/src/opus/silk/float/noise_shape_analysis_FLP.c

Source
/***********************************************************************
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, 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 Internet Society, IETF or IETF Trust, nor the
names of specific contributors, may be used to endorse or promote
products derived from this software without specific prior written
permission.
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.
***********************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "main_FLP.h"
#include "tuning_parameters.h"

/* Compute gain to make warped filter coefficients have a zero mean log frequency response on a   */
/* non-warped frequency scale. (So that it can be implemented with a minimum-phase monic filter.) */
/* Note: A monic filter is one with the first coefficient equal to 1.0. In Silk we omit the first */
/* coefficient in an array of coefficients, for monic filters.                                    */
static OPUS_INLINE silk_float warped_gain(
    const silk_float     *coefs,
    silk_float           lambda,
    opus_int             order
) {
    opus_int   i;
    silk_float gain;

    lambda = -lambda;
    gain = coefs[ order - 1 ];
    for( i = order - 2; i >= 0; i-- ) {
        gain = lambda * gain + coefs[ i ];
    }
    return (silk_float)( 1.0f / ( 1.0f - lambda * gain ) );
}

/* Convert warped filter coefficients to monic pseudo-warped coefficients and limit maximum     */
/* amplitude of monic warped coefficients by using bandwidth expansion on the true coefficients */
static OPUS_INLINE void warped_true2monic_coefs(
    silk_float           *coefs,
    silk_float           lambda,
    silk_float           limit,
    opus_int             order
) {
    opus_int   i, iter, ind = 0;
    silk_float tmp, maxabs, chirp, gain;

    /* Convert to monic coefficients */
    for( i = order - 1; i > 0; i-- ) {
        coefs[ i - 1 ] -= lambda * coefs[ i ];
    }
    gain = ( 1.0f - lambda * lambda ) / ( 1.0f + lambda * coefs[ 0 ] );
    for( i = 0; i < order; i++ ) {
        coefs[ i ] *= gain;
    }

    /* Limit */
    for( iter = 0; iter < 10; iter++ ) {
        /* Find maximum absolute value */
        maxabs = -1.0f;
        for( i = 0; i < order; i++ ) {
            tmp = silk_abs_float( coefs[ i ] );
            if( tmp > maxabs ) {
                maxabs = tmp;
                ind = i;
            }
        }
        if( maxabs <= limit ) {
            /* Coefficients are within range - done */
            return;
        }

        /* Convert back to true warped coefficients */
        for( i = 1; i < order; i++ ) {
            coefs[ i - 1 ] += lambda * coefs[ i ];
        }
        gain = 1.0f / gain;
        for( i = 0; i < order; i++ ) {
            coefs[ i ] *= gain;
        }

        /* Apply bandwidth expansion */
        chirp = 0.99f - ( 0.8f + 0.1f * iter ) * ( maxabs - limit ) / ( maxabs * ( ind + 1 ) );
        silk_bwexpander_FLP( coefs, order, chirp );

        /* Convert to monic warped coefficients */
        for( i = order - 1; i > 0; i-- ) {
            coefs[ i - 1 ] -= lambda * coefs[ i ];
        }
        gain = ( 1.0f - lambda * lambda ) / ( 1.0f + lambda * coefs[ 0 ] );
        for( i = 0; i < order; i++ ) {
            coefs[ i ] *= gain;
        }
    }
    silk_assert( 0 );
}

static OPUS_INLINE void limit_coefs(
    silk_float           *coefs,
    silk_float           limit,
    opus_int             order
) {
    opus_int   i, iter, ind = 0;
    silk_float tmp, maxabs, chirp;

    for( iter = 0; iter < 10; iter++ ) {
        /* Find maximum absolute value */
        maxabs = -1.0f;
        for( i = 0; i < order; i++ ) {
            tmp = silk_abs_float( coefs[ i ] );
            if( tmp > maxabs ) {
                maxabs = tmp;
                ind = i;
            }
        }
        if( maxabs <= limit ) {
            /* Coefficients are within range - done */
            return;
        }

        /* Apply bandwidth expansion */
        chirp = 0.99f - ( 0.8f + 0.1f * iter ) * ( maxabs - limit ) / ( maxabs * ( ind + 1 ) );
        silk_bwexpander_FLP( coefs, order, chirp );
    }
    silk_assert( 0 );
}

