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4xm.c
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1 /*
2  * 4X Technologies .4xm File Demuxer (no muxer)
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  * 4X Technologies file demuxer
25  * by Mike Melanson (melanson@pcisys.net)
26  * for more information on the .4xm file format, visit:
27  * http://www.pcisys.net/~melanson/codecs/
28  */
29 
30 #include "libavutil/intreadwrite.h"
31 #include "libavutil/intfloat.h"
32 #include "avformat.h"
33 #include "internal.h"
34 
35 #define RIFF_TAG MKTAG('R', 'I', 'F', 'F')
36 #define FOURXMV_TAG MKTAG('4', 'X', 'M', 'V')
37 #define LIST_TAG MKTAG('L', 'I', 'S', 'T')
38 #define HEAD_TAG MKTAG('H', 'E', 'A', 'D')
39 #define TRK__TAG MKTAG('T', 'R', 'K', '_')
40 #define MOVI_TAG MKTAG('M', 'O', 'V', 'I')
41 #define VTRK_TAG MKTAG('V', 'T', 'R', 'K')
42 #define STRK_TAG MKTAG('S', 'T', 'R', 'K')
43 #define std__TAG MKTAG('s', 't', 'd', '_')
44 #define name_TAG MKTAG('n', 'a', 'm', 'e')
45 #define vtrk_TAG MKTAG('v', 't', 'r', 'k')
46 #define strk_TAG MKTAG('s', 't', 'r', 'k')
47 #define ifrm_TAG MKTAG('i', 'f', 'r', 'm')
48 #define pfrm_TAG MKTAG('p', 'f', 'r', 'm')
49 #define cfrm_TAG MKTAG('c', 'f', 'r', 'm')
50 #define ifr2_TAG MKTAG('i', 'f', 'r', '2')
51 #define pfr2_TAG MKTAG('p', 'f', 'r', '2')
52 #define cfr2_TAG MKTAG('c', 'f', 'r', '2')
53 #define snd__TAG MKTAG('s', 'n', 'd', '_')
54 
55 #define vtrk_SIZE 0x44
56 #define strk_SIZE 0x28
57 
58 #define GET_LIST_HEADER() \
59  fourcc_tag = avio_rl32(pb); \
60  size = avio_rl32(pb); \
61  if (fourcc_tag != LIST_TAG) \
62  return AVERROR_INVALIDDATA; \
63  fourcc_tag = avio_rl32(pb);
64 
65 typedef struct AudioTrack {
66  int sample_rate;
67  int bits;
68  int channels;
69  int stream_index;
70  int adpcm;
71  int64_t audio_pts;
72 } AudioTrack;
73 
74 typedef struct FourxmDemuxContext {
75  int video_stream_index;
76  int track_count;
77  AudioTrack *tracks;
78 
79  int64_t video_pts;
80  float fps;
81 } FourxmDemuxContext;
82 
83 static int fourxm_probe(AVProbeData *p)
84 {
85  if ((AV_RL32(&p->buf[0]) != RIFF_TAG) ||
86  (AV_RL32(&p->buf[8]) != FOURXMV_TAG))
87  return 0;
88 
89  return AVPROBE_SCORE_MAX;
90 }
91 
92 static int parse_vtrk(AVFormatContext *s,
93  FourxmDemuxContext *fourxm, uint8_t *buf, int size,
94  int left)
95 {
96  AVStream *st;
97  /* check that there is enough data */
98  if (size != vtrk_SIZE || left < size + 8) {
99  return AVERROR_INVALIDDATA;
100  }
101 
102  /* allocate a new AVStream */
103  st = avformat_new_stream(s, NULL);
104  if (!st)
105  return AVERROR(ENOMEM);
106 
107  avpriv_set_pts_info(st, 60, 1, fourxm->fps);
108 
109  fourxm->video_stream_index = st->index;
110 
111  st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
112  st->codec->codec_id = AV_CODEC_ID_4XM;
113  st->codec->extradata_size = 4;
114  st->codec->extradata = av_malloc(4);
115  AV_WL32(st->codec->extradata, AV_RL32(buf + 16));
116  st->codec->width = AV_RL32(buf + 36);
117  st->codec->height = AV_RL32(buf + 40);
118 
119  return 0;
120 }
121 
122 
123 static int parse_strk(AVFormatContext *s,
124  FourxmDemuxContext *fourxm, uint8_t *buf, int size,
125  int left)
126 {
127  AVStream *st;
128  int track;
129  /* check that there is enough data */
130  if (size != strk_SIZE || left < size + 8)
131  return AVERROR_INVALIDDATA;
132 
133  track = AV_RL32(buf + 8);
134  if ((unsigned)track >= UINT_MAX / sizeof(AudioTrack) - 1) {
135  av_log(s, AV_LOG_ERROR, "current_track too large\n");
136  return AVERROR_INVALIDDATA;
137  }
138 
139  if (track + 1 > fourxm->track_count) {
140  if (av_reallocp_array(&fourxm->tracks, track + 1, sizeof(AudioTrack)))
