2 * Sierra VMD Format Demuxer
3 * Copyright (c) 2004 The ffmpeg Project
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * Sierra VMD file demuxer
25 * by Vladimir "VAG" Gneushev (vagsoft at mail.ru)
26 * for more information on the Sierra VMD file format, visit:
27 * http://www.pcisys.net/~melanson/codecs/
32 #define VMD_HEADER_SIZE 0x0330
33 #define BYTES_PER_FRAME_RECORD 16
37 offset_t frame_offset;
38 unsigned int frame_size;
41 unsigned char frame_record[BYTES_PER_FRAME_RECORD];
44 typedef struct VmdDemuxContext {
45 int video_stream_index;
46 int audio_stream_index;
48 unsigned int audio_type;
49 unsigned int audio_samplerate;
50 unsigned int audio_bits;
51 unsigned int audio_channels;
53 unsigned int frame_count;
54 unsigned int frames_per_block;
55 vmd_frame_t *frame_table;
56 unsigned int current_frame;
59 int64_t audio_sample_counter;
60 int audio_frame_divisor;
61 int audio_block_align;
64 unsigned char vmd_header[VMD_HEADER_SIZE];
67 static int vmd_probe(AVProbeData *p)
72 /* check if the first 2 bytes of the file contain the appropriate size
73 * of a VMD header chunk */
74 if (LE_16(&p->buf[0]) != VMD_HEADER_SIZE - 2)
77 /* only return half certainty since this check is a bit sketchy */
78 return AVPROBE_SCORE_MAX / 2;
81 /* This is a support function to determine the duration, in sample
82 * frames, of a particular audio chunk, taking into account silent
84 static int vmd_calculate_audio_duration(unsigned char *audio_chunk,
85 int audio_chunk_size, int block_align)
87 unsigned char *p = audio_chunk + 16;
88 unsigned char *p_end = audio_chunk + audio_chunk_size;
89 int total_samples = 0;
90 unsigned int sound_flags;
92 if (audio_chunk_size < 16)
94 if (audio_chunk_size == block_align + 16)
96 if (audio_chunk_size == block_align + 17)
99 sound_flags = LE_32(p);
102 total_samples += block_align;
103 if ((sound_flags & 0x01) == 0)
107 av_log(NULL,0,"Got %i samples for size %i map %08X\n", total_samples, audio_chunk_size, LE_32(audio_chunk));
109 return total_samples;
112 static int vmd_read_header(AVFormatContext *s,
113 AVFormatParameters *ap)
115 VmdDemuxContext *vmd = (VmdDemuxContext *)s->priv_data;
116 ByteIOContext *pb = &s->pb;
118 unsigned int toc_offset;
119 unsigned char *raw_frame_table;
120 int raw_frame_table_size;
121 offset_t current_offset;
123 unsigned int total_frames;
124 int64_t video_pts_inc = 0;
125 int64_t current_video_pts = 0;
126 unsigned char chunk[BYTES_PER_FRAME_RECORD];
129 /* fetch the main header, including the 2 header length bytes */
130 url_fseek(pb, 0, SEEK_SET);
131 if (get_buffer(pb, vmd->vmd_header, VMD_HEADER_SIZE) != VMD_HEADER_SIZE)
134 vmd->audio_sample_counter = 0;
135 vmd->audio_frame_divisor = 1;
136 vmd->audio_block_align = 1;
138 /* start up the decoders */
139 st = av_new_stream(s, 0);
141 return AVERROR_NOMEM;
142 av_set_pts_info(st, 33, 1, 90000);
143 vmd->video_stream_index = st->index;
144 st->codec->codec_type = CODEC_TYPE_VIDEO;
145 st->codec->codec_id = CODEC_ID_VMDVIDEO;
146 st->codec->codec_tag = 0; /* no fourcc */
147 st->codec->width = LE_16(&vmd->vmd_header[12]);
148 st->codec->height = LE_16(&vmd->vmd_header[14]);
149 st->codec->time_base.num = 1;
150 st->codec->time_base.den = 10;
151 st->codec->extradata_size = VMD_HEADER_SIZE;
152 st->codec->extradata = av_mallocz(VMD_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
153 memcpy(st->codec->extradata, vmd->vmd_header, VMD_HEADER_SIZE);
155 /* if sample rate is 0, assume no audio */
156 vmd->sample_rate = LE_16(&vmd->vmd_header[804]);
157 if (vmd->sample_rate) {
158 st = av_new_stream(s, 0);
160 return AVERROR_NOMEM;
161 av_set_pts_info(st, 33, 1, 90000);
162 vmd->audio_stream_index = st->index;
163 st->codec->codec_type = CODEC_TYPE_AUDIO;
164 st->codec->codec_id = CODEC_ID_VMDAUDIO;
165 st->codec->codec_tag = 0; /* no fourcc */
166 st->codec->channels = vmd->audio_channels = (vmd->vmd_header[811] & 0x80) ? 2 : 1;
167 st->codec->sample_rate = vmd->sample_rate;
168 st->codec->block_align = vmd->audio_block_align =
169 LE_16(&vmd->vmd_header[806]);
170 if (st->codec->block_align & 0x8000) {
171 st->codec->bits_per_sample = 16;
