LCOV - code coverage report
Current view: top level - src/libavcodec - aacenc_utils.h (source / functions) Hit Total Coverage
Test: coverage.info Lines: 96 98 98.0 %
Date: 2017-01-24 04:42:20 Functions: 14 15 93.3 %

          Line data    Source code
       1             : /*
       2             :  * AAC encoder utilities
       3             :  * Copyright (C) 2015 Rostislav Pehlivanov
       4             :  *
       5             :  * This file is part of FFmpeg.
       6             :  *
       7             :  * FFmpeg is free software; you can redistribute it and/or
       8             :  * modify it under the terms of the GNU Lesser General Public
       9             :  * License as published by the Free Software Foundation; either
      10             :  * version 2.1 of the License, or (at your option) any later version.
      11             :  *
      12             :  * FFmpeg is distributed in the hope that it will be useful,
      13             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      14             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      15             :  * Lesser General Public License for more details.
      16             :  *
      17             :  * You should have received a copy of the GNU Lesser General Public
      18             :  * License along with FFmpeg; if not, write to the Free Software
      19             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      20             :  */
      21             : 
      22             : /**
      23             :  * @file
      24             :  * AAC encoder utilities
      25             :  * @author Rostislav Pehlivanov ( atomnuker gmail com )
      26             :  */
      27             : 
      28             : #ifndef AVCODEC_AACENC_UTILS_H
      29             : #define AVCODEC_AACENC_UTILS_H
      30             : 
      31             : #include "libavutil/ffmath.h"
      32             : #include "aac.h"
      33             : #include "aacenctab.h"
      34             : #include "aactab.h"
      35             : 
      36             : #define ROUND_STANDARD 0.4054f
      37             : #define ROUND_TO_ZERO 0.1054f
      38             : #define C_QUANT 0.4054f
      39             : 
      40      778166 : static inline void abs_pow34_v(float *out, const float *in, const int size)
      41             : {
      42             :     int i;
      43    42373442 :     for (i = 0; i < size; i++) {
      44    41595276 :         float a = fabsf(in[i]);
      45    41595276 :         out[i] = sqrtf(a * sqrtf(a));
      46             :     }
      47      778166 : }
      48             : 
      49       20934 : static inline float pos_pow34(float a)
      50             : {
      51       20934 :     return sqrtf(a * sqrtf(a));
      52             : }
      53             : 
      54             : /**
      55             :  * Quantize one coefficient.
      56             :  * @return absolute value of the quantized coefficient
      57             :  * @see 3GPP TS26.403 5.6.2 "Scalefactor determination"
      58             :  */
      59     2060419 : static inline int quant(float coef, const float Q, const float rounding)
      60             : {
      61     2060419 :     float a = coef * Q;
      62     2060419 :     return sqrtf(a * sqrtf(a)) + rounding;
      63             : }
      64             : 
      65    23903466 : static inline void quantize_bands(int *out, const float *in, const float *scaled,
      66             :                                   int size, int is_signed, int maxval, const float Q34,
      67             :                                   const float rounding)
      68             : {
      69             :     int i;
      70   418109362 :     for (i = 0; i < size; i++) {
      71   394205896 :         float qc = scaled[i] * Q34;
      72   394205896 :         int tmp = (int)FFMIN(qc + rounding, (float)maxval);
      73   394205896 :         if (is_signed && in[i] < 0.0f) {
      74    95711359 :             tmp = -tmp;
      75             :         }
      76   394205896 :         out[i] = tmp;
      77             :     }
      78    23903466 : }
      79             : 
      80      656209 : static inline float find_max_val(int group_len, int swb_size, const float *scaled)
      81             : {
      82      656209 :     float maxval = 0.0f;
      83             :     int w2, i;
      84     1323716 :     for (w2 = 0; w2 < group_len; w2++) {
      85    14595043 :         for (i = 0; i < swb_size; i++) {
      86    13927536 :             maxval = FFMAX(maxval, scaled[w2*128+i]);
      87             :         }
      88             :     }
      89      656209 :     return maxval;
      90             : }
      91             : 
      92   235384224 : static inline int find_min_book(float maxval, int sf)
      93             : {
      94   235384224 :     float Q34 = ff_aac_pow34sf_tab[POW_SF2_ZERO - sf + SCALE_ONE_POS - SCALE_DIV_512];
      95             :     int qmaxval, cb;
      96   235384224 :     qmaxval = maxval * Q34 + C_QUANT;
      97   235384224 :     if (qmaxval >= (FF_ARRAY_ELEMS(aac_maxval_cb)))
