revised palette API, courtesy of Roberto Togni (rtogni at freemail.it)
[libav.git] / libavformat / idcin.c
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
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
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 AVPaletteControl palctrl;
94 } IdcinDemuxContext;
95
96 static int idcin_probe(AVProbeData *p)
97 {
98 unsigned int number;
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 /* cannot proceed without 20 bytes */
112 if (p->buf_size < 20)
113 return 0;
114
115 /* check the video width */
116 number = LE_32(&p->buf[0]);
117 if ((number == 0) || (number > 1024))
118 return 0;
119
120 /* check the video height */
121 number = LE_32(&p->buf[4]);
122 if ((number == 0) || (number > 1024))
123 return 0;
124
125 /* check the audio sample rate */
126 number = LE_32(&p->buf[8]);
127 if ((number != 0) && ((number < 8000) | (number > 48000)))
128 return 0;
129
130 /* check the audio bytes/sample */
131 number = LE_32(&p->buf[12]);
132 if (number > 2)
133 return 0;
134
135 /* check the audio channels */
136 number = LE_32(&p->buf[16]);
137 if (number > 2)
138 return 0;
139
140 /* return half certainly since this check is a bit sketchy */
141 return AVPROBE_SCORE_MAX / 2;
142 }
143
144 static int idcin_read_header(AVFormatContext *s,
145 AVFormatParameters *ap)
146 {
147 ByteIOContext *pb = &s->pb;
148 IdcinDemuxContext *idcin = (IdcinDemuxContext *)s->priv_data;
149 AVStream *st;
150 unsigned int width, height;
151 unsigned int sample_rate, bytes_per_sample, channels;
152
153 /* get the 5 header parameters */
154 width = get_le32(pb);
155 height = get_le32(pb);
156 sample_rate = get_le32(pb);
157 bytes_per_sample = get_le32(pb);
158 channels = get_le32(pb);
159
160 st = av_new_stream(s, 0);
161 if (!st)
162 return AVERROR_NOMEM;
163 idcin->video_stream_index = st->index;
164 st->codec.codec_type = CODEC_TYPE_VIDEO;
165 st->codec.codec_id = CODEC_ID_IDCIN;
166 st->codec.codec_tag = 0; /* no fourcc */
167 st->codec.width = width;
168 st->codec.height = height;
169
170 /* load up the Huffman tables into extradata */
171 st->codec.extradata_size = HUFFMAN_TABLE_SIZE;
172 st->codec.extradata = av_malloc(HUFFMAN_TABLE_SIZE);
173 if (get_buffer(pb, st->codec.extradata, HUFFMAN_TABLE_SIZE) !=
174 HUFFMAN_TABLE_SIZE)
175 return -EIO;
176 /* save a reference in order to transport the palette */
177 st->codec.palctrl = &idcin->palctrl;
178
179 /* if sample rate is 0, assume no audio */
180 if (sample_rate) {
181 idcin->audio_present = 1;
182 st = av_new_stream(s, 0);
183 if (!st)
184 return AVERROR_NOMEM;
185 idcin->audio_stream_index = st->index;
186 st->codec.codec_type = CODEC_TYPE_AUDIO;
187 st->codec.codec_tag = 1;
188 st->codec.channels = channels;
189 st->codec.sample_rate = sample_rate;
190 st->codec.bits_per_sample = bytes_per_sample * 8;
191 st->codec.bit_rate = sample_rate * bytes_per_sample * 8 * channels;
192 st->codec.block_align = bytes_per_sample * channels;
193 if (bytes_per_sample == 1)
194 st->codec.codec_id = CODEC_ID_PCM_U8;
195 else
196 st->codec.codec_id = CODEC_ID_PCM_S16LE;
197
198 if (sample_rate % 14 != 0) {
199 idcin->audio_chunk_size1 = (sample_rate / 14) *
200 bytes_per_sample * channels;
201 idcin->audio_chunk_size2 = (sample_rate / 14 + 1) *
202 bytes_per_sample * channels;
203 } else {
204 idcin->audio_chunk_size1 = idcin->audio_chunk_size2 =
205 (sample_rate / 14) * bytes_per_sample * channels;
206 }
207 idcin->current_audio_chunk = 0;
208 } else
209 idcin->audio_present = 1;
210
211 idcin->next_chunk_is_video = 1;
212 idcin->pts = 0;
213
214 /* set the pts reference (1 pts = 1/90000) */
215 s->pts_num = 1;
216 s->pts_den = 90000;
217
218 return 0;
219 }
220
221 static int idcin_read_packet(AVFormatContext *s,
222 AVPacket *pkt)
223 {
224 int ret;
225 unsigned int command;
226 unsigned int chunk_size;
227 IdcinDemuxContext *idcin = (IdcinDemuxContext *)s->priv_data;
228 ByteIOContext *pb = &s->pb;
229 int i;
230 int palette_scale;
231 unsigned char r, g, b;
232 unsigned char palette_buffer[768];
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 idcin->palctrl.palette_changed = 1;
244 if (get_buffer(pb, palette_buffer, 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_buffer[i] > 63) {
250 palette_scale = 0;
251 break;
252 }
253
254 for (i = 0; i < 256; i++) {
255 r = palette_buffer[i * 3 ] << palette_scale;
256 g = palette_buffer[i * 3 + 1] << palette_scale;
257 b = palette_buffer[i * 3 + 2] << palette_scale;
258 idcin->palctrl.palette[i] = (r << 16) | (g << 8) | (b);
259 }
260 }
261
262 chunk_size = get_le32(pb);
263 /* skip the number of decoded bytes (always equal to width * height) */
264 url_fseek(pb, 4, SEEK_CUR);
265 chunk_size -= 4;
266 if (av_new_packet(pkt, chunk_size))
267 ret = -EIO;
268 pkt->stream_index = idcin->video_stream_index;
269 pkt->pts = idcin->pts;
270 ret = get_buffer(pb, pkt->data, chunk_size);
271 if (ret != chunk_size)
272 ret = -EIO;
273 } else {
274 /* send out the audio chunk */
275 if (idcin->current_audio_chunk)
276 chunk_size = idcin->audio_chunk_size2;
277 else
278 chunk_size = idcin->audio_chunk_size1;
279 if (av_new_packet(pkt, chunk_size))
280 return -EIO;
281 pkt->stream_index = idcin->audio_stream_index;
282 pkt->pts = idcin->pts;
283 ret = get_buffer(&s->pb, pkt->data, chunk_size);
284 if (ret != chunk_size)
285 ret = -EIO;
286
287 idcin->current_audio_chunk ^= 1;
288 idcin->pts += FRAME_PTS_INC;
289 }
290
291 if (idcin->audio_present)
292 idcin->next_chunk_is_video ^= 1;
293
294 return ret;
295 }
296
297 static int idcin_read_close(AVFormatContext *s)
298 {
299
300 return 0;
301 }
302
303 static AVInputFormat idcin_iformat = {
304 "idcin",
305 "Id CIN format",
306 sizeof(IdcinDemuxContext),
307 idcin_probe,
308 idcin_read_header,
309 idcin_read_packet,
310 idcin_read_close,
311 };
312
313 int idcin_init(void)
314 {
315 av_register_input_format(&idcin_iformat);
316 return 0;
317 }