1 /*
2  * Flash Compatible Streaming Format muxer
3  * Copyright (c) 2000 Fabrice Bellard
4  * Copyright (c) 2003 Tinic Uro
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include "libavcodec/put_bits.h"
24 #include "libavutil/avassert.h"
25 #include "libavutil/fifo.h"
26 #include "avformat.h"
27 #include "swf.h"
28 
29 #define AUDIO_FIFO_SIZE 65536
30 
31 typedef struct SWFEncContext {
32     int64_t duration_pos;
33     int64_t tag_pos;
34     int64_t vframes_pos;
35     int samples_per_frame;
36     int sound_samples;
37     int swf_frame_number;
38     int video_frame_number;
39     int tag;
40     AVFifoBuffer *audio_fifo;
41     AVCodecParameters *audio_par, *video_par;
42     AVStream *video_st;
43 } SWFEncContext;
44 
put_swf_tag(AVFormatContext * s,int tag)45 static void put_swf_tag(AVFormatContext *s, int tag)
46 {
47     SWFEncContext *swf = s->priv_data;
48     AVIOContext *pb = s->pb;
49 
50     swf->tag_pos = avio_tell(pb);
51     swf->tag = tag;
52     /* reserve some room for the tag */
53     if (tag & TAG_LONG) {
54         avio_wl16(pb, 0);
55         avio_wl32(pb, 0);
56     } else {
57         avio_wl16(pb, 0);
58     }
59 }
60 
put_swf_end_tag(AVFormatContext * s)61 static void put_swf_end_tag(AVFormatContext *s)
62 {
63     SWFEncContext *swf = s->priv_data;
64     AVIOContext *pb = s->pb;
65     int64_t pos;
66     int tag_len, tag;
67 
68     pos = avio_tell(pb);
69     tag_len = pos - swf->tag_pos - 2;
70     tag = swf->tag;
71     avio_seek(pb, swf->tag_pos, SEEK_SET);
72     if (tag & TAG_LONG) {
73         tag &= ~TAG_LONG;
74         avio_wl16(pb, (tag << 6) | 0x3f);
75         avio_wl32(pb, tag_len - 4);
76     } else {
77         av_assert0(tag_len < 0x3f);
78         avio_wl16(pb, (tag << 6) | tag_len);
79     }
80     avio_seek(pb, pos, SEEK_SET);
81 }
82 
max_nbits(int * nbits_ptr,int val)83 static inline void max_nbits(int *nbits_ptr, int val)
84 {
85     int n;
86 
87     if (val == 0)
88         return;
89     val = FFABS(val);
90     n = 1;
91     while (val != 0) {
92         n++;
93         val >>= 1;
94     }
95     if (n > *nbits_ptr)
96         *nbits_ptr = n;
97 }
98 
put_swf_rect(AVIOContext * pb,int xmin,int xmax,int ymin,int ymax)99 static void put_swf_rect(AVIOContext *pb,
100                          int xmin, int xmax, int ymin, int ymax)
101 {
102     PutBitContext p;
103     uint8_t buf[256];
104     int nbits, mask;
105 
106     init_put_bits(&p, buf, sizeof(buf));
107 
108     nbits = 0;
109     max_nbits(&nbits, xmin);
110     max_nbits(&nbits, xmax);
111     max_nbits(&nbits, ymin);
112     max_nbits(&nbits, ymax);
113     mask = (1 << nbits) - 1;
114 
115     /* rectangle info */
116     put_bits(&p, 5, nbits);
117     put_bits(&p, nbits, xmin & mask);
118     put_bits(&p, nbits, xmax & mask);
119     put_bits(&p, nbits, ymin & mask);
120     put_bits(&p, nbits, ymax & mask);
121 
122     flush_put_bits(&p);
123     avio_write(pb, buf, put_bits_ptr(&p) - p.buf);
124 }
125 
put_swf_line_edge(PutBitContext * pb,int dx,int dy)126 static void put_swf_line_edge(PutBitContext *pb, int dx, int dy)
127 {
128     int nbits, mask;
129 
130     put_bits(pb, 1, 1); /* edge */
131     put_bits(pb, 1, 1); /* line select */
132     nbits = 2;
133     max_nbits(&nbits, dx);
134     max_nbits(&nbits, dy);
135 
136     mask = (1 << nbits) - 1;
137     put_bits(pb, 4, nbits - 2); /* 16 bits precision */
138     if (dx == 0) {
139         put_bits(pb, 1, 0);
140         put_bits(pb, 1, 1);
141         put_bits(pb, nbits, dy & mask);
142     } else if (dy == 0) {
143         put_bits(pb, 1, 0);
144         put_bits(pb, 1, 0);
145         put_bits(pb, nbits, dx & mask);
146     } else {
147         put_bits(pb, 1, 1);
148         put_bits(pb, nbits, dx & mask);
149         put_bits(pb, nbits, dy & mask);
150     }
151 }
152 
153 #define FRAC_BITS 16
154 
