static int vmd_read_header(AVFormatContext *s, AVFormatParameters *ap) { VmdDemuxContext *vmd = (VmdDemuxContext *)s->priv_data; ByteIOContext *pb = &s->pb; AVStream *st; unsigned int toc_offset; unsigned char *raw_frame_table; int raw_frame_table_size; offset_t current_offset; int i, j; unsigned int total_frames; int64_t video_pts_inc = 0; int64_t current_video_pts = 0; unsigned char chunk[BYTES_PER_FRAME_RECORD]; int lastframe = 0; /* fetch the main header, including the 2 header length bytes */ url_fseek(pb, 0, SEEK_SET); if (get_buffer(pb, vmd->vmd_header, VMD_HEADER_SIZE) != VMD_HEADER_SIZE) return AVERROR_IO; vmd->audio_sample_counter = 0; vmd->audio_frame_divisor = 1; vmd->audio_block_align = 1; /* start up the decoders */ st = av_new_stream(s, 0); if (!st) return AVERROR_NOMEM; av_set_pts_info(st, 33, 1, 90000); vmd->video_stream_index = st->index; st->codec->codec_type = CODEC_TYPE_VIDEO; st->codec->codec_id = CODEC_ID_VMDVIDEO; st->codec->codec_tag = 0; /* no fourcc */ st->codec->width = LE_16(&vmd->vmd_header[12]); st->codec->height = LE_16(&vmd->vmd_header[14]); st->codec->time_base.num = 1; st->codec->time_base.den = 10; st->codec->extradata_size = VMD_HEADER_SIZE; st->codec->extradata = av_mallocz(VMD_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE); memcpy(st->codec->extradata, vmd->vmd_header, VMD_HEADER_SIZE); /* if sample rate is 0, assume no audio */ vmd->sample_rate = LE_16(&vmd->vmd_header[804]); if (vmd->sample_rate) { st = av_new_stream(s, 0); if (!st) return AVERROR_NOMEM; av_set_pts_info(st, 33, 1, 90000); vmd->audio_stream_index = st->index; st->codec->codec_type = CODEC_TYPE_AUDIO; st->codec->codec_id = CODEC_ID_VMDAUDIO; st->codec->codec_tag = 0; /* no fourcc */ st->codec->channels = vmd->audio_channels = (vmd->vmd_header[811] & 0x80) ? 2 : 1; st->codec->sample_rate = vmd->sample_rate; st->codec->block_align = vmd->audio_block_align = LE_16(&vmd->vmd_header[806]); if (st->codec->block_align & 0x8000) { st->codec->bits_per_sample = 16; st->codec->block_align = -(st->codec->block_align - 0x10000); vmd->audio_block_align = -(vmd->audio_block_align - 0x10000); } else { st->codec->bits_per_sample = 8; st->codec->bit_rate = st->codec->sample_rate * st->codec->bits_per_sample * st->codec->channels; /* for calculating pts */ vmd->audio_frame_divisor = st->codec->channels; video_pts_inc = 90000; video_pts_inc *= st->codec->block_align; video_pts_inc /= st->codec->sample_rate; video_pts_inc /= st->codec->channels; } else { /* if no audio, assume 10 frames/second */ video_pts_inc = 90000 / 10; toc_offset = LE_32(&vmd->vmd_header[812]); vmd->frame_count = LE_16(&vmd->vmd_header[6]); vmd->frames_per_block = LE_16(&vmd->vmd_header[18]); url_fseek(pb, toc_offset, SEEK_SET); raw_frame_table = NULL; vmd->frame_table = NULL; raw_frame_table_size = vmd->frame_count * 6; raw_frame_table = av_malloc(raw_frame_table_size); vmd->frame_table = av_malloc(vmd->frame_count * vmd->frames_per_block * sizeof(vmd_frame_t)); if (!raw_frame_table || !vmd->frame_table) { av_free(raw_frame_table); av_free(vmd->frame_table); return AVERROR_NOMEM; if (get_buffer(pb, raw_frame_table, raw_frame_table_size) != raw_frame_table_size) { av_free(raw_frame_table); av_free(vmd->frame_table); return AVERROR_IO; total_frames = 0; for (i = 0; i < vmd->frame_count; i++) { current_offset = LE_32(&raw_frame_table[6 * i + 2]); /* handle each entry in index block */ for (j = 0; j < vmd->frames_per_block; j++) { int type; uint32_t size; get_buffer(pb, chunk, BYTES_PER_FRAME_RECORD); type = chunk[0]; size = LE_32(&chunk[2]); if(!size) continue; switch(type) { case 1: /* Audio Chunk */ vmd->frame_table[total_frames].frame_offset = current_offset; vmd->frame_table[total_frames].stream_index = vmd->audio_stream_index; vmd->frame_table[total_frames].frame_size = size; memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD); total_frames++; break; case 2: /* Video Chunk */ vmd->frame_table[total_frames].frame_offset = current_offset; vmd->frame_table[total_frames].frame_size = size; vmd->frame_table[total_frames].stream_index = vmd->video_stream_index; memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD); vmd->frame_table[total_frames].pts = current_video_pts; if (lastframe) { vmd->frame_table[lastframe].pts = current_video_pts - video_pts_inc; lastframe = total_frames; total_frames++; break; current_offset += size; current_video_pts += video_pts_inc; av_free(raw_frame_table); vmd->current_frame = 0; vmd->frame_count = total_frames; return 0;