• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 "flv.h"
28 #include "swf.h"
29 
30 #define AUDIO_FIFO_SIZE 65536
31 
32 typedef struct SWFEncContext {
33     int64_t duration_pos;
34     int64_t tag_pos;
35     int64_t vframes_pos;
36     int samples_per_frame;
37     int sound_samples;
38     int swf_frame_number;
39     int video_frame_number;
40     int tag;
41     AVFifoBuffer *audio_fifo;
42     AVCodecParameters *audio_par, *video_par;
43     AVStream *video_st;
44 } SWFEncContext;
45 
put_swf_tag(AVFormatContext * s,int tag)46 static void put_swf_tag(AVFormatContext *s, int tag)
47 {
48     SWFEncContext *swf = s->priv_data;
49     AVIOContext *pb = s->pb;
50 
51     swf->tag_pos = avio_tell(pb);
52     swf->tag = tag;
53     /* reserve some room for the tag */
54     if (tag & TAG_LONG) {
55         avio_wl16(pb, 0);
56         avio_wl32(pb, 0);
57     } else {
58         avio_wl16(pb, 0);
59     }
60 }
61 
put_swf_end_tag(AVFormatContext * s)62 static void put_swf_end_tag(AVFormatContext *s)
63 {
64     SWFEncContext *swf = s->priv_data;
65     AVIOContext *pb = s->pb;
66     int64_t pos;
67     int tag_len, tag;
68 
69     pos = avio_tell(pb);
70     tag_len = pos - swf->tag_pos - 2;
71     tag = swf->tag;
72     avio_seek(pb, swf->tag_pos, SEEK_SET);
73     if (tag & TAG_LONG) {
74         tag &= ~TAG_LONG;
75         avio_wl16(pb, (tag << 6) | 0x3f);
76         avio_wl32(pb, tag_len - 4);
77     } else {
78         av_assert0(tag_len < 0x3f);
79         avio_wl16(pb, (tag << 6) | tag_len);
80     }
81     avio_seek(pb, pos, SEEK_SET);
82 }
83 
max_nbits(int * nbits_ptr,int val)84 static inline void max_nbits(int *nbits_ptr, int val)
85 {
86     int n;
87 
88     if (val == 0)
89         return;
90     val = FFABS(val);
91     n = 1;
92     while (val != 0) {
93         n++;
94         val >>= 1;
95     }
96     if (n > *nbits_ptr)
97         *nbits_ptr = n;
98 }
99 
put_swf_rect(AVIOContext * pb,int xmin,int xmax,int ymin,int ymax)100 static void put_swf_rect(AVIOContext *pb,
101                          int xmin, int xmax, int ymin, int ymax)
102 {
103     PutBitContext p;
104     uint8_t buf[256];
105     int nbits, mask;
106 
107     init_put_bits(&p, buf, sizeof(buf));
108 
109     nbits = 0;
110     max_nbits(&nbits, xmin);
111     max_nbits(&nbits, xmax);
112     max_nbits(&nbits, ymin);
113     max_nbits(&nbits, ymax);
114     mask = (1 << nbits) - 1;
115 
116     /* rectangle info */
117     put_bits(&p, 5, nbits);
118     put_bits(&p, nbits, xmin & mask);
119     put_bits(&p, nbits, xmax & mask);
120     put_bits(&p, nbits, ymin & mask);
121     put_bits(&p, nbits, ymax & mask);
122 
123     flush_put_bits(&p);
124     avio_write(pb, buf, put_bits_ptr(&p) - p.buf);
125 }
126 
put_swf_line_edge(PutBitContext * pb,int dx,int dy)127 static void put_swf_line_edge(PutBitContext *pb, int dx, int dy)
128 {
129     int nbits, mask;
130 
131     put_bits(pb, 1, 1); /* edge */
132     put_bits(pb, 1, 1); /* line select */
133     nbits = 2;
134     max_nbits(&nbits, dx);
135     max_nbits(&nbits, dy);
136 
137     mask = (1 << nbits) - 1;
138     put_bits(pb, 4, nbits - 2); /* 16 bits precision */
139     if (dx == 0) {
140         put_bits(pb, 1, 0);
141         put_bits(pb, 1, 1);
142         put_bits(pb, nbits, dy & mask);
143     } else if (dy == 0) {
144         put_bits(pb, 1, 0);
145         put_bits(pb, 1, 0);
146         put_bits(pb, nbits, dx & mask);
147     } else {
148         put_bits(pb, 1, 1);
149         put_bits(pb, nbits, dx & mask);
150         put_bits(pb, nbits, dy & mask);
151     }
152 }
153 
154 #define FRAC_BITS 16
155 
put_swf_matrix(AVIOContext * pb,int a,int b,int c,int d,int tx,int ty)156 static void put_swf_matrix(AVIOContext *pb,
157                            int a, int b, int c, int d, int tx, int ty)
158 {
159     PutBitContext p;
160     uint8_t buf[256];
161     int nbits;
162 
163     init_put_bits(&p, buf, sizeof(buf));
164 
165     put_bits(&p, 1, 1); /* a, d present */