/* Compute noise shaping coefficients and initial gain values */
void silk_noise_shape_analysis_FLP(
    silk_encoder_state_FLP          *psEnc,                             /* I/O  Encoder state FLP                           */
    silk_encoder_control_FLP        *psEncCtrl,                         /* I/O  Encoder control FLP                         */
    const silk_float                *pitch_res,                         /* I    LPC residual from pitch analysis            */
    const silk_float                *x                                  /* I    Input signal [frame_length + la_shape]      */
)
{
    silk_shape_state_FLP *psShapeSt = &psEnc->sShape;
    opus_int     k, nSamples, nSegs;
    silk_float   SNR_adj_dB, HarmShapeGain, Tilt;
    silk_float   nrg, log_energy, log_energy_prev, energy_variation;
    silk_float   BWExp, gain_mult, gain_add, strength, b, warping;
    silk_float   x_windowed[ SHAPE_LPC_WIN_MAX ];
    silk_float   auto_corr[ MAX_SHAPE_LPC_ORDER + 1 ];
    silk_float   rc[ MAX_SHAPE_LPC_ORDER + 1 ];
    const silk_float *x_ptr, *pitch_res_ptr;

    /* Point to start of first LPC analysis block */
    x_ptr = x - psEnc->sCmn.la_shape;

    /****************/
    /* GAIN CONTROL */
    /****************/
    SNR_adj_dB = psEnc->sCmn.SNR_dB_Q7 * ( 1 / 128.0f );

    /* Input quality is the average of the quality in the lowest two VAD bands */
    psEncCtrl->input_quality = 0.5f * ( psEnc->sCmn.input_quality_bands_Q15[ 0 ] + psEnc->sCmn.input_quality_bands_Q15[ 1 ] ) * ( 1.0f / 32768.0f );

    /* Coding quality level, between 0.0 and 1.0 */
    psEncCtrl->coding_quality = silk_sigmoid( 0.25f * ( SNR_adj_dB - 20.0f ) );

    if( psEnc->sCmn.useCBR == 0 ) {
        /* Reduce coding SNR during low speech activity */
        b = 1.0f - psEnc->sCmn.speech_activity_Q8 * ( 1.0f /  256.0f );
        SNR_adj_dB -= BG_SNR_DECR_dB * psEncCtrl->coding_quality * ( 0.5f + 0.5f * psEncCtrl->input_quality ) * b * b;
    }

    if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
        /* Reduce gains for periodic signals */
        SNR_adj_dB += HARM_SNR_INCR_dB * psEnc->LTPCorr;
    } else {
        /* For unvoiced signals and low-quality input, adjust the quality slower than SNR_dB setting */
        SNR_adj_dB += ( -0.4f * psEnc->sCmn.SNR_dB_Q7 * ( 1 / 128.0f ) + 6.0f ) * ( 1.0f - psEncCtrl->input_quality );
    }

    /*************************/
    /* SPARSENESS PROCESSING */
    /*************************/
    /* Set quantizer offset */
    if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
        /* Initially set to 0; may be overruled in process_gains(..) */
        psEnc->sCmn.indices.quantOffsetType = 0;
    } else {
        /* Sparseness measure, based on relative fluctuations of energy per 2 milliseconds */
        nSamples = 2 * psEnc->sCmn.fs_kHz;
        energy_variation = 0.0f;
        log_energy_prev  = 0.0f;
        pitch_res_ptr = pitch_res;
        nSegs = silk_SMULBB( SUB_FRAME_LENGTH_MS, psEnc->sCmn.nb_subfr ) / 2;
        for( k = 0; k < nSegs; k++ ) {
            nrg = ( silk_float )nSamples + ( silk_float )silk_energy_FLP( pitch_res_ptr, nSamples );
            log_energy = silk_log2( nrg );
            if( k > 0 ) {
                energy_variation += silk_abs_float( log_energy - log_energy_prev );
            }
            log_energy_prev = log_energy;
            pitch_res_ptr += nSamples;
        }

        /* Set quantization offset depending on sparseness measure */
        if( energy_variation > ENERGY_VARIATION_THRESHOLD_QNT_OFFSET * (nSegs-1) ) {
            psEnc->sCmn.indices.quantOffsetType = 0;
        } else {
            psEnc->sCmn.indices.quantOffsetType = 1;
        }
    }

