/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: 2026-02-26 07:37

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	73.3M	) {
44	73.3M	opus_int i;
45	73.3M	silk_float gain;
46
47	73.3M	lambda = -lambda;
48	73.3M	gain = coefs[ order - 1 ];
49	1.46G	for( i = order - 2; i >= 0; i-- ) {
50	1.39G	gain = lambda * gain + coefs[ i ];
51	1.39G	}
52	73.3M	return (silk_float)( 1.0f / ( 1.0f - lambda * gain ) );
53	73.3M	}
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	73.3M	) {
63	73.3M	opus_int i, iter, ind = 0;
64	73.3M	silk_float tmp, maxabs, chirp, gain;
65
66		/* Convert to monic coefficients */
67	1.46G	for( i = order - 1; i > 0; i-- ) {
68	1.39G	coefs[ i - 1 ] -= lambda * coefs[ i ];
69	1.39G	}
70	73.3M	gain = ( 1.0f - lambda * lambda ) / ( 1.0f + lambda * coefs[ 0 ] );
71	1.54G	for( i = 0; i < order; i++ ) {
72	1.46G	coefs[ i ] *= gain;
73	1.46G	}
74
75		/* Limit */
76	73.3M	for( iter = 0; iter < 10; iter++ ) {
77		/* Find maximum absolute value */
78	73.3M	maxabs = -1.0f;
79	1.54G	for( i = 0; i < order; i++ ) {
80	1.46G	tmp = silk_abs_float( coefs[ i ] );
81	1.46G	if( tmp > maxabs ) {
82	75.2M	maxabs = tmp;
83	75.2M	ind = i;
84	75.2M	}
85	1.46G	}
86	73.3M	if( maxabs <= limit ) {
87		/* Coefficients are within range - done */
88	73.3M	return;
89	73.3M	}
90
91		/* Convert back to true warped coefficients */
92	57.1k	for( i = 1; i < order; i++ ) {
93	54.4k	coefs[ i - 1 ] += lambda * coefs[ i ];
94	54.4k	}
95	2.64k	gain = 1.0f / gain;
96	59.7k	for( i = 0; i < order; i++ ) {
97	57.1k	coefs[ i ] *= gain;
98	57.1k	}
99
100		/* Apply bandwidth expansion */
101	2.64k	chirp = 0.99f - ( 0.8f + 0.1f * iter ) * ( maxabs - limit ) / ( maxabs * ( ind + 1 ) );
102	2.64k	silk_bwexpander_FLP( coefs, order, chirp );
103
104		/* Convert to monic warped coefficients */
105	57.1k	for( i = order - 1; i > 0; i-- ) {
106	54.4k	coefs[ i - 1 ] -= lambda * coefs[ i ];
107	54.4k	}
108	2.64k	gain = ( 1.0f - lambda * lambda ) / ( 1.0f + lambda * coefs[ 0 ] );
109	59.7k	for( i = 0; i < order; i++ ) {
110	57.1k	coefs[ i ] *= gain;
111	57.1k	}
112	2.64k	}
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	120M	) {
121	120M	opus_int i, iter, ind = 0;
122	120M	silk_float tmp, maxabs, chirp;
123
124	120M	for( iter = 0; iter < 10; iter++ ) {
125		/* Find maximum absolute value */
126	120M	maxabs = -1.0f;
127	1.63G	for( i = 0; i < order; i++ ) {
128	1.51G	tmp = silk_abs_float( coefs[ i ] );
129	1.51G	if( tmp > maxabs ) {
130	141M	maxabs = tmp;
131	141M	ind = i;
132	141M	}
133	1.51G	}
134	120M	if( maxabs <= limit ) {
135		/* Coefficients are within range - done */
136	120M	return;
137	120M	}
138
139		/* Apply bandwidth expansion */
140	4.93k	chirp = 0.99f - ( 0.8f + 0.1f * iter ) * ( maxabs - limit ) / ( maxabs * ( ind + 1 ) );
141	4.93k	silk_bwexpander_FLP( coefs, order, chirp );
142	4.93k	}
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	57.9M	{
154	57.9M	silk_shape_state_FLP *psShapeSt = &psEnc->sShape;
155	57.9M	opus_int k, nSamples, nSegs;
156	57.9M	silk_float SNR_adj_dB, HarmShapeGain, Tilt;
157	57.9M	silk_float nrg, log_energy, log_energy_prev, energy_variation;
158	57.9M	silk_float BWExp, gain_mult, gain_add, strength, b, warping;
159	57.9M	silk_float x_windowed[ SHAPE_LPC_WIN_MAX ];
160	57.9M	silk_float auto_corr[ MAX_SHAPE_LPC_ORDER + 1 ];
161	57.9M	silk_float rc[ MAX_SHAPE_LPC_ORDER + 1 ];
162	57.9M	const silk_float x_ptr, pitch_res_ptr;
163
164		/* Point to start of first LPC analysis block */
165	57.9M	x_ptr = x - psEnc->sCmn.la_shape;
166
167		/****************/
168		/* GAIN CONTROL */
169		/****************/
170	57.9M	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	57.9M	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	57.9M	psEncCtrl->coding_quality = silk_sigmoid( 0.25f * ( SNR_adj_dB - 20.0f ) );
177
178	57.9M	if( psEnc->sCmn.useCBR == 0 ) {
179		/* Reduce coding SNR during low speech activity */