166     nbits = 1;
167     max_nbits(&nbits, a);
168     max_nbits(&nbits, d);
169     put_bits(&p, 5, nbits); /* nb bits */
170     put_bits(&p, nbits, a);
171     put_bits(&p, nbits, d);
172 
173     put_bits(&p, 1, 1); /* b, c present */
174     nbits = 1;
175     max_nbits(&nbits, c);
176     max_nbits(&nbits, b);
177     put_bits(&p, 5, nbits); /* nb bits */
178     put_bits(&p, nbits, c);
179     put_bits(&p, nbits, b);
180 
181     nbits = 1;
182     max_nbits(&nbits, tx);
183     max_nbits(&nbits, ty);
184     put_bits(&p, 5, nbits); /* nb bits */
185     put_bits(&p, nbits, tx);
186     put_bits(&p, nbits, ty);
187 
188     flush_put_bits(&p);
189     avio_write(pb, buf, put_bits_ptr(&p) - p.buf);
190 }
191 
swf_write_header(AVFormatContext * s)192 static int swf_write_header(AVFormatContext *s)
193 {
194     SWFEncContext *swf = s->priv_data;
195     AVIOContext *pb = s->pb;
196     PutBitContext p;
197     uint8_t buf1[256];
198     int i, width, height, rate, rate_base;
199     int version;
200 
201     swf->sound_samples = 0;
202     swf->swf_frame_number = 0;
203     swf->video_frame_number = 0;
204 
205     for(i=0;i<s->nb_streams;i++) {
206         AVCodecParameters *par = s->streams[i]->codecpar;
207         if (par->codec_type == AVMEDIA_TYPE_AUDIO) {
208             if (swf->audio_par) {
209                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports 1 audio stream\n");
210                 return AVERROR_INVALIDDATA;
211             }
212             if (par->codec_id == AV_CODEC_ID_MP3) {
213                 swf->audio_par = par;
214                 swf->audio_fifo= av_fifo_alloc(AUDIO_FIFO_SIZE);
215                 if (!swf->audio_fifo)
216                     return AVERROR(ENOMEM);
217             } else {
218                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports MP3\n");
219                 return -1;
220             }
221         } else {
222             if (swf->video_par) {
223                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports 1 video stream\n");
224                 return AVERROR_INVALIDDATA;
225             }
226             if (ff_codec_get_tag(ff_swf_codec_tags, par->codec_id) ||
227                 par->codec_id == AV_CODEC_ID_PNG ||
228                 par->codec_id == AV_CODEC_ID_MJPEG) {
229                 swf->video_st  = s->streams[i];
230                 swf->video_par = par;
231             } else {
232                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports VP6, FLV, Flash Screen Video, PNG and MJPEG\n");
233                 return -1;
234             }
235         }
236     }
237 
238     if (!swf->video_par) {
239         /* currently, cannot work correctly if audio only */
240         width = 320;
241         height = 200;
242         rate = 10;
243         rate_base= 1;
244     } else {
245         width = swf->video_par->width;
246         height = swf->video_par->height;
247         // TODO: should be avg_frame_rate
248         rate = swf->video_st->time_base.den;
249         rate_base = swf->video_st->time_base.num;
250     }
251 
252     if (!swf->audio_par)
253         swf->samples_per_frame = (44100LL * rate_base) / rate;
254     else
255         swf->samples_per_frame = (swf->audio_par->sample_rate * rate_base) / rate;
256 
257     avio_write(pb, "FWS", 3);
258 
259     if (!strcmp("avm2", s->oformat->name))
260         version = 9;
261     else if (swf->video_par && (swf->video_par->codec_id == AV_CODEC_ID_VP6A ||
262                                 swf->video_par->codec_id == AV_CODEC_ID_VP6F ||
263                                 swf->video_par->codec_id == AV_CODEC_ID_PNG))
264         version = 8; /* version 8 and above support VP6 and PNG codec */
265     else if (swf->video_par && swf->video_par->codec_id == AV_CODEC_ID_FLASHSV)
266         version = 7; /* version 7 and above support Flash Screen Video codec */
267     else if (swf->video_par && swf->video_par->codec_id == AV_CODEC_ID_FLV1)