put_swf_matrix(AVIOContext * pb,int a,int b,int c,int d,int tx,int ty)155 static void put_swf_matrix(AVIOContext *pb,
156                            int a, int b, int c, int d, int tx, int ty)
157 {
158     PutBitContext p;
159     uint8_t buf[256];
160     int nbits;
161 
162     init_put_bits(&p, buf, sizeof(buf));
163 
164     put_bits(&p, 1, 1); /* a, d present */
165     nbits = 1;
166     max_nbits(&nbits, a);
167     max_nbits(&nbits, d);
168     put_bits(&p, 5, nbits); /* nb bits */
169     put_bits(&p, nbits, a);
170     put_bits(&p, nbits, d);
171 
172     put_bits(&p, 1, 1); /* b, c present */
173     nbits = 1;
174     max_nbits(&nbits, c);
175     max_nbits(&nbits, b);
176     put_bits(&p, 5, nbits); /* nb bits */
177     put_bits(&p, nbits, c);
178     put_bits(&p, nbits, b);
179 
180     nbits = 1;
181     max_nbits(&nbits, tx);
182     max_nbits(&nbits, ty);
183     put_bits(&p, 5, nbits); /* nb bits */
184     put_bits(&p, nbits, tx);
185     put_bits(&p, nbits, ty);
186 
187     flush_put_bits(&p);
188     avio_write(pb, buf, put_bits_ptr(&p) - p.buf);
189 }
190 
swf_write_header(AVFormatContext * s)191 static int swf_write_header(AVFormatContext *s)
192 {
193     SWFEncContext *swf = s->priv_data;
194     AVIOContext *pb = s->pb;
195     PutBitContext p;
196     uint8_t buf1[256];
197     int i, width, height, rate, rate_base;
198     int version;
199 
200     swf->sound_samples = 0;
201     swf->swf_frame_number = 0;
202     swf->video_frame_number = 0;
203 
204     for(i=0;i<s->nb_streams;i++) {
205         AVCodecParameters *par = s->streams[i]->codecpar;
206         if (par->codec_type == AVMEDIA_TYPE_AUDIO) {
207             if (swf->audio_par) {
208                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports 1 audio stream\n");
209                 return AVERROR_INVALIDDATA;
210             }
211             if (par->codec_id == AV_CODEC_ID_MP3) {
212                 swf->audio_par = par;
213                 swf->audio_fifo= av_fifo_alloc(AUDIO_FIFO_SIZE);
214                 if (!swf->audio_fifo)
215                     return AVERROR(ENOMEM);
216             } else {
217                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports MP3\n");
218                 return -1;
219             }
220         } else {
221             if (swf->video_par) {
222                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports 1 video stream\n");
223                 return AVERROR_INVALIDDATA;
224             }
225             if (par->codec_id == AV_CODEC_ID_VP6F ||
226                 par->codec_id == AV_CODEC_ID_FLV1 ||
227                 par->codec_id == AV_CODEC_ID_MJPEG) {
228                 swf->video_st  = s->streams[i];
229                 swf->video_par = par;
230             } else {
231                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports VP6, FLV1 and MJPEG\n");
232                 return -1;
233             }
234         }
235     }
236 
237     if (!swf->video_par) {
238         /* currently, cannot work correctly if audio only */
239         width = 320;
240         height = 200;
241         rate = 10;
242         rate_base= 1;
243     } else {
244         width = swf->video_par->width;
245         height = swf->video_par->height;
246         // TODO: should be avg_frame_rate
247         rate = swf->video_st->time_base.den;
248         rate_base = swf->video_st->time_base.num;
249     }
250 
251     if (!swf->audio_par)
252         swf->samples_per_frame = (44100LL * rate_base) / rate;
253     else
254         swf->samples_per_frame = (swf->audio_par->sample_rate * rate_base) / rate;
255 
256     avio_write(pb, "FWS", 3);
257 
258     if (!strcmp("avm2", s->oformat->name))
259         version = 9;
260     else if (swf->video_par && swf->video_par->codec_id == AV_CODEC_ID_VP6F)
