implemented Id Quake II CIN support
[libav.git] / libavformat / idcin.c
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1/*
2 * Id Quake II CIN File Demuxer
3 * Copyright (c) 2003 The ffmpeg Project
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20/**
21 * @file idcin.c
22 * Id Quake II CIN file demuxer by Mike Melanson (melanson@pcisys.net)
23 * For more information about the Id CIN format, visit:
24 * http://www.csse.monash.edu.au/~timf/
25 *
26 * CIN is a somewhat quirky and ill-defined format. Here are some notes
27 * for anyone trying to understand the technical details of this format:
28 *
29 * The format has no definite file signature. This is problematic for a
30 * general-purpose media player that wants to automatically detect file
31 * types. However, a CIN file does start with 5 32-bit numbers that
32 * specify audio and video parameters. This demuxer gets around the lack
33 * of file signature by performing sanity checks on those parameters.
34 * Probabalistically, this is a reasonable solution since the number of
35 * valid combinations of the 5 parameters is a very small subset of the
36 * total 160-bit number space.
37 *
38 * Refer to the function idcin_probe() for the precise A/V parameters
39 * that this demuxer allows.
40 *
41 * Next, each audio and video frame has a duration of 1/14 sec. If the
42 * audio sample rate is a multiple of the common frequency 22050 Hz it will
43 * divide evenly by 14. However, if the sample rate is 11025 Hz:
44 * 11025 (samples/sec) / 14 (frames/sec) = 787.5 (samples/frame)
45 * The way the CIN stores audio in this case is by storing 787 sample
46 * frames in the first audio frame and 788 sample frames in the second
47 * audio frame. Therefore, the total number of bytes in an audio frame
48 * is given as:
49 * audio frame #0: 787 * (bytes/sample) * (# channels) bytes in frame
50 * audio frame #1: 788 * (bytes/sample) * (# channels) bytes in frame
51 * audio frame #2: 787 * (bytes/sample) * (# channels) bytes in frame
52 * audio frame #3: 788 * (bytes/sample) * (# channels) bytes in frame
53 *
54 * Finally, not all Id CIN creation tools agree on the resolution of the
55 * color palette, apparently. Some creation tools specify red, green, and
56 * blue palette components in terms of 6-bit VGA color DAC values which
57 * range from 0..63. Other tools specify the RGB components as full 8-bit
58 * values that range from 0..255. Since there are no markers in the file to
59 * differentiate between the two variants, this demuxer uses the following
60 * heuristic:
61 * - load the 768 palette bytes from disk
62 * - assume that they will need to be shifted left by 2 bits to
63 * transform them from 6-bit values to 8-bit values
64 * - scan through all 768 palette bytes
65 * - if any bytes exceed 63, do not shift the bytes at all before
66 * transmitting them to the video decoder
67 */
68
69#include "avformat.h"
70
71#define LE_16(x) ((((uint8_t*)(x))[1] << 8) | ((uint8_t*)(x))[0])
72#define LE_32(x) ((((uint8_t*)(x))[3] << 24) | \
73 (((uint8_t*)(x))[2] << 16) | \
74 (((uint8_t*)(x))[1] << 8) | \
75 ((uint8_t*)(x))[0])
76
77#define HUFFMAN_TABLE_SIZE (64 * 1024)
78#define FRAME_PTS_INC (90000 / 14)
79
80typedef struct IdcinDemuxContext {
81 int video_stream_index;
82 int audio_stream_index;
83 int audio_chunk_size1;
84 int audio_chunk_size2;
85
86 /* demux state variables */
87 int current_audio_chunk;
88 int next_chunk_is_video;
89 int audio_present;
90
91 int64_t pts;
92
93 /* keep reference to extradata but never free it */
94 void *extradata;
95} IdcinDemuxContext;
96
97static int idcin_probe(AVProbeData *p)
98{
99 unsigned int number;
100
101 /*
102 * This is what you could call a "probabilistic" file check: Id CIN
103 * files don't have a definite file signature. In lieu of such a marker,
104 * perform sanity checks on the 5 32-bit header fields:
105 * width, height: greater than 0, less than or equal to 1024
106 * audio sample rate: greater than or equal to 8000, less than or
107 * equal to 48000, or 0 for no audio
108 * audio sample width (bytes/sample): 0 for no audio, or 1 or 2
109 * audio channels: 0 for no audio, or 1 or 2
110 */
111
112 /* cannot proceed without 20 bytes */
113 if (p->buf_size < 20)
114 return 0;
115
116 /* check the video width */
117 number = LE_32(&p->buf[0]);
118 if ((number == 0) || (number > 1024))
119 return 0;
120
121 /* check the video height */
122 number = LE_32(&p->buf[4]);
123 if ((number == 0) || (number > 1024))
124 return 0;
125
126 /* check the audio sample rate */
127 number = LE_32(&p->buf[8]);
128 if ((number != 0) && ((number < 8000) | (number > 48000)))
129 return 0;
130
131 /* check the audio bytes/sample */
132 number = LE_32(&p->buf[12]);
133 if (number > 2)
134 return 0;
135
136 /* check the audio channels */
137 number = LE_32(&p->buf[16]);
138 if (number > 2)
139 return 0;
140