    /*******************************/
    /* Control bandwidth expansion */
    /*******************************/
    /* More BWE for signals with high prediction gain */
    strength = FIND_PITCH_WHITE_NOISE_FRACTION * psEncCtrl->predGain;           /* between 0.0 and 1.0 */
    BWExp = BANDWIDTH_EXPANSION / ( 1.0f + strength * strength );

    /* Slightly more warping in analysis will move quantization noise up in frequency, where it's better masked */
    warping = (silk_float)psEnc->sCmn.warping_Q16 / 65536.0f + 0.01f * psEncCtrl->coding_quality;

    /********************************************/
    /* Compute noise shaping AR coefs and gains */
    /********************************************/
    for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
        /* Apply window: sine slope followed by flat part followed by cosine slope */
        opus_int shift, slope_part, flat_part;
        flat_part = psEnc->sCmn.fs_kHz * 3;
        slope_part = ( psEnc->sCmn.shapeWinLength - flat_part ) / 2;

        silk_apply_sine_window_FLP( x_windowed, x_ptr, 1, slope_part );
        shift = slope_part;
        silk_memcpy( x_windowed + shift, x_ptr + shift, flat_part * sizeof(silk_float) );
        shift += flat_part;
        silk_apply_sine_window_FLP( x_windowed + shift, x_ptr + shift, 2, slope_part );

        /* Update pointer: next LPC analysis block */
        x_ptr += psEnc->sCmn.subfr_length;

        if( psEnc->sCmn.warping_Q16 > 0 ) {
            /* Calculate warped auto correlation */
            silk_warped_autocorrelation_FLP( auto_corr, x_windowed, warping,
                psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder );
        } else {
            /* Calculate regular auto correlation */
            silk_autocorrelation_FLP( auto_corr, x_windowed, psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder + 1, psEnc->sCmn.arch );
        }

        /* Add white noise, as a fraction of energy */
        auto_corr[ 0 ] += auto_corr[ 0 ] * SHAPE_WHITE_NOISE_FRACTION + 1.0f;

        /* Convert correlations to prediction coefficients, and compute residual energy */
        nrg = silk_schur_FLP( rc, auto_corr, psEnc->sCmn.shapingLPCOrder );
        silk_k2a_FLP( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], rc, psEnc->sCmn.shapingLPCOrder );
        psEncCtrl->Gains[ k ] = ( silk_float )sqrt( nrg );

        if( psEnc->sCmn.warping_Q16 > 0 ) {
            /* Adjust gain for warping */
            psEncCtrl->Gains[ k ] *= warped_gain( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], warping, psEnc->sCmn.shapingLPCOrder );
        }

        /* Bandwidth expansion for synthesis filter shaping */
        silk_bwexpander_FLP( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], psEnc->sCmn.shapingLPCOrder, BWExp );

        if( psEnc->sCmn.warping_Q16 > 0 ) {
            /* Convert to monic warped prediction coefficients and limit absolute values */
            warped_true2monic_coefs( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], warping, 3.999f, psEnc->sCmn.shapingLPCOrder );
        } else {
            /* Limit absolute values */
            limit_coefs( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], 3.999f, psEnc->sCmn.shapingLPCOrder );
        }
    }

    /*****************/
    /* Gain tweaking */
    /*****************/
    /* Increase gains during low speech activity */
    gain_mult = (silk_float)pow( 2.0f, -0.16f * SNR_adj_dB );
    gain_add  = (silk_float)pow( 2.0f,  0.16f * MIN_QGAIN_DB );
    for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
        psEncCtrl->Gains[ k ] *= gain_mult;
        psEncCtrl->Gains[ k ] += gain_add;
    }

