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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 #include "define.h"
32 #include "API.h"
33 #include "control.h"
34 #include "typedef.h"
35 #include "stack_alloc.h"
36 #include "structs.h"
37 #include "tuning_parameters.h"
38 #ifdef FIXED_POINT
39 #include "main_FIX.h"
40 #else
41 #include "main_FLP.h"
42 #endif
43 
44 /***************************************/
45 /* Read control structure from encoder */
46 /***************************************/
47 static opus_int silk_QueryEncoder(                      /* O    Returns error code                              */
48     const void                      *encState,          /* I    State                                           */
49     silk_EncControlStruct           *encStatus          /* O    Encoder Status                                  */
50 );
51 
52 /****************************************/
53 /* Encoder functions                    */
54 /****************************************/
55 
silk_Get_Encoder_Size(opus_int * encSizeBytes)56 opus_int silk_Get_Encoder_Size(                         /* O    Returns error code                              */
57     opus_int                        *encSizeBytes       /* O    Number of bytes in SILK encoder state           */
58 )
59 {
60     opus_int ret = SILK_NO_ERROR;
61 
62     *encSizeBytes = sizeof( silk_encoder );
63 
64     return ret;
65 }
66 
67 /*************************/
68 /* Init or Reset encoder */
69 /*************************/
silk_InitEncoder(void * encState,int arch,silk_EncControlStruct * encStatus)70 opus_int silk_InitEncoder(                              /* O    Returns error code                              */
71     void                            *encState,          /* I/O  State                                           */
72     int                              arch,              /* I    Run-time architecture                           */
73     silk_EncControlStruct           *encStatus          /* O    Encoder Status                                  */
74 )
75 {
76     silk_encoder *psEnc;
77     opus_int n, ret = SILK_NO_ERROR;
78 
79     psEnc = (silk_encoder *)encState;
80 
81     /* Reset encoder */
82     silk_memset( psEnc, 0, sizeof( silk_encoder ) );
83     for( n = 0; n < ENCODER_NUM_CHANNELS; n++ ) {
84         if( ret += silk_init_encoder( &psEnc->state_Fxx[ n ], arch ) ) {
85             celt_assert( 0 );
86         }
87     }
88 
89     psEnc->nChannelsAPI = 1;
90     psEnc->nChannelsInternal = 1;
91 
92     /* Read control structure */
93     if( ret += silk_QueryEncoder( encState, encStatus ) ) {
94         celt_assert( 0 );
95     }
96 
97     return ret;
98 }
99 
100 /***************************************/
101 /* Read control structure from encoder */
102 /***************************************/
silk_QueryEncoder(const void * encState,silk_EncControlStruct * encStatus)103 static opus_int silk_QueryEncoder(                      /* O    Returns error code                              */
104     const void                      *encState,          /* I    State                                           */
105     silk_EncControlStruct           *encStatus          /* O    Encoder Status                                  */
106 )
107 {
108     opus_int ret = SILK_NO_ERROR;
109     silk_encoder_state_Fxx *state_Fxx;
110     silk_encoder *psEnc = (silk_encoder *)encState;
111 
112     state_Fxx = psEnc->state_Fxx;
113 
114     encStatus->nChannelsAPI              = psEnc->nChannelsAPI;
115     encStatus->nChannelsInternal         = psEnc->nChannelsInternal;
116     encStatus->API_sampleRate            = state_Fxx[ 0 ].sCmn.API_fs_Hz;
117     encStatus->maxInternalSampleRate     = state_Fxx[ 0 ].sCmn.maxInternal_fs_Hz;
118     encStatus->minInternalSampleRate     = state_Fxx[ 0 ].sCmn.minInternal_fs_Hz;
119     encStatus->desiredInternalSampleRate = state_Fxx[ 0 ].sCmn.desiredInternal_fs_Hz;
