279     TheoraContext *h = avc_context->priv_data;
280     ogg_packet o_packet;
281     int result, i, ret;
282 
283     // EOS, finish and get 1st pass stats if applicable
284     if (!frame) {
285         th_encode_packetout(h->t_state, 1, &o_packet);
286         if (avc_context->flags & AV_CODEC_FLAG_PASS1)
287             if ((ret = get_stats(avc_context, 1)) < 0)
288                 return ret;
289         return 0;
290     }
291 
292     /* Copy planes to the theora yuv_buffer */
293     for (i = 0; i < 3; i++) {
294         t_yuv_buffer[i].width  = FFALIGN(avc_context->width,  16) >> (i && h->uv_hshift);
295         t_yuv_buffer[i].height = FFALIGN(avc_context->height, 16) >> (i && h->uv_vshift);
296         t_yuv_buffer[i].stride = frame->linesize[i];
297         t_yuv_buffer[i].data   = frame->data[i];
298     }
299 
300     if (avc_context->flags & AV_CODEC_FLAG_PASS2)
301         if ((ret = submit_stats(avc_context)) < 0)
302             return ret;
303 
304     /* Now call into theora_encode_YUVin */
305     result = th_encode_ycbcr_in(h->t_state, t_yuv_buffer);
306     if (result) {
307         const char* message;
308         switch (result) {
309         case -1:
310             message = "differing frame sizes";
311             break;
312         case TH_EINVAL:
313             message = "encoder is not ready or is finished";
314             break;
315         default:
316             message = "unknown reason";
317             break;
318         }
319         av_log(avc_context, AV_LOG_ERROR, "theora_encode_YUVin failed (%s) [%d]\n", message, result);
320         return AVERROR_EXTERNAL;
321     }
322 
323     if (avc_context->flags & AV_CODEC_FLAG_PASS1)
324         if ((ret = get_stats(avc_context, 0)) < 0)
325             return ret;
326 
327     /* Pick up returned ogg_packet */
328     result = th_encode_packetout(h->t_state, 0, &o_packet);
329     switch (result) {
330     case 0:
331         /* No packet is ready */
332         return 0;
333     case 1:
334         /* Success, we have a packet */
335         break;
336     default:
337         av_log(avc_context, AV_LOG_ERROR, "theora_encode_packetout failed [%d]\n", result);
338         return AVERROR_EXTERNAL;
339     }
340 
341     /* Copy ogg_packet content out to buffer */
342     if ((ret = ff_alloc_packet2(avc_context, pkt, o_packet.bytes, 0)) < 0)
343         return ret;
344     memcpy(pkt->data, o_packet.packet, o_packet.bytes);
345 
346     // HACK: assumes no encoder delay, this is true until libtheora becomes
347     // multithreaded (which will be disabled unless explicitly requested)
348     pkt->pts = pkt->dts = frame->pts;
349 #if FF_API_CODED_FRAME
350 FF_DISABLE_DEPRECATION_WARNINGS
351     avc_context->coded_frame->key_frame = !(o_packet.granulepos & h->keyframe_mask);
352 FF_ENABLE_DEPRECATION_WARNINGS
353 #endif
354     if (!(o_packet.granulepos & h->keyframe_mask))
355         pkt->flags |= AV_PKT_FLAG_KEY;
356     *got_packet = 1;
357 
358     return 0;
359 }
360 
encode_close(AVCodecContext * avc_context)361 static av_cold int encode_close(AVCodecContext* avc_context)
362 {
363     TheoraContext *h = avc_context->priv_data;
364 
365     th_encode_free(h->t_state);
366     av_freep(&h->stats);
367     av_freep(&avc_context->stats_out);
368     av_freep(&avc_context->extradata);
369     avc_context->extradata_size = 0;
370 
371     return 0;
372 }
373 
374 /** AVCodec struct exposed to libavcodec */
375 AVCodec ff_libtheora_encoder = {
376     .name           = "libtheora",
377     .long_name      = NULL_IF_CONFIG_SMALL("libtheora Theora"),
378     .type           = AVMEDIA_TYPE_VIDEO,
379     .id             = AV_CODEC_ID_THEORA,
380     .priv_data_size = sizeof(TheoraContext),
381     .init           = encode_init,
382     .close          = encode_close,
383     .encode2        = encode_frame,
384     .capabilities   = AV_CODEC_CAP_DELAY, // needed to get the statsfile summary
385     .pix_fmts       = (const enum AVPixelFormat[]){
386         AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_NONE
387     },
388     .wrapper_name   = "libtheora",
389 };
390