    /************************************************/
    /* Control low-frequency shaping and noise tilt */
    /************************************************/
    /* Less low frequency shaping for noisy inputs */
    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 ) );
    strength *= psEnc->sCmn.speech_activity_Q8 * ( 1.0f /  256.0f );
    if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
        /* Reduce low frequencies quantization noise for periodic signals, depending on pitch lag */
        /*f = 400; freqz([1, -0.98 + 2e-4 * f], [1, -0.97 + 7e-4 * f], 2^12, Fs); axis([0, 1000, -10, 1])*/
        for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
            b = 0.2f / psEnc->sCmn.fs_kHz + 3.0f / psEncCtrl->pitchL[ k ];
            psEncCtrl->LF_MA_shp[ k ] = -1.0f + b;
            psEncCtrl->LF_AR_shp[ k ] =  1.0f - b - b * strength;
        }
        Tilt = - HP_NOISE_COEF -
            (1 - HP_NOISE_COEF) * HARM_HP_NOISE_COEF * psEnc->sCmn.speech_activity_Q8 * ( 1.0f /  256.0f );
    } else {
        b = 1.3f / psEnc->sCmn.fs_kHz;
        psEncCtrl->LF_MA_shp[ 0 ] = -1.0f + b;
        psEncCtrl->LF_AR_shp[ 0 ] =  1.0f - b - b * strength * 0.6f;
        for( k = 1; k < psEnc->sCmn.nb_subfr; k++ ) {
            psEncCtrl->LF_MA_shp[ k ] = psEncCtrl->LF_MA_shp[ 0 ];
            psEncCtrl->LF_AR_shp[ k ] = psEncCtrl->LF_AR_shp[ 0 ];
        }
        Tilt = -HP_NOISE_COEF;
    }

    /****************************/
    /* HARMONIC SHAPING CONTROL */
    /****************************/
    if( USE_HARM_SHAPING && psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
        /* Harmonic noise shaping */
        HarmShapeGain = HARMONIC_SHAPING;

        /* More harmonic noise shaping for high bitrates or noisy input */
        HarmShapeGain += HIGH_RATE_OR_LOW_QUALITY_HARMONIC_SHAPING *
            ( 1.0f - ( 1.0f - psEncCtrl->coding_quality ) * psEncCtrl->input_quality );

        /* Less harmonic noise shaping for less periodic signals */
        HarmShapeGain *= ( silk_float )sqrt( psEnc->LTPCorr );
    } else {
        HarmShapeGain = 0.0f;
    }

    /*************************/
    /* Smooth over subframes */
    /*************************/
    for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
        psShapeSt->HarmShapeGain_smth += SUBFR_SMTH_COEF * ( HarmShapeGain - psShapeSt->HarmShapeGain_smth );
        psEncCtrl->HarmShapeGain[ k ]  = psShapeSt->HarmShapeGain_smth;
        psShapeSt->Tilt_smth          += SUBFR_SMTH_COEF * ( Tilt - psShapeSt->Tilt_smth );
        psEncCtrl->Tilt[ k ]           = psShapeSt->Tilt_smth;
    }
}