120     encStatus->payloadSize_ms            = state_Fxx[ 0 ].sCmn.PacketSize_ms;
121     encStatus->bitRate                   = state_Fxx[ 0 ].sCmn.TargetRate_bps;
122     encStatus->packetLossPercentage      = state_Fxx[ 0 ].sCmn.PacketLoss_perc;
123     encStatus->complexity                = state_Fxx[ 0 ].sCmn.Complexity;
124     encStatus->useInBandFEC              = state_Fxx[ 0 ].sCmn.useInBandFEC;
125     encStatus->useDTX                    = state_Fxx[ 0 ].sCmn.useDTX;
126     encStatus->useCBR                    = state_Fxx[ 0 ].sCmn.useCBR;
127     encStatus->internalSampleRate        = silk_SMULBB( state_Fxx[ 0 ].sCmn.fs_kHz, 1000 );
128     encStatus->allowBandwidthSwitch      = state_Fxx[ 0 ].sCmn.allow_bandwidth_switch;
129     encStatus->inWBmodeWithoutVariableLP = state_Fxx[ 0 ].sCmn.fs_kHz == 16 && state_Fxx[ 0 ].sCmn.sLP.mode == 0;
130 
131     return ret;
132 }
133 
134 
135 /**************************/
136 /* Encode frame with Silk */
137 /**************************/
138 /* Note: if prefillFlag is set, the input must contain 10 ms of audio, irrespective of what                     */
139 /* encControl->payloadSize_ms is set to                                                                         */
silk_Encode(void * encState,silk_EncControlStruct * encControl,const opus_int16 * samplesIn,opus_int nSamplesIn,ec_enc * psRangeEnc,opus_int32 * nBytesOut,const opus_int prefillFlag,opus_int activity)140 opus_int silk_Encode(                                   /* O    Returns error code                              */
141     void                            *encState,          /* I/O  State                                           */
142     silk_EncControlStruct           *encControl,        /* I    Control status                                  */
143     const opus_int16                *samplesIn,         /* I    Speech sample input vector                      */
144     opus_int                        nSamplesIn,         /* I    Number of samples in input vector               */
145     ec_enc                          *psRangeEnc,        /* I/O  Compressor data structure                       */
146     opus_int32                      *nBytesOut,         /* I/O  Number of bytes in payload (input: Max bytes)   */
147     const opus_int                  prefillFlag,        /* I    Flag to indicate prefilling buffers no coding   */
148     opus_int                        activity            /* I    Decision of Opus voice activity detector        */
149 )
150 {
151     opus_int   n, i, nBits, flags, tmp_payloadSize_ms = 0, tmp_complexity = 0, ret = 0;
152     opus_int   nSamplesToBuffer, nSamplesToBufferMax, nBlocksOf10ms;
153     opus_int   nSamplesFromInput = 0, nSamplesFromInputMax;
154     opus_int   speech_act_thr_for_switch_Q8;
155     opus_int32 TargetRate_bps, MStargetRates_bps[ 2 ], channelRate_bps, LBRR_symbol, sum;
156     silk_encoder *psEnc = ( silk_encoder * )encState;
157     VARDECL( opus_int16, buf );
158     opus_int transition, curr_block, tot_blocks;
159     SAVE_STACK;
160 
161     if (encControl->reducedDependency)
162     {
163        psEnc->state_Fxx[0].sCmn.first_frame_after_reset = 1;
164        psEnc->state_Fxx[1].sCmn.first_frame_after_reset = 1;
165     }
166     psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded = psEnc->state_Fxx[ 1 ].sCmn.nFramesEncoded = 0;
167 
168     /* Check values in encoder control structure */
169     if( ( ret = check_control_input( encControl ) ) != 0 ) {
170         celt_assert( 0 );
171         RESTORE_STACK;
172         return ret;
173     }
174 
175     encControl->switchReady = 0;
176 
177     if( encControl->nChannelsInternal > psEnc->nChannelsInternal ) {
178         /* Mono -> Stereo transition: init state of second channel and stereo state */
179         ret += silk_init_encoder( &psEnc->state_Fxx[ 1 ], psEnc->state_Fxx[ 0 ].sCmn.arch );