180	22.8M	b = 1.0f - psEnc->sCmn.speech_activity_Q8 * ( 1.0f / 256.0f );
181	22.8M	SNR_adj_dB -= BG_SNR_DECR_dB * psEncCtrl->coding_quality * ( 0.5f + 0.5f * psEncCtrl->input_quality ) * b * b;
182	22.8M	}
183
184	57.9M	if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
185		/* Reduce gains for periodic signals */
186	476k	SNR_adj_dB += HARM_SNR_INCR_dB * psEnc->LTPCorr;
187	57.5M	} else {
188		/* For unvoiced signals and low-quality input, adjust the quality slower than SNR_dB setting */
189	57.5M	SNR_adj_dB += ( -0.4f * psEnc->sCmn.SNR_dB_Q7 * ( 1 / 128.0f ) + 6.0f ) * ( 1.0f - psEncCtrl->input_quality );
190	57.5M	}
191
192		/*************************/
193		/* SPARSENESS PROCESSING */
194		/*************************/
195		/* Set quantizer offset */
196	57.9M	if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
197		/* Initially set to 0; may be overruled in process_gains(..) */
198	476k	psEnc->sCmn.indices.quantOffsetType = 0;
199	57.5M	} else {
200		/* Sparseness measure, based on relative fluctuations of energy per 2 milliseconds */
201	57.5M	nSamples = 2 * psEnc->sCmn.fs_kHz;
202	57.5M	energy_variation = 0.0f;
203	57.5M	log_energy_prev = 0.0f;
204	57.5M	pitch_res_ptr = pitch_res;
205	57.5M	nSegs = silk_SMULBB( SUB_FRAME_LENGTH_MS, psEnc->sCmn.nb_subfr ) / 2;
206	537M	for( k = 0; k < nSegs; k++ ) {
207	479M	nrg = ( silk_float )nSamples + ( silk_float )silk_energy_FLP( pitch_res_ptr, nSamples );
208	479M	log_energy = silk_log2( nrg );
209	479M	if( k > 0 ) {
210	422M	energy_variation += silk_abs_float( log_energy - log_energy_prev );
211	422M	}
212	479M	log_energy_prev = log_energy;
213	479M	pitch_res_ptr += nSamples;
214	479M	}
215
216		/* Set quantization offset depending on sparseness measure */
217	57.5M	if( energy_variation > ENERGY_VARIATION_THRESHOLD_QNT_OFFSET * (nSegs-1) ) {
218	798k	psEnc->sCmn.indices.quantOffsetType = 0;
219	56.7M	} else {
220	56.7M	psEnc->sCmn.indices.quantOffsetType = 1;
221	56.7M	}
222	57.5M	}
223
224		/*******************************/
225		/* Control bandwidth expansion */
226		/*******************************/
227		/* More BWE for signals with high prediction gain */
228	57.9M	strength = FIND_PITCH_WHITE_NOISE_FRACTION * psEncCtrl->predGain; /* between 0.0 and 1.0 */
229	57.9M	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	57.9M	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	251M	for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
238		/* Apply window: sine slope followed by flat part followed by cosine slope */
239	193M	opus_int shift, slope_part, flat_part;
240	193M	flat_part = psEnc->sCmn.fs_kHz * 3;
241	193M	slope_part = ( psEnc->sCmn.shapeWinLength - flat_part ) / 2;
242
243	193M	silk_apply_sine_window_FLP( x_windowed, x_ptr, 1, slope_part );
244	193M	shift = slope_part;
245	193M	silk_memcpy( x_windowed + shift, x_ptr + shift, flat_part * sizeof(silk_float) );
246	193M	shift += flat_part;
247	193M	silk_apply_sine_window_FLP( x_windowed + shift, x_ptr + shift, 2, slope_part );
248
249		/* Update pointer: next LPC analysis block */
250	193M	x_ptr += psEnc->sCmn.subfr_length;
251
252	193M	if( psEnc->sCmn.warping_Q16 > 0 ) {
253		/* Calculate warped auto correlation */
254	73.3M	silk_warped_autocorrelation_FLP( auto_corr, x_windowed, warping,
255	73.3M	psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder );
256	120M	} else {
257		/* Calculate regular auto correlation */
258	120M	silk_autocorrelation_FLP( auto_corr, x_windowed, psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder + 1, psEnc->sCmn.arch );
259	120M	}
260
261		/* Add white noise, as a fraction of energy */
262	193M	auto_corr[ 0 ] += auto_corr[ 0 ] * SHAPE_WHITE_NOISE_FRACTION + 1.0f;
263
264		/* Convert correlations to prediction coefficients, and compute residual energy */
265	193M	nrg = silk_schur_FLP( rc, auto_corr, psEnc->sCmn.shapingLPCOrder );
