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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  unsigned int w, h;
98  int i;
99 
100  /*
101  * This is what you could call a "probabilistic" file check: id CIN
102  * files don't have a definite file signature. In lieu of such a marker,
103  * perform sanity checks on the 5 32-bit header fields:
104  * width, height: greater than 0, less than or equal to 1024
105  * audio sample rate: greater than or equal to 8000, less than or
106  * equal to 48000, or 0 for no audio
107  * audio sample width (bytes/sample): 0 for no audio, or 1 or 2
108  * audio channels: 0 for no audio, or 1 or 2
109  */
110 
111  /* check we have enough data to do all checks, otherwise the
112  0-padding may cause a wrong recognition */
113  if (p->buf_size < 20 + HUFFMAN_TABLE_SIZE + 12)
114  return 0;
115 
116  /* check the video width */
117  w = AV_RL32(&p->buf[0]);
118  if ((w == 0) || (w > 1024))
119  return 0;
120 
121  /* check the video height */
122  h = AV_RL32(&p->buf[4]);
123  if ((h == 0) || (h > 1024))
124  return 0;
125 
126  /* check the audio sample rate */
127  sample_rate = AV_RL32(&p->buf[8]);
128  if (sample_rate && (sample_rate < 8000 || sample_rate > 48000))
129  return 0;
130 
131  /* check the audio bytes/sample */
132  number = AV_RL32(&p->buf[12]);
133  if (number > 2 || sample_rate && !number)
134  return 0;
135 
136  /* check the audio channels */
137  number = AV_RL32(&p->buf[16]);
138  if (number > 2 || sample_rate && !number)
139  return 0;
140 
141  i = 20 + HUFFMAN_TABLE_SIZE;
142  if (AV_RL32(&p->buf[i]) == 1)
143  i += 768;
144 
145  if (i+12 > p->buf_size || AV_RL32(&p->buf[i+8]) != w*h)
146  return 1;
147 
148  /* return half certainty since this check is a bit sketchy */
150 }
151 
153 {
154  AVIOContext *pb = s->pb;
155  IdcinDemuxContext *idcin = s->priv_data;
156  AVStream *st;
157  unsigned int width, height;
158  unsigned int sample_rate, bytes_per_sample, channels;
159  int ret;
160 
161  /* get the 5 header parameters */
162  width = avio_rl32(pb);
163  height = avio_rl32(pb);
164  sample_rate = avio_rl32(pb);
165  bytes_per_sample = avio_rl32(pb);
166  channels = avio_rl32(pb);
167 
168  if (s->pb->eof_reached) {
169  av_log(s, AV_LOG_ERROR, "incomplete header\n");
170  return s->pb->error ? s->pb->error : AVERROR_EOF;
171  }
172 
173  if (av_image_check_size(width, height, 0, s) < 0)
174  return AVERROR_INVALIDDATA;
175  if (sample_rate > 0) {
176  if (sample_rate < 14 || sample_rate > INT_MAX) {
177  av_log(s, AV_LOG_ERROR, "invalid sample rate: %u\n", sample_rate);
178  return AVERROR_INVALIDDATA;
179  }
180  if (bytes_per_sample < 1 || bytes_per_sample > 2) {
181  av_log(s, AV_LOG_ERROR, "invalid bytes per sample: %u\n",
182  bytes_per_sample);
183  return AVERROR_INVALIDDATA;
184  }
185  if (channels < 1 || channels > 2) {
186  av_log(s, AV_LOG_ERROR, "invalid channels: %u\n", channels);
187  return AVERROR_INVALIDDATA;
188  }
189  idcin->audio_present = 1;
190  } else {
191  /* if sample rate is 0, assume no audio */
192  idcin->audio_present = 0;
193  }
194 
195  st = avformat_new_stream(s, NULL);
196  if (!st)
197  return AVERROR(ENOMEM);
198  avpriv_set_pts_info(st, 33, 1, IDCIN_FPS);
199  st->start_time = 0;
200  idcin->video_stream_index = st->index;
203  st->codec->codec_tag = 0; /* no fourcc */
204  st->codec->width = width;
205  st->codec->height = height;
206 
207  /* load up the Huffman tables into extradata */
208  if ((ret = ff_get_extradata(st->codec, pb, HUFFMAN_TABLE_SIZE)) < 0)
209  return ret;
210 
211  if (idcin->audio_present) {
212  idcin->audio_present = 1;
213  st = avformat_new_stream(s, NULL);
214  if (!st)
215  return AVERROR(ENOMEM);
216  avpriv_set_pts_info(st, 63, 1, sample_rate);
217  st->start_time = 0;
218  idcin->audio_stream_index = st->index;
220  st->codec->codec_tag = 1;
221  st->codec->channels = channels;
222  st->codec->channel_layout = channels > 1 ? AV_CH_LAYOUT_STEREO :
225  st->codec->bits_per_coded_sample = bytes_per_sample * 8;
226  st->codec->bit_rate = sample_rate * bytes_per_sample * 8 * channels;
