Function dca_parse_params

libavcodec/dca_parser.c:194–305

}

static int dca_parse_params(DCAParseContext *pc1, const uint8_t *buf,
                            int buf_size, int *duration, int *sample_rate,
                            int *profile)
{
    DCAExssAsset *asset = &pc1->exss.assets[0];
    GetBitContext gb;
    DCACoreFrameHeader h;
    uint8_t hdr[DCA_CORE_FRAME_HEADER_SIZE + AV_INPUT_BUFFER_PADDING_SIZE] = { 0 };
    int ret, frame_size;

    if (buf_size < DCA_CORE_FRAME_HEADER_SIZE)
        return AVERROR_INVALIDDATA;

    if (AV_RB32(buf) == DCA_SYNCWORD_SUBSTREAM) {
        if ((ret = ff_dca_exss_parse(&pc1->exss, buf, buf_size)) < 0)
            return ret;

        if (asset->extension_mask & DCA_EXSS_LBR) {
            if ((ret = init_get_bits8(&gb, buf + asset->lbr_offset, asset->lbr_size)) < 0)
                return ret;

            if (get_bits_long(&gb, 32) != DCA_SYNCWORD_LBR)
                return AVERROR_INVALIDDATA;

            switch (get_bits(&gb, 8)) {
            case DCA_LBR_HEADER_DECODER_INIT:
                pc1->sr_code = get_bits(&gb, 8);
            case DCA_LBR_HEADER_SYNC_ONLY:
                break;
            default:
                return AVERROR_INVALIDDATA;
            }

            if (pc1->sr_code >= FF_ARRAY_ELEMS(ff_dca_sampling_freqs))
                return AVERROR_INVALIDDATA;

            *sample_rate = ff_dca_sampling_freqs[pc1->sr_code];
            *duration = 1024 << ff_dca_freq_ranges[pc1->sr_code];
            *profile = AV_PROFILE_DTS_EXPRESS;
            return 0;
        }

        if (asset->extension_mask & DCA_EXSS_XLL) {
            int nsamples_log2;

            if ((ret = init_get_bits8(&gb, buf + asset->xll_offset, asset->xll_size)) < 0)
                return ret;

            if (get_bits_long(&gb, 32) != DCA_SYNCWORD_XLL)
                return AVERROR_INVALIDDATA;

            if (get_bits(&gb, 4))
                return AVERROR_INVALIDDATA;

            skip_bits(&gb, 8);
            skip_bits_long(&gb, get_bits(&gb, 5) + 1);
            skip_bits(&gb, 4);
            nsamples_log2 = get_bits(&gb, 4) + get_bits(&gb, 4);