Libav
swfenc.c
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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 Libav.
7  *
8  * Libav 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  * Libav 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 Libav; 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 "avformat.h"
25 #include "swf.h"
26 
27 static void put_swf_tag(AVFormatContext *s, int tag)
28 {
29  SWFContext *swf = s->priv_data;
30  AVIOContext *pb = s->pb;
31 
32  swf->tag_pos = avio_tell(pb);
33  swf->tag = tag;
34  /* reserve some room for the tag */
35  if (tag & TAG_LONG) {
36  avio_wl16(pb, 0);
37  avio_wl32(pb, 0);
38  } else {
39  avio_wl16(pb, 0);
40  }
41 }
42 
44 {
45  SWFContext *swf = s->priv_data;
46  AVIOContext *pb = s->pb;
47  int64_t pos;
48  int tag_len, tag;
49 
50  pos = avio_tell(pb);
51  tag_len = pos - swf->tag_pos - 2;
52  tag = swf->tag;
53  avio_seek(pb, swf->tag_pos, SEEK_SET);
54  if (tag & TAG_LONG) {
55  tag &= ~TAG_LONG;
56  avio_wl16(pb, (tag << 6) | 0x3f);
57  avio_wl32(pb, tag_len - 4);
58  } else {
59  assert(tag_len < 0x3f);
60  avio_wl16(pb, (tag << 6) | tag_len);
61  }
62  avio_seek(pb, pos, SEEK_SET);
63 }
64 
65 static inline void max_nbits(int *nbits_ptr, int val)
66 {
67  int n;
68 
69  if (val == 0)
70  return;
71  val = abs(val);
72  n = 1;
73  while (val != 0) {
74  n++;
75  val >>= 1;
76  }
77  if (n > *nbits_ptr)
78  *nbits_ptr = n;
79 }
80 
81 static void put_swf_rect(AVIOContext *pb,
82  int xmin, int xmax, int ymin, int ymax)
83 {
84  PutBitContext p;
85  uint8_t buf[256];
86  int nbits, mask;
87 
88  init_put_bits(&p, buf, sizeof(buf));
89 
90  nbits = 0;
91  max_nbits(&nbits, xmin);
92  max_nbits(&nbits, xmax);
93  max_nbits(&nbits, ymin);
94  max_nbits(&nbits, ymax);
95  mask = (1 << nbits) - 1;
96 
97  /* rectangle info */
98  put_bits(&p, 5, nbits);
99  put_bits(&p, nbits, xmin & mask);
100  put_bits(&p, nbits, xmax & mask);
101  put_bits(&p, nbits, ymin & mask);
102  put_bits(&p, nbits, ymax & mask);
103 
104  flush_put_bits(&p);
105  avio_write(pb, buf, put_bits_ptr(&p) - p.buf);
106 }
107 
108 static void put_swf_line_edge(PutBitContext *pb, int dx, int dy)
109 {
110  int nbits, mask;
111 
112  put_bits(pb, 1, 1); /* edge */
113  put_bits(pb, 1, 1); /* line select */
114  nbits = 2;
115  max_nbits(&nbits, dx);
116  max_nbits(&nbits, dy);
117 
118  mask = (1 << nbits) - 1;
119  put_bits(pb, 4, nbits - 2); /* 16 bits precision */
120  if (dx == 0) {
121  put_bits(pb, 1, 0);
122  put_bits(pb, 1, 1);
123  put_bits(pb, nbits, dy & mask);
124  } else if (dy == 0) {
125  put_bits(pb, 1, 0);
126  put_bits(pb, 1, 0);
127  put_bits(pb, nbits, dx & mask);
128  } else {
129  put_bits(pb, 1, 1);
130  put_bits(pb, nbits, dx & mask);
131  put_bits(pb, nbits, dy & mask);
132  }
133 }
134 
135 #define FRAC_BITS 16
136 
137 static void put_swf_matrix(AVIOContext *pb,
138  int a, int b, int c, int d, int tx, int ty)
139 {
140  PutBitContext p;
141  uint8_t buf[256];
142  int nbits;
143 
144  init_put_bits(&p, buf, sizeof(buf));
145 
146  put_bits(&p, 1, 1); /* a, d present */
147  nbits = 1;
148  max_nbits(&nbits, a);
149  max_nbits(&nbits, d);
150  put_bits(&p, 5, nbits); /* nb bits */
151  put_bits(&p, nbits, a);
152  put_bits(&p, nbits, d);
153 
154  put_bits(&p, 1, 1); /* b, c present */
155  nbits = 1;
156  max_nbits(&nbits, c);
157  max_nbits(&nbits, b);
158  put_bits(&p, 5, nbits); /* nb bits */
159  put_bits(&p, nbits, c);
160  put_bits(&p, nbits, b);
