static void vp6_parse_coeff_huffman(VP56Context *s)
{
    VP56Model *model = s->modelp;
    uint8_t *permute = s->scantable.permutated;
    VLC *vlc_coeff;
    int coeff, sign, coeff_idx;
    int b, cg, idx;
    int pt = 0;    /* plane type (0 for Y, 1 for U or V) */

    for (b=0; b<6; b++) {
        int ct = 0;    /* code type */
        if (b > 3) pt = 1;
        vlc_coeff = &s->dccv_vlc[pt];

        for (coeff_idx=0; coeff_idx<64; ) {
            int run = 1;
            if (coeff_idx<2 && s->nb_null[coeff_idx][pt]) {
                s->nb_null[coeff_idx][pt]--;
                if (coeff_idx)
                    break;
            } else {
                if (get_bits_count(&s->gb) >= s->gb.size_in_bits)
                    return;
                coeff = get_vlc2(&s->gb, vlc_coeff->table, 9, 3);
                if (coeff == 0) {
                    if (coeff_idx) {
                        int pt = (coeff_idx >= 6);
                        run += get_vlc2(&s->gb, s->runv_vlc[pt].table, 9, 3);
                        if (run >= 9)
                            run += get_bits(&s->gb, 6);
                    } else
                        s->nb_null[0][pt] = vp6_get_nb_null(s);
                    ct = 0;
                } else if (coeff == 11) {  /* end of block */
                    if (coeff_idx == 1)    /* first AC coeff ? */
                        s->nb_null[1][pt] = vp6_get_nb_null(s);
                    break;
                } else {
                    int coeff2 = vp56_coeff_bias[coeff];
                    if (coeff > 4)
                        coeff2 += get_bits(&s->gb, coeff <= 9 ? coeff - 4 : 11);
                    ct = 1 + (coeff2 > 1);
                    sign = get_bits1(&s->gb);
                    coeff2 = (coeff2 ^ -sign) + sign;
                    if (coeff_idx)
                        coeff2 *= s->dequant_ac;
                    idx = model->coeff_index_to_pos[coeff_idx];
                    s->block_coeff[b][permute[idx]] = coeff2;
                }
            }
            coeff_idx+=run;
            cg = FFMIN(vp6_coeff_groups[coeff_idx], 3);
            vlc_coeff = &s->ract_vlc[pt][ct][cg];
        }
    }
}