Coverage Report

Created: 2025-12-14 07:08

Line	Count	Source
1		/***********************************************************************
2		Copyright (c) 2006-2011, Skype Limited. All rights reserved.
3		Redistribution and use in source and binary forms, with or without
4		modification, are permitted provided that the following conditions
5		are met:
6		- Redistributions of source code must retain the above copyright notice,
7		this list of conditions and the following disclaimer.
8		- Redistributions in binary form must reproduce the above copyright
9		notice, this list of conditions and the following disclaimer in the
10		documentation and/or other materials provided with the distribution.
11		- Neither the name of Internet Society, IETF or IETF Trust, nor the
12		names of specific contributors, may be used to endorse or promote
13		products derived from this software without specific prior written
14		permission.
15		THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16		AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17		IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18		ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
19		LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20		CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21		SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22		INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23		CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24		ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25		POSSIBILITY OF SUCH DAMAGE.
26		***********************************************************************/
27
28		#ifdef HAVE_CONFIG_H
29		#include "config.h"
30		#endif
31
32		#include "main_FLP.h"
33		#include "tuning_parameters.h"
34
35		/* Compute gain to make warped filter coefficients have a zero mean log frequency response on a */
36		/* non-warped frequency scale. (So that it can be implemented with a minimum-phase monic filter.) */
37		/* Note: A monic filter is one with the first coefficient equal to 1.0. In Silk we omit the first */
38		/* coefficient in an array of coefficients, for monic filters. */
39		static OPUS_INLINE silk_float warped_gain(
40		const silk_float *coefs,
41		silk_float lambda,
42		opus_int order
43	48.4M	) {
44	48.4M	opus_int i;
45	48.4M	silk_float gain;
46
47	48.4M	lambda = -lambda;
48	48.4M	gain = coefs[ order - 1 ];
49	982M	for( i = order - 2; i >= 0; i-- ) {
50	933M	gain = lambda * gain + coefs[ i ];
51	933M	}
52	48.4M	return (silk_float)( 1.0f / ( 1.0f - lambda * gain ) );
53	48.4M	}
54
55		/* Convert warped filter coefficients to monic pseudo-warped coefficients and limit maximum */
56		/* amplitude of monic warped coefficients by using bandwidth expansion on the true coefficients */
57		static OPUS_INLINE void warped_true2monic_coefs(
58		silk_float *coefs,
59		silk_float lambda,
60		silk_float limit,
61		opus_int order
62	48.4M	) {
63	48.4M	opus_int i, iter, ind = 0;
64	48.4M	silk_float tmp, maxabs, chirp, gain;
65
66		/* Convert to monic coefficients */
67	982M	for( i = order - 1; i > 0; i-- ) {
68	933M	coefs[ i - 1 ] -= lambda * coefs[ i ];
69	933M	}
70	48.4M	gain = ( 1.0f - lambda * lambda ) / ( 1.0f + lambda * coefs[ 0 ] );
71	1.03G	for( i = 0; i < order; i++ ) {
72	982M	coefs[ i ] *= gain;
73	982M	}
74
75		/* Limit */
76	48.4M	for( iter = 0; iter < 10; iter++ ) {
77		/* Find maximum absolute value */
78	48.4M	maxabs = -1.0f;
79	1.03G	for( i = 0; i < order; i++ ) {
80	982M	tmp = silk_abs_float( coefs[ i ] );
81	982M	if( tmp > maxabs ) {
82	50.1M	maxabs = tmp;
83	50.1M	ind = i;
84	50.1M	}
85	982M	}
86	48.4M	if( maxabs <= limit ) {
87		/* Coefficients are within range - done */
88	48.4M	return;
89	48.4M	}
90
91		/* Convert back to true warped coefficients */
92	48.0k	for( i = 1; i < order; i++ ) {
93	45.7k	coefs[ i - 1 ] += lambda * coefs[ i ];
