static void decode_block(BinkAudioContext *s, short *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 = s->coeffs_ptr[ch]; if (s->version_b) { coeffs[0] = av_int2flt(get_bits(gb, 32)) * s->root; coeffs[1] = av_int2flt(get_bits(gb, 32)) * s->root; } else { coeffs[0] = get_float(gb) * s->root; coeffs[1] = get_float(gb) * s->root; } for (i = 0; i < s->num_bands; i++) { /* constant is result of 0.066399999/log10(M_E) */ int value = get_bits(gb, 8); quant[i] = expf(FFMIN(value, 95) * 0.15289164787221953823f) * s->root; } k = 0; q = quant[0]; // parse coefficients i = 2; while (i < s->frame_len) { if (s->version_b) { j = i + 16; } else if (get_bits1(gb)) { j = i + rle_length_tab[get_bits(gb, 4)] * 8; } else { j = i + 8; } j = FFMIN(j, s->frame_len); width = get_bits(gb, 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++]; coeff = get_bits(gb, width); if (coeff) { if (get_bits1(gb)) 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); s->dsp.vector_fmul_scalar(coeffs, coeffs, s->frame_len / 2, s->frame_len); } else if (CONFIG_BINKAUDIO_RDFT_DECODER) s->trans.rdft.rdft_calc(&s->trans.rdft, coeffs); } s->fmt_conv.float_to_int16_interleave(out, (const float **)s->coeffs_ptr, s->frame_len, s->channels); if (!s->first) { int count = s->overlap_len * s->channels; int shift = av_log2(count); for (i = 0; i < count; i++) { out[i] = (s->previous[i] * (count - i) + out[i] * i) >> shift; } } memcpy(s->previous, out + s->block_size, s->overlap_len * s->channels * sizeof(*out)); s->first = 0; }