268         version = 6; /* version 6 and above support FLV1 codec */
269     else
270         version = 4; /* version 4 for mpeg audio support */
271     avio_w8(pb, version);
272 
273     avio_wl32(pb, DUMMY_FILE_SIZE); /* dummy size
274                                       (will be patched if not streamed) */
275 
276     put_swf_rect(pb, 0, width * 20, 0, height * 20);
277     if ((rate * 256LL) / rate_base >= (1<<16)) {
278         av_log(s, AV_LOG_ERROR, "Invalid (too large) frame rate %d/%d\n", rate, rate_base);
279         return AVERROR(EINVAL);
280     }
281     avio_wl16(pb, (rate * 256LL) / rate_base); /* frame rate */
282     swf->duration_pos = avio_tell(pb);
283     avio_wl16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */
284 
285     /* swf v8 and later files require a file attribute tag */
286     if (version >= 8) {
287         put_swf_tag(s, TAG_FILEATTRIBUTES);
288         avio_wl32(pb, (version >= 9) << 3); /* set ActionScript v3/AVM2 flag */
289         put_swf_end_tag(s);
290     }
291 
292     /* define a shape with the jpeg inside */
293     if (swf->video_par && (swf->video_par->codec_id == AV_CODEC_ID_MJPEG || swf->video_par->codec_id == AV_CODEC_ID_PNG)) {
294         put_swf_tag(s, TAG_DEFINESHAPE);
295 
296         avio_wl16(pb, SHAPE_ID); /* ID of shape */
297         /* bounding rectangle */
298         put_swf_rect(pb, 0, width, 0, height);
299         /* style info */
300         avio_w8(pb, 1); /* one fill style */
301         avio_w8(pb, 0x41); /* clipped bitmap fill */
302         avio_wl16(pb, BITMAP_ID); /* bitmap ID */
303         /* position of the bitmap */
304         put_swf_matrix(pb, 1 << FRAC_BITS, 0,
305                        0,  1 << FRAC_BITS, 0, 0);
306         avio_w8(pb, 0); /* no line style */
307 
308         /* shape drawing */
309         init_put_bits(&p, buf1, sizeof(buf1));
310         put_bits(&p, 4, 1); /* one fill bit */
311         put_bits(&p, 4, 0); /* zero line bit */
312 
313         put_bits(&p, 1, 0); /* not an edge */
314         put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0);
315         put_bits(&p, 5, 1); /* nbits */
316         put_bits(&p, 1, 0); /* X */
317         put_bits(&p, 1, 0); /* Y */
318         put_bits(&p, 1, 1); /* set fill style 1 */
319 
320         /* draw the rectangle ! */
321         put_swf_line_edge(&p, width, 0);
322         put_swf_line_edge(&p, 0, height);
323         put_swf_line_edge(&p, -width, 0);
324         put_swf_line_edge(&p, 0, -height);
325 
326         /* end of shape */
327         put_bits(&p, 1, 0); /* not an edge */
328         put_bits(&p, 5, 0);
329 
330         flush_put_bits(&p);
331         avio_write(pb, buf1, put_bits_ptr(&p) - p.buf);
332 
333         put_swf_end_tag(s);
334     }
335 
336     if (swf->audio_par && swf->audio_par->codec_id == AV_CODEC_ID_MP3) {
337         int v = 0;
338 
339         /* start sound */
340         put_swf_tag(s, TAG_STREAMHEAD2);
341         switch(swf->audio_par->sample_rate) {
342         case 11025: v |= 1 << 2; break;
343         case 22050: v |= 2 << 2; break;
344         case 44100: v |= 3 << 2; break;
345         default:
346             /* not supported */
347             av_log(s, AV_LOG_ERROR, "swf does not support that sample rate, choose from (44100, 22050, 11025).\n");
348             return -1;
349         }
350         v |= 0x02; /* 16 bit playback */
351         if (swf->audio_par->channels == 2)
352             v |= 0x01; /* stereo playback */
353         avio_w8(s->pb, v);
354         v |= 0x20; /* mp3 compressed */
355         avio_w8(s->pb, v);
356         avio_wl16(s->pb, swf->samples_per_frame);  /* avg samples per frame */
357         avio_wl16(s->pb, 0);
358 
359         put_swf_end_tag(s);
360     }
361 
362     return 0;
363 }
364 
swf_write_video(AVFormatContext * s,AVCodecParameters * par,const uint8_t * buf,int size,unsigned pkt_flags)365 static int swf_write_video(AVFormatContext *s,