141  return AVERROR(ENOMEM);
142  memset(&fourxm->tracks[fourxm->track_count], 0,
143  sizeof(AudioTrack) * (track + 1 - fourxm->track_count));
144  fourxm->track_count = track + 1;
145  }
146  fourxm->tracks[track].adpcm = AV_RL32(buf + 12);
147  fourxm->tracks[track].channels = AV_RL32(buf + 36);
148  fourxm->tracks[track].sample_rate = AV_RL32(buf + 40);
149  fourxm->tracks[track].bits = AV_RL32(buf + 44);
150  fourxm->tracks[track].audio_pts = 0;
151 
152  if (fourxm->tracks[track].channels <= 0 ||
153  fourxm->tracks[track].sample_rate <= 0 ||
154  fourxm->tracks[track].bits <= 0) {
155  av_log(s, AV_LOG_ERROR, "audio header invalid\n");
156  return AVERROR_INVALIDDATA;
157  }
158  if (!fourxm->tracks[track].adpcm && fourxm->tracks[track].bits<8) {
159  av_log(s, AV_LOG_ERROR, "bits unspecified for non ADPCM\n");
160  return AVERROR_INVALIDDATA;
161  }
162 
163  /* allocate a new AVStream */
164  st = avformat_new_stream(s, NULL);
165  if (!st)
166  return AVERROR(ENOMEM);
167 
168  st->id = track;
169  avpriv_set_pts_info(st, 60, 1, fourxm->tracks[track].sample_rate);
170 
171  fourxm->tracks[track].stream_index = st->index;
172 
173  st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
174  st->codec->codec_tag = 0;
175  st->codec->channels = fourxm->tracks[track].channels;
176  st->codec->sample_rate = fourxm->tracks[track].sample_rate;
177  st->codec->bits_per_coded_sample = fourxm->tracks[track].bits;
178  st->codec->bit_rate = st->codec->channels *
179  st->codec->sample_rate *
180  st->codec->bits_per_coded_sample;
181  st->codec->block_align = st->codec->channels *
182  st->codec->bits_per_coded_sample;
183 
184  if (fourxm->tracks[track].adpcm){
185  st->codec->codec_id = AV_CODEC_ID_ADPCM_4XM;
186  } else if (st->codec->bits_per_coded_sample == 8) {
187  st->codec->codec_id = AV_CODEC_ID_PCM_U8;
188  } else
189  st->codec->codec_id = AV_CODEC_ID_PCM_S16LE;
190 
191  return 0;
192 }
193 
194 static int fourxm_read_header(AVFormatContext *s)
195 {
196  AVIOContext *pb = s->pb;
197  unsigned int fourcc_tag;
198  unsigned int size;
199  int header_size;
200  FourxmDemuxContext *fourxm = s->priv_data;
201  unsigned char *header;
202  int i, ret;
203 
204  fourxm->track_count = 0;
205  fourxm->tracks = NULL;
206  fourxm->fps = 1.0;
207 
208  /* skip the first 3 32-bit numbers */
209  avio_skip(pb, 12);
210 
211  /* check for LIST-HEAD */
212  GET_LIST_HEADER();
213  header_size = size - 4;
214  if (fourcc_tag != HEAD_TAG || header_size < 0)
215  return AVERROR_INVALIDDATA;
216 
217  /* allocate space for the header and load the whole thing */
218  header = av_malloc(header_size);
219  if (!header)
220  return AVERROR(ENOMEM);
221  if (avio_read(pb, header, header_size) != header_size) {
222  av_free(header);
223  return AVERROR(EIO);
224  }
225 
226  /* take the lazy approach and search for any and all vtrk and strk chunks */
227  for (i = 0; i < header_size - 8; i++) {
228  fourcc_tag = AV_RL32(&header[i]);
229  size = AV_RL32(&header[i + 4]);
230  if (size > header_size - i - 8 && (fourcc_tag == vtrk_TAG || fourcc_tag == strk_TAG)) {
231  av_log(s, AV_LOG_ERROR, "chunk larger than array %d>%d\n", size, header_size - i - 8);
232  return AVERROR_INVALIDDATA;
233  }
234 
235  if (fourcc_tag == std__TAG) {
236  if (header_size - i < 16) {
237  av_log(s, AV_LOG_ERROR, "std TAG truncated\n");
238  ret = AVERROR_INVALIDDATA;
239  goto fail;
240  }
241  fourxm->fps = av_int2float(AV_RL32(&header[i + 12]));
242  } else if (fourcc_tag == vtrk_TAG) {
243  if ((ret = parse_vtrk(s, fourxm, header + i, size,
244  header_size - i)) < 0)
245  goto fail;
246 
247  i += 8 + size;
