LCOV - code coverage report
Current view: top level - src/libavcodec - aacenc_ltp.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 134 136 98.5 %
Date: 2017-06-22 08:51:55 Functions: 7 7 100.0 %

          Line data    Source code
       1             : /*
       2             :  * AAC encoder long term prediction extension
       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 long term prediction extension
      25             :  * @author Rostislav Pehlivanov ( atomnuker gmail com )
      26             :  */
      27             : 
      28             : #include "aacenc_ltp.h"
      29             : #include "aacenc_quantization.h"
      30             : #include "aacenc_utils.h"
      31             : 
      32             : /**
      33             :  * Encode LTP data.
      34             :  */
      35        6715 : void ff_aac_encode_ltp_info(AACEncContext *s, SingleChannelElement *sce,
      36             :                             int common_window)
      37             : {
      38             :     int i;
      39        6715 :     IndividualChannelStream *ics = &sce->ics;
      40        6715 :     if (s->profile != FF_PROFILE_AAC_LTP || !ics->predictor_present)
      41        6696 :         return;
      42          19 :     if (common_window)
      43          19 :         put_bits(&s->pb, 1, 0);
      44          19 :     put_bits(&s->pb, 1, ics->ltp.present);
      45          19 :     if (!ics->ltp.present)
      46           0 :         return;
      47          19 :     put_bits(&s->pb, 11, ics->ltp.lag);
      48          19 :     put_bits(&s->pb, 3,  ics->ltp.coef_idx);
      49         456 :     for (i = 0; i < FFMIN(ics->max_sfb, MAX_LTP_LONG_SFB); i++)
      50         437 :         put_bits(&s->pb, 1, ics->ltp.used[i]);
      51             : }
      52             : 
      53         411 : void ff_aac_ltp_insert_new_frame(AACEncContext *s)
      54             : {
      55         411 :     int i, ch, tag, chans, cur_channel, start_ch = 0;
      56             :     ChannelElement *cpe;
      57             :     SingleChannelElement *sce;
      58         822 :     for (i = 0; i < s->chan_map[0]; i++) {
      59         411 :         cpe = &s->cpe[i];
      60         411 :         tag      = s->chan_map[i+1];
      61         411 :         chans    = tag == TYPE_CPE ? 2 : 1;
      62        1233 :         for (ch = 0; ch < chans; ch++) {
      63         822 :             sce = &cpe->ch[ch];
      64         822 :             cur_channel = start_ch + ch;
      65             :             /* New sample + overlap */
      66         822 :             memcpy(&sce->ltp_state[0],    &sce->ltp_state[1024], 1024*sizeof(sce->ltp_state[0]));
      67         822 :             memcpy(&sce->ltp_state[1024], &s->planar_samples[cur_channel][2048], 1024*sizeof(sce->ltp_state[0]));
      68         822 :             memcpy(&sce->ltp_state[2048], &sce->ret_buf[0], 1024*sizeof(sce->ltp_state[0]));
      69         822 :             sce->ics.ltp.lag = 0;
      70             :         }
      71         411 :         start_ch += chans;
      72             :     }
      73         411 : }
      74             : 
      75         822 : static void get_lag(float *buf, const float *new, LongTermPrediction *ltp)
      76             : {
      77         822 :     int i, j, lag = 0, max_corr = 0;
      78         822 :     float max_ratio = 0.0f;
      79     1684278 :     for (i = 0; i < 2048; i++) {
      80     1683456 :         float corr, s0 = 0.0f, s1 = 0.0f;
      81     1683456 :         const int start = FFMAX(0, i - 1024);
      82  3018857472 :         for (j = start; j < 2048; j++) {
      83  3017174016 :             const int idx = j - i + 1024;
      84  3017174016 :             s0 += new[j]*buf[idx];
      85  3017174016 :             s1 += buf[idx]*buf[idx];
      86             :         }
      87     1683456 :         corr = s1 > 0.0f ? s0/sqrt(s1) : 0.0f;
      88     1683456 :         if (corr > max_corr) {
      89       93081 :             max_corr = corr;
      90       93081 :             lag = i;
      91       93081 :             max_ratio = corr/(2048-start);
      92             :         }
      93             :     }
      94         822 :     ltp->lag = FFMAX(av_clip_uintp2(lag, 11), 0);
