22a89f75aec0fc8d624409df861cbb6c2ca38595
[opus.git] / silk / fixed / noise_shape_analysis_FIX.c
1 /***********************************************************************
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26 ***********************************************************************/
27
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31
32 #include "main_FIX.h"
33 #include "stack_alloc.h"
34 #include "tuning_parameters.h"
35
36 /* Compute gain to make warped filter coefficients have a zero mean log frequency response on a   */
37 /* non-warped frequency scale. (So that it can be implemented with a minimum-phase monic filter.) */
38 /* Note: A monic filter is one with the first coefficient equal to 1.0. In Silk we omit the first */
39 /* coefficient in an array of coefficients, for monic filters.                                    */
40 static OPUS_INLINE opus_int32 warped_gain( /* gain in Q16*/
41     const opus_int32     *coefs_Q24,
42     opus_int             lambda_Q16,
43     opus_int             order
44 ) {
45     opus_int   i;
46     opus_int32 gain_Q24;
47
48     lambda_Q16 = -lambda_Q16;
49     gain_Q24 = coefs_Q24[ order - 1 ];
50     for( i = order - 2; i >= 0; i-- ) {
51         gain_Q24 = silk_SMLAWB( coefs_Q24[ i ], gain_Q24, lambda_Q16 );
52     }
53     gain_Q24  = silk_SMLAWB( SILK_FIX_CONST( 1.0, 24 ), gain_Q24, -lambda_Q16 );
54     return silk_INVERSE32_varQ( gain_Q24, 40 );
55 }
56
57 /* Convert warped filter coefficients to monic pseudo-warped coefficients and limit maximum     */
58 /* amplitude of monic warped coefficients by using bandwidth expansion on the true coefficients */
59 static OPUS_INLINE void limit_warped_coefs(
60     opus_int32           *coefs_syn_Q24,
61     opus_int32           *coefs_ana_Q24,
62     opus_int             lambda_Q16,
63     opus_int32           limit_Q24,
64     opus_int             order
65 ) {
66     opus_int   i, iter, ind = 0;
67     opus_int32 tmp, maxabs_Q24, chirp_Q16, gain_syn_Q16, gain_ana_Q16;
68     opus_int32 nom_Q16, den_Q24;
69
70     /* Convert to monic coefficients */
71     lambda_Q16 = -lambda_Q16;
72     for( i = order - 1; i > 0; i-- ) {
73         coefs_syn_Q24[ i - 1 ] = silk_SMLAWB( coefs_syn_Q24[ i - 1 ], coefs_syn_Q24[ i ], lambda_Q16 );
74         coefs_ana_Q24[ i - 1 ] = silk_SMLAWB( coefs_ana_Q24[ i - 1 ], coefs_ana_Q24[ i ], lambda_Q16 );
75     }
76     lambda_Q16 = -lambda_Q16;
77     nom_Q16  = silk_SMLAWB( SILK_FIX_CONST( 1.0, 16 ), -(opus_int32)lambda_Q16,        lambda_Q16 );
78     den_Q24  = silk_SMLAWB( SILK_FIX_CONST( 1.0, 24 ), coefs_syn_Q24[ 0 ], lambda_Q16 );
79     gain_syn_Q16 = silk_DIV32_varQ( nom_Q16, den_Q24, 24 );
80     den_Q24  = silk_SMLAWB( SILK_FIX_CONST( 1.0, 24 ), coefs_ana_Q24[ 0 ], lambda_Q16 );
81     gain_ana_Q16 = silk_DIV32_varQ( nom_Q16, den_Q24, 24 );
82     for( i = 0; i < order; i++ ) {
83         coefs_syn_Q24[ i ] = silk_SMULWW( gain_syn_Q16, coefs_syn_Q24[ i ] );
84         coefs_ana_Q24[ i ] = silk_SMULWW( gain_ana_Q16, coefs_ana_Q24[ i ] );
85     }
86
