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idcin.c
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1 /*
2  * id Quake II CIN 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  * id Quake II CIN file demuxer by Mike Melanson (melanson@pcisys.net)
25  * For more information about the id CIN format, visit:
26  * http://www.csse.monash.edu.au/~timf/
27  *
28  * CIN is a somewhat quirky and ill-defined format. Here are some notes
29  * for anyone trying to understand the technical details of this format:
30  *
31  * The format has no definite file signature. This is problematic for a
32  * general-purpose media player that wants to automatically detect file
33  * types. However, a CIN file does start with 5 32-bit numbers that
34  * specify audio and video parameters. This demuxer gets around the lack
35  * of file signature by performing sanity checks on those parameters.
36  * Probabalistically, this is a reasonable solution since the number of
37  * valid combinations of the 5 parameters is a very small subset of the
38  * total 160-bit number space.
39  *
40  * Refer to the function idcin_probe() for the precise A/V parameters
41  * that this demuxer allows.
42  *
43  * Next, each audio and video frame has a duration of 1/14 sec. If the
44  * audio sample rate is a multiple of the common frequency 22050 Hz it will
45  * divide evenly by 14. However, if the sample rate is 11025 Hz:
46  * 11025 (samples/sec) / 14 (frames/sec) = 787.5 (samples/frame)
47  * The way the CIN stores audio in this case is by storing 787 sample
48  * frames in the first audio frame and 788 sample frames in the second
49  * audio frame. Therefore, the total number of bytes in an audio frame
50  * is given as:
51  * audio frame #0: 787 * (bytes/sample) * (# channels) bytes in frame
52  * audio frame #1: 788 * (bytes/sample) * (# channels) bytes in frame
53  * audio frame #2: 787 * (bytes/sample) * (# channels) bytes in frame
54  * audio frame #3: 788 * (bytes/sample) * (# channels) bytes in frame
55  *
56  * Finally, not all id CIN creation tools agree on the resolution of the
57  * color palette, apparently. Some creation tools specify red, green, and
58  * blue palette components in terms of 6-bit VGA color DAC values which
59  * range from 0..63. Other tools specify the RGB components as full 8-bit
60  * values that range from 0..255. Since there are no markers in the file to
61  * differentiate between the two variants, this demuxer uses the following
62  * heuristic:
63  * - load the 768 palette bytes from disk
64  * - assume that they will need to be shifted left by 2 bits to
65  * transform them from 6-bit values to 8-bit values
66  * - scan through all 768 palette bytes
67  * - if any bytes exceed 63, do not shift the bytes at all before
68  * transmitting them to the video decoder
69  */
70 
72 #include "libavutil/imgutils.h"
73 #include "libavutil/intreadwrite.h"
74 #include "avformat.h"
75 #include "internal.h"
76 
77 #define HUFFMAN_TABLE_SIZE (64 * 1024)
78 #define IDCIN_FPS 14
79 
80 typedef struct IdcinDemuxContext {
86 
87  /* demux state variables */
91  int64_t first_pkt_pos;
93 
94 static int idcin_probe(AVProbeData *p)
95 {
96  unsigned int number, sample_rate;
97 
98  /*
99  * This is what you could call a "probabilistic" file check: id CIN
100  * files don't have a definite file signature. In lieu of such a marker,
101  * perform sanity checks on the 5 32-bit header fields:
102  * width, height: greater than 0, less than or equal to 1024
103  * audio sample rate: greater than or equal to 8000, less than or
104  * equal to 48000, or 0 for no audio
105  * audio sample width (bytes/sample): 0 for no audio, or 1 or 2
106  * audio channels: 0 for no audio, or 1 or 2
107  */
108 
