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ipmovie.c
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1 /*
2  * Interplay MVE File Demuxer
3  * Copyright (c) 2003 The FFmpeg Project
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * Interplay MVE file demuxer
25  * by Mike Melanson (melanson@pcisys.net)
26  * For more information regarding the Interplay MVE file format, visit:
27  * http://www.pcisys.net/~melanson/codecs/
28  * The aforementioned site also contains a command line utility for parsing
29  * IP MVE files so that you can get a good idea of the typical structure of
30  * such files. This demuxer is not the best example to use if you are trying
31  * to write your own as it uses a rather roundabout approach for splitting
32  * up and sending out the chunks.
33  */
34 
35 #include "libavutil/channel_layout.h"
36 #include "libavutil/intreadwrite.h"
37 #include "avformat.h"
38 #include "internal.h"
39 
40 #define CHUNK_PREAMBLE_SIZE 4
41 #define OPCODE_PREAMBLE_SIZE 4
42 
43 #define CHUNK_INIT_AUDIO 0x0000
44 #define CHUNK_AUDIO_ONLY 0x0001
45 #define CHUNK_INIT_VIDEO 0x0002
46 #define CHUNK_VIDEO 0x0003
47 #define CHUNK_SHUTDOWN 0x0004
48 #define CHUNK_END 0x0005
49 /* these last types are used internally */
50 #define CHUNK_DONE 0xFFFC
51 #define CHUNK_NOMEM 0xFFFD
52 #define CHUNK_EOF 0xFFFE
53 #define CHUNK_BAD 0xFFFF
54 
55 #define OPCODE_END_OF_STREAM 0x00
56 #define OPCODE_END_OF_CHUNK 0x01
57 #define OPCODE_CREATE_TIMER 0x02
58 #define OPCODE_INIT_AUDIO_BUFFERS 0x03
59 #define OPCODE_START_STOP_AUDIO 0x04
60 #define OPCODE_INIT_VIDEO_BUFFERS 0x05
61 #define OPCODE_UNKNOWN_06 0x06
62 #define OPCODE_SEND_BUFFER 0x07
63 #define OPCODE_AUDIO_FRAME 0x08
64 #define OPCODE_SILENCE_FRAME 0x09
65 #define OPCODE_INIT_VIDEO_MODE 0x0A
66 #define OPCODE_CREATE_GRADIENT 0x0B
67 #define OPCODE_SET_PALETTE 0x0C
68 #define OPCODE_SET_PALETTE_COMPRESSED 0x0D
69 #define OPCODE_UNKNOWN_0E 0x0E
70 #define OPCODE_SET_DECODING_MAP 0x0F
71 #define OPCODE_UNKNOWN_10 0x10
72 #define OPCODE_VIDEO_DATA 0x11
73 #define OPCODE_UNKNOWN_12 0x12
74 #define OPCODE_UNKNOWN_13 0x13
75 #define OPCODE_UNKNOWN_14 0x14
76 #define OPCODE_UNKNOWN_15 0x15
77 
78 #define PALETTE_COUNT 256
79 
80 typedef struct IPMVEContext {
81 
82  unsigned char *buf;
83  int buf_size;
84 
85  uint64_t frame_pts_inc;
86 
87  unsigned int video_bpp;
88  unsigned int video_width;
89  unsigned int video_height;
90  int64_t video_pts;
91  uint32_t palette[256];
92  int has_palette;
93  int changed;
94 
95  unsigned int audio_bits;
96  unsigned int audio_channels;
97  unsigned int audio_sample_rate;
98  enum AVCodecID audio_type;
99  unsigned int audio_frame_count;
100 
101  int video_stream_index;
102  int audio_stream_index;
103 
104  int64_t audio_chunk_offset;
105  int audio_chunk_size;
106  int64_t video_chunk_offset;
107  int video_chunk_size;
108  int64_t decode_map_chunk_offset;
109  int decode_map_chunk_size;
110 
111  int64_t next_chunk_offset;