      95         822 :     ltp->coef_idx = quant_array_idx(max_ratio, ltp_coef, 8);
      96         822 :     ltp->coef = ltp_coef[ltp->coef_idx];
      97         822 : }
      98             : 
      99         822 : static void generate_samples(float *buf, LongTermPrediction *ltp)
     100             : {
     101         822 :     int i, samples_num = 2048;
     102         822 :     if (!ltp->lag) {
     103          47 :         ltp->present = 0;
     104          47 :         return;
     105         775 :     } else if (ltp->lag < 1024) {
     106         615 :         samples_num = ltp->lag + 1024;
     107             :     }
     108     1071527 :     for (i = 0; i < samples_num; i++)
     109     1070752 :         buf[i] = ltp->coef*buf[i + 2048 - ltp->lag];
     110         775 :     memset(&buf[i], 0, (2048 - i)*sizeof(float));
     111             : }
     112             : 
     113             : /**
     114             :  * Process LTP parameters
     115             :  * @see Patent WO2006070265A1
     116             :  */
     117         822 : void ff_aac_update_ltp(AACEncContext *s, SingleChannelElement *sce)
     118             : {
     119         822 :     float *pred_signal = &sce->ltp_state[0];
     120         822 :     const float *samples = &s->planar_samples[s->cur_channel][1024];
     121             : 
     122         822 :     if (s->profile != FF_PROFILE_AAC_LTP)
     123           0 :         return;
     124             : 
     125             :     /* Calculate lag */
     126         822 :     get_lag(pred_signal, samples, &sce->ics.ltp);
     127         822 :     generate_samples(pred_signal, &sce->ics.ltp);
     128             : }
     129             : 
     130         417 : void ff_aac_adjust_common_ltp(AACEncContext *s, ChannelElement *cpe)
     131             : {
     132         417 :     int sfb, count = 0;
     133         417 :     SingleChannelElement *sce0 = &cpe->ch[0];
     134         417 :     SingleChannelElement *sce1 = &cpe->ch[1];
     135             : 
     136         814 :     if (!cpe->common_window ||
     137         785 :         sce0->ics.window_sequence[0] == EIGHT_SHORT_SEQUENCE ||
     138         388 :         sce1->ics.window_sequence[0] == EIGHT_SHORT_SEQUENCE) {
     139          29 :         sce0->ics.ltp.present = 0;
     140          29 :         return;
     141             :     }
     142             : 
     143        9312 :     for (sfb = 0; sfb < FFMIN(sce0->ics.max_sfb, MAX_LTP_LONG_SFB); sfb++) {
     144        8924 :         int sum = sce0->ics.ltp.used[sfb] + sce1->ics.ltp.used[sfb];
     145        8924 :         if (sum != 2) {
     146        8885 :             sce0->ics.ltp.used[sfb] = 0;
     147          39 :         } else if (sum == 2) {
     148          39 :             count++;
     149             :         }
     150             :     }
     151             : 
     152         388 :     sce0->ics.ltp.present = !!count;
     153         388 :     sce0->ics.predictor_present = !!count;
     154             : }
     155             : 
     156             : /**
     157             :  * Mark LTP sfb's
     158             :  */
     159         834 : void ff_aac_search_for_ltp(AACEncContext *s, SingleChannelElement *sce,
     160             :                            int common_window)
     161             : {
     162         834 :     int w, g, w2, i, start = 0, count = 0;
     163         834 :     int saved_bits = -(15 + FFMIN(sce->ics.max_sfb, MAX_LTP_LONG_SFB));
     164         834 :     float *C34 = &s->scoefs[128*0], *PCD = &s->scoefs[128*1];
     165         834 :     float *PCD34 = &s->scoefs[128*2];
     166         834 :     const int max_ltp = FFMIN(sce->ics.max_sfb, MAX_LTP_LONG_SFB);
     167             : 
     168         834 :     if (sce->ics.window_sequence[0] == EIGHT_SHORT_SEQUENCE) {
     169          28 :         if (sce->ics.ltp.lag) {
     170          12 :             memset(&sce->ltp_state[0], 0, 3072*sizeof(sce->ltp_state[0]));
     171          12 :             memset(&sce->ics.ltp, 0, sizeof(LongTermPrediction));
     172             :         }
     173          28 :         return;
     174             :     }
     175             : 