161 
162  nbits = 1;
163  max_nbits(&nbits, tx);
164  max_nbits(&nbits, ty);
165  put_bits(&p, 5, nbits); /* nb bits */
166  put_bits(&p, nbits, tx);
167  put_bits(&p, nbits, ty);
168 
169  flush_put_bits(&p);
170  avio_write(pb, buf, put_bits_ptr(&p) - p.buf);
171 }
172 
174 {
175  SWFContext *swf = s->priv_data;
176  AVIOContext *pb = s->pb;
177  PutBitContext p;
178  uint8_t buf1[256];
179  int i, width, height, rate, rate_base;
180  int version;
181 
182  swf->sound_samples = 0;
183  swf->swf_frame_number = 0;
184  swf->video_frame_number = 0;
185 
186  for(i=0;i<s->nb_streams;i++) {
187  AVCodecContext *enc = s->streams[i]->codec;
188  if (enc->codec_type == AVMEDIA_TYPE_AUDIO) {
189  if (swf->audio_enc) {
190  av_log(s, AV_LOG_ERROR, "SWF muxer only supports 1 audio stream\n");
191  return AVERROR_INVALIDDATA;
192  }
193  if (enc->codec_id == AV_CODEC_ID_MP3) {
194  swf->audio_enc = enc;
196  if (!swf->audio_fifo)
197  return AVERROR(ENOMEM);
198  } else {
199  av_log(s, AV_LOG_ERROR, "SWF muxer only supports MP3\n");
200  return -1;
201  }
202  } else {
203  if (swf->video_enc) {
204  av_log(s, AV_LOG_ERROR, "SWF muxer only supports 1 video stream\n");
205  return AVERROR_INVALIDDATA;
206  }
207  if (enc->codec_id == AV_CODEC_ID_VP6F ||
208  enc->codec_id == AV_CODEC_ID_FLV1 ||
209  enc->codec_id == AV_CODEC_ID_MJPEG) {
210  swf->video_enc = enc;
211  } else {
212  av_log(s, AV_LOG_ERROR, "SWF muxer only supports VP6, FLV1 and MJPEG\n");
213  return -1;
214  }
215  }
216  }
217 
218  if (!swf->video_enc) {
219  /* currently, cannot work correctly if audio only */
220  width = 320;
221  height = 200;
222  rate = 10;
223  rate_base= 1;
224  } else {
225  width = swf->video_enc->width;
226  height = swf->video_enc->height;
227  rate = swf->video_enc->time_base.den;
228  rate_base = swf->video_enc->time_base.num;
229  }
230 
231  if (!swf->audio_enc)
232  swf->samples_per_frame = (44100.0 * rate_base) / rate;
233  else
234  swf->samples_per_frame = (swf->audio_enc->sample_rate * rate_base) / rate;
235 
236  avio_write(pb, "FWS", 3);
237 
238  if (!strcmp("avm2", s->oformat->name))
239  version = 9;
240  else if (swf->video_enc && swf->video_enc->codec_id == AV_CODEC_ID_VP6F)
241  version = 8; /* version 8 and above support VP6 codec */
242  else if (swf->video_enc && swf->video_enc->codec_id == AV_CODEC_ID_FLV1)
243  version = 6; /* version 6 and above support FLV1 codec */
244  else
245  version = 4; /* version 4 for mpeg audio support */
246  avio_w8(pb, version);
247 
248  avio_wl32(pb, DUMMY_FILE_SIZE); /* dummy size
249  (will be patched if not streamed) */
250 
251  put_swf_rect(pb, 0, width * 20, 0, height * 20);
252  avio_wl16(pb, (rate * 256) / rate_base); /* frame rate */
253  swf->duration_pos = avio_tell(pb);
254  avio_wl16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */
255 
256  /* avm2/swf v9 (also v8?) files require a file attribute tag */
257  if (version == 9) {
259  avio_wl32(pb, 1<<3); /* set ActionScript v3/AVM2 flag */
260  put_swf_end_tag(s);
261  }
262 
263  /* define a shape with the jpeg inside */
264  if (swf->video_enc && swf->video_enc->codec_id == AV_CODEC_ID_MJPEG) {
266 
267  avio_wl16(pb, SHAPE_ID); /* ID of shape */
268  /* bounding rectangle */
269  put_swf_rect(pb, 0, width, 0, height);
270  /* style info */
271  avio_w8(pb, 1); /* one fill style */
272  avio_w8(pb, 0x41); /* clipped bitmap fill */
273  avio_wl16(pb, BITMAP_ID); /* bitmap ID */
274  /* position of the bitmap */