109  /* check we have enough data to do all checks, otherwise the
110  0-padding may cause a wrong recognition */
111  if (p->buf_size < 20)
112  return 0;
113 
114  /* check the video width */
115  number = AV_RL32(&p->buf[0]);
116  if ((number == 0) || (number > 1024))
117  return 0;
118 
119  /* check the video height */
120  number = AV_RL32(&p->buf[4]);
121  if ((number == 0) || (number > 1024))
122  return 0;
123 
124  /* check the audio sample rate */
125  sample_rate = AV_RL32(&p->buf[8]);
126  if (sample_rate && (sample_rate < 8000 || sample_rate > 48000))
127  return 0;
128 
129  /* check the audio bytes/sample */
130  number = AV_RL32(&p->buf[12]);
131  if (number > 2 || sample_rate && !number)
132  return 0;
133 
134  /* check the audio channels */
135  number = AV_RL32(&p->buf[16]);
136  if (number > 2 || sample_rate && !number)
137  return 0;
138 
139  /* return half certainty since this check is a bit sketchy */
141 }
142 
144 {
145  AVIOContext *pb = s->pb;
146  IdcinDemuxContext *idcin = s->priv_data;
147  AVStream *st;
148  unsigned int width, height;
149  unsigned int sample_rate, bytes_per_sample, channels;
150  int ret;
151 
152  /* get the 5 header parameters */
153  width = avio_rl32(pb);
154  height = avio_rl32(pb);
155  sample_rate = avio_rl32(pb);
156  bytes_per_sample = avio_rl32(pb);
157  channels = avio_rl32(pb);
158 
159  if (s->pb->eof_reached) {
160  av_log(s, AV_LOG_ERROR, "incomplete header\n");
161  return s->pb->error ? s->pb->error : AVERROR_EOF;
162  }
163 
164  if (av_image_check_size(width, height, 0, s) < 0)
165  return AVERROR_INVALIDDATA;
166  if (sample_rate > 0) {
167  if (sample_rate < 14 || sample_rate > INT_MAX) {
168  av_log(s, AV_LOG_ERROR, "invalid sample rate: %u\n", sample_rate);
169  return AVERROR_INVALIDDATA;
170  }
171  if (bytes_per_sample < 1 || bytes_per_sample > 2) {
172  av_log(s, AV_LOG_ERROR, "invalid bytes per sample: %u\n",
173  bytes_per_sample);
174  return AVERROR_INVALIDDATA;
175  }
176  if (channels < 1 || channels > 2) {
177  av_log(s, AV_LOG_ERROR, "invalid channels: %u\n", channels);
178  return AVERROR_INVALIDDATA;
179  }
180  idcin->audio_present = 1;
181  } else {
182  /* if sample rate is 0, assume no audio */
183  idcin->audio_present = 0;
184  }
185 
186  st = avformat_new_stream(s, NULL);
187  if (!st)
188  return AVERROR(ENOMEM);
189  avpriv_set_pts_info(st, 33, 1, IDCIN_FPS);
190  st->start_time = 0;
191  idcin->video_stream_index = st->index;
194  st->codec->codec_tag = 0; /* no fourcc */
195  st->codec->width = width;
196  st->codec->height = height;
197 
198  /* load up the Huffman tables into extradata */
200  return AVERROR(ENOMEM);
201  ret = avio_read(pb, st->codec->extradata, HUFFMAN_TABLE_SIZE);
202  if (ret < 0) {
203  return ret;
204  } else if (ret != HUFFMAN_TABLE_SIZE) {
205  av_log(s, AV_LOG_ERROR, "incomplete header\n");
206  return AVERROR(EIO);
207  }
208 
209  if (idcin->audio_present) {
210  idcin->audio_present = 1;
211  st = avformat_new_stream(s, NULL);
212  if (!st)
213  return AVERROR(ENOMEM);
214  avpriv_set_pts_info(st, 63, 1, sample_rate);
215  st->start_time = 0;
216  idcin->audio_stream_index = st->index;
218  st->codec->codec_tag = 1;
219  st->codec->channels = channels;
220  st->codec->channel_layout = channels > 1 ? AV_CH_LAYOUT_STEREO :
223  st->codec->bits_per_coded_sample = bytes_per_sample * 8;
224  st->codec->bit_rate = sample_rate * bytes_per_sample * 8 * channels;
225  st->codec->block_align = idcin->block_align = bytes_per_sample * channels;
226  if (bytes_per_sample == 1)
228  else
230 
231  if (sample_rate % 14 != 0) {
232  idcin->audio_chunk_size1 = (sample_rate / 14) *
233  bytes_per_sample * channels;
234  idcin->audio_chunk_size2 = (sample_rate / 14 + 1) *
235  bytes_per_sample * channels;
236  } else {