261         version = 8; /* version 8 and above support VP6 codec */
262     else if (swf->video_par && swf->video_par->codec_id == AV_CODEC_ID_FLV1)
263         version = 6; /* version 6 and above support FLV1 codec */
264     else
265         version = 4; /* version 4 for mpeg audio support */
266     avio_w8(pb, version);
267 
268     avio_wl32(pb, DUMMY_FILE_SIZE); /* dummy size
269                                       (will be patched if not streamed) */
270 
271     put_swf_rect(pb, 0, width * 20, 0, height * 20);
272     if ((rate * 256LL) / rate_base >= (1<<16)) {
273         av_log(s, AV_LOG_ERROR, "Invalid (too large) frame rate %d/%d\n", rate, rate_base);
274         return AVERROR(EINVAL);
275     }
276     avio_wl16(pb, (rate * 256LL) / rate_base); /* frame rate */
277     swf->duration_pos = avio_tell(pb);
278     avio_wl16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */
279 
280     /* avm2/swf v9 (also v8?) files require a file attribute tag */
281     if (version == 9) {
282         put_swf_tag(s, TAG_FILEATTRIBUTES);
283         avio_wl32(pb, 1<<3); /* set ActionScript v3/AVM2 flag */
284         put_swf_end_tag(s);
285     }
286 
287     /* define a shape with the jpeg inside */
288     if (swf->video_par && swf->video_par->codec_id == AV_CODEC_ID_MJPEG) {
289         put_swf_tag(s, TAG_DEFINESHAPE);
290 
291         avio_wl16(pb, SHAPE_ID); /* ID of shape */
292         /* bounding rectangle */
293         put_swf_rect(pb, 0, width, 0, height);
294         /* style info */
295         avio_w8(pb, 1); /* one fill style */
296         avio_w8(pb, 0x41); /* clipped bitmap fill */
297         avio_wl16(pb, BITMAP_ID); /* bitmap ID */
298         /* position of the bitmap */
299         put_swf_matrix(pb, 1 << FRAC_BITS, 0,
300                        0,  1 << FRAC_BITS, 0, 0);
301         avio_w8(pb, 0); /* no line style */
302 
303         /* shape drawing */
304         init_put_bits(&p, buf1, sizeof(buf1));
305         put_bits(&p, 4, 1); /* one fill bit */
306         put_bits(&p, 4, 0); /* zero line bit */
307 
308         put_bits(&p, 1, 0); /* not an edge */
309         put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0);
310         put_bits(&p, 5, 1); /* nbits */
311         put_bits(&p, 1, 0); /* X */
312         put_bits(&p, 1, 0); /* Y */
313         put_bits(&p, 1, 1); /* set fill style 1 */
314 
315         /* draw the rectangle ! */
316         put_swf_line_edge(&p, width, 0);
317         put_swf_line_edge(&p, 0, height);
318         put_swf_line_edge(&p, -width, 0);
319         put_swf_line_edge(&p, 0, -height);
320 
321         /* end of shape */
322         put_bits(&p, 1, 0); /* not an edge */
323         put_bits(&p, 5, 0);
324 
325         flush_put_bits(&p);
326         avio_write(pb, buf1, put_bits_ptr(&p) - p.buf);
327 
328         put_swf_end_tag(s);
329     }
330 
331     if (swf->audio_par && swf->audio_par->codec_id == AV_CODEC_ID_MP3) {
332         int v = 0;
333 
334         /* start sound */
335         put_swf_tag(s, TAG_STREAMHEAD2);
336         switch(swf->audio_par->sample_rate) {
337         case 11025: v |= 1 << 2; break;
338         case 22050: v |= 2 << 2; break;
339         case 44100: v |= 3 << 2; break;
340         default:
341             /* not supported */
342             av_log(s, AV_LOG_ERROR, "swf does not support that sample rate, choose from (44100, 22050, 11025).\n");
343             return -1;
344         }
345         v |= 0x02; /* 16 bit playback */
346         if (swf->audio_par->channels == 2)
347             v |= 0x01; /* stereo playback */
348         avio_w8(s->pb, v);
349         v |= 0x20; /* mp3 compressed */
350         avio_w8(s->pb, v);
351         avio_wl16(s->pb, swf->samples_per_frame);  /* avg samples per frame */
352         avio_wl16(s->pb, 0);
353 
354         put_swf_end_tag(s);
355     }
356 
357     return 0;
358 }
359 