87     for( iter = 0; iter < 10; iter++ ) {
88         /* Find maximum absolute value */
89         maxabs_Q24 = -1;
90         for( i = 0; i < order; i++ ) {
91             tmp = silk_max( silk_abs_int32( coefs_syn_Q24[ i ] ), silk_abs_int32( coefs_ana_Q24[ i ] ) );
92             if( tmp > maxabs_Q24 ) {
93                 maxabs_Q24 = tmp;
94                 ind = i;
95             }
96         }
97         if( maxabs_Q24 <= limit_Q24 ) {
98             /* Coefficients are within range - done */
99             return;
100         }
101
102         /* Convert back to true warped coefficients */
103         for( i = 1; i < order; i++ ) {
104             coefs_syn_Q24[ i - 1 ] = silk_SMLAWB( coefs_syn_Q24[ i - 1 ], coefs_syn_Q24[ i ], lambda_Q16 );
105             coefs_ana_Q24[ i - 1 ] = silk_SMLAWB( coefs_ana_Q24[ i - 1 ], coefs_ana_Q24[ i ], lambda_Q16 );
106         }
107         gain_syn_Q16 = silk_INVERSE32_varQ( gain_syn_Q16, 32 );
108         gain_ana_Q16 = silk_INVERSE32_varQ( gain_ana_Q16, 32 );
109         for( i = 0; i < order; i++ ) {
110             coefs_syn_Q24[ i ] = silk_SMULWW( gain_syn_Q16, coefs_syn_Q24[ i ] );
111             coefs_ana_Q24[ i ] = silk_SMULWW( gain_ana_Q16, coefs_ana_Q24[ i ] );
112         }
113
114         /* Apply bandwidth expansion */
115         chirp_Q16 = SILK_FIX_CONST( 0.99, 16 ) - silk_DIV32_varQ(
116             silk_SMULWB( maxabs_Q24 - limit_Q24, silk_SMLABB( SILK_FIX_CONST( 0.8, 10 ), SILK_FIX_CONST( 0.1, 10 ), iter ) ),
117             silk_MUL( maxabs_Q24, ind + 1 ), 22 );
118         silk_bwexpander_32( coefs_syn_Q24, order, chirp_Q16 );
119         silk_bwexpander_32( coefs_ana_Q24, order, chirp_Q16 );
120
121         /* Convert to monic warped coefficients */
122         lambda_Q16 = -lambda_Q16;
123         for( i = order - 1; i > 0; i-- ) {
124             coefs_syn_Q24[ i - 1 ] = silk_SMLAWB( coefs_syn_Q24[ i - 1 ], coefs_syn_Q24[ i ], lambda_Q16 );
125             coefs_ana_Q24[ i - 1 ] = silk_SMLAWB( coefs_ana_Q24[ i - 1 ], coefs_ana_Q24[ i ], lambda_Q16 );
126         }
127         lambda_Q16 = -lambda_Q16;
128         nom_Q16  = silk_SMLAWB( SILK_FIX_CONST( 1.0, 16 ), -(opus_int32)lambda_Q16,        lambda_Q16 );
129         den_Q24  = silk_SMLAWB( SILK_FIX_CONST( 1.0, 24 ), coefs_syn_Q24[ 0 ], lambda_Q16 );
130         gain_syn_Q16 = silk_DIV32_varQ( nom_Q16, den_Q24, 24 );
131         den_Q24  = silk_SMLAWB( SILK_FIX_CONST( 1.0, 24 ), coefs_ana_Q24[ 0 ], lambda_Q16 );
132         gain_ana_Q16 = silk_DIV32_varQ( nom_Q16, den_Q24, 24 );
133         for( i = 0; i < order; i++ ) {
134             coefs_syn_Q24[ i ] = silk_SMULWW( gain_syn_Q16, coefs_syn_Q24[ i ] );
135             coefs_ana_Q24[ i ] = silk_SMULWW( gain_ana_Q16, coefs_ana_Q24[ i ] );
136         }
137     }
138     silk_assert( 0 );
139 }
140
141 #if defined(MIPSr1_ASM)
142 #include "mips/noise_shape_analysis_FIX_mipsr1.h"
143 #endif
144
145 /**************************************************************/
146 /* Compute noise shaping coefficients and initial gain values */