      98    15086666 :         cb = 11;
      99             :     else
     100   220297558 :         cb = aac_maxval_cb[qmaxval];
     101   235384224 :     return cb;
     102             : }
     103             : 
     104     1116324 : static inline float find_form_factor(int group_len, int swb_size, float thresh,
     105             :                                      const float *scaled, float nzslope) {
     106     1116324 :     const float iswb_size = 1.0f / swb_size;
     107     1116324 :     const float iswb_sizem1 = 1.0f / (swb_size - 1);
     108     1116324 :     const float ethresh = thresh;
     109     1116324 :     float form = 0.0f, weight = 0.0f;
     110             :     int w2, i;
     111     2253592 :     for (w2 = 0; w2 < group_len; w2++) {
     112     1137268 :         float e = 0.0f, e2 = 0.0f, var = 0.0f, maxval = 0.0f;
     113     1137268 :         float nzl = 0;
     114    23746076 :         for (i = 0; i < swb_size; i++) {
     115    22608808 :             float s = fabsf(scaled[w2*128+i]);
     116    22608808 :             maxval = FFMAX(maxval, s);
     117    22608808 :             e += s;
     118    22608808 :             e2 += s *= s;
     119             :             /* We really don't want a hard non-zero-line count, since
     120             :              * even below-threshold lines do add up towards band spectral power.
     121             :              * So, fall steeply towards zero, but smoothly
     122             :              */
     123    22608808 :             if (s >= ethresh) {
     124     6882216 :                 nzl += 1.0f;
     125             :             } else {
     126    15726592 :                 if (nzslope == 2.f)
     127     6370374 :                     nzl += (s / ethresh) * (s / ethresh);
     128             :                 else
     129     9356218 :                     nzl += ff_fast_powf(s / ethresh, nzslope);
     130             :             }
     131             :         }
     132     1137268 :         if (e2 > thresh) {
     133             :             float frm;
     134     1136188 :             e *= iswb_size;
     135             : 
     136             :             /** compute variance */
     137    23735380 :             for (i = 0; i < swb_size; i++) {
     138    22599192 :                 float d = fabsf(scaled[w2*128+i]) - e;
     139    22599192 :                 var += d*d;
     140             :             }
     141     1136188 :             var = sqrtf(var * iswb_sizem1);
     142             : 
     143     1136188 :             e2 *= iswb_size;
     144     1136188 :             frm = e / FFMIN(e+4*var,maxval);
     145     1136188 :             form += e2 * sqrtf(frm) / FFMAX(0.5f,nzl);
     146     1136188 :             weight += e2;
     147             :         }
     148             :     }
     149     1116324 :     if (weight > 0) {
     150     1115864 :         return form / weight;
     151             :     } else {
     152         460 :         return 1.0f;
     153             :     }
     154             : }
     155             : 
     156             : /** Return the minimum scalefactor where the quantized coef does not clip. */
     157      587544 : static inline uint8_t coef2minsf(float coef)
     158             : {
     159      587544 :     return av_clip_uint8(log2f(coef)*4 - 69 + SCALE_ONE_POS - SCALE_DIV_512);
     160             : }
     161             : 
     162             : /** Return the maximum scalefactor where the quantized coef is not zero. */
     163           0 : static inline uint8_t coef2maxsf(float coef)
     164             : {
     165           0 :     return av_clip_uint8(log2f(coef)*4 +  6 + SCALE_ONE_POS - SCALE_DIV_512);
     166             : }
     167             : 
     168             : /*
     169             :  * Returns the closest possible index to an array of float values, given a value.
     170             :  */
     171        1322 : static inline int quant_array_idx(const float val, const float *arr, const int num)
     172             : {
     173        1322 :     int i, index = 0;
     174        1322 :     float quant_min_err = INFINITY;
     175       15898 :     for (i = 0; i < num; i++) {
     176       14576 :         float error = (val - arr[i])*(val - arr[i]);
     177       14576 :         if (error < quant_min_err) {
     178        1831 :             quant_min_err = error;
     179        1831 :             index = i;
     180             :         }
     181             :     }
     182        1322 :     return index;
     183             : }
     184             : 
     185             : /**
     186             :  * approximates exp10f(-3.0f*(0.5f + 0.5f * cosf(FFMIN(b,15.5f) / 15.5f)))
     187             :  */
     188        5362 : static av_always_inline float bval2bmax(float b)
     189             : {
     190        5362 :     return 0.001f + 0.0035f * (b*b*b) / (15.5f*15.5f*15.5f);
     191             : }
     192             : 
     193             : /*
     194             :  * Compute a nextband map to be used with SF delta constraint utilities.