172 st->codec->block_align = -(st->codec->block_align - 0x10000);
173 vmd->audio_block_align = -(vmd->audio_block_align - 0x10000);
175 st->codec->bits_per_sample = 8;
177 st->codec->bit_rate = st->codec->sample_rate *
178 st->codec->bits_per_sample * st->codec->channels;
180 /* for calculating pts */
181 vmd->audio_frame_divisor = st->codec->channels;
183 video_pts_inc = 90000;
184 video_pts_inc *= st->codec->block_align;
185 video_pts_inc /= st->codec->sample_rate;
186 video_pts_inc /= st->codec->channels;
188 /* if no audio, assume 10 frames/second */
189 video_pts_inc = 90000 / 10;
192 toc_offset = LE_32(&vmd->vmd_header[812]);
193 vmd->frame_count = LE_16(&vmd->vmd_header[6]);
194 vmd->frames_per_block = LE_16(&vmd->vmd_header[18]);
195 url_fseek(pb, toc_offset, SEEK_SET);
197 raw_frame_table = NULL;
198 vmd->frame_table = NULL;
199 raw_frame_table_size = vmd->frame_count * 6;
200 raw_frame_table = av_malloc(raw_frame_table_size);
201 if(vmd->frame_count * vmd->frames_per_block >= UINT_MAX / sizeof(vmd_frame_t)){
202 av_log(s, AV_LOG_ERROR, "vmd->frame_count * vmd->frames_per_block too large\n");
205 vmd->frame_table = av_malloc(vmd->frame_count * vmd->frames_per_block * sizeof(vmd_frame_t));
206 if (!raw_frame_table || !vmd->frame_table) {
207 av_free(raw_frame_table);
208 av_free(vmd->frame_table);
209 return AVERROR_NOMEM;
211 if (get_buffer(pb, raw_frame_table, raw_frame_table_size) !=
212 raw_frame_table_size) {
213 av_free(raw_frame_table);
214 av_free(vmd->frame_table);
219 for (i = 0; i < vmd->frame_count; i++) {
221 current_offset = LE_32(&raw_frame_table[6 * i + 2]);
223 /* handle each entry in index block */
224 for (j = 0; j < vmd->frames_per_block; j++) {
228 get_buffer(pb, chunk, BYTES_PER_FRAME_RECORD);
230 size = LE_32(&chunk[2]);
234 case 1: /* Audio Chunk */
235 vmd->frame_table[total_frames].frame_offset = current_offset;
236 vmd->frame_table[total_frames].stream_index = vmd->audio_stream_index;
237 vmd->frame_table[total_frames].frame_size = size;
238 memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
241 case 2: /* Video Chunk */
242 vmd->frame_table[total_frames].frame_offset = current_offset;
243 vmd->frame_table[total_frames].frame_size = size;
244 vmd->frame_table[total_frames].stream_index = vmd->video_stream_index;
245 memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
246 vmd->frame_table[total_frames].pts = current_video_pts;
248 vmd->frame_table[lastframe].pts = current_video_pts - video_pts_inc;
250 lastframe = total_frames;
254 current_offset += size;
256 current_video_pts += video_pts_inc;
259 av_free(raw_frame_table);
261 vmd->current_frame = 0;
262 vmd->frame_count = total_frames;
267 static int vmd_read_packet(AVFormatContext *s,
270 VmdDemuxContext *vmd = (VmdDemuxContext *)s->priv_data;
271 ByteIOContext *pb = &s->pb;
275 if (vmd->current_frame >= vmd->frame_count)
278 frame = &vmd->frame_table[vmd->current_frame];
279 /* position the stream (will probably be there already) */
280 url_fseek(pb, frame->frame_offset, SEEK_SET);
282 if (av_new_packet(pkt, frame->frame_size + BYTES_PER_FRAME_RECORD))
283 return AVERROR_NOMEM;
284 pkt->pos= url_ftell(pb);
285 memcpy(pkt->data, frame->frame_record, BYTES_PER_FRAME_RECORD);
286 ret = get_buffer(pb, pkt->data + BYTES_PER_FRAME_RECORD,
289 if (ret != frame->frame_size) {
293 pkt->stream_index = frame->stream_index;
294 if (frame->frame_record[0] == 0x02)
295 pkt->pts = frame->pts;
297 pkt->pts = vmd->audio_sample_counter;
299 pkt->pts /= vmd->sample_rate;
300 pkt->pts /= vmd->audio_channels;
301 vmd->audio_sample_counter += vmd_calculate_audio_duration(
302 pkt->data, pkt->size, vmd->audio_block_align);
305 av_log(NULL, AV_LOG_INFO, " dispatching %s frame with %d bytes and pts %"PRId64" (%0.1f sec)\n",
306 (frame->frame_record[0] == 0x02) ? "video" : "audio",
307 frame->frame_size + BYTES_PER_FRAME_RECORD,
308 pkt->pts, (float)(pkt->pts / 90000.0));
310 vmd->current_frame++;
315 static int vmd_read_close(AVFormatContext *s)
317 VmdDemuxContext *vmd = (VmdDemuxContext *)s->priv_data;
319 av_free(vmd->frame_table);
324 AVInputFormat vmd_demuxer = {
327 sizeof(VmdDemuxContext),