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source: vbox/trunk/src/libs/ffmpeg-20060710/libavformat/sierravmd.c@ 8234

Last change on this file since 8234 was 5776, checked in by vboxsync, 17 years ago

ffmpeg: exported to OSE
File size: 10.7 KB
Line 
1/*
2 * Sierra VMD Format Demuxer
3 * Copyright (c) 2004 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20/**
21 * @file sierravmd.c
22 * Sierra VMD file demuxer
23 * by Vladimir "VAG" Gneushev (vagsoft at mail.ru)
24 * for more information on the Sierra VMD file format, visit:
25 * http://www.pcisys.net/~melanson/codecs/
26 */
27
28#include "avformat.h"
29
30#define VMD_HEADER_SIZE 0x0330
31#define BYTES_PER_FRAME_RECORD 16
32
33typedef struct {
34 int stream_index;
35 offset_t frame_offset;
36 unsigned int frame_size;
37 int64_t pts;
38 int keyframe;
39 unsigned char frame_record[BYTES_PER_FRAME_RECORD];
40} vmd_frame_t;
41
42typedef struct VmdDemuxContext {
43 int video_stream_index;
44 int audio_stream_index;
45
46 unsigned int audio_type;
47 unsigned int audio_samplerate;
48 unsigned int audio_bits;
49 unsigned int audio_channels;
50
51 unsigned int frame_count;
52 unsigned int frames_per_block;
53 vmd_frame_t *frame_table;
54 unsigned int current_frame;
55
56 int sample_rate;
57 int64_t audio_sample_counter;
58 int audio_frame_divisor;
59 int audio_block_align;
60 int skiphdr;
61
62 unsigned char vmd_header[VMD_HEADER_SIZE];
63} VmdDemuxContext;
64
65static int vmd_probe(AVProbeData *p)
66{
67 if (p->buf_size < 2)
68 return 0;
69
70 /* check if the first 2 bytes of the file contain the appropriate size
71 * of a VMD header chunk */
72 if (LE_16(&p->buf[0]) != VMD_HEADER_SIZE - 2)
73 return 0;
74
75 /* only return half certainty since this check is a bit sketchy */
76 return AVPROBE_SCORE_MAX / 2;
77}
78
79/* This is a support function to determine the duration, in sample
80 * frames, of a particular audio chunk, taking into account silent
81 * encodings. */
82static int vmd_calculate_audio_duration(unsigned char *audio_chunk,
83 int audio_chunk_size, int block_align)
84{
85 unsigned char *p = audio_chunk + 16;
86 unsigned char *p_end = audio_chunk + audio_chunk_size;
87 int total_samples = 0;
88 unsigned int sound_flags;
89
90 if (audio_chunk_size < 16)
91 return 0;
92 if (audio_chunk_size == block_align + 16)
93 return block_align;
94 if (audio_chunk_size == block_align + 17)
95 return block_align;
96
97 sound_flags = LE_32(p);
98 p += 4;
99 while (p < p_end) {
100 total_samples += block_align;
101 if ((sound_flags & 0x01) == 0)
102 p += block_align;
103 sound_flags >>= 1;
104 }
105 av_log(NULL,0,"Got %i samples for size %i map %08X\n", total_samples, audio_chunk_size, LE_32(audio_chunk));
106
107 return total_samples;
108}
109
110static int vmd_read_header(AVFormatContext *s,
111 AVFormatParameters *ap)
112{
113 VmdDemuxContext *vmd = (VmdDemuxContext *)s->priv_data;
114 ByteIOContext *pb = &s->pb;
115 AVStream *st;
116 unsigned int toc_offset;
117 unsigned char *raw_frame_table;
118 int raw_frame_table_size;
119 offset_t current_offset;
120 int i, j;
121 unsigned int total_frames;
122 int64_t video_pts_inc = 0;
123 int64_t current_video_pts = 0;
124 unsigned char chunk[BYTES_PER_FRAME_RECORD];
125 int lastframe = 0;
126
127 /* fetch the main header, including the 2 header length bytes */
128 url_fseek(pb, 0, SEEK_SET);
