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

Source (jump to first uncovered line)
/***********************************************************************
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: 2024-09-06 07:53

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