Merge branch 'exp_surround1'
[opus.git] / silk / control_codec.c
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 #ifdef FIXED_POINT
32 #include "main_FIX.h"
33 #define silk_encoder_state_Fxx      silk_encoder_state_FIX
34 #else
35 #include "main_FLP.h"
36 #define silk_encoder_state_Fxx      silk_encoder_state_FLP
37 #endif
38 #include "stack_alloc.h"
39 #include "tuning_parameters.h"
40 #include "pitch_est_defines.h"
41
42 static opus_int silk_setup_resamplers(
43     silk_encoder_state_Fxx          *psEnc,             /* I/O                      */
44     opus_int                        fs_kHz              /* I                        */
45 );
46
47 static opus_int silk_setup_fs(
48     silk_encoder_state_Fxx          *psEnc,             /* I/O                      */
49     opus_int                        fs_kHz,             /* I                        */
50     opus_int                        PacketSize_ms       /* I                        */
51 );
52
53 static opus_int silk_setup_complexity(
54     silk_encoder_state              *psEncC,            /* I/O                      */
55     opus_int                        Complexity          /* I                        */
56 );
57
58 static inline opus_int silk_setup_LBRR(
59     silk_encoder_state              *psEncC,            /* I/O                      */
60     const opus_int32                TargetRate_bps      /* I                        */
61 );
62
63
64 /* Control encoder */
65 opus_int silk_control_encoder(
66     silk_encoder_state_Fxx          *psEnc,                                 /* I/O  Pointer to Silk encoder state                                               */
67     silk_EncControlStruct           *encControl,                            /* I    Control structure                                                           */
68     const opus_int32                TargetRate_bps,                         /* I    Target max bitrate (bps)                                                    */
69     const opus_int                  allow_bw_switch,                        /* I    Flag to allow switching audio bandwidth                                     */
70     const opus_int                  channelNb,                              /* I    Channel number                                                              */
71     const opus_int                  force_fs_kHz
72 )
73 {
74     opus_int   fs_kHz, ret = 0;
75
76     psEnc->sCmn.useDTX                 = encControl->useDTX;
77     psEnc->sCmn.useCBR                 = encControl->useCBR;
78     psEnc->sCmn.API_fs_Hz              = encControl->API_sampleRate;
79     psEnc->sCmn.maxInternal_fs_Hz      = encControl->maxInternalSampleRate;
80     psEnc->sCmn.minInternal_fs_Hz      = encControl->minInternalSampleRate;
81     psEnc->sCmn.desiredInternal_fs_Hz  = encControl->desiredInternalSampleRate;
82     psEnc->sCmn.useInBandFEC           = encControl->useInBandFEC;
83     psEnc->sCmn.nChannelsAPI           = encControl->nChannelsAPI;
84     psEnc->sCmn.nChannelsInternal      = encControl->nChannelsInternal;
85     psEnc->sCmn.allow_bandwidth_switch = allow_bw_switch;
86     psEnc->sCmn.channelNb              = channelNb;
87
88     if( psEnc->sCmn.controlled_since_last_payload != 0 && psEnc->sCmn.prefillFlag == 0 ) {
89         if( psEnc->sCmn.API_fs_Hz != psEnc->sCmn.prev_API_fs_Hz && psEnc->sCmn.fs_kHz > 0 ) {
90             /* Change in API sampling rate in the middle of encoding a packet */
91             ret += silk_setup_resamplers( psEnc, psEnc->sCmn.fs_kHz );
92         }
93         return ret;
94     }
95
96     /* Beyond this point we know that there are no previously coded frames in the payload buffer */
97
98     /********************************************/
99     /* Determine internal sampling rate         */
100     /********************************************/
101     fs_kHz = silk_control_audio_bandwidth( &psEnc->sCmn, encControl );
102     if( force_fs_kHz ) {
103        fs_kHz = force_fs_kHz;
104     }
105     /********************************************/