     176         806 :     if (!sce->ics.ltp.lag || s->lambda > 120.0f)
     177         702 :         return;
     178             : 
     179         208 :     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
     180         104 :         start = 0;
     181        5200 :         for (g = 0;  g < sce->ics.num_swb; g++) {
     182        5096 :             int bits1 = 0, bits2 = 0;
     183        5096 :             float dist1 = 0.0f, dist2 = 0.0f;
     184        5096 :             if (w*16+g > max_ltp) {
     185        2600 :                 start += sce->ics.swb_sizes[g];
     186        2600 :                 continue;
     187             :             }
     188        4992 :             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
     189             :                 int bits_tmp1, bits_tmp2;
     190        2496 :                 FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
     191       22880 :                 for (i = 0; i < sce->ics.swb_sizes[g]; i++)
     192       20384 :                     PCD[i] = sce->coeffs[start+(w+w2)*128+i] - sce->lcoeffs[start+(w+w2)*128+i];
     193        2496 :                 s->abs_pow34(C34,  &sce->coeffs[start+(w+w2)*128],  sce->ics.swb_sizes[g]);
     194        2496 :                 s->abs_pow34(PCD34, PCD, sce->ics.swb_sizes[g]);
     195        7488 :                 dist1 += quantize_band_cost(s, &sce->coeffs[start+(w+w2)*128], C34, sce->ics.swb_sizes[g],
     196        4992 :                                             sce->sf_idx[(w+w2)*16+g], sce->band_type[(w+w2)*16+g],
     197        2496 :                                             s->lambda/band->threshold, INFINITY, &bits_tmp1, NULL, 0);
     198        7488 :                 dist2 += quantize_band_cost(s, PCD, PCD34, sce->ics.swb_sizes[g],
     199        2496 :                                             sce->sf_idx[(w+w2)*16+g],
     200        2496 :                                             sce->band_type[(w+w2)*16+g],
     201        2496 :                                             s->lambda/band->threshold, INFINITY, &bits_tmp2, NULL, 0);
     202        2496 :                 bits1 += bits_tmp1;
     203        2496 :                 bits2 += bits_tmp2;
     204             :             }
     205        2496 :             if (dist2 < dist1 && bits2 < bits1) {
     206         638 :                 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++)
     207        2563 :                     for (i = 0; i < sce->ics.swb_sizes[g]; i++)
     208        2244 :                         sce->coeffs[start+(w+w2)*128+i] -= sce->lcoeffs[start+(w+w2)*128+i];
     209         319 :                 sce->ics.ltp.used[w*16+g] = 1;
     210         319 :                 saved_bits += bits1 - bits2;
     211         319 :                 count++;
     212             :             }
     213        2496 :             start += sce->ics.swb_sizes[g];
     214             :         }
     215             :     }
     216             : 
     217         104 :     sce->ics.ltp.present = !!count && (saved_bits >= 0);
     218         104 :     sce->ics.predictor_present = !!sce->ics.ltp.present;
     219             : 
     220             :     /* Reset any marked sfbs */
     221         104 :     if (!sce->ics.ltp.present && !!count) {
     222         166 :         for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
     223          83 :             start = 0;
     224        4150 :             for (g = 0;  g < sce->ics.num_swb; g++) {
     225        4067 :                 if (sce->ics.ltp.used[w*16+g]) {
     226        1362 :                     for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
     227       21073 :                         for (i = 0; i < sce->ics.swb_sizes[g]; i++) {
     228       20392 :                             sce->coeffs[start+(w+w2)*128+i] += sce->lcoeffs[start+(w+w2)*128+i];
     229             :                         }
     230             :                     }
     231             :                 }
     232        4067 :                 start += sce->ics.swb_sizes[g];
     233             :             }
     234             :         }
     235             :     }
     236             : }

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