266	193M	silk_k2a_FLP( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], rc, psEnc->sCmn.shapingLPCOrder );
267	193M	psEncCtrl->Gains[ k ] = ( silk_float )sqrt( nrg );
268
269	193M	if( psEnc->sCmn.warping_Q16 > 0 ) {
270		/* Adjust gain for warping */
271	73.3M	psEncCtrl->Gains[ k ] = warped_gain( &psEncCtrl->AR[ k MAX_SHAPE_LPC_ORDER ], warping, psEnc->sCmn.shapingLPCOrder );
272	73.3M	}
273
274		/* Bandwidth expansion for synthesis filter shaping */
275	193M	silk_bwexpander_FLP( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], psEnc->sCmn.shapingLPCOrder, BWExp );
276
277	193M	if( psEnc->sCmn.warping_Q16 > 0 ) {
278		/* Convert to monic warped prediction coefficients and limit absolute values */
279	73.3M	warped_true2monic_coefs( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], warping, 3.999f, psEnc->sCmn.shapingLPCOrder );
280	120M	} else {
281		/* Limit absolute values */
282	120M	limit_coefs( &psEncCtrl->AR[ k * MAX_SHAPE_LPC_ORDER ], 3.999f, psEnc->sCmn.shapingLPCOrder );
283	120M	}
284	193M	}
285
286		/*****************/
287		/* Gain tweaking */
288		/*****************/
289		/* Increase gains during low speech activity */
290	57.9M	gain_mult = (silk_float)pow( 2.0f, -0.16f * SNR_adj_dB );
291	57.9M	gain_add = (silk_float)pow( 2.0f, 0.16f * MIN_QGAIN_DB );
292	251M	for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
293	193M	psEncCtrl->Gains[ k ] *= gain_mult;
294	193M	psEncCtrl->Gains[ k ] += gain_add;
295	193M	}
296
297		/************************************************/
298		/* Control low-frequency shaping and noise tilt */
299		/************************************************/
300		/* Less low frequency shaping for noisy inputs */
301	57.9M	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	57.9M	strength = psEnc->sCmn.speech_activity_Q8 ( 1.0f / 256.0f );
303	57.9M	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	2.18M	for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
307	1.70M	b = 0.2f / psEnc->sCmn.fs_kHz + 3.0f / psEncCtrl->pitchL[ k ];
308	1.70M	psEncCtrl->LF_MA_shp[ k ] = -1.0f + b;
309	1.70M	psEncCtrl->LF_AR_shp[ k ] = 1.0f - b - b * strength;
310	1.70M	}
311	476k	Tilt = - HP_NOISE_COEF -
312	476k	(1 - HP_NOISE_COEF) * HARM_HP_NOISE_COEF * psEnc->sCmn.speech_activity_Q8 * ( 1.0f / 256.0f );
313	57.5M	} else {
314	57.5M	b = 1.3f / psEnc->sCmn.fs_kHz;
315	57.5M	psEncCtrl->LF_MA_shp[ 0 ] = -1.0f + b;
316	57.5M	psEncCtrl->LF_AR_shp[ 0 ] = 1.0f - b - b * strength * 0.6f;
317	191M	for( k = 1; k < psEnc->sCmn.nb_subfr; k++ ) {
318	134M	psEncCtrl->LF_MA_shp[ k ] = psEncCtrl->LF_MA_shp[ 0 ];
319	134M	psEncCtrl->LF_AR_shp[ k ] = psEncCtrl->LF_AR_shp[ 0 ];
320	134M	}
321	57.5M	Tilt = -HP_NOISE_COEF;
322	57.5M	}
323
324		/****************************/
325		/* HARMONIC SHAPING CONTROL */
326		/****************************/
327	57.9M	if( USE_HARM_SHAPING && psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
328		/* Harmonic noise shaping */
329	476k	HarmShapeGain = HARMONIC_SHAPING;
330
331		/* More harmonic noise shaping for high bitrates or noisy input */
332	476k	HarmShapeGain += HIGH_RATE_OR_LOW_QUALITY_HARMONIC_SHAPING *
333	476k	( 1.0f - ( 1.0f - psEncCtrl->coding_quality ) * psEncCtrl->input_quality );
334
335		/* Less harmonic noise shaping for less periodic signals */
336	476k	HarmShapeGain *= ( silk_float )sqrt( psEnc->LTPCorr );
337	57.5M	} else {
338	57.5M	HarmShapeGain = 0.0f;
339	57.5M	}
340
341		/*************************/
342		/* Smooth over subframes */
343		/*************************/
344	251M	for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
345	193M	psShapeSt->HarmShapeGain_smth += SUBFR_SMTH_COEF * ( HarmShapeGain - psShapeSt->HarmShapeGain_smth );
346	193M	psEncCtrl->HarmShapeGain[ k ] = psShapeSt->HarmShapeGain_smth;
347	193M	psShapeSt->Tilt_smth += SUBFR_SMTH_COEF * ( Tilt - psShapeSt->Tilt_smth );
348	193M	psEncCtrl->Tilt[ k ] = psShapeSt->Tilt_smth;
349	193M	}
350	57.9M	}