Function parse_sub_headers

libavcodec/dca_xll.c:915–961

}

static int parse_sub_headers(DCAXllDecoder *s, DCAExssAsset *asset)
{
    DCAContext *dca = s->avctx->priv_data;
    DCAXllChSet *c;
    int i, ret;

    // Parse channel set headers
    s->nfreqbands = 0;
    s->nchannels = 0;
    s->nreschsets = 0;
    for (i = 0, c = s->chset; i < s->nchsets; i++, c++) {
        c->hier_ofs = s->nchannels;
        if ((ret = chs_parse_header(s, c, asset)) < 0)
            return ret;
        if (c->nfreqbands > s->nfreqbands)
            s->nfreqbands = c->nfreqbands;
        if (c->hier_chset)
            s->nchannels += c->nchannels;
        if (c->residual_encode != (1 << c->nchannels) - 1)
            s->nreschsets++;
    }

    // Pre-scale downmixing coefficients for all non-primary channel sets
    for (i = s->nchsets - 1, c = &s->chset[i]; i > 0; i--, c--) {
        if (is_hier_dmix_chset(c)) {
            DCAXllChSet *o = find_next_hier_dmix_chset(s, c);
            if (o)
                prescale_down_mix(c, o);
        }
    }

    // Determine number of active channel sets to decode
    switch (dca->request_channel_layout) {
    case DCA_SPEAKER_LAYOUT_STEREO:
        s->nactivechsets = 1;
        break;
    case DCA_SPEAKER_LAYOUT_5POINT0:
    case DCA_SPEAKER_LAYOUT_5POINT1:
        s->nactivechsets = (s->chset[0].nchannels < 5 && s->nchsets > 1) ? 2 : 1;
        break;
    default:
        s->nactivechsets = s->nchsets;
        break;
    }

    return 0;
}

static int parse_navi_table(DCAXllDecoder *s)
{