147 /**************************************************************/
148 #ifndef OVERRIDE_silk_noise_shape_analysis_FIX
149 void silk_noise_shape_analysis_FIX(
150     silk_encoder_state_FIX          *psEnc,                                 /* I/O  Encoder state FIX                                                           */
151     silk_encoder_control_FIX        *psEncCtrl,                             /* I/O  Encoder control FIX                                                         */
152     const opus_int16                *pitch_res,                             /* I    LPC residual from pitch analysis                                            */
153     const opus_int16                *x,                                     /* I    Input signal [ frame_length + la_shape ]                                    */
154     int                              arch                                   /* I    Run-time architecture                                                       */
155 )
156 {
157     silk_shape_state_FIX *psShapeSt = &psEnc->sShape;
158     opus_int     k, i, nSamples, Qnrg, b_Q14, warping_Q16, scale = 0;
159     opus_int32   SNR_adj_dB_Q7, HarmBoost_Q16, HarmShapeGain_Q16, Tilt_Q16, tmp32;
160     opus_int32   nrg, pre_nrg_Q30, log_energy_Q7, log_energy_prev_Q7, energy_variation_Q7;
161     opus_int32   delta_Q16, BWExp1_Q16, BWExp2_Q16, gain_mult_Q16, gain_add_Q16, strength_Q16, b_Q8;
162     opus_int32   auto_corr[     MAX_SHAPE_LPC_ORDER + 1 ];
163     opus_int32   refl_coef_Q16[ MAX_SHAPE_LPC_ORDER ];
164     opus_int32   AR1_Q24[       MAX_SHAPE_LPC_ORDER ];
165     opus_int32   AR2_Q24[       MAX_SHAPE_LPC_ORDER ];
166     VARDECL( opus_int16, x_windowed );
167     const opus_int16 *x_ptr, *pitch_res_ptr;
168     SAVE_STACK;
169
170     /* Point to start of first LPC analysis block */
171     x_ptr = x - psEnc->sCmn.la_shape;
172
173     /****************/
174     /* GAIN CONTROL */
175     /****************/
176     SNR_adj_dB_Q7 = psEnc->sCmn.SNR_dB_Q7;
177
178     /* Input quality is the average of the quality in the lowest two VAD bands */
179     psEncCtrl->input_quality_Q14 = ( opus_int )silk_RSHIFT( (opus_int32)psEnc->sCmn.input_quality_bands_Q15[ 0 ]
180         + psEnc->sCmn.input_quality_bands_Q15[ 1 ], 2 );
181
182     /* Coding quality level, between 0.0_Q0 and 1.0_Q0, but in Q14 */
183     psEncCtrl->coding_quality_Q14 = silk_RSHIFT( silk_sigm_Q15( silk_RSHIFT_ROUND( SNR_adj_dB_Q7 -
184         SILK_FIX_CONST( 20.0, 7 ), 4 ) ), 1 );
185
186     /* Reduce coding SNR during low speech activity */
187     if( psEnc->sCmn.useCBR == 0 ) {
188         b_Q8 = SILK_FIX_CONST( 1.0, 8 ) - psEnc->sCmn.speech_activity_Q8;
189         b_Q8 = silk_SMULWB( silk_LSHIFT( b_Q8, 8 ), b_Q8 );
190         SNR_adj_dB_Q7 = silk_SMLAWB( SNR_adj_dB_Q7,
191             silk_SMULBB( SILK_FIX_CONST( -BG_SNR_DECR_dB, 7 ) >> ( 4 + 1 ), b_Q8 ),                                       /* Q11*/
192             silk_SMULWB( SILK_FIX_CONST( 1.0, 14 ) + psEncCtrl->input_quality_Q14, psEncCtrl->coding_quality_Q14 ) );     /* Q12*/
193     }
194