248  } else if (fourcc_tag == strk_TAG) {
249  if ((ret = parse_strk(s, fourxm, header + i, size,
250  header_size - i)) < 0)
251  goto fail;
252 
253  i += 8 + size;
254  }
255  }
256 
257  /* skip over the LIST-MOVI chunk (which is where the stream should be */
258  GET_LIST_HEADER();
259  if (fourcc_tag != MOVI_TAG) {
260  ret = AVERROR_INVALIDDATA;
261  goto fail;
262  }
263 
264  av_free(header);
265  /* initialize context members */
266  fourxm->video_pts = -1; /* first frame will push to 0 */
267 
268  return 0;
269 fail:
270  av_freep(&fourxm->tracks);
271  av_free(header);
272  return ret;
273 }
274 
275 static int fourxm_read_packet(AVFormatContext *s,
276  AVPacket *pkt)
277 {
278  FourxmDemuxContext *fourxm = s->priv_data;
279  AVIOContext *pb = s->pb;
280  unsigned int fourcc_tag;
281  unsigned int size;
282  int ret = 0;
283  unsigned int track_number;
284  int packet_read = 0;
285  unsigned char header[8];
286  int audio_frame_count;
287 
288  while (!packet_read) {
289  if ((ret = avio_read(s->pb, header, 8)) < 0)
290  return ret;
291  fourcc_tag = AV_RL32(&header[0]);
292  size = AV_RL32(&header[4]);
293  if (url_feof(pb))
294  return AVERROR(EIO);
295  switch (fourcc_tag) {
296  case LIST_TAG:
297  /* this is a good time to bump the video pts */
298  fourxm->video_pts++;
299 
300  /* skip the LIST-* tag and move on to the next fourcc */
301  avio_rl32(pb);
302  break;
303 
304  case ifrm_TAG:
305  case pfrm_TAG:
306  case cfrm_TAG:
307  case ifr2_TAG:
308  case pfr2_TAG:
309  case cfr2_TAG:
310  /* allocate 8 more bytes than 'size' to account for fourcc
311  * and size */
312  if (size + 8 < size || av_new_packet(pkt, size + 8))
313  return AVERROR(EIO);
314  pkt->stream_index = fourxm->video_stream_index;
315  pkt->pts = fourxm->video_pts;
316  pkt->pos = avio_tell(s->pb);
317  memcpy(pkt->data, header, 8);
318  ret = avio_read(s->pb, &pkt->data[8], size);
319 
320  if (ret < 0) {
321  av_free_packet(pkt);
322  } else {
323  packet_read = 1;
324  av_shrink_packet(pkt, ret + 8);
325  }
326  break;
327 
328  case snd__TAG:
329  track_number = avio_rl32(pb);
330  avio_skip(pb, 4);
331  size -= 8;
332 
333  if (track_number < fourxm->track_count &&
334  fourxm->tracks[track_number].channels > 0) {
335  ret = av_get_packet(s->pb, pkt, size);
336  if (ret < 0)
337  return AVERROR(EIO);
338  pkt->stream_index =
339  fourxm->tracks[track_number].stream_index;
340  pkt->pts = fourxm->tracks[track_number].audio_pts;
341  packet_read = 1;
342 
343  /* pts accounting */
344  audio_frame_count = size;
345  if (fourxm->tracks[track_number].adpcm)
346  audio_frame_count -= 2 * (fourxm->tracks[track_number].channels);
347  audio_frame_count /= fourxm->tracks[track_number].channels;
348  if (fourxm->tracks[track_number].adpcm) {
349  audio_frame_count *= 2;
350  } else
351  audio_frame_count /=
352  (fourxm->tracks[track_number].bits / 8);
353  fourxm->tracks[track_number].audio_pts += audio_frame_count;
354  } else {
355  avio_skip(pb, size);
356  }
357  break;
358 
359  default:
360  avio_skip(pb, size);
361  break;
362  }
363  }
364  return ret;
365 }
366 
367 static int fourxm_read_close(AVFormatContext *s)
368 {
369  FourxmDemuxContext *fourxm = s->priv_data;
370 
371  av_freep(&fourxm->tracks);
372 
373  return 0;
374 }
375 
376 AVInputFormat ff_fourxm_demuxer = {
377  .name = "4xm",
378  .long_name = NULL_IF_CONFIG_SMALL("4X Technologies"),
379  .priv_data_size = sizeof(FourxmDemuxContext),
380  .read_probe = fourxm_probe,
381  .read_header = fourxm_read_header,
382  .read_packet = fourxm_read_packet,
383  .read_close = fourxm_read_close,
384 };
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