112 
113 } IPMVEContext;
114 
115 static int load_ipmovie_packet(IPMVEContext *s, AVIOContext *pb,
116  AVPacket *pkt) {
117 
118  int chunk_type;
119 
120  if (s->audio_chunk_offset && s->audio_channels && s->audio_bits) {
121  if (s->audio_type == AV_CODEC_ID_NONE) {
122  av_log(NULL, AV_LOG_ERROR, "Can not read audio packet before"
123  "audio codec is known\n");
124  return CHUNK_BAD;
125  }
126 
127  /* adjust for PCM audio by skipping chunk header */
128  if (s->audio_type != AV_CODEC_ID_INTERPLAY_DPCM) {
129  s->audio_chunk_offset += 6;
130  s->audio_chunk_size -= 6;
131  }
132 
133  avio_seek(pb, s->audio_chunk_offset, SEEK_SET);
134  s->audio_chunk_offset = 0;
135 
136  if (s->audio_chunk_size != av_get_packet(pb, pkt, s->audio_chunk_size))
137  return CHUNK_EOF;
138 
139  pkt->stream_index = s->audio_stream_index;
140  pkt->pts = s->audio_frame_count;
141 
142  /* audio frame maintenance */
143  if (s->audio_type != AV_CODEC_ID_INTERPLAY_DPCM)
144  s->audio_frame_count +=
145  (s->audio_chunk_size / s->audio_channels / (s->audio_bits / 8));
146  else
147  s->audio_frame_count +=
148  (s->audio_chunk_size - 6 - s->audio_channels) / s->audio_channels;
149 
150  av_dlog(NULL, "sending audio frame with pts %"PRId64" (%d audio frames)\n",
151  pkt->pts, s->audio_frame_count);
152 
153  chunk_type = CHUNK_VIDEO;
154 
155  } else if (s->decode_map_chunk_offset) {
156 
157  /* send both the decode map and the video data together */
158 
159  if (av_new_packet(pkt, s->decode_map_chunk_size + s->video_chunk_size))
160  return CHUNK_NOMEM;
161 
162  if (s->has_palette) {
163  uint8_t *pal;
164 
165  pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE,
166  AVPALETTE_SIZE);
167  if (pal) {
168  memcpy(pal, s->palette, AVPALETTE_SIZE);
169  s->has_palette = 0;
170  }
171  }
172 
173  if (s->changed) {
174  ff_add_param_change(pkt, 0, 0, 0, s->video_width, s->video_height);
175  s->changed = 0;
176  }
177  pkt->pos= s->decode_map_chunk_offset;
178  avio_seek(pb, s->decode_map_chunk_offset, SEEK_SET);
179  s->decode_map_chunk_offset = 0;
180 
181  if (avio_read(pb, pkt->data, s->decode_map_chunk_size) !=
182  s->decode_map_chunk_size) {
183  av_free_packet(pkt);
184  return CHUNK_EOF;
185  }
186 
187  avio_seek(pb, s->video_chunk_offset, SEEK_SET);
188  s->video_chunk_offset = 0;
189 
190  if (avio_read(pb, pkt->data + s->decode_map_chunk_size,
191  s->video_chunk_size) != s->video_chunk_size) {
192  av_free_packet(pkt);
193  return CHUNK_EOF;
194  }
195 
196  pkt->stream_index = s->video_stream_index;
197  pkt->pts = s->video_pts;
198 
199  av_dlog(NULL, "sending video frame with pts %"PRId64"\n", pkt->pts);
200 
201  s->video_pts += s->frame_pts_inc;
202 
203  chunk_type = CHUNK_VIDEO;
204 
205  } else {
206 
207  avio_seek(pb, s->next_chunk_offset, SEEK_SET);
208  chunk_type = CHUNK_DONE;
209 
210  }
211 
212  return chunk_type;
213 }
214 
215 /* This function loads and processes a single chunk in an IP movie file.
