/* * AC-3 DSP functions * Copyright (c) 2011 Justin Ruggles * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include <math.h> #include <stdlib.h> #include <string.h> #include "config.h" #include "libavutil/attributes.h" #include "libavutil/common.h" #include "libavutil/intmath.h" #include "libavutil/mem_internal.h" #include "ac3defs.h" #include "ac3dsp.h" #include "ac3tab.h" #include "mathops.h" static void ac3_exponent_min_c(uint8_t *exp, int num_reuse_blocks, int nb_coefs) { int blk, i; if (!num_reuse_blocks) return; for (i = 0; i < nb_coefs; i++) { uint8_t min_exp = *exp; uint8_t *exp1 = exp + 256; for (blk = 0; blk < num_reuse_blocks; blk++) { uint8_t next_exp = *exp1; if (next_exp < min_exp) min_exp = next_exp; exp1 += 256; } *exp++ = min_exp; } } static void float_to_fixed24_c(int32_t *dst, const float *src, unsigned int len) { const float scale = 1 << 24; do { *dst++ = lrintf(*src++ * scale); *dst++ = lrintf(*src++ * scale); *dst++ = lrintf(*src++ * scale); *dst++ = lrintf(*src++ * scale); *dst++ = lrintf(*src++ * scale); *dst++ = lrintf(*src++ * scale); *dst++ = lrintf(*src++ * scale); *dst++ = lrintf(*src++ * scale); len -= 8; } while (len > 0); } static void ac3_bit_alloc_calc_bap_c(int16_t *mask, int16_t *psd, int start, int end, int snr_offset, int floor, const uint8_t *bap_tab, uint8_t *bap) { int bin, band, band_end; /* special case, if snr offset is -960, set all bap's to zero */ if (snr_offset == -960) { memset(bap, 0, AC3_MAX_COEFS); return; } bin = start; band = ff_ac3_bin_to_band_tab[start]; do { int m = (FFMAX(mask[band] - snr_offset - floor, 0) & 0x1FE0) + floor; band_end = ff_ac3_band_start_tab[++band]; band_end = FFMIN(band_end, end); for (; bin < band_end; bin++) { int address = av_clip_uintp2((psd[bin] - m) >> 5, 6); bap[bin] = bap_tab[address]; } } while (end > band_end); } static void ac3_update_bap_counts_c(uint16_t mant_cnt[16], uint8_t *bap, int len) { while (len-- > 0) mant_cnt[bap[len]]++; } DECLARE_ALIGNED(16, const uint16_t, ff_ac3_bap_bits)[16] = { 0, 0, 0, 3, 0, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16 }; static int ac3_compute_mantissa_size_c(uint16_t mant_cnt[6][16]) { int blk, bap; int bits = 0; for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { // bap=1 : 3 mantissas in 5 bits bits += (mant_cnt[blk][1] / 3) * 5; // bap=2 : 3 mantissas in 7 bits // bap=4 : 2 mantissas in 7 bits bits += ((mant_cnt[blk][2] / 3) + (mant_cnt[blk][4] >> 1)) * 7; // bap=3 : 1 mantissa in 3 bits bits += mant_cnt[blk][3] * 3; // bap=5 to 15 : get bits per mantissa from table for (bap = 5; bap < 16; bap++) bits += mant_cnt[blk][bap] * ff_ac3_bap_bits[bap]; } return bits; } static void ac3_extract_exponents_c(uint8_t *exp, int32_t *coef, int nb_coefs) { int i; for (i = 0; i < nb_coefs; i++) { int v = abs(coef[i]); exp[i] = v ? 