mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-11-26 19:01:44 +02:00
228 lines
7.9 KiB
C
228 lines
7.9 KiB
C
/*
|
|
* AAC encoder TNS
|
|
* 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 long term prediction
|
|
* @author Rostislav Pehlivanov ( atomnuker gmail com )
|
|
*/
|
|
|
|
#include "aacenc_ltp.h"
|
|
#include "aacenc_quantization.h"
|
|
#include "aacenc_utils.h"
|
|
|
|
/**
|
|
* Encode LTP data.
|
|
*/
|
|
void ff_aac_encode_ltp_info(AACEncContext *s, SingleChannelElement *sce,
|
|
int common_window)
|
|
{
|
|
int i;
|
|
IndividualChannelStream *ics = &sce->ics;
|
|
if (s->profile != FF_PROFILE_AAC_LTP || !ics->predictor_present)
|
|
return;
|
|
if (common_window)
|
|
put_bits(&s->pb, 1, 0);
|
|
put_bits(&s->pb, 1, ics->ltp.present);
|
|
if (!ics->ltp.present)
|
|
return;
|
|
put_bits(&s->pb, 11, ics->ltp.lag);
|
|
put_bits(&s->pb, 3, ics->ltp.coef_idx);
|
|
for (i = 0; i < FFMIN(ics->max_sfb, MAX_LTP_LONG_SFB); i++)
|
|
put_bits(&s->pb, 1, ics->ltp.used[i]);
|
|
}
|
|
|
|
void ff_aac_ltp_insert_new_frame(AACEncContext *s)
|
|
{
|
|
int i, ch, tag, chans, cur_channel, start_ch = 0;
|
|
ChannelElement *cpe;
|
|
SingleChannelElement *sce;
|
|
for (i = 0; i < s->chan_map[0]; i++) {
|
|
cpe = &s->cpe[i];
|
|
tag = s->chan_map[i+1];
|
|
chans = tag == TYPE_CPE ? 2 : 1;
|
|
for (ch = 0; ch < chans; ch++) {
|
|
sce = &cpe->ch[ch];
|
|
cur_channel = start_ch + ch;
|
|
/* New sample + overlap */
|
|
memcpy(&sce->ltp_state[0], &sce->ltp_state[1024], 1024*sizeof(sce->ltp_state[0]));
|
|
memcpy(&sce->ltp_state[1024], &s->planar_samples[cur_channel][2048], 1024*sizeof(sce->ltp_state[0]));
|
|
memcpy(&sce->ltp_state[2048], &sce->ret_buf[0], 1024*sizeof(sce->ltp_state[0]));
|
|
}
|
|
start_ch += chans;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Process LTP parameters
|
|
* @see Patent WO2006070265A1
|
|
*/
|
|
void ff_aac_update_ltp(AACEncContext *s, SingleChannelElement *sce)
|
|
{
|
|
int i, j, lag;
|
|
float corr, s0, s1, max_corr = 0.0f;
|
|
float *samples = &s->planar_samples[s->cur_channel][1024];
|
|
float *pred_signal = &sce->ltp_state[0];
|
|
int samples_num = 2048;
|
|
|
|
if (s->profile != FF_PROFILE_AAC_LTP)
|
|
return;
|
|
|
|
/* Calculate lag */
|
|
for (i = 0; i < samples_num; i++) {
|
|
s0 = s1 = 0.0f;
|
|
for (j = 0; j < samples_num; j++) {
|
|
if (j + 1024 < i)
|
|
continue;
|
|
s0 += samples[j]*pred_signal[j-i+1024];
|
|
s1 += pred_signal[j-i+1024]*pred_signal[j-i+1024];
|
|
}
|
|
corr = s1 > 0.0f ? s0/sqrt(s1) : 0.0f;
|
|
if (corr > max_corr) {
|
|
max_corr = corr;
|
|
lag = i;
|
|
}
|
|
}
|
|
lag = av_clip_uintp2(lag, 11); /* 11 bits => 2^11 = 0->2047 */
|
|
|
|
if (!lag) {
|
|
sce->ics.ltp.lag = lag;
|
|
return;
|
|
}
|
|
|
|
s0 = s1 = 0.0f;
|
|
for (i = 0; i < lag; i++) {
|
|
s0 += samples[i];
|
|
s1 += pred_signal[i-lag+1024];
|
|
}
|
|
|
|
sce->ics.ltp.coef_idx = quant_array_idx(s0/s1, ltp_coef, 8);
|
|
sce->ics.ltp.coef = ltp_coef[sce->ics.ltp.coef_idx];
|
|
|
|
/* Predict the new samples */
|
|
if (lag < 1024)
|
|
samples_num = lag + 1024;
|
|
for (i = 0; i < samples_num; i++)
|
|
pred_signal[i+1024] = sce->ics.ltp.coef*pred_signal[i-lag+1024];
|
|
memset(&pred_signal[samples_num], 0, (2048 - samples_num)*sizeof(float));
|
|
|
|
sce->ics.ltp.lag = lag;
|
|
}
|
|
|
|
void ff_aac_adjust_common_ltp(AACEncContext *s, ChannelElement *cpe)