366                            AVCodecParameters *par, const uint8_t *buf, int size, unsigned pkt_flags)
367 {
368     SWFEncContext *swf = s->priv_data;
369     AVIOContext *pb = s->pb;
370     unsigned codec_tag = ff_codec_get_tag(ff_swf_codec_tags, par->codec_id);
371 
372     /* Flash Player limit */
373     if (swf->swf_frame_number == 16000)
374         av_log(s, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
375 
376     if (codec_tag) {
377         if (swf->video_frame_number == 0) {
378             /* create a new video object */
379             put_swf_tag(s, TAG_VIDEOSTREAM);
380             avio_wl16(pb, VIDEO_ID);
381             swf->vframes_pos = avio_tell(pb);
382             avio_wl16(pb, 15000); /* hard flash player limit */
383             avio_wl16(pb, par->width);
384             avio_wl16(pb, par->height);
385             avio_w8(pb, 0);
386             avio_w8(pb, codec_tag);
387             put_swf_end_tag(s);
388 
389             /* place the video object for the first time */
390             put_swf_tag(s, TAG_PLACEOBJECT2);
391             avio_w8(pb, 0x36);
392             avio_wl16(pb, 1);
393             avio_wl16(pb, VIDEO_ID);
394             put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
395             avio_wl16(pb, swf->video_frame_number);
396             avio_write(pb, "video", 5);
397             avio_w8(pb, 0x00);
398             put_swf_end_tag(s);
399         } else {
400             /* mark the character for update */
401             put_swf_tag(s, TAG_PLACEOBJECT2);
402             avio_w8(pb, 0x11);
403             avio_wl16(pb, 1);
404             avio_wl16(pb, swf->video_frame_number);
405             put_swf_end_tag(s);
406         }
407 
408         /* set video frame data */
409         put_swf_tag(s, TAG_VIDEOFRAME | TAG_LONG);
410         avio_wl16(pb, VIDEO_ID);
411         avio_wl16(pb, swf->video_frame_number++);
412         if (par->codec_id == AV_CODEC_ID_FLASHSV) {
413             /* FrameType and CodecId is needed here even if it is not documented correctly in the SWF specs */
414             int flags = codec_tag | (pkt_flags & AV_PKT_FLAG_KEY ? FLV_FRAME_KEY : FLV_FRAME_INTER);
415             avio_w8(pb, flags);
416         }
417         avio_write(pb, buf, size);
418         put_swf_end_tag(s);
419     } else if (par->codec_id == AV_CODEC_ID_MJPEG || par->codec_id == AV_CODEC_ID_PNG) {
420         if (swf->swf_frame_number > 0) {
421             /* remove the shape */
422             put_swf_tag(s, TAG_REMOVEOBJECT);
423             avio_wl16(pb, SHAPE_ID); /* shape ID */
424             avio_wl16(pb, 1); /* depth */
425             put_swf_end_tag(s);
426 
427             /* free the bitmap */
428             put_swf_tag(s, TAG_FREECHARACTER);
429             avio_wl16(pb, BITMAP_ID);
430             put_swf_end_tag(s);
431         }
432 
433         put_swf_tag(s, TAG_JPEG2 | TAG_LONG);
434 
435         avio_wl16(pb, BITMAP_ID); /* ID of the image */
436 
437         /* a dummy jpeg header seems to be required */
438         if (par->codec_id == AV_CODEC_ID_MJPEG)
439             avio_wb32(pb, 0xffd8ffd9);
440         /* write the jpeg/png image */
441         avio_write(pb, buf, size);
442 
443         put_swf_end_tag(s);
444 
445         /* draw the shape */
446 
447         put_swf_tag(s, TAG_PLACEOBJECT);
448         avio_wl16(pb, SHAPE_ID); /* shape ID */
449         avio_wl16(pb, 1); /* depth */
450         put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
451         put_swf_end_tag(s);
452     }
453 
454     swf->swf_frame_number++;
455 
456     /* streaming sound always should be placed just before showframe tags */
457     if (swf->audio_par && av_fifo_size(swf->audio_fifo)) {
458         int frame_size = av_fifo_size(swf->audio_fifo);
459         put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG);
460         avio_wl16(pb, swf->sound_samples);
461         avio_wl16(pb, 0); // seek samples
462         av_fifo_generic_read(swf->audio_fifo, pb, frame_size, (void*)avio_write);