23 - av_log2(v) : 24; } } static void ac3_sum_square_butterfly_int32_c(int64_t sum[4], const int32_t *coef0, const int32_t *coef1, int len) { int i; sum[0] = sum[1] = sum[2] = sum[3] = 0; for (i = 0; i < len; i++) { int lt = coef0[i]; int rt = coef1[i]; int md = lt + rt; int sd = lt - rt; MAC64(sum[0], lt, lt); MAC64(sum[1], rt, rt); MAC64(sum[2], md, md); MAC64(sum[3], sd, sd); } } static void ac3_sum_square_butterfly_float_c(float sum[4], const float *coef0, const float *coef1, int len) { int i; sum[0] = sum[1] = sum[2] = sum[3] = 0; for (i = 0; i < len; i++) { float lt = coef0[i]; float rt = coef1[i]; float md = lt + rt; float sd = lt - rt; sum[0] += lt * lt; sum[1] += rt * rt; sum[2] += md * md; sum[3] += sd * sd; } } static void ac3_downmix_5_to_2_symmetric_c(float **samples, float **matrix, int len) { int i; float v0, v1; float front_mix = matrix[0][0]; float center_mix = matrix[0][1]; float surround_mix = matrix[0][3]; for (i = 0; i < len; i++) { v0 = samples[0][i] * front_mix + samples[1][i] * center_mix + samples[3][i] * surround_mix; v1 = samples[1][i] * center_mix + samples[2][i] * front_mix + samples[4][i] * surround_mix; samples[0][i] = v0; samples[1][i] = v1; } } static void ac3_downmix_5_to_1_symmetric_c(float **samples, float **matrix, int len) { int i; float front_mix = matrix[0][0]; float center_mix = matrix[0][1]; float surround_mix = matrix[0][3]; for (i = 0; i < len; i++) { samples[0][i] = samples[0][i] * front_mix + samples[1][i] * center_mix + samples[2][i] * front_mix + samples[3][i] * surround_mix + samples[4][i] * surround_mix; } } static void ac3_downmix_c(float **samples, float **matrix, int out_ch, int in_ch, int len) { int i, j; float v0, v1; if (out_ch == 2) { for (i = 0; i < len; i++) { v0 = v1 = 0.0f; for (j = 0; j < in_ch; j++) { v0 += samples[j][i] * matrix[0][j]; v1 += samples[j][i] * matrix[1][j]; } samples[0][i] = v0; samples[1][i] = v1; } } else if (out_ch == 1) { for (i = 0; i < len; i++) { v0 = 0.0f; for (j = 0; j < in_ch; j++) v0 += samples[j][i] * matrix[0][j]; samples[0][i] = v0; } } } static void ac3_downmix_5_to_2_symmetric_c_fixed(int32_t **samples, int16_t **matrix, int len) { int i; int64_t v0, v1; int16_t front_mix = matrix[0][0]; int16_t center_mix = matrix[0][1]; int16_t surround_mix = matrix[0][3]; for (i = 0; i < len; i++) { v0 = (int64_t)samples[0][i] * front_mix + (int64_t)samples[1][i] * center_mix + (int64_t)samples[3][i] * surround_mix; v1 = (int64_t)samples[1][i] * center_mix + (int64_t)samples[2][i] * front_mix + (int64_t)samples[4][i] * surround_mix; samples[0][i] = (v0+2048)>>12; samples[1][i] = (v1+2048)>>12; } } static void ac3_downmix_5_to_1_symmetric_c_fixed(int32_t **samples, int16_t **matrix, int len) { int i; int64_t v0; int16_t front_mix = matrix[0][0]; int16_t center_mix = matrix[0][1]; int16_t surround_mix = matrix[0][3]; for (i = 0; i < len; i++) { v0 = (int64_t)samples[0][i] * front_mix + (int64_t)samples[1][i] * center_mix + (int64_t)samples[2][i] * front_mix + (int64_t)samples[3][i] * surround_mix + (int64_t)samples[4][i] * surround_mix; samples[0][i] = (v0+2048)>>12; } } static void ac3_downmix_c_fixed(int32_t **samples, int16_t **matrix, int out_ch, int in_ch, int len) { int i, j; int64_t v0, v1; if (out_ch == 2) { for (i = 0; i < len; i++) { v0 = v1 = 0; for (j = 0; j < in_ch; j++) { v0 += (int64_t)samples[j][i] * matrix[0][j]; v1 += (int64_t)samples[j][i] * matrix[1][j]; } samples[0][i] = (v0+2048)>>12; samples[1][i] = (v1+2048)>>12; } } else if (out_ch == 1) { for (i = 0; i < len; i++) { v0 = 0; for (j = 0; j < in_ch; j++) v0 += (int64_t)samples[j][i] * matrix[0][j]; samples[0][i] = (v0+2048)>>12; } } } void ff_ac3dsp_downmix_fixed(AC3DSPContext *c, int32_t **samples, int16_t **matrix, int out_ch, int in_ch, int len) { if (c->in_channels != in_ch || c->out_channels != out_ch) { c->in_channels = in_ch; c->out_channels = out_ch; c->downmix_fixed = NULL; if (in_ch == 5 && out_ch == 2 && !(matrix[1][0] | matrix[0][2] | matrix[1][3] | matrix[0][4] | (matrix[0][1] ^ matrix[1][1]) | (matrix[0][0] ^ matrix[1][2]))) { c->downmix_fixed = ac3_downmix_5_to_2_symmetric_c_fixed; } else if (in_ch == 5 && out_ch == 1 && matrix[0][0] == matrix[0][2] && matrix[0][3] == matrix[0][4]) { c->downmix_fixed = ac3_downmix_5_to_1_symmetric_c_fixed; } } if (c->downmix_fixed) c->downmix_fixed(samples, matrix, len); else ac3_downmix_c_fixed(samples, matrix, out_ch, in_ch, len); } void ff_ac3dsp_downmix(AC3DSPContext *c, float **samples, float **matrix, int out_ch, int in_ch, int len) { if (c->in_channels != in_ch || c->out_channels != out_ch) { int **matrix_cmp = (int **)matrix; c->in_channels = in_ch; c->out_channels = out_ch; c->downmix = NULL; if (in_ch == 5 && out_ch == 2 && !(matrix_cmp[1][0] | matrix_cmp[0][2] | matrix_cmp[1][3] | matrix_cmp[0][4] | (matrix_cmp[0][1] ^ matrix_cmp[1][1]) | (matrix_cmp[0][0] ^ matrix_cmp[1][2]))) { c->downmix = ac3_downmix_5_to_2_symmetric_c; } else if (in_ch == 5 && out_ch == 1 && matrix_cmp[0][0] == matrix_cmp[0][2] && matrix_cmp[0][3] == matrix_cmp[0][4]) { c->downmix = ac3_downmix_5_to_1_symmetric_c; } #if ARCH_X86 ff_ac3dsp_set_downmix_x86(c); #endif } if (c->downmix) c->downmix(samples, matrix, len); else ac3_downmix_c(samples, matrix, out_ch, in_ch, len); } av_cold void ff_ac3dsp_init(AC3DSPContext *c) { c->ac3_exponent_min = ac3_exponent_min_c; c->float_to_fixed24 = float_to_fixed24_c; c->bit_alloc_calc_bap = ac3_bit_alloc_calc_bap_c; c->update_bap_counts = ac3_update_bap_counts_c; c->compute_mantissa_size = ac3_compute_mantissa_size_c; c->extract_exponents = ac3_extract_exponents_c; c->sum_square_butterfly_int32 = ac3_sum_square_butterfly_int32_c; c->sum_square_butterfly_float = ac3_sum_square_butterfly_float_c; c->in_channels = 0; c->out_channels = 0; c->downmix = NULL; c->downmix_fixed = NULL; #if ARCH_ARM ff_ac3dsp_init_arm(c); #elif ARCH_X86 ff_ac3dsp_init_x86(c); #elif ARCH_MIPS ff_ac3dsp_init_mips(c); #endif }