Chris@69: /*********************************************************************** Chris@69: Copyright (c) 2006-2011, Skype Limited. All rights reserved. Chris@69: Redistribution and use in source and binary forms, with or without Chris@69: modification, are permitted provided that the following conditions Chris@69: are met: Chris@69: - Redistributions of source code must retain the above copyright notice, Chris@69: this list of conditions and the following disclaimer. Chris@69: - Redistributions in binary form must reproduce the above copyright Chris@69: notice, this list of conditions and the following disclaimer in the Chris@69: documentation and/or other materials provided with the distribution. Chris@69: - Neither the name of Internet Society, IETF or IETF Trust, nor the Chris@69: names of specific contributors, may be used to endorse or promote Chris@69: products derived from this software without specific prior written Chris@69: permission. Chris@69: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" Chris@69: AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE Chris@69: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE Chris@69: ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE Chris@69: LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR Chris@69: CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF Chris@69: SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS Chris@69: INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN Chris@69: CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) Chris@69: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE Chris@69: POSSIBILITY OF SUCH DAMAGE. Chris@69: ***********************************************************************/ Chris@69: Chris@69: #ifdef HAVE_CONFIG_H Chris@69: #include "config.h" Chris@69: #endif Chris@69: Chris@69: #include "main_FLP.h" Chris@69: #include "tuning_parameters.h" Chris@69: Chris@69: /* Compute gain to make warped filter coefficients have a zero mean log frequency response on a */ Chris@69: /* non-warped frequency scale. (So that it can be implemented with a minimum-phase monic filter.) */ Chris@69: /* Note: A monic filter is one with the first coefficient equal to 1.0. In Silk we omit the first */ Chris@69: /* coefficient in an array of coefficients, for monic filters. */ Chris@69: static OPUS_INLINE silk_float warped_gain( Chris@69: const silk_float *coefs, Chris@69: silk_float lambda, Chris@69: opus_int order Chris@69: ) { Chris@69: opus_int i; Chris@69: silk_float gain; Chris@69: Chris@69: lambda = -lambda; Chris@69: gain = coefs[ order - 1 ]; Chris@69: for( i = order - 2; i >= 0; i-- ) { Chris@69: gain = lambda * gain + coefs[ i ]; Chris@69: } Chris@69: return (silk_float)( 1.0f / ( 1.0f - lambda * gain ) ); Chris@69: } Chris@69: Chris@69: /* Convert warped filter coefficients to monic pseudo-warped coefficients and limit maximum */ Chris@69: /* amplitude of monic warped coefficients by using bandwidth expansion on the true coefficients */ Chris@69: static OPUS_INLINE void warped_true2monic_coefs( Chris@69: silk_float *coefs, Chris@69: silk_float lambda, Chris@69: silk_float limit, Chris@69: opus_int order Chris@69: ) { Chris@69: opus_int i, iter, ind = 0; Chris@69: silk_float tmp, maxabs, chirp, gain; Chris@69: Chris@69: /* Convert to monic coefficients */ Chris@69: for( i = order - 1; i > 0; i-- ) { Chris@69: coefs[ i - 1 ] -= lambda * coefs[ i ]; Chris@69: } Chris@69: gain = ( 1.0f - lambda * lambda ) / ( 1.0f + lambda * coefs[ 0 ] ); Chris@69: for( i = 0; i < order; i++ ) { Chris@69: coefs[ i ] *= gain; Chris@69: } Chris@69: Chris@69: /* Limit */ Chris@69: for( iter = 0; iter < 10; iter++ ) { Chris@69: /* Find maximum absolute value */ Chris@69: maxabs = -1.0f; Chris@69: for( i = 0; i < order; i++ ) { Chris@69: tmp = silk_abs_float( coefs[ i ] ); Chris@69: if( tmp > maxabs ) { Chris@69: maxabs = tmp; Chris@69: ind = i; Chris@69: } Chris@69: } Chris@69: if( maxabs <= limit ) { Chris@69: /* Coefficients are within range - done */ Chris@69: return; Chris@69: } Chris@69: Chris@69: /* Convert back to true warped coefficients */ Chris@69: for( i = 1; i < order; i++ ) { Chris@69: coefs[ i - 1 ] += lambda * coefs[ i ]; Chris@69: } Chris@69: gain = 1.0f / gain; Chris@69: for( i = 0; i < order; i++ ) { Chris@69: coefs[ i ] *= gain; Chris@69: } Chris@69: Chris@69: /* Apply bandwidth expansion */ Chris@69: chirp = 0.99f - ( 0.8f + 0.1f * iter ) * ( maxabs - limit ) / ( maxabs * ( ind + 1 ) ); Chris@69: silk_bwexpander_FLP( coefs, order, chirp ); Chris@69: Chris@69: /* Convert to monic warped coefficients */ Chris@69: for( i = order - 1; i > 0; i-- ) { Chris@69: coefs[ i - 1 ] -= lambda * coefs[ i ]; Chris@69: } Chris@69: gain = ( 1.0f - lambda * lambda ) / ( 1.0f + lambda * coefs[ 0 ] ); Chris@69: for( i = 0; i < order; i++ ) { Chris@69: coefs[ i ] *= gain; Chris@69: } Chris@69: } Chris@69: silk_assert( 0 ); Chris@69: } Chris@69: Chris@69: static OPUS_INLINE void limit_coefs( Chris@69: silk_float *coefs, Chris@69: silk_float limit, Chris@69: opus_int order Chris@69: ) { Chris@69: opus_int i, iter, ind = 0; Chris@69: silk_float tmp, maxabs, chirp; Chris@69: Chris@69: for( iter = 0; iter < 10; iter++ ) { Chris@69: /* Find maximum absolute value */ Chris@69: maxabs = -1.0f; Chris@69: for( i = 0; i < order; i++ ) { Chris@69: tmp = silk_abs_float( coefs[ i ] ); Chris@69: if( tmp > maxabs ) { Chris@69: maxabs = tmp; Chris@69: ind = i; Chris@69: } Chris@69: } Chris@69: if( maxabs <= limit ) { Chris@69: /* Coefficients are within range - done */ Chris@69: return; Chris@69: } Chris@69: Chris@69: /* Apply bandwidth expansion */ Chris@69: chirp = 0.99f - ( 0.8f + 0.1f * iter ) * ( maxabs - limit ) / ( maxabs * ( ind + 1 ) ); Chris@69: silk_bwexpander_FLP( coefs, order, chirp ); Chris@69: } Chris@69: silk_assert( 0 ); Chris@69: } Chris@69: Chris@69: /* Compute noise shaping coefficients and initial gain values */ Chris@69: void silk_noise_shape_analysis_FLP( Chris@69: silk_encoder_state_FLP *psEnc, /* I/O Encoder state FLP */ Chris@69: silk_encoder_control_FLP *psEncCtrl, /* I/O Encoder control FLP */ Chris@69: const silk_float *pitch_res, /* I LPC residual from pitch analysis */ Chris@69: const silk_float *x /* I Input signal [frame_length + la_shape] */ Chris@69: ) Chris@69: { Chris@69: silk_shape_state_FLP *psShapeSt = &psEnc->sShape; Chris@69: opus_int k, nSamples, nSegs; Chris@69: silk_float SNR_adj_dB, HarmShapeGain, Tilt; Chris@69: silk_float nrg, log_energy, log_energy_prev, energy_variation; Chris@69: silk_float BWExp, gain_mult, gain_add, strength, b, warping; Chris@69: silk_float x_windowed[ SHAPE_LPC_WIN_MAX ]; Chris@69: silk_float auto_corr[ MAX_SHAPE_LPC_ORDER + 1 ]; Chris@69: silk_float rc[ MAX_SHAPE_LPC_ORDER + 1 ]; Chris@69: const silk_float *x_ptr, *pitch_res_ptr; Chris@69: Chris@69: /* Point to start of first LPC analysis block */ Chris@69: x_ptr = x - psEnc->sCmn.la_shape; Chris@69: Chris@69: /****************/ Chris@69: /* GAIN CONTROL */ Chris@69: /****************/ Chris@69: SNR_adj_dB = psEnc->sCmn.SNR_dB_Q7 * ( 1 / 128.0f ); Chris@69: Chris@69: /* Input quality is the average of the quality in the lowest two VAD bands */ Chris@69: psEncCtrl->input_quality = 0.5f * ( psEnc->sCmn.input_quality_bands_Q15[ 0 ] + psEnc->sCmn.input_quality_bands_Q15[ 1 ] ) * ( 1.0f / 32768.0f ); Chris@69: Chris@69: /* Coding quality level, between 0.0 and 1.0 */ Chris@69: psEncCtrl->coding_quality = silk_sigmoid( 0.25f * ( SNR_adj_dB - 20.0f ) ); Chris@69: Chris@69: if( psEnc->sCmn.useCBR == 0 ) { Chris@69: /* Reduce coding SNR during low speech activity */ Chris@69: b = 1.0f - psEnc->sCmn.speech_activity_Q8 * ( 1.0f / 256.0f ); Chris@69: SNR_adj_dB -= BG_SNR_DECR_dB * psEncCtrl->coding_quality * ( 0.5f + 0.5f * psEncCtrl->input_quality ) * b * b; Chris@69: } Chris@69: Chris@69: if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) { Chris@69: /* Reduce gains for periodic signals */ Chris@69: SNR_adj_dB += HARM_SNR_INCR_dB * psEnc->LTPCorr; Chris@69: } else { Chris@69: /* For unvoiced signals and low-quality input, adjust the quality slower than SNR_dB setting */ Chris@69: SNR_adj_dB += ( -0.4f * psEnc->sCmn.SNR_dB_Q7 * ( 1 / 128.0f ) + 6.0f ) * ( 1.0f - psEncCtrl->input_quality ); Chris@69: } Chris@69: Chris@69: /*************************/ Chris@69: /* SPARSENESS PROCESSING */ Chris@69: /*************************/ Chris@69: /* Set quantizer offset */ Chris@69: if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) { Chris@69: /* Initially set to 0; may be overruled in process_gains(..) */ Chris@69: psEnc->sCmn.indices.quantOffsetType = 0; Chris@69: } else { Chris@69: /* Sparseness measure, based on relative fluctuations of energy per 2 milliseconds */ Chris@69: nSamples = 2 * psEnc->sCmn.fs_kHz; Chris@69: energy_variation = 0.0f; Chris@69: log_energy_prev = 0.0f; Chris@69: pitch_res_ptr = pitch_res; Chris@69: nSegs = silk_SMULBB( SUB_FRAME_LENGTH_MS, psEnc->sCmn.nb_subfr ) / 2; Chris@69: for( k = 0; k < nSegs; k++ ) { Chris@69: nrg = ( silk_float )nSamples + ( silk_float )silk_energy_FLP( pitch_res_ptr, nSamples ); Chris@69: log_energy = silk_log2( nrg ); Chris@69: if( k > 0 ) { Chris@69: energy_variation += silk_abs_float( log_energy - log_energy_prev ); Chris@69: } Chris@69: log_energy_prev = log_energy; Chris@69: pitch_res_ptr += nSamples; Chris@69: } Chris@69: Chris@69: /* Set quantization offset depending on sparseness measure */ Chris@69: if( energy_variation > ENERGY_VARIATION_THRESHOLD_QNT_OFFSET * (nSegs-1) ) { Chris@69: psEnc->sCmn.indices.quantOffsetType = 0; Chris@69: } else { Chris@69: psEnc->sCmn.indices.quantOffsetType = 1; Chris@69: } Chris@69: } Chris@69: Chris@69: /*******************************/ Chris@69: /* Control bandwidth expansion */ Chris@69: /*******************************/ Chris@69: /* More BWE for signals with high prediction gain */ Chris@69: strength = FIND_PITCH_WHITE_NOISE_FRACTION * psEncCtrl->predGain; /* between 0.0 and 1.0 */ Chris@69: BWExp = BANDWIDTH_EXPANSION / ( 1.0f + strength * strength ); Chris@69: Chris@69: /* Slightly more warping in analysis will move quantization noise up in frequency, where it's better masked */ Chris@69: warping = (silk_float)psEnc->sCmn.warping_Q16 / 65536.0f + 0.01f * psEncCtrl->coding_quality; Chris@69: Chris@69: /********************************************/ Chris@69: /* Compute noise shaping AR coefs and gains */ Chris@69: /********************************************/ Chris@69: for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) { Chris@69: /* Apply window: sine slope followed by flat part followed by cosine slope */ Chris@69: opus_int shift, slope_part, flat_part; Chris@69: flat_part = psEnc->sCmn.fs_kHz * 3; Chris@69: slope_part = ( psEnc->sCmn.shapeWinLength - flat_part ) / 2; Chris@69: Chris@69: silk_apply_sine_window_FLP( x_windowed, x_ptr, 1, slope_part ); Chris@69: shift = slope_part; Chris@69: silk_memcpy( x_windowed + shift, x_ptr + shift, flat_part * sizeof(silk_float) ); Chris@69: shift += flat_part; Chris@69: silk_apply_sine_window_FLP( x_windowed + shift, x_ptr + shift, 2, slope_part ); Chris@69: Chris@69: /* Update pointer: next LPC analysis block */ Chris@69: x_ptr += psEnc->sCmn.subfr_length; Chris@69: Chris@69: if( psEnc->sCmn.warping_Q16 > 0 ) { Chris@69: /* Calculate warped auto correlation */ Chris@69: silk_warped_autocorrelation_FLP( auto_corr, x_windowed, warping, Chris@69: psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder ); Chris@69: } else { Chris@69: /* Calculate regular auto correlation */ Chris@69: silk_autocorrelation_FLP( auto_corr, x_windowed, psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder + 1 ); Chris@69: } Chris@69: Chris@69: /* Add white noise, as a fraction of energy */ Chris@69: auto_corr[ 0 ] += auto_corr[ 0 ] * SHAPE_WHITE_NOISE_FRACTION + 1.0f; Chris@69: Chris@69: /* Convert correlations to prediction coefficients, and compute residual energy */ Chris@69: nrg = silk_schur_FLP( rc, auto_corr, psEnc->sCmn.shapingLPCOrder ); Chris@69: silk_k2a_FLP( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], rc, psEnc->sCmn.shapingLPCOrder ); Chris@69: psEncCtrl->Gains[ k ] = ( silk_float )sqrt( nrg ); Chris@69: Chris@69: if( psEnc->sCmn.warping_Q16 > 0 ) { Chris@69: /* Adjust gain for warping */ Chris@69: psEncCtrl->Gains[ k ] *= warped_gain( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], warping, psEnc->sCmn.shapingLPCOrder ); Chris@69: } Chris@69: Chris@69: /* Bandwidth expansion for synthesis filter shaping */ Chris@69: silk_bwexpander_FLP( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], psEnc->sCmn.shapingLPCOrder, BWExp ); Chris@69: Chris@69: if( psEnc->sCmn.warping_Q16 > 0 ) { Chris@69: /* Convert to monic warped prediction coefficients and limit absolute values */ Chris@69: warped_true2monic_coefs( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], warping, 3.999f, psEnc->sCmn.shapingLPCOrder ); Chris@69: } else { Chris@69: /* Limit absolute values */ Chris@69: limit_coefs( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], 3.999f, psEnc->sCmn.shapingLPCOrder ); Chris@69: } Chris@69: } Chris@69: Chris@69: /*****************/ Chris@69: /* Gain tweaking */ Chris@69: /*****************/ Chris@69: /* Increase gains during low speech activity */ Chris@69: gain_mult = (silk_float)pow( 2.0f, -0.16f * SNR_adj_dB ); Chris@69: gain_add = (silk_float)pow( 2.0f, 0.16f * MIN_QGAIN_DB ); Chris@69: for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) { Chris@69: psEncCtrl->Gains[ k ] *= gain_mult; Chris@69: psEncCtrl->Gains[ k ] += gain_add; Chris@69: } Chris@69: Chris@69: /************************************************/ Chris@69: /* Control low-frequency shaping and noise tilt */ Chris@69: /************************************************/ Chris@69: /* Less low frequency shaping for noisy inputs */ Chris@69: strength = LOW_FREQ_SHAPING * ( 1.0f + LOW_QUALITY_LOW_FREQ_SHAPING_DECR * ( psEnc->sCmn.input_quality_bands_Q15[ 0 ] * ( 1.0f / 32768.0f ) - 1.0f ) ); Chris@69: strength *= psEnc->sCmn.speech_activity_Q8 * ( 1.0f / 256.0f ); Chris@69: if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) { Chris@69: /* Reduce low frequencies quantization noise for periodic signals, depending on pitch lag */ Chris@69: /*f = 400; freqz([1, -0.98 + 2e-4 * f], [1, -0.97 + 7e-4 * f], 2^12, Fs); axis([0, 1000, -10, 1])*/ Chris@69: for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) { Chris@69: b = 0.2f / psEnc->sCmn.fs_kHz + 3.0f / psEncCtrl->pitchL[ k ]; Chris@69: psEncCtrl->LF_MA_shp[ k ] = -1.0f + b; Chris@69: psEncCtrl->LF_AR_shp[ k ] = 1.0f - b - b * strength; Chris@69: } Chris@69: Tilt = - HP_NOISE_COEF - Chris@69: (1 - HP_NOISE_COEF) * HARM_HP_NOISE_COEF * psEnc->sCmn.speech_activity_Q8 * ( 1.0f / 256.0f ); Chris@69: } else { Chris@69: b = 1.3f / psEnc->sCmn.fs_kHz; Chris@69: psEncCtrl->LF_MA_shp[ 0 ] = -1.0f + b; Chris@69: psEncCtrl->LF_AR_shp[ 0 ] = 1.0f - b - b * strength * 0.6f; Chris@69: for( k = 1; k < psEnc->sCmn.nb_subfr; k++ ) { Chris@69: psEncCtrl->LF_MA_shp[ k ] = psEncCtrl->LF_MA_shp[ 0 ]; Chris@69: psEncCtrl->LF_AR_shp[ k ] = psEncCtrl->LF_AR_shp[ 0 ]; Chris@69: } Chris@69: Tilt = -HP_NOISE_COEF; Chris@69: } Chris@69: Chris@69: /****************************/ Chris@69: /* HARMONIC SHAPING CONTROL */ Chris@69: /****************************/ Chris@69: if( USE_HARM_SHAPING && psEnc->sCmn.indices.signalType == TYPE_VOICED ) { Chris@69: /* Harmonic noise shaping */ Chris@69: HarmShapeGain = HARMONIC_SHAPING; Chris@69: Chris@69: /* More harmonic noise shaping for high bitrates or noisy input */ Chris@69: HarmShapeGain += HIGH_RATE_OR_LOW_QUALITY_HARMONIC_SHAPING * Chris@69: ( 1.0f - ( 1.0f - psEncCtrl->coding_quality ) * psEncCtrl->input_quality ); Chris@69: Chris@69: /* Less harmonic noise shaping for less periodic signals */ Chris@69: HarmShapeGain *= ( silk_float )sqrt( psEnc->LTPCorr ); Chris@69: } else { Chris@69: HarmShapeGain = 0.0f; Chris@69: } Chris@69: Chris@69: /*************************/ Chris@69: /* Smooth over subframes */ Chris@69: /*************************/ Chris@69: for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) { Chris@69: psShapeSt->HarmShapeGain_smth += SUBFR_SMTH_COEF * ( HarmShapeGain - psShapeSt->HarmShapeGain_smth ); Chris@69: psEncCtrl->HarmShapeGain[ k ] = psShapeSt->HarmShapeGain_smth; Chris@69: psShapeSt->Tilt_smth += SUBFR_SMTH_COEF * ( Tilt - psShapeSt->Tilt_smth ); Chris@69: psEncCtrl->Tilt[ k ] = psShapeSt->Tilt_smth; Chris@69: } Chris@69: }