216  * It returns the type of chunk that was processed. */
217 static int process_ipmovie_chunk(IPMVEContext *s, AVIOContext *pb,
218  AVPacket *pkt)
219 {
220  unsigned char chunk_preamble[CHUNK_PREAMBLE_SIZE];
221  int chunk_type;
222  int chunk_size;
223  unsigned char opcode_preamble[OPCODE_PREAMBLE_SIZE];
224  unsigned char opcode_type;
225  unsigned char opcode_version;
226  int opcode_size;
227  unsigned char scratch[1024];
228  int i, j;
229  int first_color, last_color;
230  int audio_flags;
231  unsigned char r, g, b;
232  unsigned int width, height;
233 
234  /* see if there are any pending packets */
235  chunk_type = load_ipmovie_packet(s, pb, pkt);
236  if (chunk_type != CHUNK_DONE)
237  return chunk_type;
238 
239  /* read the next chunk, wherever the file happens to be pointing */
240  if (avio_feof(pb))
241  return CHUNK_EOF;
242  if (avio_read(pb, chunk_preamble, CHUNK_PREAMBLE_SIZE) !=
243  CHUNK_PREAMBLE_SIZE)
244  return CHUNK_BAD;
245  chunk_size = AV_RL16(&chunk_preamble[0]);
246  chunk_type = AV_RL16(&chunk_preamble[2]);
247 
248  av_dlog(NULL, "chunk type 0x%04X, 0x%04X bytes: ", chunk_type, chunk_size);
249 
250  switch (chunk_type) {
251 
252  case CHUNK_INIT_AUDIO:
253  av_dlog(NULL, "initialize audio\n");
254  break;
255 
256  case CHUNK_AUDIO_ONLY:
257  av_dlog(NULL, "audio only\n");
258  break;
259 
260  case CHUNK_INIT_VIDEO:
261  av_dlog(NULL, "initialize video\n");
262  break;
263 
264  case CHUNK_VIDEO:
265  av_dlog(NULL, "video (and audio)\n");
266  break;
267 
268  case CHUNK_SHUTDOWN:
269  av_dlog(NULL, "shutdown\n");
270  break;
271 
272  case CHUNK_END:
273  av_dlog(NULL, "end\n");
274  break;
275 
276  default:
277  av_dlog(NULL, "invalid chunk\n");
278  chunk_type = CHUNK_BAD;
279  break;
280 
281  }
282 
283  while ((chunk_size > 0) && (chunk_type != CHUNK_BAD)) {
284 
285  /* read the next chunk, wherever the file happens to be pointing */
286  if (avio_feof(pb)) {
287  chunk_type = CHUNK_EOF;
288  break;
289  }
290  if (avio_read(pb, opcode_preamble, CHUNK_PREAMBLE_SIZE) !=
291  CHUNK_PREAMBLE_SIZE) {
292  chunk_type = CHUNK_BAD;
293  break;
294  }
295 
296  opcode_size = AV_RL16(&opcode_preamble[0]);
297  opcode_type = opcode_preamble[2];
298  opcode_version = opcode_preamble[3];
299 
300  chunk_size -= OPCODE_PREAMBLE_SIZE;
301  chunk_size -= opcode_size;
302  if (chunk_size < 0) {
303  av_dlog(NULL, "chunk_size countdown just went negative\n");
304  chunk_type = CHUNK_BAD;
305  break;
306  }
307 
308  av_dlog(NULL, " opcode type %02X, version %d, 0x%04X bytes: ",
309  opcode_type, opcode_version, opcode_size);
310  switch (opcode_type) {
311 
312  case OPCODE_END_OF_STREAM:
313  av_dlog(NULL, "end of stream\n");
314  avio_skip(pb, opcode_size);
315  break;
316 
317  case OPCODE_END_OF_CHUNK:
318  av_dlog(NULL, "end of chunk\n");
319  avio_skip(pb, opcode_size);
320  break;
321 
322  case OPCODE_CREATE_TIMER:
323  av_dlog(NULL, "create timer\n");
324  if ((opcode_version > 0) || (opcode_size != 6)) {
325  av_dlog(NULL, "bad create_timer opcode\n");
326  chunk_type = CHUNK_BAD;
327  break;
328  }
329  if (avio_read(pb, scratch, opcode_size) !=
330  opcode_size) {
331  chunk_type = CHUNK_BAD;
332  break;
333  }
334  s->frame_pts_inc = ((uint64_t)AV_RL32(&scratch[0])) * AV_RL16(&scratch[4]);
335  av_dlog(NULL, " %.2f frames/second (timer div = %d, subdiv = %d)\n",
336  1000000.0 / s->frame_pts_inc, AV_RL32(&scratch[0]),
337  AV_RL16(&scratch[4]));
338  break;
339 
340  case OPCODE_INIT_AUDIO_BUFFERS:
341  av_dlog(NULL, "initialize audio buffers\n");
342  if (opcode_version > 1 || opcode_size > 10 || opcode_size < 6) {
343  av_dlog(NULL, "bad init_audio_buffers opcode\n");
344  chunk_type = CHUNK_BAD;
345  break;
346  }
347  if (avio_read(pb, scratch, opcode_size) !=
348  opcode_size) {
349  chunk_type = CHUNK_BAD;
350  break;
351  }
352  s->audio_sample_rate = AV_RL16(&scratch[4]);
353  audio_flags = AV_RL16(&scratch[2]);
354  /* bit 0 of the flags: 0 = mono, 1 = stereo */
355  s->audio_channels = (audio_flags & 1) + 1;
356  /* bit 1 of the flags: 0 = 8 bit, 1 = 16 bit */
357  s->audio_bits = (((audio_flags >> 1) & 1) + 1) * 8;
358  /* bit 2 indicates compressed audio in version 1 opcode */
359  if ((opcode_version == 1) && (audio_flags & 0x4))
360  s->audio_type = AV_CODEC_ID_INTERPLAY_DPCM;
361  else if (s->audio_bits == 16)
362  s->audio_type = AV_CODEC_ID_PCM_S16LE;
363  else
364  s->audio_type = AV_CODEC_ID_PCM_U8;
365  av_dlog(NULL, "audio: %d bits, %d Hz, %s, %s format\n",
366  s->audio_bits, s->audio_sample_rate,
367  (s->audio_channels == 2) ? "stereo" : "mono",
368  (s->audio_type == AV_CODEC_ID_INTERPLAY_DPCM) ?
