libxaac/encoder/ixheaace_stereo_preproc.c
akshayragir833 1ce177ea0e
Encoder enhancements and minor bug fixes (#73)
Test done: Smoke test
2023-12-28 17:47:33 +05:30

256 lines
9.8 KiB
C

/******************************************************************************
* *
* Copyright (C) 2023 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*****************************************************************************
* Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore
*/
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include "ixheaac_type_def.h"
#include "ixheaac_constants.h"
#include "ixheaace_aac_constants.h"
#include "ixheaac_basic_ops32.h"
#include "ixheaac_basic_ops16.h"
#include "ixheaac_basic_ops40.h"
#include "ixheaac_basic_ops.h"
#include "ixheaace_psy_const.h"
#include "ixheaace_tns.h"
#include "ixheaace_tns_params.h"
#include "ixheaace_rom.h"
#include "ixheaace_common_rom.h"
#include "ixheaace_bitbuffer.h"
#include "ixheaace_block_switch.h"
#include "ixheaace_psy_data.h"
#include "ixheaace_interface.h"
#include "ixheaace_adjust_threshold_data.h"
#include "ixheaace_dynamic_bits.h"
#include "ixheaace_qc_data.h"
#include "ixheaac_error_standards.h"
#include "ixheaace_stereo_preproc.h"
#include "ixheaace_common_utils.h"
IA_ERRORCODE iaace_init_stereo_pre_processing(ixheaace_stereo_pre_pro_pstr pstr_stereo_pre_pro,
WORD32 no_channels, WORD32 bit_rate, WORD32 sample_rate,
FLOAT32 used_scf_ratio) {
FLOAT32 bpf = bit_rate * 1024.0f / sample_rate;
FLOAT32 tmp;
memset(pstr_stereo_pre_pro, 0, sizeof(ixheaace_stereo_pre_pro_struct));
if (no_channels == 2) {
(pstr_stereo_pre_pro)->stereo_attenuation_flag = 1;
(pstr_stereo_pre_pro)->norm_pe_fac = 230.0f * used_scf_ratio / bpf;
(pstr_stereo_pre_pro)->impact_factor =
MIN(1, 400000.0f / (FLOAT32)(bit_rate - sample_rate * sample_rate / 72000.0f));
(pstr_stereo_pre_pro)->inc_stereo_attenuation = 22050.0f / sample_rate * 400.0f / bpf;
(pstr_stereo_pre_pro)->dec_stereo_attenuation = 22050.0f / sample_rate * 200.0f / bpf;
(pstr_stereo_pre_pro)->const_attenuation = 0.0f;
(pstr_stereo_pre_pro)->stereo_attenuation_max = 12.0f;
/* energy ratio thresholds (dB) */
(pstr_stereo_pre_pro)->sm_min = 0.0f;
(pstr_stereo_pre_pro)->sm_max = 15.0f;
(pstr_stereo_pre_pro)->lr_min = 10.0f;
(pstr_stereo_pre_pro)->lr_max = 30.0f;
/* pe thresholds */
(pstr_stereo_pre_pro)->pe_crit = 1200.0f;
(pstr_stereo_pre_pro)->pe_min = 700.0f;
(pstr_stereo_pre_pro)->pe_impact_max = 100.0f;
/* init start values */
(pstr_stereo_pre_pro)->average_freq_energy_l = 0.0f;
(pstr_stereo_pre_pro)->average_freq_energy_r = 0.0f;
(pstr_stereo_pre_pro)->average_freq_energy_s = 0.0f;
(pstr_stereo_pre_pro)->average_freq_energy_m = 0.0f;
(pstr_stereo_pre_pro)->smoothed_pe_sum_sum = 7000.0f; /* typical start value */
(pstr_stereo_pre_pro)->avg_s_to_m = -10.0f; /* typical start value */
