mirror of
https://github.com/rehlds/revoice.git
synced 2025-01-30 07:28:14 +03:00
105 lines
5.0 KiB
C
105 lines
5.0 KiB
C
/***********************************************************************
|
|
Copyright (c) 2006-2012, Skype Limited. All rights reserved.
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, (subject to the limitations in the disclaimer below)
|
|
are permitted provided that the following conditions are met:
|
|
- Redistributions of source code must retain the above copyright notice,
|
|
this list of conditions and the following disclaimer.
|
|
- Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in the
|
|
documentation and/or other materials provided with the distribution.
|
|
- Neither the name of Skype Limited, nor the names of specific
|
|
contributors, may be used to endorse or promote products derived from
|
|
this software without specific prior written permission.
|
|
NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED
|
|
BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
|
|
CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
|
|
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
|
|
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
|
|
USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
|
|
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
***********************************************************************/
|
|
|
|
#include "SKP_Silk_main_FLP.h"
|
|
#include "SKP_Silk_tuning_parameters.h"
|
|
|
|
#if HIGH_PASS_INPUT
|
|
|
|
/* High-pass filter with cutoff frequency adaptation based on pitch lag statistics */
|
|
void SKP_Silk_HP_variable_cutoff_FLP(
|
|
SKP_Silk_encoder_state_FLP *psEnc, /* I/O Encoder state FLP */
|
|
SKP_Silk_encoder_control_FLP *psEncCtrl, /* I/O Encoder control FLP */
|
|
SKP_int16 *out, /* O High-pass filtered output signal */
|
|
const SKP_int16 *in /* I Input signal */
|
|
)
|
|
{
|
|
SKP_float pitch_freq_Hz, pitch_freq_log, quality, delta_freq, smth_coef, Fc, r;
|
|
SKP_int32 B_Q28[ 3 ], A_Q28[ 2 ];
|
|
|
|
/*********************************************/
|
|
/* Estimate low end of pitch frequency range */
|
|
/*********************************************/
|
|
if( psEnc->sCmn.prev_sigtype == SIG_TYPE_VOICED ) {
|
|
|
|
/* Difference, in log domain */
|
|
pitch_freq_Hz = 1e3f * psEnc->sCmn.fs_kHz / psEnc->sCmn.prevLag;
|
|
pitch_freq_log = SKP_Silk_log2( pitch_freq_Hz );
|
|
|
|
/* Adjustment based on quality */
|
|
quality = psEncCtrl->input_quality_bands[ 0 ];
|
|
pitch_freq_log -= quality * quality * ( pitch_freq_log - SKP_Silk_log2( VARIABLE_HP_MIN_FREQ ) );
|
|
pitch_freq_log += 0.5f * ( 0.6f - quality );
|
|
|
|
delta_freq = pitch_freq_log - psEnc->variable_HP_smth1;
|
|
if( delta_freq < 0.0 ) {
|
|
/* Less smoothing for decreasing pitch frequency, to track something close to the minimum */
|
|
delta_freq *= 3.0f;
|
|
}
|
|
|
|
/* Limit delta, to reduce impact of outliers */
|
|
delta_freq = SKP_LIMIT_float( delta_freq, -VARIABLE_HP_MAX_DELTA_FREQ, VARIABLE_HP_MAX_DELTA_FREQ );
|
|
|
|
/* Update smoother */
|
|
smth_coef = VARIABLE_HP_SMTH_COEF1 * psEnc->speech_activity;
|
|
psEnc->variable_HP_smth1 += smth_coef * delta_freq;
|
|
}
|
|
|
|
/* Second smoother */
|
|
psEnc->variable_HP_smth2 += VARIABLE_HP_SMTH_COEF2 * ( psEnc->variable_HP_smth1 - psEnc->variable_HP_smth2 );
|
|
|
|
/* Convert from log scale to Hertz */
|
|
psEncCtrl->pitch_freq_low_Hz = ( SKP_float )pow( 2.0f, psEnc->variable_HP_smth2 );
|
|
|
|
/* Limit frequency range */
|
|
psEncCtrl->pitch_freq_low_Hz = SKP_LIMIT_float( psEncCtrl->pitch_freq_low_Hz, VARIABLE_HP_MIN_FREQ, VARIABLE_HP_MAX_FREQ );
|
|
|
|
/*******************************/
|
|
/* Compute filter coefficients */
|
|
/*******************************/
|
|
/* Compute cut-off frequency, in radians */
|
|
Fc = ( SKP_float )( 0.45f * 2.0f * 3.14159265359 * psEncCtrl->pitch_freq_low_Hz / ( 1e3f * psEnc->sCmn.fs_kHz ) );
|
|
|
|
/* 2nd order ARMA coefficients */
|
|
r = 1.0f - 0.92f * Fc;
|
|
|
|
/* b = r * [1; -2; 1]; */
|
|
/* a = [1; -2 * r * (1 - 0.5 * Fc^2); r^2]; */
|
|
B_Q28[ 0 ] = SKP_float2int( ( 1 << 28 ) * r );
|
|
B_Q28[ 1 ] = SKP_float2int( ( 1 << 28 ) * -2.0f * r );
|
|
B_Q28[ 2 ] = B_Q28[ 0 ];
|
|
A_Q28[ 0 ] = SKP_float2int( ( 1 << 28 ) * -2.0f * r * ( 1.0f - 0.5f * Fc * Fc ) );
|
|
A_Q28[ 1 ] = SKP_float2int( ( 1 << 28 ) * r * r );
|
|
|
|
/********************/
|
|
/* High-pass filter */
|
|
/********************/
|
|
SKP_Silk_biquad_alt( in, B_Q28, A_Q28, psEnc->sCmn.In_HP_State, out, psEnc->sCmn.frame_length );
|
|
}
|
|
|
|
#endif // HIGH_PASS_INPUT
|