static int mtv_read_header(AVFormatContext *s) { MTVDemuxContext *mtv = s->priv_data; AVIOContext *pb = s->pb; AVStream *st; unsigned int audio_subsegments; avio_skip(pb, 3); mtv->file_size = avio_rl32(pb); mtv->segments = avio_rl32(pb); avio_skip(pb, 32); mtv->audio_identifier = avio_rl24(pb); mtv->audio_br = avio_rl16(pb); mtv->img_colorfmt = avio_rl24(pb); mtv->img_bpp = avio_r8(pb); mtv->img_width = avio_rl16(pb); mtv->img_height = avio_rl16(pb); mtv->img_segment_size = avio_rl16(pb); /* Calculate width and height if missing from header */ if(mtv->img_bpp>>3){ if(!mtv->img_width && mtv->img_height) mtv->img_width=mtv->img_segment_size / (mtv->img_bpp>>3) / mtv->img_height; if(!mtv->img_height && mtv->img_width) mtv->img_height=mtv->img_segment_size / (mtv->img_bpp>>3) / mtv->img_width; } if(!mtv->img_height || !mtv->img_width || !mtv->img_segment_size){ av_log(s, AV_LOG_ERROR, "width or height or segment_size is invalid and I cannot calculate them from other information\n"); return AVERROR(EINVAL); } avio_skip(pb, 4); audio_subsegments = avio_rl16(pb); if (audio_subsegments == 0) { avpriv_request_sample(s, "MTV files without audio"); return AVERROR_PATCHWELCOME; } mtv->full_segment_size = audio_subsegments * (MTV_AUDIO_PADDING_SIZE + MTV_ASUBCHUNK_DATA_SIZE) + mtv->img_segment_size; mtv->video_fps = (mtv->audio_br / 4) / audio_subsegments; // FIXME Add sanity check here // all systems go! init decoders // video - raw rgb565 st = avformat_new_stream(s, NULL); if(!st) return AVERROR(ENOMEM); avpriv_set_pts_info(st, 64, 1, mtv->video_fps); st->codec->codec_type = AVMEDIA_TYPE_VIDEO; st->codec->codec_id = AV_CODEC_ID_RAWVIDEO; st->codec->pix_fmt = AV_PIX_FMT_RGB565BE; st->codec->width = mtv->img_width; st->codec->height = mtv->img_height; st->codec->sample_rate = mtv->video_fps; st->codec->extradata = av_strdup("BottomUp"); st->codec->extradata_size = 9; // audio - mp3 st = avformat_new_stream(s, NULL); if(!st) return AVERROR(ENOMEM); avpriv_set_pts_info(st, 64, 1, AUDIO_SAMPLING_RATE); st->codec->codec_type = AVMEDIA_TYPE_AUDIO; st->codec->codec_id = AV_CODEC_ID_MP3; st->codec->bit_rate = mtv->audio_br; st->need_parsing = AVSTREAM_PARSE_FULL; // Jump over header if(avio_seek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE) return AVERROR(EIO); return 0; }