static int wsvqa_read_header(AVFormatContext *s) { WsVqaDemuxContext *wsvqa = s->priv_data; AVIOContext *pb = s->pb; AVStream *st; unsigned char *header; unsigned char scratch[VQA_PREAMBLE_SIZE]; unsigned int chunk_tag; unsigned int chunk_size; int fps; /* initialize the video decoder stream */ st = avformat_new_stream(s, NULL); if (!st) return AVERROR(ENOMEM); st->start_time = 0; wsvqa->video_stream_index = st->index; st->codec->codec_type = AVMEDIA_TYPE_VIDEO; st->codec->codec_id = AV_CODEC_ID_WS_VQA; st->codec->codec_tag = 0; /* no fourcc */ /* skip to the start of the VQA header */ avio_seek(pb, 20, SEEK_SET); /* the VQA header needs to go to the decoder */ st->codec->extradata_size = VQA_HEADER_SIZE; st->codec->extradata = av_mallocz(VQA_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE); header = (unsigned char *)st->codec->extradata; if (avio_read(pb, st->codec->extradata, VQA_HEADER_SIZE) != VQA_HEADER_SIZE) { av_free(st->codec->extradata); return AVERROR(EIO); } st->codec->width = AV_RL16(&header[6]); st->codec->height = AV_RL16(&header[8]); fps = header[12]; st->nb_frames = st->duration = AV_RL16(&header[4]); if (fps < 1 || fps > 30) { av_log(s, AV_LOG_ERROR, "invalid fps: %d\n", fps); return AVERROR_INVALIDDATA; } avpriv_set_pts_info(st, 64, 1, fps); wsvqa->version = AV_RL16(&header[ 0]); wsvqa->sample_rate = AV_RL16(&header[24]); wsvqa->channels = header[26]; wsvqa->bps = header[27]; wsvqa->audio_stream_index = -1; s->ctx_flags |= AVFMTCTX_NOHEADER; /* there are 0 or more chunks before the FINF chunk; iterate until * FINF has been skipped and the file will be ready to be demuxed */ do { if (avio_read(pb, scratch, VQA_PREAMBLE_SIZE) != VQA_PREAMBLE_SIZE) return AVERROR(EIO); chunk_tag = AV_RB32(&scratch[0]); chunk_size = AV_RB32(&scratch[4]); /* catch any unknown header tags, for curiousity */ switch (chunk_tag) { case CINF_TAG: case CINH_TAG: case CIND_TAG: case PINF_TAG: case PINH_TAG: case PIND_TAG: case FINF_TAG: case CMDS_TAG: break; default: av_log (s, AV_LOG_ERROR, " note: unknown chunk seen (%c%c%c%c)\n", scratch[0], scratch[1], scratch[2], scratch[3]); break; } avio_skip(pb, chunk_size); } while (chunk_tag != FINF_TAG); return 0; }