463         put_swf_end_tag(s);
464 
465         /* update FIFO */
466         swf->sound_samples = 0;
467     }
468 
469     /* output the frame */
470     put_swf_tag(s, TAG_SHOWFRAME);
471     put_swf_end_tag(s);
472 
473     return 0;
474 }
475 
swf_write_audio(AVFormatContext * s,AVCodecParameters * par,uint8_t * buf,int size)476 static int swf_write_audio(AVFormatContext *s,
477                            AVCodecParameters *par, uint8_t *buf, int size)
478 {
479     SWFEncContext *swf = s->priv_data;
480 
481     /* Flash Player limit */
482     if (swf->swf_frame_number == 16000)
483         av_log(s, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
484 
485     if (av_fifo_size(swf->audio_fifo) + size > AUDIO_FIFO_SIZE) {
486         av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");
487         return -1;
488     }
489 
490     av_fifo_generic_write(swf->audio_fifo, buf, size, NULL);
491     swf->sound_samples += av_get_audio_frame_duration2(par, size);
492 
493     /* if audio only stream make sure we add swf frames */
494     if (!swf->video_par)
495         swf_write_video(s, par, 0, 0, 0);
496 
497     return 0;
498 }
499 
swf_write_packet(AVFormatContext * s,AVPacket * pkt)500 static int swf_write_packet(AVFormatContext *s, AVPacket *pkt)
501 {
502     AVCodecParameters *par = s->streams[pkt->stream_index]->codecpar;
503     if (par->codec_type == AVMEDIA_TYPE_AUDIO)
504         return swf_write_audio(s, par, pkt->data, pkt->size);
505     else
506         return swf_write_video(s, par, pkt->data, pkt->size, pkt->flags);
507 }
508 
swf_write_trailer(AVFormatContext * s)509 static int swf_write_trailer(AVFormatContext *s)
510 {
511     SWFEncContext *swf = s->priv_data;
512     AVIOContext *pb = s->pb;
513     int file_size;
514 
515     put_swf_tag(s, TAG_END);
516     put_swf_end_tag(s);
517 
518     /* patch file size and number of frames if not streamed */
519     if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) && swf->video_par) {
520         file_size = avio_tell(pb);
521         avio_seek(pb, 4, SEEK_SET);
522         avio_wl32(pb, file_size);
523         avio_seek(pb, swf->duration_pos, SEEK_SET);
524         avio_wl16(pb, swf->video_frame_number);
525         if (swf->vframes_pos) {
526         avio_seek(pb, swf->vframes_pos, SEEK_SET);
527         avio_wl16(pb, swf->video_frame_number);
528         }
529         avio_seek(pb, file_size, SEEK_SET);
530     }
531     return 0;
532 }
533 
swf_deinit(AVFormatContext * s)534 static void swf_deinit(AVFormatContext *s)
535 {
536     SWFEncContext *swf = s->priv_data;
537 
538     av_fifo_freep(&swf->audio_fifo);
539 }
540 
541 #if CONFIG_SWF_MUXER
542 AVOutputFormat ff_swf_muxer = {
543     .name              = "swf",
544     .long_name         = NULL_IF_CONFIG_SMALL("SWF (ShockWave Flash)"),
545     .mime_type         = "application/x-shockwave-flash",
546     .extensions        = "swf",
547     .priv_data_size    = sizeof(SWFEncContext),
548     .audio_codec       = AV_CODEC_ID_MP3,
549     .video_codec       = AV_CODEC_ID_FLV1,
550     .write_header      = swf_write_header,
551     .write_packet      = swf_write_packet,
552     .write_trailer     = swf_write_trailer,
553     .deinit            = swf_deinit,
554     .flags             = AVFMT_TS_NONSTRICT,
555 };
556 #endif
557 #if CONFIG_AVM2_MUXER
558 AVOutputFormat ff_avm2_muxer = {
559     .name              = "avm2",
560     .long_name         = NULL_IF_CONFIG_SMALL("SWF (ShockWave Flash) (AVM2)"),
561     .mime_type         = "application/x-shockwave-flash",
562     .priv_data_size    = sizeof(SWFEncContext),
563     .audio_codec       = AV_CODEC_ID_MP3,
564     .video_codec       = AV_CODEC_ID_FLV1,
565     .write_header      = swf_write_header,
566     .write_packet      = swf_write_packet,
567     .write_trailer     = swf_write_trailer,
568     .deinit            = swf_deinit,
569     .flags             = AVFMT_TS_NONSTRICT,
570 };
571 #endif
572