94	45.7k	}
95	2.31k	gain = 1.0f / gain;
96	50.3k	for( i = 0; i < order; i++ ) {
97	48.0k	coefs[ i ] *= gain;
98	48.0k	}
99
100		/* Apply bandwidth expansion */
101	2.31k	chirp = 0.99f - ( 0.8f + 0.1f * iter ) * ( maxabs - limit ) / ( maxabs * ( ind + 1 ) );
102	2.31k	silk_bwexpander_FLP( coefs, order, chirp );
103
104		/* Convert to monic warped coefficients */
105	48.0k	for( i = order - 1; i > 0; i-- ) {
106	45.7k	coefs[ i - 1 ] -= lambda * coefs[ i ];
107	45.7k	}
108	2.31k	gain = ( 1.0f - lambda * lambda ) / ( 1.0f + lambda * coefs[ 0 ] );
109	50.3k	for( i = 0; i < order; i++ ) {
110	48.0k	coefs[ i ] *= gain;
111	48.0k	}
112	2.31k	}
113	0	silk_assert( 0 );
114	0	}
115
116		static OPUS_INLINE void limit_coefs(
117		silk_float *coefs,
118		silk_float limit,
119		opus_int order
120	57.8M	) {
121	57.8M	opus_int i, iter, ind = 0;
122	57.8M	silk_float tmp, maxabs, chirp;
123
124	57.8M	for( iter = 0; iter < 10; iter++ ) {
125		/* Find maximum absolute value */
126	57.8M	maxabs = -1.0f;
127	787M	for( i = 0; i < order; i++ ) {
128	729M	tmp = silk_abs_float( coefs[ i ] );
129	729M	if( tmp > maxabs ) {
130	68.6M	maxabs = tmp;
131	68.6M	ind = i;
132	68.6M	}
133	729M	}
134	57.8M	if( maxabs <= limit ) {
135		/* Coefficients are within range - done */
136	57.8M	return;
137	57.8M	}
138
139		/* Apply bandwidth expansion */
140	4.02k	chirp = 0.99f - ( 0.8f + 0.1f * iter ) * ( maxabs - limit ) / ( maxabs * ( ind + 1 ) );
141	4.02k	silk_bwexpander_FLP( coefs, order, chirp );
142	4.02k	}
143	0	silk_assert( 0 );
144	0	}
145
146		/* Compute noise shaping coefficients and initial gain values */
147		void silk_noise_shape_analysis_FLP(
148		silk_encoder_state_FLP psEnc, / I/O Encoder state FLP */
149		silk_encoder_control_FLP psEncCtrl, / I/O Encoder control FLP */
150		const silk_float pitch_res, / I LPC residual from pitch analysis */
151		const silk_float x / I Input signal [frame_length + la_shape] */
152		)
153	33.5M	{
154	33.5M	silk_shape_state_FLP *psShapeSt = &psEnc->sShape;
155	33.5M	opus_int k, nSamples, nSegs;
156	33.5M	silk_float SNR_adj_dB, HarmShapeGain, Tilt;
157	33.5M	silk_float nrg, log_energy, log_energy_prev, energy_variation;
158	33.5M	silk_float BWExp, gain_mult, gain_add, strength, b, warping;
159	33.5M	silk_float x_windowed[ SHAPE_LPC_WIN_MAX ];
160	33.5M	silk_float auto_corr[ MAX_SHAPE_LPC_ORDER + 1 ];
161	33.5M	silk_float rc[ MAX_SHAPE_LPC_ORDER + 1 ];
162	33.5M	const silk_float x_ptr, pitch_res_ptr;
163
164		/* Point to start of first LPC analysis block */
165	33.5M	x_ptr = x - psEnc->sCmn.la_shape;
166
167		/****************/
168		/* GAIN CONTROL */
169		/****************/
170	33.5M	SNR_adj_dB = psEnc->sCmn.SNR_dB_Q7 * ( 1 / 128.0f );
171
172		/* Input quality is the average of the quality in the lowest two VAD bands */
173	33.5M	psEncCtrl->input_quality = 0.5f * ( psEnc->sCmn.input_quality_bands_Q15[ 0 ] + psEnc->sCmn.input_quality_bands_Q15[ 1 ] ) * ( 1.0f / 32768.0f );
174
175		/* Coding quality level, between 0.0 and 1.0 */
176	33.5M	psEncCtrl->coding_quality = silk_sigmoid( 0.25f * ( SNR_adj_dB - 20.0f ) );
177
178	33.5M	if( psEnc->sCmn.useCBR == 0 ) {
179		/* Reduce coding SNR during low speech activity */
180	15.7M	b = 1.0f - psEnc->sCmn.speech_activity_Q8 * ( 1.0f / 256.0f );
181	15.7M	SNR_adj_dB -= BG_SNR_DECR_dB * psEncCtrl->coding_quality * ( 0.5f + 0.5f * psEncCtrl->input_quality ) * b * b;
182	15.7M	}
183
184	33.5M	if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
185		/* Reduce gains for periodic signals */
186	368k	SNR_adj_dB += HARM_SNR_INCR_dB * psEnc->LTPCorr;
187	33.1M	} else {
188		/* For unvoiced signals and low-quality input, adjust the quality slower than SNR_dB setting */
189	33.1M	SNR_adj_dB += ( -0.4f * psEnc->sCmn.SNR_dB_Q7 * ( 1 / 128.0f ) + 6.0f ) * ( 1.0f - psEncCtrl->input_quality );
190	33.1M	}
191
192		/*************************/