195     if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
196         /* Reduce gains for periodic signals */
197         SNR_adj_dB_Q7 = silk_SMLAWB( SNR_adj_dB_Q7, SILK_FIX_CONST( HARM_SNR_INCR_dB, 8 ), psEnc->LTPCorr_Q15 );
198     } else {
199         /* For unvoiced signals and low-quality input, adjust the quality slower than SNR_dB setting */
200         SNR_adj_dB_Q7 = silk_SMLAWB( SNR_adj_dB_Q7,
201             silk_SMLAWB( SILK_FIX_CONST( 6.0, 9 ), -SILK_FIX_CONST( 0.4, 18 ), psEnc->sCmn.SNR_dB_Q7 ),
202             SILK_FIX_CONST( 1.0, 14 ) - psEncCtrl->input_quality_Q14 );
203     }
204
205     /*************************/
206     /* SPARSENESS PROCESSING */
207     /*************************/
208     /* Set quantizer offset */
209     if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
210         /* Initially set to 0; may be overruled in process_gains(..) */
211         psEnc->sCmn.indices.quantOffsetType = 0;
212         psEncCtrl->sparseness_Q8 = 0;
213     } else {
214         /* Sparseness measure, based on relative fluctuations of energy per 2 milliseconds */
215         nSamples = silk_LSHIFT( psEnc->sCmn.fs_kHz, 1 );
216         energy_variation_Q7 = 0;
217         log_energy_prev_Q7  = 0;
218         pitch_res_ptr = pitch_res;
219         for( k = 0; k < silk_SMULBB( SUB_FRAME_LENGTH_MS, psEnc->sCmn.nb_subfr ) / 2; k++ ) {
220             silk_sum_sqr_shift( &nrg, &scale, pitch_res_ptr, nSamples );
221             nrg += silk_RSHIFT( nSamples, scale );           /* Q(-scale)*/
222
223             log_energy_Q7 = silk_lin2log( nrg );
224             if( k > 0 ) {
225                 energy_variation_Q7 += silk_abs( log_energy_Q7 - log_energy_prev_Q7 );
226             }
227             log_energy_prev_Q7 = log_energy_Q7;
228             pitch_res_ptr += nSamples;
229         }
230
231         psEncCtrl->sparseness_Q8 = silk_RSHIFT( silk_sigm_Q15( silk_SMULWB( energy_variation_Q7 -
232             SILK_FIX_CONST( 5.0, 7 ), SILK_FIX_CONST( 0.1, 16 ) ) ), 7 );
233
234         /* Set quantization offset depending on sparseness measure */
235         if( psEncCtrl->sparseness_Q8 > SILK_FIX_CONST( SPARSENESS_THRESHOLD_QNT_OFFSET, 8 ) ) {
236             psEnc->sCmn.indices.quantOffsetType = 0;
237         } else {
238             psEnc->sCmn.indices.quantOffsetType = 1;
239         }
240
241         /* Increase coding SNR for sparse signals */
242         SNR_adj_dB_Q7 = silk_SMLAWB( SNR_adj_dB_Q7, SILK_FIX_CONST( SPARSE_SNR_INCR_dB, 15 ), psEncCtrl->sparseness_Q8 - SILK_FIX_CONST( 0.5, 8 ) );
243     }
244
245     /*******************************/
246     /* Control bandwidth expansion */
247     /*******************************/
248     /* More BWE for signals with high prediction gain */
249     strength_Q16 = silk_SMULWB( psEncCtrl->predGain_Q16, SILK_FIX_CONST( FIND_PITCH_WHITE_NOISE_FRACTION, 16 ) );
250     BWExp1_Q16 = BWExp2_Q16 = silk_DIV32_varQ( SILK_FIX_CONST( BANDWIDTH_EXPANSION, 16 ),
251         silk_SMLAWW( SILK_FIX_CONST( 1.0, 16 ), strength_Q16, strength_Q16 ), 16 );