275  put_swf_matrix(pb, (int)(1.0 * (1 << FRAC_BITS)), 0,
276  0, (int)(1.0 * (1 << FRAC_BITS)), 0, 0);
277  avio_w8(pb, 0); /* no line style */
278 
279  /* shape drawing */
280  init_put_bits(&p, buf1, sizeof(buf1));
281  put_bits(&p, 4, 1); /* one fill bit */
282  put_bits(&p, 4, 0); /* zero line bit */
283 
284  put_bits(&p, 1, 0); /* not an edge */
286  put_bits(&p, 5, 1); /* nbits */
287  put_bits(&p, 1, 0); /* X */
288  put_bits(&p, 1, 0); /* Y */
289  put_bits(&p, 1, 1); /* set fill style 1 */
290 
291  /* draw the rectangle ! */
292  put_swf_line_edge(&p, width, 0);
293  put_swf_line_edge(&p, 0, height);
294  put_swf_line_edge(&p, -width, 0);
295  put_swf_line_edge(&p, 0, -height);
296 
297  /* end of shape */
298  put_bits(&p, 1, 0); /* not an edge */
299  put_bits(&p, 5, 0);
300 
301  flush_put_bits(&p);
302  avio_write(pb, buf1, put_bits_ptr(&p) - p.buf);
303 
304  put_swf_end_tag(s);
305  }
306 
307  if (swf->audio_enc && swf->audio_enc->codec_id == AV_CODEC_ID_MP3) {
308  int v = 0;
309 
310  /* start sound */
312  switch(swf->audio_enc->sample_rate) {
313  case 11025: v |= 1 << 2; break;
314  case 22050: v |= 2 << 2; break;
315  case 44100: v |= 3 << 2; break;
316  default:
317  /* not supported */
318  av_log(s, AV_LOG_ERROR, "swf does not support that sample rate, choose from (44100, 22050, 11025).\n");
319  return -1;
320  }
321  v |= 0x02; /* 16 bit playback */
322  if (swf->audio_enc->channels == 2)
323  v |= 0x01; /* stereo playback */
324  avio_w8(s->pb, v);
325  v |= 0x20; /* mp3 compressed */
326  avio_w8(s->pb, v);
327  avio_wl16(s->pb, swf->samples_per_frame); /* avg samples per frame */
328  avio_wl16(s->pb, 0);
329 
330  put_swf_end_tag(s);
331  }
332 
333  avio_flush(s->pb);
334  return 0;
335 }
336 
338  AVCodecContext *enc, const uint8_t *buf, int size)
339 {
340  SWFContext *swf = s->priv_data;
341  AVIOContext *pb = s->pb;
342 
343  /* Flash Player limit */
344  if (swf->swf_frame_number == 16000)
345  av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
346 
347  if (enc->codec_id == AV_CODEC_ID_VP6F ||
348  enc->codec_id == AV_CODEC_ID_FLV1) {
349  if (swf->video_frame_number == 0) {
350  /* create a new video object */
352  avio_wl16(pb, VIDEO_ID);
353  swf->vframes_pos = avio_tell(pb);
354  avio_wl16(pb, 15000); /* hard flash player limit */
355  avio_wl16(pb, enc->width);
356  avio_wl16(pb, enc->height);
357  avio_w8(pb, 0);
359  put_swf_end_tag(s);
360 
361  /* place the video object for the first time */
363  avio_w8(pb, 0x36);
364  avio_wl16(pb, 1);
365  avio_wl16(pb, VIDEO_ID);
366  put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
367  avio_wl16(pb, swf->video_frame_number);
368  avio_write(pb, "video", 5);
369  avio_w8(pb, 0x00);
370  put_swf_end_tag(s);
371  } else {
372  /* mark the character for update */
374  avio_w8(pb, 0x11);
375  avio_wl16(pb, 1);
376  avio_wl16(pb, swf->video_frame_number);
377  put_swf_end_tag(s);
378  }
379 
380  /* set video frame data */
382  avio_wl16(pb, VIDEO_ID);
383  avio_wl16(pb, swf->video_frame_number++);
384  avio_write(pb, buf, size);
385  put_swf_end_tag(s);
386  } else if (enc->codec_id == AV_CODEC_ID_MJPEG) {
387  if (swf->swf_frame_number > 0) {
388  /* remove the shape */
390  avio_wl16(pb, SHAPE_ID); /* shape ID */
391  avio_wl16(pb, 1); /* depth */
392  put_swf_end_tag(s);
393 
394  /* free the bitmap */
396  avio_wl16(pb, BITMAP_ID);
397  put_swf_end_tag(s);
398  }
399 
401 
402  avio_wl16(pb, BITMAP_ID); /* ID of the image */
