changing AVCodecContext codec -> *codec in AVStream so additions to AVCodecContext...
[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
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71#define HUFFMAN_TABLE_SIZE (64 * 1024)
72#define FRAME_PTS_INC (90000 / 14)
73
74typedef struct IdcinDemuxContext {
75 int video_stream_index;
76 int audio_stream_index;
77 int audio_chunk_size1;
78 int audio_chunk_size2;
79
80 /* demux state variables */
81 int current_audio_chunk;
82 int next_chunk_is_video;
83 int audio_present;
84
85 int64_t pts;
86
2a2bbcb0 87 AVPaletteControl palctrl;
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88} IdcinDemuxContext;
89
90static int idcin_probe(AVProbeData *p)
91{
92 unsigned int number;
93
94 /*
95 * This is what you could call a "probabilistic" file check: Id CIN
96 * files don't have a definite file signature. In lieu of such a marker,
97 * perform sanity checks on the 5 32-bit header fields:
98 * width, height: greater than 0, less than or equal to 1024
99 * audio sample rate: greater than or equal to 8000, less than or
100 * equal to 48000, or 0 for no audio
101 * audio sample width (bytes/sample): 0 for no audio, or 1 or 2
102 * audio channels: 0 for no audio, or 1 or 2
103 */
104
105 /* cannot proceed without 20 bytes */
106 if (p->buf_size < 20)
107 return 0;
108
109 /* check the video width */
110 number = LE_32(&p->buf[0]);
111 if ((number == 0) || (number > 1024))
112 return 0;
113
114 /* check the video height */
115 number = LE_32(&p->buf[4]);
116 if ((number == 0) || (number > 1024))
117 return 0;
118
119 /* check the audio sample rate */
120 number = LE_32(&p->buf[8]);
121 if ((number != 0) && ((number < 8000) | (number > 48000)))
122 return 0;
123
124 /* check the audio bytes/sample */
125 number = LE_32(&p->buf[12]);
126 if (number > 2)
127 return 0;
128
129 /* check the audio channels */
130 number = LE_32(&p->buf[16]);
131 if (number > 2)
132 return 0;
133
134 /* return half certainly since this check is a bit sketchy */
135 return AVPROBE_SCORE_MAX / 2;
136}
137
138static int idcin_read_header(AVFormatContext *s,
139 AVFormatParameters *ap)
140{
141 ByteIOContext *pb = &s->pb;
142 IdcinDemuxContext *idcin = (IdcinDemuxContext *)s->priv_data;
143 AVStream *st;
144 unsigned int width, height;
145 unsigned int sample_rate, bytes_per_sample, channels;
146
147 /* get the 5 header parameters */
148 width = get_le32(pb);
149 height = get_le32(pb);
150 sample_rate = get_le32(pb);
151 bytes_per_sample = get_le32(pb);
152 channels = get_le32(pb);
153
154 st = av_new_stream(s, 0);
155 if (!st)
156 return AVERROR_NOMEM;
9ee91c2f 157 av_set_pts_info(st, 33, 1, 90000);
4120a53a 158 idcin->video_stream_index = st->index;
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159 st->codec->codec_type = CODEC_TYPE_VIDEO;
160 st->codec->codec_id = CODEC_ID_IDCIN;
161 st->codec->codec_tag = 0; /* no fourcc */
162 st->codec->width = width;
163 st->codec->height = height;
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164
165 /* load up the Huffman tables into extradata */
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166 st->codec->extradata_size = HUFFMAN_TABLE_SIZE;
167 st->codec->extradata = av_malloc(HUFFMAN_TABLE_SIZE);
168 if (get_buffer(pb, st->codec->extradata, HUFFMAN_TABLE_SIZE) !=
4120a53a 169 HUFFMAN_TABLE_SIZE)
0bd586c5 170 return AVERROR_IO;
4120a53a 171 /* save a reference in order to transport the palette */
01f4895c 172 st->codec->palctrl = &idcin->palctrl;
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173
174 /* if sample rate is 0, assume no audio */
175 if (sample_rate) {
176 idcin->audio_present = 1;
177 st = av_new_stream(s, 0);
178 if (!st)
179 return AVERROR_NOMEM;
9ee91c2f 180 av_set_pts_info(st, 33, 1, 90000);
4120a53a 181 idcin->audio_stream_index = st->index;
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182 st->codec->codec_type = CODEC_TYPE_AUDIO;
183 st->codec->codec_tag = 1;
184 st->codec->channels = channels;
185 st->codec->sample_rate = sample_rate;
186 st->codec->bits_per_sample = bytes_per_sample * 8;
187 st->codec->bit_rate = sample_rate * bytes_per_sample * 8 * channels;