369  "Interplay audio" : "PCM");
370  break;
371 
372  case OPCODE_START_STOP_AUDIO:
373  av_dlog(NULL, "start/stop audio\n");
374  avio_skip(pb, opcode_size);
375  break;
376 
377  case OPCODE_INIT_VIDEO_BUFFERS:
378  av_dlog(NULL, "initialize video buffers\n");
379  if ((opcode_version > 2) || (opcode_size > 8) || opcode_size < 4
380  || opcode_version == 2 && opcode_size < 8
381  ) {
382  av_dlog(NULL, "bad init_video_buffers opcode\n");
383  chunk_type = CHUNK_BAD;
384  break;
385  }
386  if (avio_read(pb, scratch, opcode_size) !=
387  opcode_size) {
388  chunk_type = CHUNK_BAD;
389  break;
390  }
391  width = AV_RL16(&scratch[0]) * 8;
392  height = AV_RL16(&scratch[2]) * 8;
393  if (width != s->video_width) {
394  s->video_width = width;
395  s->changed++;
396  }
397  if (height != s->video_height) {
398  s->video_height = height;
399  s->changed++;
400  }
401  if (opcode_version < 2 || !AV_RL16(&scratch[6])) {
402  s->video_bpp = 8;
403  } else {
404  s->video_bpp = 16;
405  }
406  av_dlog(NULL, "video resolution: %d x %d\n",
407  s->video_width, s->video_height);
408  break;
409 
410  case OPCODE_UNKNOWN_06:
411  case OPCODE_UNKNOWN_0E:
412  case OPCODE_UNKNOWN_10:
413  case OPCODE_UNKNOWN_12:
414  case OPCODE_UNKNOWN_13:
415  case OPCODE_UNKNOWN_14:
416  case OPCODE_UNKNOWN_15:
417  av_dlog(NULL, "unknown (but documented) opcode %02X\n", opcode_type);
418  avio_skip(pb, opcode_size);
419  break;
420 
421  case OPCODE_SEND_BUFFER:
422  av_dlog(NULL, "send buffer\n");
423  avio_skip(pb, opcode_size);
424  break;
425 
426  case OPCODE_AUDIO_FRAME:
427  av_dlog(NULL, "audio frame\n");
428 
429  /* log position and move on for now */
430  s->audio_chunk_offset = avio_tell(pb);
431  s->audio_chunk_size = opcode_size;
432  avio_skip(pb, opcode_size);
433  break;
434 
435  case OPCODE_SILENCE_FRAME:
436  av_dlog(NULL, "silence frame\n");
437  avio_skip(pb, opcode_size);
438  break;
439 
440  case OPCODE_INIT_VIDEO_MODE:
441  av_dlog(NULL, "initialize video mode\n");
442  avio_skip(pb, opcode_size);
443  break;
444 
445  case OPCODE_CREATE_GRADIENT:
446  av_dlog(NULL, "create gradient\n");
447  avio_skip(pb, opcode_size);
448  break;
449 
450  case OPCODE_SET_PALETTE:
451  av_dlog(NULL, "set palette\n");
452  /* check for the logical maximum palette size
453  * (3 * 256 + 4 bytes) */
454  if (opcode_size > 0x304 || opcode_size < 4) {
455  av_dlog(NULL, "demux_ipmovie: set_palette opcode with invalid size\n");
456  chunk_type = CHUNK_BAD;
457  break;
458  }
459  if (avio_read(pb, scratch, opcode_size) != opcode_size) {
460  chunk_type = CHUNK_BAD;
461  break;
462  }
463 
464  /* load the palette into internal data structure */
465  first_color = AV_RL16(&scratch[0]);
466  last_color = first_color + AV_RL16(&scratch[2]) - 1;
467  /* sanity check (since they are 16 bit values) */
468  if ( (first_color > 0xFF) || (last_color > 0xFF)
469  || (last_color - first_color + 1)*3 + 4 > opcode_size) {
470  av_dlog(NULL, "demux_ipmovie: set_palette indexes out of range (%d -> %d)\n",
471  first_color, last_color);
472  chunk_type = CHUNK_BAD;
473  break;
474  }