227  st->codec->block_align = idcin->block_align = bytes_per_sample * channels;
228  if (bytes_per_sample == 1)
230  else
232 
233  if (sample_rate % 14 != 0) {
234  idcin->audio_chunk_size1 = (sample_rate / 14) *
235  bytes_per_sample * channels;
236  idcin->audio_chunk_size2 = (sample_rate / 14 + 1) *
237  bytes_per_sample * channels;
238  } else {
239  idcin->audio_chunk_size1 = idcin->audio_chunk_size2 =
240  (sample_rate / 14) * bytes_per_sample * channels;
241  }
242  idcin->current_audio_chunk = 0;
243  }
244 
245  idcin->next_chunk_is_video = 1;
246  idcin->first_pkt_pos = avio_tell(s->pb);
247 
248  return 0;
249 }
250 
252  AVPacket *pkt)
253 {
254  int ret;
255  unsigned int command;
256  unsigned int chunk_size;
257  IdcinDemuxContext *idcin = s->priv_data;
258  AVIOContext *pb = s->pb;
259  int i;
260  int palette_scale;
261  unsigned char r, g, b;
262  unsigned char palette_buffer[768];
263  uint32_t palette[256];
264 
265  if (avio_feof(s->pb))
266  return s->pb->error ? s->pb->error : AVERROR_EOF;
267 
268  if (idcin->next_chunk_is_video) {
269  command = avio_rl32(pb);
270  if (command == 2) {
271  return AVERROR(EIO);
272  } else if (command == 1) {
273  /* trigger a palette change */
274  ret = avio_read(pb, palette_buffer, 768);
275  if (ret < 0) {
276  return ret;
277  } else if (ret != 768) {
278  av_log(s, AV_LOG_ERROR, "incomplete packet\n");
279  return AVERROR(EIO);
280  }
281  /* scale the palette as necessary */
282  palette_scale = 2;
283  for (i = 0; i < 768; i++)
284  if (palette_buffer[i] > 63) {
285  palette_scale = 0;
286  break;
287  }
288 
289  for (i = 0; i < 256; i++) {
290  r = palette_buffer[i * 3 ] << palette_scale;
291  g = palette_buffer[i * 3 + 1] << palette_scale;
292  b = palette_buffer[i * 3 + 2] << palette_scale;
293  palette[i] = (0xFFU << 24) | (r << 16) | (g << 8) | (b);
294  if (palette_scale == 2)
295  palette[i] |= palette[i] >> 6 & 0x30303;
296  }
297  }
298 
299  if (s->pb->eof_reached) {
300  av_log(s, AV_LOG_ERROR, "incomplete packet\n");
301  return s->pb->error ? s->pb->error : AVERROR_EOF;
302  }
303  chunk_size = avio_rl32(pb);
304  if (chunk_size < 4 || chunk_size > INT_MAX - 4) {
305  av_log(s, AV_LOG_ERROR, "invalid chunk size: %u\n", chunk_size);
306  return AVERROR_INVALIDDATA;
307  }
308  /* skip the number of decoded bytes (always equal to width * height) */
309  avio_skip(pb, 4);
310  if (chunk_size < 4)
311  return AVERROR_INVALIDDATA;
312  chunk_size -= 4;
313  ret= av_get_packet(pb, pkt, chunk_size);
314  if (ret < 0)
315  return ret;
316  else if (ret != chunk_size) {
317  av_log(s, AV_LOG_ERROR, "incomplete packet\n");
318  av_free_packet(pkt);
319  return AVERROR(EIO);
320  }
321  if (command == 1) {
322  uint8_t *pal;
323 
326  if (!pal) {
327  av_free_packet(pkt);
328  return AVERROR(ENOMEM);
329  }
330  memcpy(pal, palette, AVPALETTE_SIZE);
331  pkt->flags |= AV_PKT_FLAG_KEY;
332  }
333  pkt->stream_index = idcin->video_stream_index;
334  pkt->duration = 1;
335  } else {
336  /* send out the audio chunk */
337  if (idcin->current_audio_chunk)
338  chunk_size = idcin->audio_chunk_size2;
339  else
340  chunk_size = idcin->audio_chunk_size1;
341  ret= av_get_packet(pb, pkt, chunk_size);
342  if (ret < 0)
343  return ret;
344  pkt->stream_index = idcin->audio_stream_index;
345  pkt->duration = chunk_size / idcin->block_align;
346 
347  idcin->current_audio_chunk ^= 1;
348  }
349 
350  if (idcin->audio_present)
351  idcin->next_chunk_is_video ^= 1;
352 
353  return 0;
354 }
355 
356 static int idcin_read_seek(AVFormatContext *s, int stream_index,
357  int64_t timestamp, int flags)
358 {
359  IdcinDemuxContext *idcin = s->priv_data;
360 
361  if (idcin->first_pkt_pos > 0) {
362  int ret = avio_seek(s->pb, idcin->first_pkt_pos, SEEK_SET);
363  if (ret < 0)
364  return ret;
365  ff_update_cur_dts(s, s->streams[idcin->video_stream_index], 0);
366  idcin->next_chunk_is_video = 1;
367  idcin->current_audio_chunk = 0;
368  return 0;
369  }
370  return -1;
371 }
372 
374  .name = "idcin",
375  .long_name = NULL_IF_CONFIG_SMALL("id Cinematic"),
376  .priv_data_size = sizeof(IdcinDemuxContext),
382 };