static int decode_block(BinkAudioContext *s, float **out, int use_dct) { int ch, i, j, k; float q, quant[25]; int width, coeff; GetBitContext *gb = &s->gb; if (use_dct) skip_bits(gb, 2); for (ch = 0; ch < s->channels; ch++) { FFTSample *coeffs = out[ch]; if (s->version_b) { if (get_bits_left(gb) < 64) return AVERROR_INVALIDDATA; coeffs[0] = av_int2float(get_bits_long(gb, 32)) * s->root; coeffs[1] = av_int2float(get_bits_long(gb, 32)) * s->root; } else { if (get_bits_left(gb) < 58) return AVERROR_INVALIDDATA; coeffs[0] = get_float(gb) * s->root; coeffs[1] = get_float(gb) * s->root; } if (get_bits_left(gb) < s->num_bands * 8) return AVERROR_INVALIDDATA; for (i = 0; i < s->num_bands; i++) { int value = get_bits(gb, 8); quant[i] = quant_table[FFMIN(value, 95)]; } k = 0; q = quant[0]; // parse coefficients i = 2; while (i < s->frame_len) { if (s->version_b) { j = i + 16; } else { int v; GET_BITS_SAFE(v, 1); if (v) { GET_BITS_SAFE(v, 4); j = i + rle_length_tab[v] * 8; } else { j = i + 8; } } j = FFMIN(j, s->frame_len); GET_BITS_SAFE(width, 4); if (width == 0) { memset(coeffs + i, 0, (j - i) * sizeof(*coeffs)); i = j; while (s->bands[k] < i) q = quant[k++]; } else { while (i < j) { if (s->bands[k] == i) q = quant[k++]; GET_BITS_SAFE(coeff, width); if (coeff) { int v; GET_BITS_SAFE(v, 1); if (v) coeffs[i] = -q * coeff; else coeffs[i] = q * coeff; } else { coeffs[i] = 0.0f; } i++; } } } if (CONFIG_BINKAUDIO_DCT_DECODER && use_dct) { coeffs[0] /= 0.5; s->trans.dct.dct_calc(&s->trans.dct, coeffs); } else if (CONFIG_BINKAUDIO_RDFT_DECODER) s->trans.rdft.rdft_calc(&s->trans.rdft, coeffs); } for (ch = 0; ch < s->channels; ch++) { int j; int count = s->overlap_len * s->channels; if (!s->first) { j = ch; for (i = 0; i < s->overlap_len; i++, j += s->channels) out[ch][i] = (s->previous[ch][i] * (count - j) + out[ch][i] * j) / count; } memcpy(s->previous[ch], &out[ch][s->frame_len - s->overlap_len], s->overlap_len * sizeof(*s->previous[ch])); } s->first = 0; return 0; }