106     /* Prepare resampler and buffered data      */
107     /********************************************/
108     ret += silk_setup_resamplers( psEnc, fs_kHz );
109
110     /********************************************/
111     /* Set internal sampling frequency          */
112     /********************************************/
113     ret += silk_setup_fs( psEnc, fs_kHz, encControl->payloadSize_ms );
114
115     /********************************************/
116     /* Set encoding complexity                  */
117     /********************************************/
118     ret += silk_setup_complexity( &psEnc->sCmn, encControl->complexity  );
119
120     /********************************************/
121     /* Set packet loss rate measured by farend  */
122     /********************************************/
123     psEnc->sCmn.PacketLoss_perc = encControl->packetLossPercentage;
124
125     /********************************************/
126     /* Set LBRR usage                           */
127     /********************************************/
128     ret += silk_setup_LBRR( &psEnc->sCmn, TargetRate_bps );
129
130     psEnc->sCmn.controlled_since_last_payload = 1;
131
132     return ret;
133 }
134
135 static opus_int silk_setup_resamplers(
136     silk_encoder_state_Fxx          *psEnc,             /* I/O                      */
137     opus_int                         fs_kHz              /* I                        */
138 )
139 {
140     opus_int   ret = SILK_NO_ERROR;
141     SAVE_STACK;
142
143     if( psEnc->sCmn.fs_kHz != fs_kHz || psEnc->sCmn.prev_API_fs_Hz != psEnc->sCmn.API_fs_Hz )
144     {
145         if( psEnc->sCmn.fs_kHz == 0 ) {
146             /* Initialize the resampler for enc_API.c preparing resampling from API_fs_Hz to fs_kHz */
147             ret += silk_resampler_init( &psEnc->sCmn.resampler_state, psEnc->sCmn.API_fs_Hz, fs_kHz * 1000, 1 );
148         } else {
149             VARDECL( opus_int16, x_buf_API_fs_Hz );
150             VARDECL( silk_resampler_state_struct, temp_resampler_state );
151 #ifdef FIXED_POINT
152             opus_int16 *x_bufFIX = psEnc->x_buf;
153 #else
154             VARDECL( opus_int16, x_bufFIX );
155             opus_int32 new_buf_samples;
156 #endif
157             opus_int32 api_buf_samples;
158             opus_int32 old_buf_samples;
159             opus_int32 buf_length_ms;
160
161             buf_length_ms = silk_LSHIFT( psEnc->sCmn.nb_subfr * 5, 1 ) + LA_SHAPE_MS;
162             old_buf_samples = buf_length_ms * psEnc->sCmn.fs_kHz;
163
164 #ifndef FIXED_POINT
165             new_buf_samples = buf_length_ms * fs_kHz;
166             ALLOC( x_bufFIX, silk_max( old_buf_samples, new_buf_samples ),
167                    opus_int16 );
168             silk_float2short_array( x_bufFIX, psEnc->x_buf, old_buf_samples );
169 #endif
170
171             /* Initialize resampler for temporary resampling of x_buf data to API_fs_Hz */
172             ALLOC( temp_resampler_state, 1, silk_resampler_state_struct );
173             ret += silk_resampler_init( temp_resampler_state, silk_SMULBB( psEnc->sCmn.fs_kHz, 1000 ), psEnc->sCmn.API_fs_Hz, 0 );
174
175             /* Calculate number of samples to temporarily upsample */
176             api_buf_samples = buf_length_ms * silk_DIV32_16( psEnc->sCmn.API_fs_Hz, 1000 );
177
178             /* Temporary resampling of x_buf data to API_fs_Hz */
179             ALLOC( x_buf_API_fs_Hz, api_buf_samples, opus_int16 );
180             ret += silk_resampler( temp_resampler_state, x_buf_API_fs_Hz, x_bufFIX, old_buf_samples );
181
182             /* Initialize the resampler for enc_API.c preparing resampling from API_fs_Hz to fs_kHz */
183             ret += silk_resampler_init( &psEnc->sCmn.resampler_state, psEnc->sCmn.API_fs_Hz, silk_SMULBB( fs_kHz, 1000 ), 1 );
184
185             /* Correct resampler state by resampling buffered data from API_fs_Hz to fs_kHz */
186             ret += silk_resampler( &psEnc->sCmn.resampler_state, x_bufFIX, x_buf_API_fs_Hz, api_buf_samples );
187
188 #ifndef FIXED_POINT
189             silk_short2float_array( psEnc->x_buf, x_bufFIX, new_buf_samples);