403 
404  /* a dummy jpeg header seems to be required */
405  avio_wb32(pb, 0xffd8ffd9);
406  /* write the jpeg image */
407  avio_write(pb, buf, size);
408 
409  put_swf_end_tag(s);
410 
411  /* draw the shape */
412 
414  avio_wl16(pb, SHAPE_ID); /* shape ID */
415  avio_wl16(pb, 1); /* depth */
416  put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
417  put_swf_end_tag(s);
418  }
419 
420  swf->swf_frame_number++;
421 
422  /* streaming sound always should be placed just before showframe tags */
423  if (swf->audio_enc && av_fifo_size(swf->audio_fifo)) {
424  int frame_size = av_fifo_size(swf->audio_fifo);
426  avio_wl16(pb, swf->sound_samples);
427  avio_wl16(pb, 0); // seek samples
428  av_fifo_generic_read(swf->audio_fifo, pb, frame_size, &avio_write);
429  put_swf_end_tag(s);
430 
431  /* update FIFO */
432  swf->sound_samples = 0;
433  }
434 
435  /* output the frame */
437  put_swf_end_tag(s);
438 
439  return 0;
440 }
441 
443  AVCodecContext *enc, uint8_t *buf, int size)
444 {
445  SWFContext *swf = s->priv_data;
446 
447  /* Flash Player limit */
448  if (swf->swf_frame_number == 16000)
449  av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
450 
451  if (av_fifo_size(swf->audio_fifo) + size > AUDIO_FIFO_SIZE) {
452  av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");
453  return -1;
454  }
455 
456  av_fifo_generic_write(swf->audio_fifo, buf, size, NULL);
457  swf->sound_samples += av_get_audio_frame_duration(enc, size);
458 
459  /* if audio only stream make sure we add swf frames */
460  if (!swf->video_enc)
461  swf_write_video(s, enc, 0, 0);
462 
463  return 0;
464 }
465 
467 {
468  AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
469  if (codec->codec_type == AVMEDIA_TYPE_AUDIO)
470  return swf_write_audio(s, codec, pkt->data, pkt->size);
471  else
472  return swf_write_video(s, codec, pkt->data, pkt->size);
473 }
474 
476 {
477  SWFContext *swf = s->priv_data;
478  AVIOContext *pb = s->pb;
479  AVCodecContext *enc, *video_enc;
480  int file_size, i;
481 
482  video_enc = NULL;
483  for(i=0;i<s->nb_streams;i++) {
484  enc = s->streams[i]->codec;
485  if (enc->codec_type == AVMEDIA_TYPE_VIDEO)
486  video_enc = enc;
487  else
488  av_fifo_free(swf->audio_fifo);
489  }
490 
491  put_swf_tag(s, TAG_END);
492  put_swf_end_tag(s);
493 
494  /* patch file size and number of frames if not streamed */
495  if (s->pb->seekable && video_enc) {
496  file_size = avio_tell(pb);
497  avio_seek(pb, 4, SEEK_SET);
498  avio_wl32(pb, file_size);
499  avio_seek(pb, swf->duration_pos, SEEK_SET);
500  avio_wl16(pb, swf->video_frame_number);
501  avio_seek(pb, swf->vframes_pos, SEEK_SET);
502  avio_wl16(pb, swf->video_frame_number);
503  avio_seek(pb, file_size, SEEK_SET);
504  }
505  return 0;
506 }
507 
508 #if CONFIG_SWF_MUXER
509 AVOutputFormat ff_swf_muxer = {
510  .name = "swf",
511  .long_name = NULL_IF_CONFIG_SMALL("SWF (ShockWave Flash)"),
512  .mime_type = "application/x-shockwave-flash",
513  .extensions = "swf",
514  .priv_data_size = sizeof(SWFContext),
515  .audio_codec = AV_CODEC_ID_MP3,
516  .video_codec = AV_CODEC_ID_FLV1,
521 };
522 #endif
523 #if CONFIG_AVM2_MUXER
524 AVOutputFormat ff_avm2_muxer = {
525  .name = "avm2",
526  .long_name = NULL_IF_CONFIG_SMALL("SWF (ShockWave Flash) (AVM2)"),
527  .mime_type = "application/x-shockwave-flash",
528  .priv_data_size = sizeof(SWFContext),
529  .audio_codec = AV_CODEC_ID_MP3,
530  .video_codec = AV_CODEC_ID_FLV1,
535 };
536 #endif