193		/* SPARSENESS PROCESSING */
194		/*************************/
195		/* Set quantizer offset */
196	33.5M	if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
197		/* Initially set to 0; may be overruled in process_gains(..) */
198	368k	psEnc->sCmn.indices.quantOffsetType = 0;
199	33.1M	} else {
200		/* Sparseness measure, based on relative fluctuations of energy per 2 milliseconds */
201	33.1M	nSamples = 2 * psEnc->sCmn.fs_kHz;
202	33.1M	energy_variation = 0.0f;
203	33.1M	log_energy_prev = 0.0f;
204	33.1M	pitch_res_ptr = pitch_res;
205	33.1M	nSegs = silk_SMULBB( SUB_FRAME_LENGTH_MS, psEnc->sCmn.nb_subfr ) / 2;
206	295M	for( k = 0; k < nSegs; k++ ) {
207	262M	nrg = ( silk_float )nSamples + ( silk_float )silk_energy_FLP( pitch_res_ptr, nSamples );
208	262M	log_energy = silk_log2( nrg );
209	262M	if( k > 0 ) {
210	229M	energy_variation += silk_abs_float( log_energy - log_energy_prev );
211	229M	}
212	262M	log_energy_prev = log_energy;
213	262M	pitch_res_ptr += nSamples;
214	262M	}
215
216		/* Set quantization offset depending on sparseness measure */
217	33.1M	if( energy_variation > ENERGY_VARIATION_THRESHOLD_QNT_OFFSET * (nSegs-1) ) {
218	663k	psEnc->sCmn.indices.quantOffsetType = 0;
219	32.5M	} else {
220	32.5M	psEnc->sCmn.indices.quantOffsetType = 1;
221	32.5M	}
222	33.1M	}
223
224		/*******************************/
225		/* Control bandwidth expansion */
226		/*******************************/
227		/* More BWE for signals with high prediction gain */
228	33.5M	strength = FIND_PITCH_WHITE_NOISE_FRACTION * psEncCtrl->predGain; /* between 0.0 and 1.0 */
229	33.5M	BWExp = BANDWIDTH_EXPANSION / ( 1.0f + strength * strength );
230
231		/* Slightly more warping in analysis will move quantization noise up in frequency, where it's better masked */
232	33.5M	warping = (silk_float)psEnc->sCmn.warping_Q16 / 65536.0f + 0.01f * psEncCtrl->coding_quality;
233
234		/********************************************/
235		/* Compute noise shaping AR coefs and gains */
236		/********************************************/
237	139M	for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
238		/* Apply window: sine slope followed by flat part followed by cosine slope */
239	106M	opus_int shift, slope_part, flat_part;
240	106M	flat_part = psEnc->sCmn.fs_kHz * 3;
241	106M	slope_part = ( psEnc->sCmn.shapeWinLength - flat_part ) / 2;
242
243	106M	silk_apply_sine_window_FLP( x_windowed, x_ptr, 1, slope_part );
244	106M	shift = slope_part;
245	106M	silk_memcpy( x_windowed + shift, x_ptr + shift, flat_part * sizeof(silk_float) );
246	106M	shift += flat_part;
247	106M	silk_apply_sine_window_FLP( x_windowed + shift, x_ptr + shift, 2, slope_part );
248
249		/* Update pointer: next LPC analysis block */
250	106M	x_ptr += psEnc->sCmn.subfr_length;
251
252	106M	if( psEnc->sCmn.warping_Q16 > 0 ) {
253		/* Calculate warped auto correlation */
254	48.4M	silk_warped_autocorrelation_FLP( auto_corr, x_windowed, warping,
255	48.4M	psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder );
256	57.8M	} else {
257		/* Calculate regular auto correlation */
258	57.8M	silk_autocorrelation_FLP( auto_corr, x_windowed, psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder + 1, psEnc->sCmn.arch );
259	57.8M	}
260
261		/* Add white noise, as a fraction of energy */
262	106M	auto_corr[ 0 ] += auto_corr[ 0 ] * SHAPE_WHITE_NOISE_FRACTION + 1.0f;
263
264		/* Convert correlations to prediction coefficients, and compute residual energy */
265	106M	nrg = silk_schur_FLP( rc, auto_corr, psEnc->sCmn.shapingLPCOrder );
266	106M	silk_k2a_FLP( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], rc, psEnc->sCmn.shapingLPCOrder );
267	106M	psEncCtrl->Gains[ k ] = ( silk_float )sqrt( nrg );
268
269	106M	if( psEnc->sCmn.warping_Q16 > 0 ) {
270		/* Adjust gain for warping */