190 #endif
191         }
192     }
193
194     psEnc->sCmn.prev_API_fs_Hz = psEnc->sCmn.API_fs_Hz;
195
196     RESTORE_STACK;
197     return ret;
198 }
199
200 static opus_int silk_setup_fs(
201     silk_encoder_state_Fxx          *psEnc,             /* I/O                      */
202     opus_int                        fs_kHz,             /* I                        */
203     opus_int                        PacketSize_ms       /* I                        */
204 )
205 {
206     opus_int ret = SILK_NO_ERROR;
207
208     /* Set packet size */
209     if( PacketSize_ms != psEnc->sCmn.PacketSize_ms ) {
210         if( ( PacketSize_ms !=  10 ) &&
211             ( PacketSize_ms !=  20 ) &&
212             ( PacketSize_ms !=  40 ) &&
213             ( PacketSize_ms !=  60 ) ) {
214             ret = SILK_ENC_PACKET_SIZE_NOT_SUPPORTED;
215         }
216         if( PacketSize_ms <= 10 ) {
217             psEnc->sCmn.nFramesPerPacket = 1;
218             psEnc->sCmn.nb_subfr = PacketSize_ms == 10 ? 2 : 1;
219             psEnc->sCmn.frame_length = silk_SMULBB( PacketSize_ms, fs_kHz );
220             psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS_2_SF, fs_kHz );
221             if( psEnc->sCmn.fs_kHz == 8 ) {
222                 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_NB_iCDF;
223             } else {
224                 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_iCDF;
225             }
226         } else {
227             psEnc->sCmn.nFramesPerPacket = silk_DIV32_16( PacketSize_ms, MAX_FRAME_LENGTH_MS );
228             psEnc->sCmn.nb_subfr = MAX_NB_SUBFR;
229             psEnc->sCmn.frame_length = silk_SMULBB( 20, fs_kHz );
230             psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS, fs_kHz );
231             if( psEnc->sCmn.fs_kHz == 8 ) {
232                 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_NB_iCDF;
233             } else {
234                 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_iCDF;
235             }
236         }
237         psEnc->sCmn.PacketSize_ms  = PacketSize_ms;
238         psEnc->sCmn.TargetRate_bps = 0;         /* trigger new SNR computation */
239     }
240
241     /* Set internal sampling frequency */
242     silk_assert( fs_kHz == 8 || fs_kHz == 12 || fs_kHz == 16 );
243     silk_assert( psEnc->sCmn.nb_subfr == 2 || psEnc->sCmn.nb_subfr == 4 );
244     if( psEnc->sCmn.fs_kHz != fs_kHz ) {
245         /* reset part of the state */
246         silk_memset( &psEnc->sShape,               0, sizeof( psEnc->sShape ) );
247         silk_memset( &psEnc->sPrefilt,             0, sizeof( psEnc->sPrefilt ) );
248         silk_memset( &psEnc->sCmn.sNSQ,            0, sizeof( psEnc->sCmn.sNSQ ) );
249         silk_memset( psEnc->sCmn.prev_NLSFq_Q15,   0, sizeof( psEnc->sCmn.prev_NLSFq_Q15 ) );
250         silk_memset( &psEnc->sCmn.sLP.In_LP_State, 0, sizeof( psEnc->sCmn.sLP.In_LP_State ) );
251         psEnc->sCmn.inputBufIx                  = 0;
252         psEnc->sCmn.nFramesEncoded              = 0;
253         psEnc->sCmn.TargetRate_bps              = 0;     /* trigger new SNR computation */
254
255         /* Initialize non-zero parameters */
256         psEnc->sCmn.prevLag                     = 100;
257         psEnc->sCmn.first_frame_after_reset     = 1;
258         psEnc->sPrefilt.lagPrev                 = 100;
259         psEnc->sShape.LastGainIndex             = 10;
260         psEnc->sCmn.sNSQ.lagPrev                = 100;
261         psEnc->sCmn.sNSQ.prev_gain_Q16          = 65536;
262         psEnc->sCmn.prevSignalType              = TYPE_NO_VOICE_ACTIVITY;
263
264         psEnc->sCmn.fs_kHz = fs_kHz;
265         if( psEnc->sCmn.fs_kHz == 8 ) {
266             if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) {
267                 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_NB_iCDF;
268             } else {
269                 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_NB_iCDF;
270             }
271         } else {
272             if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) {