475  j = 4; /* offset of first palette data */
476  for (i = first_color; i <= last_color; i++) {
477  /* the palette is stored as a 6-bit VGA palette, thus each
478  * component is shifted up to a 8-bit range */
479  r = scratch[j++] * 4;
480  g = scratch[j++] * 4;
481  b = scratch[j++] * 4;
482  s->palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | (b);
483  s->palette[i] |= s->palette[i] >> 6 & 0x30303;
484  }
485  s->has_palette = 1;
486  break;
487 
488  case OPCODE_SET_PALETTE_COMPRESSED:
489  av_dlog(NULL, "set palette compressed\n");
490  avio_skip(pb, opcode_size);
491  break;
492 
493  case OPCODE_SET_DECODING_MAP:
494  av_dlog(NULL, "set decoding map\n");
495 
496  /* log position and move on for now */
497  s->decode_map_chunk_offset = avio_tell(pb);
498  s->decode_map_chunk_size = opcode_size;
499  avio_skip(pb, opcode_size);
500  break;
501 
502  case OPCODE_VIDEO_DATA:
503  av_dlog(NULL, "set video data\n");
504 
505  /* log position and move on for now */
506  s->video_chunk_offset = avio_tell(pb);
507  s->video_chunk_size = opcode_size;
508  avio_skip(pb, opcode_size);
509  break;
510 
511  default:
512  av_dlog(NULL, "*** unknown opcode type\n");
513  chunk_type = CHUNK_BAD;
514  break;
515 
516  }
517  }
518 
519  /* make a note of where the stream is sitting */
520  s->next_chunk_offset = avio_tell(pb);
521 
522  /* dispatch the first of any pending packets */
523  if ((chunk_type == CHUNK_VIDEO) || (chunk_type == CHUNK_AUDIO_ONLY))
524  chunk_type = load_ipmovie_packet(s, pb, pkt);
525 
526  return chunk_type;
527 }
528 
529 static const char signature[] = "Interplay MVE File\x1A\0\x1A";
530 
531 static int ipmovie_probe(AVProbeData *p)
532 {
533  const uint8_t *b = p->buf;
534  const uint8_t *b_end = p->buf + p->buf_size - sizeof(signature);
535  do {
536  if (b[0] == signature[0] && memcmp(b, signature, sizeof(signature)) == 0)
537  return AVPROBE_SCORE_MAX;
538  b++;
539  } while (b < b_end);
540 
541  return 0;
542 }
543 
544 static int ipmovie_read_header(AVFormatContext *s)
545 {
546  IPMVEContext *ipmovie = s->priv_data;
547  AVIOContext *pb = s->pb;
548  AVPacket pkt;
549  AVStream *st;
550  unsigned char chunk_preamble[CHUNK_PREAMBLE_SIZE];
551  int chunk_type, i;
552  uint8_t signature_buffer[sizeof(signature)];
553 
554  avio_read(pb, signature_buffer, sizeof(signature_buffer));
555  while (memcmp(signature_buffer, signature, sizeof(signature))) {
556  memmove(signature_buffer, signature_buffer + 1, sizeof(signature_buffer) - 1);
557  signature_buffer[sizeof(signature_buffer) - 1] = avio_r8(pb);
558  if (avio_feof(pb))
559  return AVERROR_EOF;
560  }
561  /* initialize private context members */
562  ipmovie->video_pts = ipmovie->audio_frame_count = 0;
563  ipmovie->audio_chunk_offset = ipmovie->video_chunk_offset =
564  ipmovie->decode_map_chunk_offset = 0;
565 
566  /* on the first read, this will position the stream at the first chunk */
567  ipmovie->next_chunk_offset = avio_tell(pb) + 4;
568 
569  for (i = 0; i < 256; i++)
570  ipmovie->palette[i] = 0xFFU << 24;
571 
572  /* process the first chunk which should be CHUNK_INIT_VIDEO */