swf_write_video(AVFormatContext * s,AVCodecParameters * par,const uint8_t * buf,int size)360 static int swf_write_video(AVFormatContext *s,
361                            AVCodecParameters *par, const uint8_t *buf, int size)
362 {
363     SWFEncContext *swf = s->priv_data;
364     AVIOContext *pb = s->pb;
365 
366     /* Flash Player limit */
367     if (swf->swf_frame_number == 16000)
368         av_log(s, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
369 
370     if (par->codec_id == AV_CODEC_ID_VP6F ||
371         par->codec_id == AV_CODEC_ID_FLV1) {
372         if (swf->video_frame_number == 0) {
373             /* create a new video object */
374             put_swf_tag(s, TAG_VIDEOSTREAM);
375             avio_wl16(pb, VIDEO_ID);
376             swf->vframes_pos = avio_tell(pb);
377             avio_wl16(pb, 15000); /* hard flash player limit */
378             avio_wl16(pb, par->width);
379             avio_wl16(pb, par->height);
380             avio_w8(pb, 0);
381             avio_w8(pb,ff_codec_get_tag(ff_swf_codec_tags, par->codec_id));
382             put_swf_end_tag(s);
383 
384             /* place the video object for the first time */
385             put_swf_tag(s, TAG_PLACEOBJECT2);
386             avio_w8(pb, 0x36);
387             avio_wl16(pb, 1);
388             avio_wl16(pb, VIDEO_ID);
389             put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
390             avio_wl16(pb, swf->video_frame_number);
391             avio_write(pb, "video", 5);
392             avio_w8(pb, 0x00);
393             put_swf_end_tag(s);
394         } else {
395             /* mark the character for update */
396             put_swf_tag(s, TAG_PLACEOBJECT2);
397             avio_w8(pb, 0x11);
398             avio_wl16(pb, 1);
399             avio_wl16(pb, swf->video_frame_number);
400             put_swf_end_tag(s);
401         }
402 
403         /* set video frame data */
404         put_swf_tag(s, TAG_VIDEOFRAME | TAG_LONG);
405         avio_wl16(pb, VIDEO_ID);
406         avio_wl16(pb, swf->video_frame_number++);
407         avio_write(pb, buf, size);
408         put_swf_end_tag(s);
409     } else if (par->codec_id == AV_CODEC_ID_MJPEG) {
410         if (swf->swf_frame_number > 0) {
411             /* remove the shape */
412             put_swf_tag(s, TAG_REMOVEOBJECT);
413             avio_wl16(pb, SHAPE_ID); /* shape ID */
414             avio_wl16(pb, 1); /* depth */
415             put_swf_end_tag(s);
416 
417             /* free the bitmap */
418             put_swf_tag(s, TAG_FREECHARACTER);
419             avio_wl16(pb, BITMAP_ID);
420             put_swf_end_tag(s);
421         }
422 
423         put_swf_tag(s, TAG_JPEG2 | TAG_LONG);
424 
425         avio_wl16(pb, BITMAP_ID); /* ID of the image */
426 
427         /* a dummy jpeg header seems to be required */
428         avio_wb32(pb, 0xffd8ffd9);
429         /* write the jpeg image */
430         avio_write(pb, buf, size);
431 
432         put_swf_end_tag(s);
433 
434         /* draw the shape */
435 
436         put_swf_tag(s, TAG_PLACEOBJECT);
437         avio_wl16(pb, SHAPE_ID); /* shape ID */
438         avio_wl16(pb, 1); /* depth */
439         put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
440         put_swf_end_tag(s);
441     }
442 
443     swf->swf_frame_number++;
444 
445     /* streaming sound always should be placed just before showframe tags */
446     if (swf->audio_par && av_fifo_size(swf->audio_fifo)) {
447         int frame_size = av_fifo_size(swf->audio_fifo);
448         put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG);
449         avio_wl16(pb, swf->sound_samples);
450         avio_wl16(pb, 0); // seek samples
451         av_fifo_generic_read(swf->audio_fifo, pb, frame_size, (void*)avio_write);
452         put_swf_end_tag(s);
453 
454         /* update FIFO */
455         swf->sound_samples = 0;