273                 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_iCDF;
274             } else {
275                 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_iCDF;
276             }
277         }
278         if( psEnc->sCmn.fs_kHz == 8 || psEnc->sCmn.fs_kHz == 12 ) {
279             psEnc->sCmn.predictLPCOrder = MIN_LPC_ORDER;
280             psEnc->sCmn.psNLSF_CB  = &silk_NLSF_CB_NB_MB;
281         } else {
282             psEnc->sCmn.predictLPCOrder = MAX_LPC_ORDER;
283             psEnc->sCmn.psNLSF_CB  = &silk_NLSF_CB_WB;
284         }
285         psEnc->sCmn.subfr_length   = SUB_FRAME_LENGTH_MS * fs_kHz;
286         psEnc->sCmn.frame_length   = silk_SMULBB( psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr );
287         psEnc->sCmn.ltp_mem_length = silk_SMULBB( LTP_MEM_LENGTH_MS, fs_kHz );
288         psEnc->sCmn.la_pitch       = silk_SMULBB( LA_PITCH_MS, fs_kHz );
289         psEnc->sCmn.max_pitch_lag  = silk_SMULBB( 18, fs_kHz );
290         if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) {
291             psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS, fs_kHz );
292         } else {
293             psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS_2_SF, fs_kHz );
294         }
295         if( psEnc->sCmn.fs_kHz == 16 ) {
296             psEnc->sCmn.mu_LTP_Q9 = SILK_FIX_CONST( MU_LTP_QUANT_WB, 9 );
297             psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform8_iCDF;
298         } else if( psEnc->sCmn.fs_kHz == 12 ) {
299             psEnc->sCmn.mu_LTP_Q9 = SILK_FIX_CONST( MU_LTP_QUANT_MB, 9 );
300             psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform6_iCDF;
301         } else {
302             psEnc->sCmn.mu_LTP_Q9 = SILK_FIX_CONST( MU_LTP_QUANT_NB, 9 );
303             psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform4_iCDF;
304         }
305     }
306
307     /* Check that settings are valid */
308     silk_assert( ( psEnc->sCmn.subfr_length * psEnc->sCmn.nb_subfr ) == psEnc->sCmn.frame_length );
309
310     return ret;
311 }
312
313 static opus_int silk_setup_complexity(
314     silk_encoder_state              *psEncC,            /* I/O                      */
315     opus_int                        Complexity          /* I                        */
316 )
317 {
318     opus_int ret = 0;
319
320     /* Set encoding complexity */
321     silk_assert( Complexity >= 0 && Complexity <= 10 );
322     if( Complexity < 2 ) {
323         psEncC->pitchEstimationComplexity       = SILK_PE_MIN_COMPLEX;
324         psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.8, 16 );
325         psEncC->pitchEstimationLPCOrder         = 6;
326         psEncC->shapingLPCOrder                 = 8;
327         psEncC->la_shape                        = 3 * psEncC->fs_kHz;
328         psEncC->nStatesDelayedDecision          = 1;
329         psEncC->useInterpolatedNLSFs            = 0;
330         psEncC->LTPQuantLowComplexity           = 1;
331         psEncC->NLSF_MSVQ_Survivors             = 2;
332         psEncC->warping_Q16                     = 0;
333     } else if( Complexity < 4 ) {
334         psEncC->pitchEstimationComplexity       = SILK_PE_MID_COMPLEX;
335         psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.76, 16 );
336         psEncC->pitchEstimationLPCOrder         = 8;
337         psEncC->shapingLPCOrder                 = 10;
338         psEncC->la_shape                        = 5 * psEncC->fs_kHz;
339         psEncC->nStatesDelayedDecision          = 1;
340         psEncC->useInterpolatedNLSFs            = 0;
341         psEncC->LTPQuantLowComplexity           = 0;
342         psEncC->NLSF_MSVQ_Survivors             = 4;
343         psEncC->warping_Q16                     = 0;
344     } else if( Complexity < 6 ) {
345         psEncC->pitchEstimationComplexity       = SILK_PE_MID_COMPLEX;
346         psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.74, 16 );
347         psEncC->pitchEstimationLPCOrder         = 10;
348         psEncC->shapingLPCOrder                 = 12;