573  if (process_ipmovie_chunk(ipmovie, pb, &pkt) != CHUNK_INIT_VIDEO)
574  return AVERROR_INVALIDDATA;
575 
576  /* peek ahead to the next chunk-- if it is an init audio chunk, process
577  * it; if it is the first video chunk, this is a silent file */
578  if (avio_read(pb, chunk_preamble, CHUNK_PREAMBLE_SIZE) !=
579  CHUNK_PREAMBLE_SIZE)
580  return AVERROR(EIO);
581  chunk_type = AV_RL16(&chunk_preamble[2]);
582  avio_seek(pb, -CHUNK_PREAMBLE_SIZE, SEEK_CUR);
583 
584  if (chunk_type == CHUNK_VIDEO)
585  ipmovie->audio_type = AV_CODEC_ID_NONE; /* no audio */
586  else if (process_ipmovie_chunk(ipmovie, pb, &pkt) != CHUNK_INIT_AUDIO)
587  return AVERROR_INVALIDDATA;
588 
589  /* initialize the stream decoders */
590  st = avformat_new_stream(s, NULL);
591  if (!st)
592  return AVERROR(ENOMEM);
593  avpriv_set_pts_info(st, 63, 1, 1000000);
594  ipmovie->video_stream_index = st->index;
595  st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
596  st->codec->codec_id = AV_CODEC_ID_INTERPLAY_VIDEO;
597  st->codec->codec_tag = 0; /* no fourcc */
598  st->codec->width = ipmovie->video_width;
599  st->codec->height = ipmovie->video_height;
600  st->codec->bits_per_coded_sample = ipmovie->video_bpp;
601 
602  if (ipmovie->audio_type) {
603  st = avformat_new_stream(s, NULL);
604  if (!st)
605  return AVERROR(ENOMEM);
606  avpriv_set_pts_info(st, 32, 1, ipmovie->audio_sample_rate);
607  ipmovie->audio_stream_index = st->index;
608  st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
609  st->codec->codec_id = ipmovie->audio_type;
610  st->codec->codec_tag = 0; /* no tag */
611  st->codec->channels = ipmovie->audio_channels;
612  st->codec->channel_layout = st->codec->channels == 1 ? AV_CH_LAYOUT_MONO :
613  AV_CH_LAYOUT_STEREO;
614  st->codec->sample_rate = ipmovie->audio_sample_rate;
615  st->codec->bits_per_coded_sample = ipmovie->audio_bits;
616  st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
617  st->codec->bits_per_coded_sample;
618  if (st->codec->codec_id == AV_CODEC_ID_INTERPLAY_DPCM)
619  st->codec->bit_rate /= 2;
620  st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample;
621  }
622 
623  return 0;
624 }
625 
626 static int ipmovie_read_packet(AVFormatContext *s,
627  AVPacket *pkt)
628 {
629  IPMVEContext *ipmovie = s->priv_data;
630  AVIOContext *pb = s->pb;
631  int ret;
632 
633  for (;;) {
634  ret = process_ipmovie_chunk(ipmovie, pb, pkt);
635  if (ret == CHUNK_BAD)
636  ret = AVERROR_INVALIDDATA;
637  else if (ret == CHUNK_EOF)
638  ret = AVERROR(EIO);
639  else if (ret == CHUNK_NOMEM)
640  ret = AVERROR(ENOMEM);
641  else if (ret == CHUNK_VIDEO)
642  ret = 0;
643  else if (ret == CHUNK_INIT_VIDEO || ret == CHUNK_INIT_AUDIO)
644  continue;
645  else
646  ret = -1;
647 
648  return ret;
649  }
650 }
651 
652 AVInputFormat ff_ipmovie_demuxer = {
653  .name = "ipmovie",
654  .long_name = NULL_IF_CONFIG_SMALL("Interplay MVE"),
655  .priv_data_size = sizeof(IPMVEContext),
656  .read_probe = ipmovie_probe,
657  .read_header = ipmovie_read_header,
658  .read_packet = ipmovie_read_packet,
659 };
Generated on Sun Mar 8 2015 02:35:09 for FFmpeg by   doxygen 1.8.2