252     delta_Q16  = silk_SMULWB( SILK_FIX_CONST( 1.0, 16 ) - silk_SMULBB( 3, psEncCtrl->coding_quality_Q14 ),
253         SILK_FIX_CONST( LOW_RATE_BANDWIDTH_EXPANSION_DELTA, 16 ) );
254     BWExp1_Q16 = silk_SUB32( BWExp1_Q16, delta_Q16 );
255     BWExp2_Q16 = silk_ADD32( BWExp2_Q16, delta_Q16 );
256     /* BWExp1 will be applied after BWExp2, so make it relative */
257     BWExp1_Q16 = silk_DIV32_16( silk_LSHIFT( BWExp1_Q16, 14 ), silk_RSHIFT( BWExp2_Q16, 2 ) );
258
259     if( psEnc->sCmn.warping_Q16 > 0 ) {
260         /* Slightly more warping in analysis will move quantization noise up in frequency, where it's better masked */
261         warping_Q16 = silk_SMLAWB( psEnc->sCmn.warping_Q16, (opus_int32)psEncCtrl->coding_quality_Q14, SILK_FIX_CONST( 0.01, 18 ) );
262     } else {
263         warping_Q16 = 0;
264     }
265
266     /********************************************/
267     /* Compute noise shaping AR coefs and gains */
268     /********************************************/
269     ALLOC( x_windowed, psEnc->sCmn.shapeWinLength, opus_int16 );
270     for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
271         /* Apply window: sine slope followed by flat part followed by cosine slope */
272         opus_int shift, slope_part, flat_part;
273         flat_part = psEnc->sCmn.fs_kHz * 3;
274         slope_part = silk_RSHIFT( psEnc->sCmn.shapeWinLength - flat_part, 1 );
275
276         silk_apply_sine_window( x_windowed, x_ptr, 1, slope_part );
277         shift = slope_part;
278         silk_memcpy( x_windowed + shift, x_ptr + shift, flat_part * sizeof(opus_int16) );
279         shift += flat_part;
280         silk_apply_sine_window( x_windowed + shift, x_ptr + shift, 2, slope_part );
281
282         /* Update pointer: next LPC analysis block */
283         x_ptr += psEnc->sCmn.subfr_length;
284
285         if( psEnc->sCmn.warping_Q16 > 0 ) {
286             /* Calculate warped auto correlation */
287             silk_warped_autocorrelation_FIX( auto_corr, &scale, x_windowed, warping_Q16, psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder );
288         } else {
289             /* Calculate regular auto correlation */
290             silk_autocorr( auto_corr, &scale, x_windowed, psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder + 1, arch );
291         }
292
293         /* Add white noise, as a fraction of energy */
294         auto_corr[0] = silk_ADD32( auto_corr[0], silk_max_32( silk_SMULWB( silk_RSHIFT( auto_corr[ 0 ], 4 ),
295             SILK_FIX_CONST( SHAPE_WHITE_NOISE_FRACTION, 20 ) ), 1 ) );
296
297         /* Calculate the reflection coefficients using schur */
298         nrg = silk_schur64( refl_coef_Q16, auto_corr, psEnc->sCmn.shapingLPCOrder );
299         silk_assert( nrg >= 0 );
300
301         /* Convert reflection coefficients to prediction coefficients */
302         silk_k2a_Q16( AR2_Q24, refl_coef_Q16, psEnc->sCmn.shapingLPCOrder );
303
304         Qnrg = -scale;          /* range: -12...30*/
305         silk_assert( Qnrg >= -12 );
306         silk_assert( Qnrg <=  30 );