349         psEncC->la_shape                        = 5 * psEncC->fs_kHz;
350         psEncC->nStatesDelayedDecision          = 2;
351         psEncC->useInterpolatedNLSFs            = 1;
352         psEncC->LTPQuantLowComplexity           = 0;
353         psEncC->NLSF_MSVQ_Survivors             = 8;
354         psEncC->warping_Q16                     = psEncC->fs_kHz * SILK_FIX_CONST( WARPING_MULTIPLIER, 16 );
355     } else if( Complexity < 8 ) {
356         psEncC->pitchEstimationComplexity       = SILK_PE_MID_COMPLEX;
357         psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.72, 16 );
358         psEncC->pitchEstimationLPCOrder         = 12;
359         psEncC->shapingLPCOrder                 = 14;
360         psEncC->la_shape                        = 5 * psEncC->fs_kHz;
361         psEncC->nStatesDelayedDecision          = 3;
362         psEncC->useInterpolatedNLSFs            = 1;
363         psEncC->LTPQuantLowComplexity           = 0;
364         psEncC->NLSF_MSVQ_Survivors             = 16;
365         psEncC->warping_Q16                     = psEncC->fs_kHz * SILK_FIX_CONST( WARPING_MULTIPLIER, 16 );
366     } else {
367         psEncC->pitchEstimationComplexity       = SILK_PE_MAX_COMPLEX;
368         psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.7, 16 );
369         psEncC->pitchEstimationLPCOrder         = 16;
370         psEncC->shapingLPCOrder                 = 16;
371         psEncC->la_shape                        = 5 * psEncC->fs_kHz;
372         psEncC->nStatesDelayedDecision          = MAX_DEL_DEC_STATES;
373         psEncC->useInterpolatedNLSFs            = 1;
374         psEncC->LTPQuantLowComplexity           = 0;
375         psEncC->NLSF_MSVQ_Survivors             = 32;
376         psEncC->warping_Q16                     = psEncC->fs_kHz * SILK_FIX_CONST( WARPING_MULTIPLIER, 16 );
377     }
378
379     /* Do not allow higher pitch estimation LPC order than predict LPC order */
380     psEncC->pitchEstimationLPCOrder = silk_min_int( psEncC->pitchEstimationLPCOrder, psEncC->predictLPCOrder );
381     psEncC->shapeWinLength          = SUB_FRAME_LENGTH_MS * psEncC->fs_kHz + 2 * psEncC->la_shape;
382     psEncC->Complexity              = Complexity;
383
384     silk_assert( psEncC->pitchEstimationLPCOrder <= MAX_FIND_PITCH_LPC_ORDER );
385     silk_assert( psEncC->shapingLPCOrder         <= MAX_SHAPE_LPC_ORDER      );
386     silk_assert( psEncC->nStatesDelayedDecision  <= MAX_DEL_DEC_STATES       );
387     silk_assert( psEncC->warping_Q16             <= 32767                    );
388     silk_assert( psEncC->la_shape                <= LA_SHAPE_MAX             );
389     silk_assert( psEncC->shapeWinLength          <= SHAPE_LPC_WIN_MAX        );
390     silk_assert( psEncC->NLSF_MSVQ_Survivors     <= NLSF_VQ_MAX_SURVIVORS    );
391
392     return ret;
393 }
394
395 static inline opus_int silk_setup_LBRR(
396     silk_encoder_state          *psEncC,            /* I/O                      */
397     const opus_int32            TargetRate_bps      /* I                        */
398 )
399 {
400     opus_int   ret = SILK_NO_ERROR;
401     opus_int32 LBRR_rate_thres_bps;
402
403     psEncC->LBRR_enabled = 0;
404     if( psEncC->useInBandFEC && psEncC->PacketLoss_perc > 0 ) {
405         if( psEncC->fs_kHz == 8 ) {
406             LBRR_rate_thres_bps = LBRR_NB_MIN_RATE_BPS;
407         } else if( psEncC->fs_kHz == 12 ) {
408             LBRR_rate_thres_bps = LBRR_MB_MIN_RATE_BPS;
409         } else {
410             LBRR_rate_thres_bps = LBRR_WB_MIN_RATE_BPS;
411         }
412         LBRR_rate_thres_bps = silk_SMULWB( silk_MUL( LBRR_rate_thres_bps, 125 - silk_min( psEncC->PacketLoss_perc, 25 ) ), SILK_FIX_CONST( 0.01, 16 ) );
413
414         if( TargetRate_bps > LBRR_rate_thres_bps ) {
415             /* Set gain increase for coding LBRR excitation */
416             psEncC->LBRR_enabled = 1;
417             psEncC->LBRR_GainIncreases = silk_max_int( 7 - silk_SMULWB( (opus_int32)psEncC->PacketLoss_perc, SILK_FIX_CONST( 0.4, 16 ) ), 2 );
418         }
419     }
420
421     return ret;
422 }