| /* |
| * AAC encoder utilities |
| * Copyright (C) 2015 Rostislav Pehlivanov |
| * |
| * 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 |
| */ |
| |
| /** |
| * @file |
| * AAC encoder utilities |
| * @author Rostislav Pehlivanov ( atomnuker gmail com ) |
| */ |
| |
| #ifndef AVCODEC_AACENC_UTILS_H |
| #define AVCODEC_AACENC_UTILS_H |
| |
| #include "aac.h" |
| #include "aac_tablegen_decl.h" |
| #include "aacenctab.h" |
| |
| #define ROUND_STANDARD 0.4054f |
| #define ROUND_TO_ZERO 0.1054f |
| #define C_QUANT 0.4054f |
| |
| static inline void abs_pow34_v(float *out, const float *in, const int size) |
| { |
| int i; |
| for (i = 0; i < size; i++) { |
| float a = fabsf(in[i]); |
| out[i] = sqrtf(a * sqrtf(a)); |
| } |
| } |
| |
| /** |
| * Quantize one coefficient. |
| * @return absolute value of the quantized coefficient |
| * @see 3GPP TS26.403 5.6.2 "Scalefactor determination" |
| */ |
| static inline int quant(float coef, const float Q, const float rounding) |
| { |
| float a = coef * Q; |
| return sqrtf(a * sqrtf(a)) + rounding; |
| } |
| |
| static inline void quantize_bands(int *out, const float *in, const float *scaled, |
| int size, float Q34, int is_signed, int maxval, |
| const float rounding) |
| { |
| int i; |
| double qc; |
| for (i = 0; i < size; i++) { |
| qc = scaled[i] * Q34; |
| out[i] = (int)FFMIN(qc + rounding, (double)maxval); |
| if (is_signed && in[i] < 0.0f) { |
| out[i] = -out[i]; |
| } |
| } |
| } |
| |
| static inline float find_max_val(int group_len, int swb_size, const float *scaled) |
| { |
| float maxval = 0.0f; |
| int w2, i; |
| for (w2 = 0; w2 < group_len; w2++) { |
| for (i = 0; i < swb_size; i++) { |
| maxval = FFMAX(maxval, scaled[w2*128+i]); |
| } |
| } |
| return maxval; |
| } |
| |
| static inline int find_min_book(float maxval, int sf) |
| { |
| float Q = ff_aac_pow2sf_tab[POW_SF2_ZERO - sf + SCALE_ONE_POS - SCALE_DIV_512]; |
| float Q34 = sqrtf(Q * sqrtf(Q)); |
| int qmaxval, cb; |
| qmaxval = maxval * Q34 + C_QUANT; |
| if (qmaxval == 0) cb = 0; |
| else if (qmaxval == 1) cb = 1; |
| else if (qmaxval == 2) cb = 3; |
| else if (qmaxval <= 4) cb = 5; |
| else if (qmaxval <= 7) cb = 7; |
| else if (qmaxval <= 12) cb = 9; |
| else cb = 11; |
| return cb; |
| } |
| |
| /** Return the minimum scalefactor where the quantized coef does not clip. */ |
| static inline uint8_t coef2minsf(float coef) |
| { |
| return av_clip_uint8(log2f(coef)*4 - 69 + SCALE_ONE_POS - SCALE_DIV_512); |
| } |
| |
| /** Return the maximum scalefactor where the quantized coef is not zero. */ |
| static inline uint8_t coef2maxsf(float coef) |
| { |
| return av_clip_uint8(log2f(coef)*4 + 6 + SCALE_ONE_POS - SCALE_DIV_512); |
| } |
| |
| /* |
| * Returns the closest possible index to an array of float values, given a value. |
| */ |
| static inline int quant_array_idx(const float val, const float *arr, const int num) |
| { |
| int i, index = 0; |
| float quant_min_err = INFINITY; |
| for (i = 0; i < num; i++) { |
| float error = (val - arr[i])*(val - arr[i]); |
| if (error < quant_min_err) { |
| quant_min_err = error; |
| index = i; |
| } |
| } |
| return index; |
| } |
| |
| #define ERROR_IF(cond, ...) \ |
| if (cond) { \ |
| av_log(avctx, AV_LOG_ERROR, __VA_ARGS__); \ |
| return AVERROR(EINVAL); \ |
| } |
| |
| #define WARN_IF(cond, ...) \ |
| if (cond) { \ |
| av_log(avctx, AV_LOG_WARNING, __VA_ARGS__); \ |
| } |
| |
| |
| #endif /* AVCODEC_AACENC_UTILS_H */ |