141 /* return half certainly since this check is a bit sketchy */
142 return AVPROBE_SCORE_MAX / 2;
143}
144
145static int idcin_read_header(AVFormatContext *s,
146 AVFormatParameters *ap)
147{
148 ByteIOContext *pb = &s->pb;
149 IdcinDemuxContext *idcin = (IdcinDemuxContext *)s->priv_data;
150 AVStream *st;
151 unsigned int width, height;
152 unsigned int sample_rate, bytes_per_sample, channels;
153
154 /* get the 5 header parameters */
155 width = get_le32(pb);
156 height = get_le32(pb);
157 sample_rate = get_le32(pb);
158 bytes_per_sample = get_le32(pb);
159 channels = get_le32(pb);
160
161 st = av_new_stream(s, 0);
162 if (!st)
163 return AVERROR_NOMEM;
164 idcin->video_stream_index = st->index;
165 st->codec.codec_type = CODEC_TYPE_VIDEO;
166 st->codec.codec_id = CODEC_ID_IDCIN;
167 st->codec.codec_tag = 0; /* no fourcc */
168 st->codec.width = width;
169 st->codec.height = height;
170
171 /* load up the Huffman tables into extradata */
172 st->codec.extradata_size = HUFFMAN_TABLE_SIZE;
173 st->codec.extradata = av_malloc(HUFFMAN_TABLE_SIZE);
174 if (get_buffer(pb, st->codec.extradata, HUFFMAN_TABLE_SIZE) !=
175 HUFFMAN_TABLE_SIZE)
176 return -EIO;
177 /* save a reference in order to transport the palette */
178 idcin->extradata = st->codec.extradata;
179
180 /* if sample rate is 0, assume no audio */
181 if (sample_rate) {
182 idcin->audio_present = 1;
183 st = av_new_stream(s, 0);
184 if (!st)
185 return AVERROR_NOMEM;
186 idcin->audio_stream_index = st->index;
187 st->codec.codec_type = CODEC_TYPE_AUDIO;
188 st->codec.codec_tag = 1;
189 st->codec.channels = channels;
190 st->codec.sample_rate = sample_rate;
191 st->codec.bits_per_sample = bytes_per_sample * 8;
192 st->codec.bit_rate = sample_rate * bytes_per_sample * 8 * channels;
193 st->codec.block_align = bytes_per_sample * channels;
194 if (bytes_per_sample == 1)
195 st->codec.codec_id = CODEC_ID_PCM_U8;
196 else
197 st->codec.codec_id = CODEC_ID_PCM_S16LE;
198
199 if (sample_rate % 14 != 0) {
200 idcin->audio_chunk_size1 = (sample_rate / 14) *
201 bytes_per_sample * channels;
202 idcin->audio_chunk_size2 = (sample_rate / 14 + 1) *
203 bytes_per_sample * channels;
204 } else {
205 idcin->audio_chunk_size1 = idcin->audio_chunk_size2 =
206 (sample_rate / 14) * bytes_per_sample * channels;
207 }
208 idcin->current_audio_chunk = 0;
209 } else
210 idcin->audio_present = 1;
211
212 idcin->next_chunk_is_video = 1;
213 idcin->pts = 0;
214
215 /* set the pts reference (1 pts = 1/90000) */
216 s->pts_num = 1;
217 s->pts_den = 90000;
218
219 return 0;
220}
221
222static int idcin_read_packet(AVFormatContext *s,
223 AVPacket *pkt)
224{
225 int ret;
226 unsigned int command;
227 unsigned int chunk_size;
228 IdcinDemuxContext *idcin = (IdcinDemuxContext *)s->priv_data;
229 ByteIOContext *pb = &s->pb;
230 AVPaletteControl *palette_control = (AVPaletteControl *)idcin->extradata;
231 int i;
232 int palette_scale;
233
234 if (url_feof(&s->pb))
235 return -EIO;
236
237 if (idcin->next_chunk_is_video) {
238 command = get_le32(pb);
239 if (command == 2) {
240 return -EIO;
241 } else if (command == 1) {
242 /* trigger a palette change */
243 palette_control->palette_changed = 1;
244 if (get_buffer(pb, palette_control->palette, 768) != 768)
245 return -EIO;
246 /* scale the palette as necessary */
247 palette_scale = 2;
248 for (i = 0; i < 768; i++)
249 if (palette_control->palette[i] > 63) {
250 palette_scale = 0;
251 break;
252 }
253
254 if (palette_scale)
255 for (i = 0; i < 768; i++)
256 palette_control->palette[i] <<= palette_scale;
257 }
258
259 chunk_size = get_le32(pb);
260 /* skip the number of decoded bytes (always equal to width * height) */
261 url_fseek(pb, 4, SEEK_CUR);
262 chunk_size -= 4;
263 if (av_new_packet(pkt, chunk_size))
264 ret = -EIO;
265 pkt->stream_index = idcin->video_stream_index;
266 pkt->pts = idcin->pts;
267 ret = get_buffer(pb, pkt->data, chunk_size);
268 if (ret != chunk_size)
269 ret = -EIO;
270 } else {
271 /* send out the audio chunk */
272 if (idcin->current_audio_chunk)
273 chunk_size = idcin->audio_chunk_size2;
274 else
275 chunk_size = idcin->audio_chunk_size1;
276 if (av_new_packet(pkt, chunk_size))
277 return -EIO;
278 pkt->stream_index = idcin->audio_stream_index;
279 pkt->pts = idcin->pts;
280 ret = get_buffer(&s->pb, pkt->data, chunk_size);
281 if (ret != chunk_size)
282 ret = -EIO;
283
284 idcin->current_audio_chunk ^= 1;
285 idcin->pts += FRAME_PTS_INC;
286 }
287
288 if (idcin->audio_present)
289 idcin->next_chunk_is_video ^= 1;
290
291 return ret;
292}
293
294static int idcin_read_close(AVFormatContext *s)
295{
296 return 0;
297}
298
299static AVInputFormat idcin_iformat = {
300 "idcin",
301 "Id CIN format",
302 sizeof(IdcinDemuxContext),
303 idcin_probe,
304 idcin_read_header,
305 idcin_read_packet,
306 idcin_read_close,
307};
308
309int idcin_init(void)
310{
311 av_register_input_format(&idcin_iformat);
312 return 0;
313}