237  idcin->audio_chunk_size1 = idcin->audio_chunk_size2 =
238  (sample_rate / 14) * bytes_per_sample * channels;
239  }
240  idcin->current_audio_chunk = 0;
241  }
242 
243  idcin->next_chunk_is_video = 1;
244  idcin->first_pkt_pos = avio_tell(s->pb);
245 
246  return 0;
247 }
248 
250  AVPacket *pkt)
251 {
252  int ret;
253  unsigned int command;
254  unsigned int chunk_size;
255  IdcinDemuxContext *idcin = s->priv_data;
256  AVIOContext *pb = s->pb;
257  int i;
258  int palette_scale;
259  unsigned char r, g, b;
260  unsigned char palette_buffer[768];
261  uint32_t palette[256];
262 
263  if (url_feof(s->pb))
264  return s->pb->error ? s->pb->error : AVERROR_EOF;
265 
266  if (idcin->next_chunk_is_video) {
267  command = avio_rl32(pb);
268  if (command == 2) {
269  return AVERROR(EIO);
270  } else if (command == 1) {
271  /* trigger a palette change */
272  ret = avio_read(pb, palette_buffer, 768);
273  if (ret < 0) {
274  return ret;
275  } else if (ret != 768) {
276  av_log(s, AV_LOG_ERROR, "incomplete packet\n");
277  return AVERROR(EIO);
278  }
279  /* scale the palette as necessary */
280  palette_scale = 2;
281  for (i = 0; i < 768; i++)
282  if (palette_buffer[i] > 63) {
283  palette_scale = 0;
284  break;
285  }
286 
287  for (i = 0; i < 256; i++) {
288  r = palette_buffer[i * 3 ] << palette_scale;
289  g = palette_buffer[i * 3 + 1] << palette_scale;
290  b = palette_buffer[i * 3 + 2] << palette_scale;
291  palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | (b);
292  if (palette_scale == 2)
293  palette[i] |= palette[i] >> 6 & 0x30303;
294  }
295  }
296 
297  if (s->pb->eof_reached) {
298  av_log(s, AV_LOG_ERROR, "incomplete packet\n");
299  return s->pb->error ? s->pb->error : AVERROR_EOF;
300  }
301  chunk_size = avio_rl32(pb);
302  if (chunk_size < 4 || chunk_size > INT_MAX - 4) {
303  av_log(s, AV_LOG_ERROR, "invalid chunk size: %u\n", chunk_size);
304  return AVERROR_INVALIDDATA;
305  }
306  /* skip the number of decoded bytes (always equal to width * height) */
307  avio_skip(pb, 4);
308  if (chunk_size < 4)
309  return AVERROR_INVALIDDATA;
310  chunk_size -= 4;
311  ret= av_get_packet(pb, pkt, chunk_size);
312  if (ret < 0)
313  return ret;
314  else if (ret != chunk_size) {
315  av_log(s, AV_LOG_ERROR, "incomplete packet\n");
316  av_free_packet(pkt);
317  return AVERROR(EIO);
318  }
319  if (command == 1) {
320  uint8_t *pal;
321 
324  if (!pal) {
325  av_free_packet(pkt);
326  return AVERROR(ENOMEM);
327  }
328  memcpy(pal, palette, AVPALETTE_SIZE);
329  pkt->flags |= AV_PKT_FLAG_KEY;
330  }
331  pkt->stream_index = idcin->video_stream_index;
332  pkt->duration = 1;
333  } else {
334  /* send out the audio chunk */
335  if (idcin->current_audio_chunk)
336  chunk_size = idcin->audio_chunk_size2;
337  else
338  chunk_size = idcin->audio_chunk_size1;
339  ret= av_get_packet(pb, pkt, chunk_size);
340  if (ret < 0)
341  return ret;
342  pkt->stream_index = idcin->audio_stream_index;
343  pkt->duration = chunk_size / idcin->block_align;
344 
345  idcin->current_audio_chunk ^= 1;
346  }
347 
348  if (idcin->audio_present)
349  idcin->next_chunk_is_video ^= 1;
350 
351  return 0;
352 }
353 
354 static int idcin_read_seek(AVFormatContext *s, int stream_index,
355  int64_t timestamp, int flags)
356 {
357  IdcinDemuxContext *idcin = s->priv_data;
358 
359  if (idcin->first_pkt_pos > 0) {
360  int ret = avio_seek(s->pb, idcin->first_pkt_pos, SEEK_SET);
361  if (ret < 0)
362  return ret;
363  ff_update_cur_dts(s, s->streams[idcin->video_stream_index], 0);
364  idcin->next_chunk_is_video = 1;
365  idcin->current_audio_chunk = 0;
366  return 0;
367  }
368  return -1;
369 }
370 
372  .name = "idcin",
373  .long_name = NULL_IF_CONFIG_SMALL("id Cinematic"),
374  .priv_data_size = sizeof(IdcinDemuxContext),
380 };