(pstr_stereo_pre_pro)->last_l_to_r = 0.0f;
(pstr_stereo_pre_pro)->last_nrg_lr = 0.0f;
tmp = 1.0f - (bpf / 2600.0f);
tmp = MAX(tmp, 0.0f);
(pstr_stereo_pre_pro)->stereo_attenuation =
tmp * (pstr_stereo_pre_pro)->stereo_attenuation_max;
}
return IA_NO_ERROR;
}
VOID iaace_apply_stereo_preproc(ixheaace_stereo_pre_pro_pstr pstr_stereo_pre_pro,
WORD32 num_channels, ixheaace_element_info *pstr_elem_info,
FLOAT32 *ptr_time_data, WORD32 granule_len) {
FLOAT32 sm_ratio, s_to_m;
FLOAT32 lr_ratio, l_to_r, delta_l_to_r, delta_nrg;
FLOAT32 en_impact, pe_impact, pe_norm;
FLOAT32 att, att_aimed;
FLOAT32 max_inc, max_dec, swift_factor;
FLOAT32 delta = 0.1f;
FLOAT32 fac = pstr_stereo_pre_pro->stereo_attenuation_fac;
FLOAT32 m_part, upper, div;
FLOAT32 l_fac, r_fac;
FLOAT32 L, R;
WORD32 i;
if (!pstr_stereo_pre_pro->stereo_attenuation_flag) {
return;
}
m_part = 2.0f * pstr_stereo_pre_pro->average_freq_energy_m * (1.0f - fac * fac);
upper = pstr_stereo_pre_pro->average_freq_energy_l * (1.0f + fac) +
pstr_stereo_pre_pro->average_freq_energy_r * (1.0f - fac) - m_part;
div = pstr_stereo_pre_pro->average_freq_energy_r * (1.0f + fac) +
pstr_stereo_pre_pro->average_freq_energy_l * (1.0f - fac) - m_part;
if ((div == 0.0f) || (upper == 0.0f)) {
l_to_r = pstr_stereo_pre_pro->lr_max;
} else {
lr_ratio = (FLOAT32)fabs(upper / div);
l_to_r = (FLOAT32)fabs(10.0f * log10(lr_ratio));
}
/* Calculate delta energy to previous frame */
delta_nrg = (pstr_stereo_pre_pro->average_freq_energy_l +
pstr_stereo_pre_pro->average_freq_energy_r + 1.0f) /
(pstr_stereo_pre_pro->last_nrg_lr + 1.0f);
delta_nrg = (FLOAT32)(fabs(10.0f * log10(delta_nrg)));
/* Smooth S/M over time */
sm_ratio = (pstr_stereo_pre_pro->average_freq_energy_s + 1.0f) /
(pstr_stereo_pre_pro->average_freq_energy_m + 1.0f);
s_to_m = (FLOAT32)(10.0f * log10(sm_ratio));
pstr_stereo_pre_pro->avg_s_to_m =
delta * s_to_m + (1 - delta) * pstr_stereo_pre_pro->avg_s_to_m;
en_impact = 1.0f;
if (pstr_stereo_pre_pro->avg_s_to_m > pstr_stereo_pre_pro->sm_min) {
if (pstr_stereo_pre_pro->avg_s_to_m > pstr_stereo_pre_pro->sm_max) {
en_impact = 0.0f;
} else {
en_impact = (pstr_stereo_pre_pro->sm_max - pstr_stereo_pre_pro->avg_s_to_m) /
(pstr_stereo_pre_pro->sm_max - pstr_stereo_pre_pro->sm_min);
}
}
if (l_to_r > pstr_stereo_pre_pro->lr_min) {
if (l_to_r > pstr_stereo_pre_pro->lr_max) {
en_impact = 0.0f;
} else {
en_impact *= (pstr_stereo_pre_pro->lr_max - l_to_r) /
(pstr_stereo_pre_pro->lr_max - pstr_stereo_pre_pro->lr_min);
}
}
pe_impact = 0.0f;
pe_norm = pstr_stereo_pre_pro->smoothed_pe_sum_sum * pstr_stereo_pre_pro->norm_pe_fac;
if (pe_norm > pstr_stereo_pre_pro->pe_min) {
pe_impact = ((pe_norm - pstr_stereo_pre_pro->pe_min) /
(pstr_stereo_pre_pro->pe_crit - pstr_stereo_pre_pro->pe_min));
}
pe_impact = MIN(pe_impact, pstr_stereo_pre_pro->pe_impact_max);
att_aimed = MIN((en_impact * pe_impact * pstr_stereo_pre_pro->impact_factor),
