2 * Sierra VMD Format Demuxer
3 * Copyright (c) 2004 The ffmpeg Project
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.
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.
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
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/
30 #define VMD_HEADER_SIZE 0x0330
31 #define BYTES_PER_FRAME_RECORD 16
35 offset_t frame_offset;
36 unsigned int frame_size;
39 unsigned char frame_record[BYTES_PER_FRAME_RECORD];
42 typedef struct VmdDemuxContext {
43 int video_stream_index;
44 int audio_stream_index;
46 unsigned int audio_type;
47 unsigned int audio_samplerate;
48 unsigned int audio_bits;
49 unsigned int audio_channels;
51 unsigned int frame_count;
52 unsigned int frames_per_block;
53 vmd_frame_t *frame_table;
54 unsigned int current_frame;
57 int64_t audio_sample_counter;
58 int audio_frame_divisor;
59 int audio_block_align;
62 unsigned char vmd_header[VMD_HEADER_SIZE];
65 static int vmd_probe(AVProbeData *p)
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)
75 /* only return half certainty since this check is a bit sketchy */
76 return AVPROBE_SCORE_MAX / 2;
79 /* This is a support function to determine the duration, in sample
80 * frames, of a particular audio chunk, taking into account silent
82 static int vmd_calculate_audio_duration(unsigned char *audio_chunk,
83 int audio_chunk_size, int block_align)
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;
90 if (audio_chunk_size < 16)
92 if (audio_chunk_size == block_align + 16)
94 if (audio_chunk_size == block_align + 17)
97 sound_flags = LE_32(p);
100 total_samples += block_align;
101 if ((sound_flags & 0x01) == 0)
105 av_log(NULL,0,"Got %i samples for size %i map %08X\n", total_samples, audio_chunk_size, LE_32(audio_chunk));
107 return total_samples;
110 static int vmd_read_header(AVFormatContext *s,
111 AVFormatParameters *ap)
113 VmdDemuxContext *vmd = (VmdDemuxContext *)s->priv_data;
114 ByteIOContext *pb = &s->pb;
116 unsigned int toc_offset;
117 unsigned char *raw_frame_table;
118 int raw_frame_table_size;
119 offset_t current_offset;
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];
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)
132 vmd->audio_sample_counter = 0;
133 vmd->audio_frame_divisor = 1;
134 vmd->audio_block_align = 1;
136 /* start up the decoders */
137 st = av_new_stream(s, 0);
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);
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);
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);
173 st->codec->bits_per_sample = 8;
175 st->codec->bit_rate = st->codec->sample_rate *
176 st->codec->bits_per_sample * st->codec->channels;
178 /* for calculating pts */
179 vmd->audio_frame_divisor = st->codec->channels;
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;
186 /* if no audio, assume 10 frames/second */
187 video_pts_inc = 90000 / 10;
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);
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");
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;
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);
217 for (i = 0; i < vmd->frame_count; i++) {
219 current_offset = LE_32(&raw_frame_table[6 * i + 2]);
221 /* handle each entry in index block */
222 for (j = 0; j < vmd->frames_per_block; j++) {
226 get_buffer(pb, chunk, BYTES_PER_FRAME_RECORD);
228 size = LE_32(&chunk[2]);
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);
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;
246 vmd->frame_table[lastframe].pts = current_video_pts - video_pts_inc;
248 lastframe = total_frames;
252 current_offset += size;
254 current_video_pts += video_pts_inc;
257 av_free(raw_frame_table);
259 vmd->current_frame = 0;
260 vmd->frame_count = total_frames;
265 static int vmd_read_packet(AVFormatContext *s,
268 VmdDemuxContext *vmd = (VmdDemuxContext *)s->priv_data;
269 ByteIOContext *pb = &s->pb;
273 if (vmd->current_frame >= vmd->frame_count)
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);
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,
287 if (ret != frame->frame_size) {
291 pkt->stream_index = frame->stream_index;
292 if (frame->frame_record[0] == 0x02)
293 pkt->pts = frame->pts;
295 pkt->pts = vmd->audio_sample_counter;
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);
303 av_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));
308 vmd->current_frame++;
313 static int vmd_read_close(AVFormatContext *s)
315 VmdDemuxContext *vmd = (VmdDemuxContext *)s->priv_data;
317 av_free(vmd->frame_table);
322 AVInputFormat vmd_demuxer = {
325 sizeof(VmdDemuxContext),