129 if (get_buffer(pb, vmd->vmd_header, VMD_HEADER_SIZE) != VMD_HEADER_SIZE)
130 return AVERROR_IO;
131
132 vmd->audio_sample_counter = 0;
133 vmd->audio_frame_divisor = 1;
134 vmd->audio_block_align = 1;
135
136 /* start up the decoders */
137 st = av_new_stream(s, 0);
138 if (!st)
139 return AVERROR_NOMEM;
140 av_set_pts_info(st, 33, 1, 90000);
141 vmd->video_stream_index = st->index;
142 st->codec->codec_type = CODEC_TYPE_VIDEO;
143 st->codec->codec_id = CODEC_ID_VMDVIDEO;
144 st->codec->codec_tag = 0; /* no fourcc */
145 st->codec->width = LE_16(&vmd->vmd_header[12]);
146 st->codec->height = LE_16(&vmd->vmd_header[14]);
147 st->codec->time_base.num = 1;
148 st->codec->time_base.den = 10;
149 st->codec->extradata_size = VMD_HEADER_SIZE;
150 st->codec->extradata = av_mallocz(VMD_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
151 memcpy(st->codec->extradata, vmd->vmd_header, VMD_HEADER_SIZE);
152
153 /* if sample rate is 0, assume no audio */
154 vmd->sample_rate = LE_16(&vmd->vmd_header[804]);
155 if (vmd->sample_rate) {
156 st = av_new_stream(s, 0);
157 if (!st)
158 return AVERROR_NOMEM;
159 av_set_pts_info(st, 33, 1, 90000);
160 vmd->audio_stream_index = st->index;
161 st->codec->codec_type = CODEC_TYPE_AUDIO;
162 st->codec->codec_id = CODEC_ID_VMDAUDIO;
163 st->codec->codec_tag = 0; /* no fourcc */
164 st->codec->channels = vmd->audio_channels = (vmd->vmd_header[811] & 0x80) ? 2 : 1;
165 st->codec->sample_rate = vmd->sample_rate;
166 st->codec->block_align = vmd->audio_block_align =
167 LE_16(&vmd->vmd_header[806]);
168 if (st->codec->block_align & 0x8000) {
169 st->codec->bits_per_sample = 16;
170 st->codec->block_align = -(st->codec->block_align - 0x10000);
171 vmd->audio_block_align = -(vmd->audio_block_align - 0x10000);
172 } else {
173 st->codec->bits_per_sample = 8;
174 }
175 st->codec->bit_rate = st->codec->sample_rate *
176 st->codec->bits_per_sample * st->codec->channels;
177
178 /* for calculating pts */
179 vmd->audio_frame_divisor = st->codec->channels;
180
181 video_pts_inc = 90000;
182 video_pts_inc *= st->codec->block_align;
183 video_pts_inc /= st->codec->sample_rate;
184 video_pts_inc /= st->codec->channels;
185 } else {
186 /* if no audio, assume 10 frames/second */
187 video_pts_inc = 90000 / 10;
188 }
189
190 toc_offset = LE_32(&vmd->vmd_header[812]);
191 vmd->frame_count = LE_16(&vmd->vmd_header[6]);
192 vmd->frames_per_block = LE_16(&vmd->vmd_header[18]);
193 url_fseek(pb, toc_offset, SEEK_SET);
194
195 raw_frame_table = NULL;
196 vmd->frame_table = NULL;
197 raw_frame_table_size = vmd->frame_count * 6;
198 raw_frame_table = av_malloc(raw_frame_table_size);
199 if(vmd->frame_count * vmd->frames_per_block >= UINT_MAX / sizeof(vmd_frame_t)){
200 av_log(s, AV_LOG_ERROR, "vmd->frame_count * vmd->frames_per_block too large\n");
201 return -1;
202 }
203 vmd->frame_table = av_malloc(vmd->frame_count * vmd->frames_per_block * sizeof(vmd_frame_t));
204 if (!raw_frame_table || !vmd->frame_table) {
205 av_free(raw_frame_table);
206 av_free(vmd->frame_table);
207 return AVERROR_NOMEM;
208 }
209 if (get_buffer(pb, raw_frame_table, raw_frame_table_size) !=
210 raw_frame_table_size) {
211 av_free(raw_frame_table);
212 av_free(vmd->frame_table);
213 return AVERROR_IO;
214 }
215
216 total_frames = 0;
217 for (i = 0; i < vmd->frame_count; i++) {
218
219 current_offset = LE_32(&raw_frame_table[6 * i + 2]);