pstr_stereo_pre_pro->stereo_attenuation_max);
/* Only accept changes if they are large enough */
if ((fabs(att_aimed - pstr_stereo_pre_pro->stereo_attenuation) < 1.0f) && (att_aimed != 0.0f)) {
att_aimed = pstr_stereo_pre_pro->stereo_attenuation;
}
att = att_aimed;
swift_factor = (6.0f + pstr_stereo_pre_pro->stereo_attenuation) / (10.0f + l_to_r) *
MAX(1.0f, 0.2f * delta_nrg);
delta_l_to_r = MAX(3.0f, l_to_r - pstr_stereo_pre_pro->last_l_to_r);
max_dec = MIN((delta_l_to_r * delta_l_to_r / 9.0f * swift_factor), 5.0f);
max_dec *= pstr_stereo_pre_pro->dec_stereo_attenuation;
max_dec = MIN(max_dec, pstr_stereo_pre_pro->stereo_attenuation * 0.8f);
delta_l_to_r = MAX(3.0f, pstr_stereo_pre_pro->last_l_to_r - l_to_r);
max_inc = MIN((delta_l_to_r * delta_l_to_r / 9.0f * swift_factor), 5.0f);
max_inc *= pstr_stereo_pre_pro->inc_stereo_attenuation;
att = MIN(att, pstr_stereo_pre_pro->stereo_attenuation + max_inc);
att = MAX(att, pstr_stereo_pre_pro->stereo_attenuation - max_dec);
pstr_stereo_pre_pro->stereo_attenuation = (pstr_stereo_pre_pro->const_attenuation == 0)
? att
: pstr_stereo_pre_pro->const_attenuation;
/* Perform attenuation of side channel */
pstr_stereo_pre_pro->stereo_attenuation_fac =
(FLOAT32)pow(10.0f, 0.05f * (-pstr_stereo_pre_pro->stereo_attenuation));
l_fac = 0.5f * (1.0f + pstr_stereo_pre_pro->stereo_attenuation_fac);
r_fac = 0.5f * (1.0f - pstr_stereo_pre_pro->stereo_attenuation_fac);
for (i = 0; i < granule_len; i++) {
L = l_fac * ptr_time_data[num_channels * i + pstr_elem_info->channel_index[0]] +
r_fac * ptr_time_data[num_channels * i + pstr_elem_info->channel_index[1]];
R = r_fac * ptr_time_data[num_channels * i + pstr_elem_info->channel_index[0]] +
l_fac * ptr_time_data[num_channels * i + pstr_elem_info->channel_index[1]];
ptr_time_data[num_channels * i + pstr_elem_info->channel_index[0]] = L;
ptr_time_data[num_channels * i + pstr_elem_info->channel_index[1]] = R;
}
pstr_stereo_pre_pro->last_l_to_r = l_to_r;
pstr_stereo_pre_pro->last_nrg_lr =
pstr_stereo_pre_pro->average_freq_energy_l + pstr_stereo_pre_pro->average_freq_energy_r;
}
VOID iaace_update_stereo_pre_process(ixheaace_psy_out_channel **pstr_psy_out,
ixheaace_qc_out_element *pstr_qc_out,
ixheaace_stereo_pre_pro_pstr pstr_stereo_pre_pro,
FLOAT32 weight_pe_fac) {
if (pstr_stereo_pre_pro->stereo_attenuation_flag) {
FLOAT32 delta = 0.1f;
pstr_stereo_pre_pro->average_freq_energy_l = pstr_psy_out[0]->sfb_sum_lr_energy;
pstr_stereo_pre_pro->average_freq_energy_r = pstr_psy_out[1]->sfb_sum_lr_energy;
pstr_stereo_pre_pro->average_freq_energy_m = pstr_psy_out[0]->sfb_sum_ms_energy;
pstr_stereo_pre_pro->average_freq_energy_s = pstr_psy_out[1]->sfb_sum_ms_energy;
pstr_stereo_pre_pro->smoothed_pe_sum_sum =
delta * pstr_qc_out->pe * weight_pe_fac +
(1 - delta) * pstr_stereo_pre_pro->smoothed_pe_sum_sum;
}
}