271	48.4M	psEncCtrl->Gains[ k ] = warped_gain( &psEncCtrl->AR[ k MAX_SHAPE_LPC_ORDER ], warping, psEnc->sCmn.shapingLPCOrder );
272	48.4M	}
273
274		/* Bandwidth expansion for synthesis filter shaping */
275	106M	silk_bwexpander_FLP( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], psEnc->sCmn.shapingLPCOrder, BWExp );
276
277	106M	if( psEnc->sCmn.warping_Q16 > 0 ) {
278		/* Convert to monic warped prediction coefficients and limit absolute values */
279	48.4M	warped_true2monic_coefs( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], warping, 3.999f, psEnc->sCmn.shapingLPCOrder );
280	57.8M	} else {
281		/* Limit absolute values */
282	57.8M	limit_coefs( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], 3.999f, psEnc->sCmn.shapingLPCOrder );
283	57.8M	}
284	106M	}
285
286		/*****************/
287		/* Gain tweaking */
288		/*****************/
289		/* Increase gains during low speech activity */
290	33.5M	gain_mult = (silk_float)pow( 2.0f, -0.16f * SNR_adj_dB );
291	33.5M	gain_add = (silk_float)pow( 2.0f, 0.16f * MIN_QGAIN_DB );
292	139M	for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
293	106M	psEncCtrl->Gains[ k ] *= gain_mult;
294	106M	psEncCtrl->Gains[ k ] += gain_add;
295	106M	}
296
297		/************************************************/
298		/* Control low-frequency shaping and noise tilt */
299		/************************************************/
300		/* Less low frequency shaping for noisy inputs */
301	33.5M	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 ) );
302	33.5M	strength = psEnc->sCmn.speech_activity_Q8 ( 1.0f / 256.0f );
303	33.5M	if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
304		/* Reduce low frequencies quantization noise for periodic signals, depending on pitch lag */
305		/f = 400; freqz([1, -0.98 + 2e-4 f], [1, -0.97 + 7e-4 * f], 2^12, Fs); axis([0, 1000, -10, 1])*/
306	1.69M	for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
307	1.32M	b = 0.2f / psEnc->sCmn.fs_kHz + 3.0f / psEncCtrl->pitchL[ k ];
308	1.32M	psEncCtrl->LF_MA_shp[ k ] = -1.0f + b;
309	1.32M	psEncCtrl->LF_AR_shp[ k ] = 1.0f - b - b * strength;
310	1.32M	}
311	368k	Tilt = - HP_NOISE_COEF -
312	368k	(1 - HP_NOISE_COEF) * HARM_HP_NOISE_COEF * psEnc->sCmn.speech_activity_Q8 * ( 1.0f / 256.0f );
313	33.1M	} else {
314	33.1M	b = 1.3f / psEnc->sCmn.fs_kHz;
315	33.1M	psEncCtrl->LF_MA_shp[ 0 ] = -1.0f + b;
316	33.1M	psEncCtrl->LF_AR_shp[ 0 ] = 1.0f - b - b * strength * 0.6f;
317	105M	for( k = 1; k < psEnc->sCmn.nb_subfr; k++ ) {
318	71.8M	psEncCtrl->LF_MA_shp[ k ] = psEncCtrl->LF_MA_shp[ 0 ];
319	71.8M	psEncCtrl->LF_AR_shp[ k ] = psEncCtrl->LF_AR_shp[ 0 ];
320	71.8M	}
321	33.1M	Tilt = -HP_NOISE_COEF;
322	33.1M	}
323
324		/****************************/
325		/* HARMONIC SHAPING CONTROL */
326		/****************************/
327	33.5M	if( USE_HARM_SHAPING && psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
328		/* Harmonic noise shaping */
329	368k	HarmShapeGain = HARMONIC_SHAPING;
330
331		/* More harmonic noise shaping for high bitrates or noisy input */
332	368k	HarmShapeGain += HIGH_RATE_OR_LOW_QUALITY_HARMONIC_SHAPING *
333	368k	( 1.0f - ( 1.0f - psEncCtrl->coding_quality ) * psEncCtrl->input_quality );
334
335		/* Less harmonic noise shaping for less periodic signals */
336	368k	HarmShapeGain *= ( silk_float )sqrt( psEnc->LTPCorr );
337	33.1M	} else {
338	33.1M	HarmShapeGain = 0.0f;
339	33.1M	}
340
341		/*************************/
342		/* Smooth over subframes */
343		/*************************/
344	139M	for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
345	106M	psShapeSt->HarmShapeGain_smth += SUBFR_SMTH_COEF * ( HarmShapeGain - psShapeSt->HarmShapeGain_smth );
346	106M	psEncCtrl->HarmShapeGain[ k ] = psShapeSt->HarmShapeGain_smth;
347	106M	psShapeSt->Tilt_smth += SUBFR_SMTH_COEF * ( Tilt - psShapeSt->Tilt_smth );
348	106M	psEncCtrl->Tilt[ k ] = psShapeSt->Tilt_smth;
349	106M	}
350	33.5M	}