307
308         /* Make sure that Qnrg is an even number */
309         if( Qnrg & 1 ) {
310             Qnrg -= 1;
311             nrg >>= 1;
312         }
313
314         tmp32 = silk_SQRT_APPROX( nrg );
315         Qnrg >>= 1;             /* range: -6...15*/
316
317         psEncCtrl->Gains_Q16[ k ] = silk_LSHIFT_SAT32( tmp32, 16 - Qnrg );
318
319         if( psEnc->sCmn.warping_Q16 > 0 ) {
320             /* Adjust gain for warping */
321             gain_mult_Q16 = warped_gain( AR2_Q24, warping_Q16, psEnc->sCmn.shapingLPCOrder );
322             silk_assert( psEncCtrl->Gains_Q16[ k ] >= 0 );
323             if ( silk_SMULWW( silk_RSHIFT_ROUND( psEncCtrl->Gains_Q16[ k ], 1 ), gain_mult_Q16 ) >= ( silk_int32_MAX >> 1 ) ) {
324                psEncCtrl->Gains_Q16[ k ] = silk_int32_MAX;
325             } else {
326                psEncCtrl->Gains_Q16[ k ] = silk_SMULWW( psEncCtrl->Gains_Q16[ k ], gain_mult_Q16 );
327             }
328         }
329
330         /* Bandwidth expansion for synthesis filter shaping */
331         silk_bwexpander_32( AR2_Q24, psEnc->sCmn.shapingLPCOrder, BWExp2_Q16 );
332
333         /* Compute noise shaping filter coefficients */
334         silk_memcpy( AR1_Q24, AR2_Q24, psEnc->sCmn.shapingLPCOrder * sizeof( opus_int32 ) );
335
336         /* Bandwidth expansion for analysis filter shaping */
337         silk_assert( BWExp1_Q16 <= SILK_FIX_CONST( 1.0, 16 ) );
338         silk_bwexpander_32( AR1_Q24, psEnc->sCmn.shapingLPCOrder, BWExp1_Q16 );
339
340         /* Ratio of prediction gains, in energy domain */
341         pre_nrg_Q30 = silk_LPC_inverse_pred_gain_Q24( AR2_Q24, psEnc->sCmn.shapingLPCOrder );
342         nrg         = silk_LPC_inverse_pred_gain_Q24( AR1_Q24, psEnc->sCmn.shapingLPCOrder );
343
344         /*psEncCtrl->GainsPre[ k ] = 1.0f - 0.7f * ( 1.0f - pre_nrg / nrg ) = 0.3f + 0.7f * pre_nrg / nrg;*/
345         pre_nrg_Q30 = silk_LSHIFT32( silk_SMULWB( pre_nrg_Q30, SILK_FIX_CONST( 0.7, 15 ) ), 1 );
346         psEncCtrl->GainsPre_Q14[ k ] = ( opus_int ) SILK_FIX_CONST( 0.3, 14 ) + silk_DIV32_varQ( pre_nrg_Q30, nrg, 14 );
347
348         /* Convert to monic warped prediction coefficients and limit absolute values */
349         limit_warped_coefs( AR2_Q24, AR1_Q24, warping_Q16, SILK_FIX_CONST( 3.999, 24 ), psEnc->sCmn.shapingLPCOrder );
350
351         /* Convert from Q24 to Q13 and store in int16 */
352         for( i = 0; i < psEnc->sCmn.shapingLPCOrder; i++ ) {
353             psEncCtrl->AR1_Q13[ k * MAX_SHAPE_LPC_ORDER + i ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( AR1_Q24[ i ], 11 ) );
354             psEncCtrl->AR2_Q13[ k * MAX_SHAPE_LPC_ORDER + i ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( AR2_Q24[ i ], 11 ) );
355         }
356     }
357
358     /*****************/
359     /* Gain tweaking */
360     /*****************/
361     /* Increase gains during low speech activity and put lower limit on gains */
362     gain_mult_Q16 = silk_log2lin( -silk_SMLAWB( -SILK_FIX_CONST( 16.0, 7 ), SNR_adj_dB_Q7, SILK_FIX_CONST( 0.16, 16 ) ) );
