static int decode_tns(AACContext * ac, TemporalNoiseShaping * tns, GetBitContext * gb, const IndividualChannelStream * ics) { int w, filt, i, coef_len, coef_res, coef_compress; const int is8 = ics->window_sequence[0] == EIGHT_SHORT_SEQUENCE; const int tns_max_order = is8 ? 7 : ac->m4ac.object_type == AOT_AAC_MAIN ? 20 : 12; for (w = 0; w < ics->num_windows; w++) { tns->n_filt[w] = get_bits(gb, 2 - is8); if (tns->n_filt[w]) coef_res = get_bits1(gb); for (filt = 0; filt < tns->n_filt[w]; filt++) { int tmp2_idx; tns->length[w][filt] = get_bits(gb, 6 - 2*is8); if ((tns->order[w][filt] = get_bits(gb, 5 - 2*is8)) > tns_max_order) { av_log(ac->avccontext, AV_LOG_ERROR, "TNS filter order %d is greater than maximum %d.", tns->order[w][filt], tns_max_order); tns->order[w][filt] = 0; return -1; } tns->direction[w][filt] = get_bits1(gb); coef_compress = get_bits1(gb); coef_len = coef_res + 3 - coef_compress; tmp2_idx = 2*coef_compress + coef_res; for (i = 0; i < tns->order[w][filt]; i++) tns->coef[w][filt][i] = tns_tmp2_map[tmp2_idx][get_bits(gb, coef_len)]; } } return 0; }