456     }
457 
458     /* output the frame */
459     put_swf_tag(s, TAG_SHOWFRAME);
460     put_swf_end_tag(s);
461 
462     return 0;
463 }
464 
swf_write_audio(AVFormatContext * s,AVCodecParameters * par,uint8_t * buf,int size)465 static int swf_write_audio(AVFormatContext *s,
466                            AVCodecParameters *par, uint8_t *buf, int size)
467 {
468     SWFEncContext *swf = s->priv_data;
469 
470     /* Flash Player limit */
471     if (swf->swf_frame_number == 16000)
472         av_log(s, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
473 
474     if (av_fifo_size(swf->audio_fifo) + size > AUDIO_FIFO_SIZE) {
475         av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");
476         return -1;
477     }
478 
479     av_fifo_generic_write(swf->audio_fifo, buf, size, NULL);
480     swf->sound_samples += av_get_audio_frame_duration2(par, size);
481 
482     /* if audio only stream make sure we add swf frames */
483     if (!swf->video_par)
484         swf_write_video(s, par, 0, 0);
485 
486     return 0;
487 }
488 
swf_write_packet(AVFormatContext * s,AVPacket * pkt)489 static int swf_write_packet(AVFormatContext *s, AVPacket *pkt)
490 {
491     AVCodecParameters *par = s->streams[pkt->stream_index]->codecpar;
492     if (par->codec_type == AVMEDIA_TYPE_AUDIO)
493         return swf_write_audio(s, par, pkt->data, pkt->size);
494     else
495         return swf_write_video(s, par, pkt->data, pkt->size);
496 }
497 
swf_write_trailer(AVFormatContext * s)498 static int swf_write_trailer(AVFormatContext *s)
499 {
500     SWFEncContext *swf = s->priv_data;
501     AVIOContext *pb = s->pb;
502     int file_size;
503 
504     put_swf_tag(s, TAG_END);
505     put_swf_end_tag(s);
506 
507     /* patch file size and number of frames if not streamed */
508     if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) && swf->video_par) {
509         file_size = avio_tell(pb);
510         avio_seek(pb, 4, SEEK_SET);
511         avio_wl32(pb, file_size);
512         avio_seek(pb, swf->duration_pos, SEEK_SET);
513         avio_wl16(pb, swf->video_frame_number);
514         if (swf->vframes_pos) {
515         avio_seek(pb, swf->vframes_pos, SEEK_SET);
516         avio_wl16(pb, swf->video_frame_number);
517         }
518         avio_seek(pb, file_size, SEEK_SET);
519     }
520     return 0;
521 }
522 
swf_deinit(AVFormatContext * s)523 static void swf_deinit(AVFormatContext *s)
524 {
525     SWFEncContext *swf = s->priv_data;
526 
527     av_fifo_freep(&swf->audio_fifo);
528 }
529 
530 #if CONFIG_SWF_MUXER
531 AVOutputFormat ff_swf_muxer = {
532     .name              = "swf",
533     .long_name         = NULL_IF_CONFIG_SMALL("SWF (ShockWave Flash)"),
534     .mime_type         = "application/x-shockwave-flash",
535     .extensions        = "swf",
536     .priv_data_size    = sizeof(SWFEncContext),
537     .audio_codec       = AV_CODEC_ID_MP3,
538     .video_codec       = AV_CODEC_ID_FLV1,
539     .write_header      = swf_write_header,
540     .write_packet      = swf_write_packet,
541     .write_trailer     = swf_write_trailer,
542     .deinit            = swf_deinit,
543     .flags             = AVFMT_TS_NONSTRICT,
544 };
545 #endif
546 #if CONFIG_AVM2_MUXER
547 AVOutputFormat ff_avm2_muxer = {
548     .name              = "avm2",
549     .long_name         = NULL_IF_CONFIG_SMALL("SWF (ShockWave Flash) (AVM2)"),
550     .mime_type         = "application/x-shockwave-flash",
551     .priv_data_size    = sizeof(SWFEncContext),
552     .audio_codec       = AV_CODEC_ID_MP3,
553     .video_codec       = AV_CODEC_ID_FLV1,
554     .write_header      = swf_write_header,
555     .write_packet      = swf_write_packet,
556     .write_trailer     = swf_write_trailer,
557     .deinit            = swf_deinit,
558     .flags             = AVFMT_TS_NONSTRICT,
559 };
560 #endif
561