363     gain_add_Q16  = silk_log2lin(  silk_SMLAWB(  SILK_FIX_CONST( 16.0, 7 ), SILK_FIX_CONST( MIN_QGAIN_DB, 7 ), SILK_FIX_CONST( 0.16, 16 ) ) );
364     silk_assert( gain_mult_Q16 > 0 );
365     for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
366         psEncCtrl->Gains_Q16[ k ] = silk_SMULWW( psEncCtrl->Gains_Q16[ k ], gain_mult_Q16 );
367         silk_assert( psEncCtrl->Gains_Q16[ k ] >= 0 );
368         psEncCtrl->Gains_Q16[ k ] = silk_ADD_POS_SAT32( psEncCtrl->Gains_Q16[ k ], gain_add_Q16 );
369     }
370
371     gain_mult_Q16 = SILK_FIX_CONST( 1.0, 16 ) + silk_RSHIFT_ROUND( silk_MLA( SILK_FIX_CONST( INPUT_TILT, 26 ),
372         psEncCtrl->coding_quality_Q14, SILK_FIX_CONST( HIGH_RATE_INPUT_TILT, 12 ) ), 10 );
373     for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
374         psEncCtrl->GainsPre_Q14[ k ] = silk_SMULWB( gain_mult_Q16, psEncCtrl->GainsPre_Q14[ k ] );
375     }
376
377     /************************************************/
378     /* Control low-frequency shaping and noise tilt */
379     /************************************************/
380     /* Less low frequency shaping for noisy inputs */
381     strength_Q16 = silk_MUL( SILK_FIX_CONST( LOW_FREQ_SHAPING, 4 ), silk_SMLAWB( SILK_FIX_CONST( 1.0, 12 ),
382         SILK_FIX_CONST( LOW_QUALITY_LOW_FREQ_SHAPING_DECR, 13 ), psEnc->sCmn.input_quality_bands_Q15[ 0 ] - SILK_FIX_CONST( 1.0, 15 ) ) );
383     strength_Q16 = silk_RSHIFT( silk_MUL( strength_Q16, psEnc->sCmn.speech_activity_Q8 ), 8 );
384     if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
385         /* Reduce low frequencies quantization noise for periodic signals, depending on pitch lag */
386         /*f = 400; freqz([1, -0.98 + 2e-4 * f], [1, -0.97 + 7e-4 * f], 2^12, Fs); axis([0, 1000, -10, 1])*/
387         opus_int fs_kHz_inv = silk_DIV32_16( SILK_FIX_CONST( 0.2, 14 ), psEnc->sCmn.fs_kHz );
388         for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
389             b_Q14 = fs_kHz_inv + silk_DIV32_16( SILK_FIX_CONST( 3.0, 14 ), psEncCtrl->pitchL[ k ] );
390             /* Pack two coefficients in one int32 */
391             psEncCtrl->LF_shp_Q14[ k ]  = silk_LSHIFT( SILK_FIX_CONST( 1.0, 14 ) - b_Q14 - silk_SMULWB( strength_Q16, b_Q14 ), 16 );
392             psEncCtrl->LF_shp_Q14[ k ] |= (opus_uint16)( b_Q14 - SILK_FIX_CONST( 1.0, 14 ) );
393         }
394         silk_assert( SILK_FIX_CONST( HARM_HP_NOISE_COEF, 24 ) < SILK_FIX_CONST( 0.5, 24 ) ); /* Guarantees that second argument to SMULWB() is within range of an opus_int16*/
395         Tilt_Q16 = - SILK_FIX_CONST( HP_NOISE_COEF, 16 ) -
396             silk_SMULWB( SILK_FIX_CONST( 1.0, 16 ) - SILK_FIX_CONST( HP_NOISE_COEF, 16 ),
397                 silk_SMULWB( SILK_FIX_CONST( HARM_HP_NOISE_COEF, 24 ), psEnc->sCmn.speech_activity_Q8 ) );
398     } else {
399         b_Q14 = silk_DIV32_16( 21299, psEnc->sCmn.fs_kHz ); /* 1.3_Q0 = 21299_Q14*/
400         /* Pack two coefficients in one int32 */
401         psEncCtrl->LF_shp_Q14[ 0 ]  = silk_LSHIFT( SILK_FIX_CONST( 1.0, 14 ) - b_Q14 -