220
221 /* handle each entry in index block */
222 for (j = 0; j < vmd->frames_per_block; j++) {
223 int type;
224 uint32_t size;
225
226 get_buffer(pb, chunk, BYTES_PER_FRAME_RECORD);
227 type = chunk[0];
228 size = LE_32(&chunk[2]);
229 if(!size)
230 continue;
231 switch(type) {
232 case 1: /* Audio Chunk */
233 vmd->frame_table[total_frames].frame_offset = current_offset;
234 vmd->frame_table[total_frames].stream_index = vmd->audio_stream_index;
235 vmd->frame_table[total_frames].frame_size = size;
236 memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
237 total_frames++;
238 break;
239 case 2: /* Video Chunk */
240 vmd->frame_table[total_frames].frame_offset = current_offset;
241 vmd->frame_table[total_frames].frame_size = size;
242 vmd->frame_table[total_frames].stream_index = vmd->video_stream_index;
243 memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
244 vmd->frame_table[total_frames].pts = current_video_pts;
245 if (lastframe) {
246 vmd->frame_table[lastframe].pts = current_video_pts - video_pts_inc;
247 }
248 lastframe = total_frames;
249 total_frames++;
250 break;
251 }
252 current_offset += size;
253 }
254 current_video_pts += video_pts_inc;
255 }
256
257 av_free(raw_frame_table);
258
259 vmd->current_frame = 0;
260 vmd->frame_count = total_frames;
261
262 return 0;
263}
264
265static int vmd_read_packet(AVFormatContext *s,
266 AVPacket *pkt)
267{
268 VmdDemuxContext *vmd = (VmdDemuxContext *)s->priv_data;
269 ByteIOContext *pb = &s->pb;
270 int ret = 0;
271 vmd_frame_t *frame;
272
273 if (vmd->current_frame >= vmd->frame_count)
274 return AVERROR_IO;
275
276 frame = &vmd->frame_table[vmd->current_frame];
277 /* position the stream (will probably be there already) */
278 url_fseek(pb, frame->frame_offset, SEEK_SET);
279
280 if (av_new_packet(pkt, frame->frame_size + BYTES_PER_FRAME_RECORD))
281 return AVERROR_NOMEM;
282 pkt->pos= url_ftell(pb);
283 memcpy(pkt->data, frame->frame_record, BYTES_PER_FRAME_RECORD);
284 ret = get_buffer(pb, pkt->data + BYTES_PER_FRAME_RECORD,
285 frame->frame_size);
286
287 if (ret != frame->frame_size) {
288 av_free_packet(pkt);
289 ret = AVERROR_IO;
290 }
291 pkt->stream_index = frame->stream_index;
292 if (frame->frame_record[0] == 0x02)
293 pkt->pts = frame->pts;
294 else {
295 pkt->pts = vmd->audio_sample_counter;
296 pkt->pts *= 90000;
297 pkt->pts /= vmd->sample_rate;
298 pkt->pts /= vmd->audio_channels;
299 vmd->audio_sample_counter += vmd_calculate_audio_duration(
300 pkt->data, pkt->size, vmd->audio_block_align);
301
302 }
303av_log(NULL, AV_LOG_INFO, " dispatching %s frame with %d bytes and pts %"PRId64" (%0.1f sec)\n",
304 (frame->frame_record[0] == 0x02) ? "video" : "audio",
305 frame->frame_size + BYTES_PER_FRAME_RECORD,
306 pkt->pts, (float)(pkt->pts / 90000.0));
307
308 vmd->current_frame++;
309
310 return ret;
311}
312
313static int vmd_read_close(AVFormatContext *s)
314{
315 VmdDemuxContext *vmd = (VmdDemuxContext *)s->priv_data;
316
317 av_free(vmd->frame_table);
318
319 return 0;
320}
321
322static AVInputFormat vmd_demuxer = {
323 "vmd",
324 "Sierra VMD format",
325 sizeof(VmdDemuxContext),
326 vmd_probe,
327 vmd_read_header,
328 vmd_read_packet,
329 vmd_read_close,
330};
331
332int vmd_init(void)
333{
334 av_register_input_format(&vmd_demuxer);
335 return 0;
336}
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