silly typo fixes
[libav.git] / libavformat / idcin.c
1 /*
2 * id Quake II CIN File Demuxer
3 * Copyright (c) 2003 The ffmpeg Project
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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
71 #include "libavutil/channel_layout.h"
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 {
81 int video_stream_index;
82 int audio_stream_index;
83 int audio_chunk_size1;
84 int audio_chunk_size2;
85 int block_align;
86
87 /* demux state variables */
88 int current_audio_chunk;
89 int next_chunk_is_video;
90 int audio_present;
91 int64_t first_pkt_pos;
92 } IdcinDemuxContext;
93
94 static int idcin_probe(AVProbeData *p)
95 {
96 unsigned int number;
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 number = AV_RL32(&p->buf[8]);
126 if ((number != 0) && ((number < 8000) | (number > 48000)))
127 return 0;
128
129 /* check the audio bytes/sample */
130 number = AV_RL32(&p->buf[12]);
131 if (number > 2)
132 return 0;
133
134 /* check the audio channels */
135 number = AV_RL32(&p->buf[16]);
136 if (number > 2)
137 return 0;
138
139 /* return half certainty since this check is a bit sketchy */
140 return AVPROBE_SCORE_MAX / 2;
141 }
142
143 static int idcin_read_header(AVFormatContext *s)
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;
192 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
193 st->codec->codec_id = AV_CODEC_ID_IDCIN;
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 */
199 st->codec->extradata_size = HUFFMAN_TABLE_SIZE;
200 st->codec->extradata = av_malloc(HUFFMAN_TABLE_SIZE);
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;
217 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
218 st->codec->codec_tag = 1;
219 st->codec->channels = channels;
220 st->codec->channel_layout = channels > 1 ? AV_CH_LAYOUT_STEREO :
221 AV_CH_LAYOUT_MONO;
222 st->codec->sample_rate = sample_rate;
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)
227 st->codec->codec_id = AV_CODEC_ID_PCM_U8;
228 else
229 st->codec->codec_id = AV_CODEC_ID_PCM_S16LE;
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
249 static int idcin_read_packet(AVFormatContext *s,
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 (s->pb->eof_reached)
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] = (r << 16) | (g << 8) | (b);
292 }
293 }
294
295 if (s->pb->eof_reached) {
296 av_log(s, AV_LOG_ERROR, "incomplete packet\n");
297 return s->pb->error ? s->pb->error : AVERROR_EOF;
298 }
299 chunk_size = avio_rl32(pb);
300 if (chunk_size < 4 || chunk_size > INT_MAX - 4) {
301 av_log(s, AV_LOG_ERROR, "invalid chunk size: %u\n", chunk_size);
302 return AVERROR_INVALIDDATA;
303 }
304 /* skip the number of decoded bytes (always equal to width * height) */
305 avio_skip(pb, 4);
306 chunk_size -= 4;
307 ret= av_get_packet(pb, pkt, chunk_size);
308 if (ret < 0)
309 return ret;
310 else if (ret != chunk_size) {
311 av_log(s, AV_LOG_ERROR, "incomplete packet\n");
312 av_free_packet(pkt);
313 return AVERROR(EIO);
314 }
315 if (command == 1) {
316 uint8_t *pal;
317
318 pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE,
319 AVPALETTE_SIZE);
320 if (ret < 0) {
321 av_free_packet(pkt);
322 return ret;
323 }
324 memcpy(pal, palette, AVPALETTE_SIZE);
325 pkt->flags |= AV_PKT_FLAG_KEY;
326 }
327 pkt->stream_index = idcin->video_stream_index;
328 pkt->duration = 1;
329 } else {
330 /* send out the audio chunk */
331 if (idcin->current_audio_chunk)
332 chunk_size = idcin->audio_chunk_size2;
333 else
334 chunk_size = idcin->audio_chunk_size1;
335 ret= av_get_packet(pb, pkt, chunk_size);
336 if (ret < 0)
337 return ret;
338 pkt->stream_index = idcin->audio_stream_index;
339 pkt->duration = chunk_size / idcin->block_align;
340
341 idcin->current_audio_chunk ^= 1;
342 }
343
344 if (idcin->audio_present)
345 idcin->next_chunk_is_video ^= 1;
346
347 return 0;
348 }
349
350 static int idcin_read_seek(AVFormatContext *s, int stream_index,
351 int64_t timestamp, int flags)
352 {
353 IdcinDemuxContext *idcin = s->priv_data;
354
355 if (idcin->first_pkt_pos > 0) {
356 int ret = avio_seek(s->pb, idcin->first_pkt_pos, SEEK_SET);
357 if (ret < 0)
358 return ret;
359 ff_update_cur_dts(s, s->streams[idcin->video_stream_index], 0);
360 idcin->next_chunk_is_video = 1;
361 idcin->current_audio_chunk = 0;
362 return 0;
363 }
364 return -1;
365 }
366
367 AVInputFormat ff_idcin_demuxer = {
368 .name = "idcin",
369 .long_name = NULL_IF_CONFIG_SMALL("id Cinematic"),
370 .priv_data_size = sizeof(IdcinDemuxContext),
371 .read_probe = idcin_probe,
372 .read_header = idcin_read_header,
373 .read_packet = idcin_read_packet,
374 .read_seek = idcin_read_seek,
375 .flags = AVFMT_NO_BYTE_SEEK,
376 };