402             silk_SMULWB( strength_Q16, silk_SMULWB( SILK_FIX_CONST( 0.6, 16 ), b_Q14 ) ), 16 );
403         psEncCtrl->LF_shp_Q14[ 0 ] |= (opus_uint16)( b_Q14 - SILK_FIX_CONST( 1.0, 14 ) );
404         for( k = 1; k < psEnc->sCmn.nb_subfr; k++ ) {
405             psEncCtrl->LF_shp_Q14[ k ] = psEncCtrl->LF_shp_Q14[ 0 ];
406         }
407         Tilt_Q16 = -SILK_FIX_CONST( HP_NOISE_COEF, 16 );
408     }
409
410     /****************************/
411     /* HARMONIC SHAPING CONTROL */
412     /****************************/
413     /* Control boosting of harmonic frequencies */
414     HarmBoost_Q16 = silk_SMULWB( silk_SMULWB( SILK_FIX_CONST( 1.0, 17 ) - silk_LSHIFT( psEncCtrl->coding_quality_Q14, 3 ),
415         psEnc->LTPCorr_Q15 ), SILK_FIX_CONST( LOW_RATE_HARMONIC_BOOST, 16 ) );
416
417     /* More harmonic boost for noisy input signals */
418     HarmBoost_Q16 = silk_SMLAWB( HarmBoost_Q16,
419         SILK_FIX_CONST( 1.0, 16 ) - silk_LSHIFT( psEncCtrl->input_quality_Q14, 2 ), SILK_FIX_CONST( LOW_INPUT_QUALITY_HARMONIC_BOOST, 16 ) );
420
421     if( USE_HARM_SHAPING && psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
422         /* More harmonic noise shaping for high bitrates or noisy input */
423         HarmShapeGain_Q16 = silk_SMLAWB( SILK_FIX_CONST( HARMONIC_SHAPING, 16 ),
424                 SILK_FIX_CONST( 1.0, 16 ) - silk_SMULWB( SILK_FIX_CONST( 1.0, 18 ) - silk_LSHIFT( psEncCtrl->coding_quality_Q14, 4 ),
425                 psEncCtrl->input_quality_Q14 ), SILK_FIX_CONST( HIGH_RATE_OR_LOW_QUALITY_HARMONIC_SHAPING, 16 ) );
426
427         /* Less harmonic noise shaping for less periodic signals */
428         HarmShapeGain_Q16 = silk_SMULWB( silk_LSHIFT( HarmShapeGain_Q16, 1 ),
429             silk_SQRT_APPROX( silk_LSHIFT( psEnc->LTPCorr_Q15, 15 ) ) );
430     } else {
431         HarmShapeGain_Q16 = 0;
432     }
433
434     /*************************/
435     /* Smooth over subframes */
436     /*************************/
437     for( k = 0; k < MAX_NB_SUBFR; k++ ) {
438         psShapeSt->HarmBoost_smth_Q16 =
439             silk_SMLAWB( psShapeSt->HarmBoost_smth_Q16,     HarmBoost_Q16     - psShapeSt->HarmBoost_smth_Q16,     SILK_FIX_CONST( SUBFR_SMTH_COEF, 16 ) );
440         psShapeSt->HarmShapeGain_smth_Q16 =
441             silk_SMLAWB( psShapeSt->HarmShapeGain_smth_Q16, HarmShapeGain_Q16 - psShapeSt->HarmShapeGain_smth_Q16, SILK_FIX_CONST( SUBFR_SMTH_COEF, 16 ) );
442         psShapeSt->Tilt_smth_Q16 =
443             silk_SMLAWB( psShapeSt->Tilt_smth_Q16,          Tilt_Q16          - psShapeSt->Tilt_smth_Q16,          SILK_FIX_CONST( SUBFR_SMTH_COEF, 16 ) );
444
445         psEncCtrl->HarmBoost_Q14[ k ]     = ( opus_int )silk_RSHIFT_ROUND( psShapeSt->HarmBoost_smth_Q16,     2 );
446         psEncCtrl->HarmShapeGain_Q14[ k ] = ( opus_int )silk_RSHIFT_ROUND( psShapeSt->HarmShapeGain_smth_Q16, 2 );
447         psEncCtrl->Tilt_Q14[ k ]          = ( opus_int )silk_RSHIFT_ROUND( psShapeSt->Tilt_smth_Q16,          2 );
448     }
449     RESTORE_STACK;
450 }
451 #endif /* OVERRIDE_silk_noise_shape_analysis_FIX */