|
|
{
|
|
int sfb, count = 0;
|
|
SingleChannelElement *sce0 = &cpe->ch[0];
|
|
SingleChannelElement *sce1 = &cpe->ch[1];
|
|
|
|
if (!cpe->common_window ||
|
|
sce0->ics.window_sequence[0] == EIGHT_SHORT_SEQUENCE ||
|
|
sce1->ics.window_sequence[0] == EIGHT_SHORT_SEQUENCE)
|
|
return;
|
|
|
|
for (sfb = 0; sfb < FFMIN(sce0->ics.max_sfb, MAX_LTP_LONG_SFB); sfb++) {
|
|
int sum = sce0->ics.ltp.used[sfb] + sce1->ics.ltp.used[sfb];
|
|
if (sum != 2) {
|
|
sce0->ics.ltp.used[sfb] = 0;
|
|
} else if (sum == 2) {
|
|
count++;
|
|
}
|
|
}
|
|
|
|
sce0->ics.ltp.present = !!count;
|
|
sce0->ics.predictor_present = !!count;
|
|
}
|
|
|
|
/**
|
|
* Mark LTP sfb's
|
|
*/
|
|
void ff_aac_search_for_ltp(AACEncContext *s, SingleChannelElement *sce,
|
|
int common_window)
|
|
{
|
|
int w, g, w2, i, start = 0, count = 0;
|
|
int saved_bits = -(15 + FFMIN(sce->ics.max_sfb, MAX_LTP_LONG_SFB));
|
|
float *C34 = &s->scoefs[128*0], *PCD = &s->scoefs[128*1];
|
|
float *PCD34 = &s->scoefs[128*2];
|
|
const int max_ltp = FFMIN(sce->ics.max_sfb, MAX_LTP_LONG_SFB);
|
|
|
|
if (sce->ics.window_sequence[0] == EIGHT_SHORT_SEQUENCE ||
|
|
!sce->ics.ltp.lag)
|
|
return;
|
|
|
|
for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
|
|
start = 0;
|
|
for (g = 0; g < sce->ics.num_swb; g++) {
|
|
int bits1 = 0, bits2 = 0;
|
|
float dist1 = 0.0f, dist2 = 0.0f;
|
|
if (w*16+g > max_ltp) {
|
|
start += sce->ics.swb_sizes[g];
|
|
continue;
|
|
}
|
|
for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
|
|
int bits_tmp1, bits_tmp2;
|
|
FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
|
|
for (i = 0; i < sce->ics.swb_sizes[g]; i++)
|
|
PCD[i] = sce->coeffs[start+(w+w2)*128+i] - sce->lcoeffs[start+(w+w2)*128+i];
|
|
abs_pow34_v(C34, &sce->coeffs[start+(w+w2)*128], sce->ics.swb_sizes[g]);
|
|
abs_pow34_v(PCD34, PCD, sce->ics.swb_sizes[g]);
|
|
dist1 += quantize_band_cost(s, &sce->coeffs[start+(w+w2)*128], C34, sce->ics.swb_sizes[g],
|
|
sce->sf_idx[(w+w2)*16+g], sce->band_type[(w+w2)*16+g],
|
|
s->lambda/band->threshold, INFINITY, &bits_tmp1, NULL, 0);
|
|
dist2 += quantize_band_cost(s, PCD, PCD34, sce->ics.swb_sizes[g],
|
|
sce->sf_idx[(w+w2)*16+g],
|
|
sce->band_type[(w+w2)*16+g],
|
|
s->lambda/band->threshold, INFINITY, &bits_tmp2, NULL, 0);
|
|
bits1 += bits_tmp1;
|
|
bits2 += bits_tmp2;
|
|
}
|
|
if (dist2 < dist1 && bits2 < bits1) {
|
|
for (w2 = 0; w2 < sce->ics.group_len[w]; w2++)
|
|
for (i = 0; i < sce->ics.swb_sizes[g]; i++)
|
|
sce->coeffs[start+(w+w2)*128+i] -= sce->lcoeffs[start+(w+w2)*128+i];
|
|
sce->ics.ltp.used[w*16+g] = 1;
|
|
saved_bits += bits1 - bits2;
|
|
count++;
|
|
}
|
|
start += sce->ics.swb_sizes[g];
|
|
}
|
|
}
|
|
|
|
sce->ics.ltp.present = !!count && (saved_bits >= 0);
|
|
sce->ics.predictor_present = !!sce->ics.ltp.present;
|
|
|
|
/* Reset any marked sfbs */
|
|
if (!sce->ics.ltp.present && !!count) {
|
|
for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
|
|
start = 0;
|
|
for (g = 0; g < sce->ics.num_swb; g++) {
|
|
if (sce->ics.ltp.used[w*16+g]) {
|
|
for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
|
|
for (i = 0; i < sce->ics.swb_sizes[g]; i++) {
|
|
sce->coeffs[start+(w+w2)*128+i] += sce->lcoeffs[start+(w+w2)*128+i];
|
|
}
|
|
}
|
|
}
|
|
start += sce->ics.swb_sizes[g];
|
|
}
|
|
}
|
|
}
|
|
}
|