188 st->codec->block_align = bytes_per_sample * channels;
4120a53a 189 if (bytes_per_sample == 1)
01f4895c 190 st->codec->codec_id = CODEC_ID_PCM_U8;
4120a53a 191 else
01f4895c 192 st->codec->codec_id = CODEC_ID_PCM_S16LE;
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193
194 if (sample_rate % 14 != 0) {
195 idcin->audio_chunk_size1 = (sample_rate / 14) *
196 bytes_per_sample * channels;
197 idcin->audio_chunk_size2 = (sample_rate / 14 + 1) *
198 bytes_per_sample * channels;
199 } else {
200 idcin->audio_chunk_size1 = idcin->audio_chunk_size2 =
201 (sample_rate / 14) * bytes_per_sample * channels;
202 }
203 idcin->current_audio_chunk = 0;
204 } else
205 idcin->audio_present = 1;
206
207 idcin->next_chunk_is_video = 1;
208 idcin->pts = 0;
209
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210 return 0;
211}
212
213static int idcin_read_packet(AVFormatContext *s,
214 AVPacket *pkt)
215{
216 int ret;
217 unsigned int command;
218 unsigned int chunk_size;
219 IdcinDemuxContext *idcin = (IdcinDemuxContext *)s->priv_data;
220 ByteIOContext *pb = &s->pb;
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221 int i;
222 int palette_scale;
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223 unsigned char r, g, b;
224 unsigned char palette_buffer[768];
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225
226 if (url_feof(&s->pb))
0bd586c5 227 return AVERROR_IO;
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228
229 if (idcin->next_chunk_is_video) {
230 command = get_le32(pb);
231 if (command == 2) {
0bd586c5 232 return AVERROR_IO;
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233 } else if (command == 1) {
234 /* trigger a palette change */
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235 idcin->palctrl.palette_changed = 1;
236 if (get_buffer(pb, palette_buffer, 768) != 768)
0bd586c5 237 return AVERROR_IO;
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238 /* scale the palette as necessary */
239 palette_scale = 2;
240 for (i = 0; i < 768; i++)
2a2bbcb0 241 if (palette_buffer[i] > 63) {
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242 palette_scale = 0;
243 break;
244 }
245
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246 for (i = 0; i < 256; i++) {
247 r = palette_buffer[i * 3 ] << palette_scale;
248 g = palette_buffer[i * 3 + 1] << palette_scale;
249 b = palette_buffer[i * 3 + 2] << palette_scale;
250 idcin->palctrl.palette[i] = (r << 16) | (g << 8) | (b);
251 }
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252 }
253
254 chunk_size = get_le32(pb);
255 /* skip the number of decoded bytes (always equal to width * height) */
256 url_fseek(pb, 4, SEEK_CUR);
257 chunk_size -= 4;
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258 ret= av_get_packet(pb, pkt, chunk_size);
259 if (ret != chunk_size)
260 return AVERROR_IO;
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261 pkt->stream_index = idcin->video_stream_index;
262 pkt->pts = idcin->pts;
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263 } else {
264 /* send out the audio chunk */
265 if (idcin->current_audio_chunk)
266 chunk_size = idcin->audio_chunk_size2;
267 else
268 chunk_size = idcin->audio_chunk_size1;
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269 ret= av_get_packet(pb, pkt, chunk_size);
270 if (ret != chunk_size)
0bd586c5 271 return AVERROR_IO;
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272 pkt->stream_index = idcin->audio_stream_index;
273 pkt->pts = idcin->pts;
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274
275 idcin->current_audio_chunk ^= 1;
276 idcin->pts += FRAME_PTS_INC;
277 }
278
279 if (idcin->audio_present)
280 idcin->next_chunk_is_video ^= 1;
281
282 return ret;
283}
284
285static int idcin_read_close(AVFormatContext *s)
286{
2a2bbcb0 287
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288 return 0;
289}
290
291static AVInputFormat idcin_iformat = {
292 "idcin",
293 "Id CIN format",
294 sizeof(IdcinDemuxContext),
295 idcin_probe,
296 idcin_read_header,
297 idcin_read_packet,
298 idcin_read_close,
299};
300
301int idcin_init(void)
302{
303 av_register_input_format(&idcin_iformat);
304 return 0;
305}