void ff_ac3_bit_alloc_calc_mask(AC3BitAllocParameters *s, int16_t *band_psd, int start, int end, int fast_gain, int is_lfe, int dba_mode, int dba_nsegs, uint8_t *dba_offsets, uint8_t *dba_lengths, uint8_t *dba_values, int16_t *mask) { int16_t excite[50]; /* excitation */ int bin, k; int bndstrt, bndend, begin, end1, tmp; int lowcomp, fastleak, slowleak; /* excitation function */ bndstrt = bin_to_band_tab[start]; bndend = bin_to_band_tab[end-1] + 1; if (bndstrt == 0) { lowcomp = 0; lowcomp = calc_lowcomp1(lowcomp, band_psd[0], band_psd[1], 384); excite[0] = band_psd[0] - fast_gain - lowcomp; lowcomp = calc_lowcomp1(lowcomp, band_psd[1], band_psd[2], 384); excite[1] = band_psd[1] - fast_gain - lowcomp; begin = 7; for (bin = 2; bin < 7; bin++) { if (!(is_lfe && bin == 6)) lowcomp = calc_lowcomp1(lowcomp, band_psd[bin], band_psd[bin+1], 384); fastleak = band_psd[bin] - fast_gain; slowleak = band_psd[bin] - s->slow_gain; excite[bin] = fastleak - lowcomp; if (!(is_lfe && bin == 6)) { if (band_psd[bin] <= band_psd[bin+1]) { begin = bin + 1; break; } } } end1=bndend; if (end1 > 22) end1=22; for (bin = begin; bin < end1; bin++) { if (!(is_lfe && bin == 6)) lowcomp = calc_lowcomp(lowcomp, band_psd[bin], band_psd[bin+1], bin); fastleak = FFMAX(fastleak - s->fast_decay, band_psd[bin] - fast_gain); slowleak = FFMAX(slowleak - s->slow_decay, band_psd[bin] - s->slow_gain); excite[bin] = FFMAX(fastleak - lowcomp, slowleak); } begin = 22; } else { /* coupling channel */ begin = bndstrt; fastleak = (s->cpl_fast_leak << 8) + 768; slowleak = (s->cpl_slow_leak << 8) + 768; } for (bin = begin; bin < bndend; bin++) { fastleak = FFMAX(fastleak - s->fast_decay, band_psd[bin] - fast_gain); slowleak = FFMAX(slowleak - s->slow_decay, band_psd[bin] - s->slow_gain); excite[bin] = FFMAX(fastleak, slowleak); } /* compute masking curve */ for (bin = bndstrt; bin < bndend; bin++) { tmp = s->db_per_bit - band_psd[bin]; if (tmp > 0) { excite[bin] += tmp >> 2; } mask[bin] = FFMAX(ff_ac3_hearing_threshold_tab[bin >> s->sr_shift][s->sr_code], excite[bin]); } /* delta bit allocation */ if (dba_mode == DBA_REUSE || dba_mode == DBA_NEW) { int band, seg, delta; band = 0; for (seg = 0; seg < FFMIN(8, dba_nsegs); seg++) { band = FFMIN(49, band + dba_offsets[seg]); if (dba_values[seg] >= 4) { delta = (dba_values[seg] - 3) << 7; } else { delta = (dba_values[seg] - 4) << 7; } for (k = 0; k < dba_lengths[seg]; k++) { mask[band] += delta; band++; } } } }