     195             :  * The nextband array should contain 128 elements, and positions that don't
     196             :  * map to valid, nonzero bands of the form w*16+g (with w being the initial
     197             :  * window of the window group, only) are left indetermined.
     198             :  */
     199       14698 : static inline void ff_init_nextband_map(const SingleChannelElement *sce, uint8_t *nextband)
     200             : {
     201       14698 :     unsigned char prevband = 0;
     202             :     int w, g;
     203             :     /** Just a safe default */
     204     1896042 :     for (g = 0; g < 128; g++)
     205     1881344 :         nextband[g] = g;
     206             : 
     207             :     /** Now really navigate the nonzero band chain */
     208       30152 :     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
     209      732387 :         for (g = 0; g < sce->ics.num_swb; g++) {
     210      716933 :             if (!sce->zeroes[w*16+g] && sce->band_type[w*16+g] < RESERVED_BT)
     211      640303 :                 prevband = nextband[prevband] = w*16+g;
     212             :         }
     213             :     }
     214       14698 :     nextband[prevband] = prevband; /* terminate */
     215       14698 : }
     216             : 
     217             : /*
     218             :  * Updates nextband to reflect a removed band (equivalent to
     219             :  * calling ff_init_nextband_map after marking a band as zero)
     220             :  */
     221             : static inline void ff_nextband_remove(uint8_t *nextband, int prevband, int band)
     222             : {
     223             :     nextband[prevband] = nextband[band];
     224             : }
     225             : 
     226             : /*
     227             :  * Checks whether the specified band could be removed without inducing
     228             :  * scalefactor delta that violates SF delta encoding constraints.
     229             :  * prev_sf has to be the scalefactor of the previous nonzero, nonspecial
     230             :  * band, in encoding order, or negative if there was no such band.
     231             :  */
     232       33086 : static inline int ff_sfdelta_can_remove_band(const SingleChannelElement *sce,
     233             :     const uint8_t *nextband, int prev_sf, int band)
     234             : {
     235             :     return prev_sf >= 0
     236       33018 :         && sce->sf_idx[nextband[band]] >= (prev_sf - SCALE_MAX_DIFF)
     237       66094 :         && sce->sf_idx[nextband[band]] <= (prev_sf + SCALE_MAX_DIFF);
     238             : }
     239             : 
     240             : /*
     241             :  * Checks whether the specified band's scalefactor could be replaced
     242             :  * with another one without violating SF delta encoding constraints.
     243             :  * prev_sf has to be the scalefactor of the previous nonzero, nonsepcial
     244             :  * band, in encoding order, or negative if there was no such band.
     245             :  */
     246        6070 : static inline int ff_sfdelta_can_replace(const SingleChannelElement *sce,
     247             :     const uint8_t *nextband, int prev_sf, int new_sf, int band)
     248             : {
     249        6070 :     return new_sf >= (prev_sf - SCALE_MAX_DIFF)
     250        6070 :         && new_sf <= (prev_sf + SCALE_MAX_DIFF)
     251        6070 :         && sce->sf_idx[nextband[band]] >= (new_sf - SCALE_MAX_DIFF)
     252       12140 :         && sce->sf_idx[nextband[band]] <= (new_sf + SCALE_MAX_DIFF);
     253             : }
     254             : 
     255             : /**
     256             :  * linear congruential pseudorandom number generator
     257             :  *
     258             :  * @param   previous_val    pointer to the current state of the generator
     259             :  *
     260             :  * @return  Returns a 32-bit pseudorandom integer
     261             :  */
     262      808324 : static av_always_inline int lcg_random(unsigned previous_val)
     263             : {
     264      808324 :     union { unsigned u; int s; } v = { previous_val * 1664525u + 1013904223 };
     265      808324 :     return v.s;
     266             : }
     267             : 
     268             : #define ERROR_IF(cond, ...) \
     269             :     if (cond) { \
     270             :         av_log(avctx, AV_LOG_ERROR, __VA_ARGS__); \
     271             :         return AVERROR(EINVAL); \
     272             :     }
     273             : 
     274             : #define WARN_IF(cond, ...) \
     275             :     if (cond) { \
     276             :         av_log(avctx, AV_LOG_WARNING, __VA_ARGS__); \
     277             :     }
     278             : 
     279             : #endif /* AVCODEC_AACENC_UTILS_H */

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