static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
                                       ALSChannelData **cd, int *reverted,
                                       unsigned int offset, int c)
{
    ALSChannelData *ch = cd[c];
    unsigned int   dep = 0;
    unsigned int channels = ctx->avctx->channels;

    if (reverted[c])
        return 0;

    reverted[c] = 1;

    while (dep < channels && !ch[dep].stop_flag) {
        revert_channel_correlation(ctx, bd, cd, reverted, offset,
                                   ch[dep].master_channel);

        dep++;
    }

    if (dep == channels) {
        av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation.\n");
        return AVERROR_INVALIDDATA;
    }

    bd->const_block = ctx->const_block + c;
    bd->shift_lsbs  = ctx->shift_lsbs + c;
    bd->opt_order   = ctx->opt_order + c;
    bd->store_prev_samples = ctx->store_prev_samples + c;
    bd->use_ltp     = ctx->use_ltp + c;
    bd->ltp_lag     = ctx->ltp_lag + c;
    bd->ltp_gain    = ctx->ltp_gain[c];
    bd->lpc_cof     = ctx->lpc_cof[c];
    bd->quant_cof   = ctx->quant_cof[c];
    bd->raw_samples = ctx->raw_samples[c] + offset;

    for (dep = 0; !ch[dep].stop_flag; dep++) {
        unsigned int smp;
        unsigned int begin = 1;
        unsigned int end   = bd->block_length - 1;
        int64_t y;
        int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;

        if (ch[dep].master_channel == c)
            continue;

        if (ch[dep].time_diff_flag) {
            int t = ch[dep].time_diff_index;

            if (ch[dep].time_diff_sign) {
                t      = -t;
                begin -= t;
            } else {
                end   -= t;
            }

            for (smp = begin; smp < end; smp++) {
                y  = (1 << 6) +
                     MUL64(ch[dep].weighting[0], master[smp - 1    ]) +
                     MUL64(ch[dep].weighting[1], master[smp        ]) +
                     MUL64(ch[dep].weighting[2], master[smp + 1    ]) +
                     MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +
                     MUL64(ch[dep].weighting[4], master[smp     + t]) +
                     MUL64(ch[dep].weighting[5], master[smp + 1 + t]);

                bd->raw_samples[smp] += y >> 7;
            }
        } else {
            for (smp = begin; smp < end; smp++) {
                y  = (1 << 6) +
                     MUL64(ch[dep].weighting[0], master[smp - 1]) +
                     MUL64(ch[dep].weighting[1], master[smp    ]) +
                     MUL64(ch[dep].weighting[2], master[smp + 1]);

                bd->raw_samples[smp] += y >> 7;
            }
        }
    }

    return 0;
}
Unknown