180         silk_memset( psEnc->sStereo.pred_prev_Q13, 0, sizeof( psEnc->sStereo.pred_prev_Q13 ) );
181         silk_memset( psEnc->sStereo.sSide, 0, sizeof( psEnc->sStereo.sSide ) );
182         psEnc->sStereo.mid_side_amp_Q0[ 0 ] = 0;
183         psEnc->sStereo.mid_side_amp_Q0[ 1 ] = 1;
184         psEnc->sStereo.mid_side_amp_Q0[ 2 ] = 0;
185         psEnc->sStereo.mid_side_amp_Q0[ 3 ] = 1;
186         psEnc->sStereo.width_prev_Q14 = 0;
187         psEnc->sStereo.smth_width_Q14 = SILK_FIX_CONST( 1, 14 );
188         if( psEnc->nChannelsAPI == 2 ) {
189             silk_memcpy( &psEnc->state_Fxx[ 1 ].sCmn.resampler_state, &psEnc->state_Fxx[ 0 ].sCmn.resampler_state, sizeof( silk_resampler_state_struct ) );
190             silk_memcpy( &psEnc->state_Fxx[ 1 ].sCmn.In_HP_State,     &psEnc->state_Fxx[ 0 ].sCmn.In_HP_State,     sizeof( psEnc->state_Fxx[ 1 ].sCmn.In_HP_State ) );
191         }
192     }
193 
194     transition = (encControl->payloadSize_ms != psEnc->state_Fxx[ 0 ].sCmn.PacketSize_ms) || (psEnc->nChannelsInternal != encControl->nChannelsInternal);
195 
196     psEnc->nChannelsAPI = encControl->nChannelsAPI;
197     psEnc->nChannelsInternal = encControl->nChannelsInternal;
198 
199     nBlocksOf10ms = silk_DIV32( 100 * nSamplesIn, encControl->API_sampleRate );
200     tot_blocks = ( nBlocksOf10ms > 1 ) ? nBlocksOf10ms >> 1 : 1;
201     curr_block = 0;
202     if( prefillFlag ) {
203         silk_LP_state save_LP;
204         /* Only accept input length of 10 ms */
205         if( nBlocksOf10ms != 1 ) {
206             celt_assert( 0 );
207             RESTORE_STACK;
208             return SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
209         }
210         if ( prefillFlag == 2 ) {
211             save_LP = psEnc->state_Fxx[ 0 ].sCmn.sLP;
212             /* Save the sampling rate so the bandwidth switching code can keep handling transitions. */
213             save_LP.saved_fs_kHz = psEnc->state_Fxx[ 0 ].sCmn.fs_kHz;
214         }
215         /* Reset Encoder */
216         for( n = 0; n < encControl->nChannelsInternal; n++ ) {
217             ret = silk_init_encoder( &psEnc->state_Fxx[ n ], psEnc->state_Fxx[ n ].sCmn.arch );
218             /* Restore the variable LP state. */
219             if ( prefillFlag == 2 ) {
220                 psEnc->state_Fxx[ n ].sCmn.sLP = save_LP;
221             }
222             celt_assert( !ret );
223         }
224         tmp_payloadSize_ms = encControl->payloadSize_ms;
225         encControl->payloadSize_ms = 10;
226         tmp_complexity = encControl->complexity;
227         encControl->complexity = 0;
228         for( n = 0; n < encControl->nChannelsInternal; n++ ) {
229             psEnc->state_Fxx[ n ].sCmn.controlled_since_last_payload = 0;
230             psEnc->state_Fxx[ n ].sCmn.prefillFlag = 1;
231         }
232     } else {
233         /* Only accept input lengths that are a multiple of 10 ms */
234         if( nBlocksOf10ms * encControl->API_sampleRate != 100 * nSamplesIn || nSamplesIn < 0 ) {
235             celt_assert( 0 );
236             RESTORE_STACK;
237             return SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
238         }
239         /* Make sure no more than one packet can be produced */
240         if( 1000 * (opus_int32)nSamplesIn > encControl->payloadSize_ms * encControl->API_sampleRate ) {
241             celt_assert( 0 );
242             RESTORE_STACK;
243             return SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
244         }
245     }
246 
247     for( n = 0; n < encControl->nChannelsInternal; n++ ) {
248         /* Force the side channel to the same rate as the mid */
249         opus_int force_fs_kHz = (n==1) ? psEnc->state_Fxx[0].sCmn.fs_kHz : 0;
250         if( ( ret = silk_control_encoder( &psEnc->state_Fxx[ n ], encControl, psEnc->allowBandwidthSwitch, n, force_fs_kHz ) ) != 0 ) {
251             silk_assert( 0 );
252             RESTORE_STACK;
253             return ret;
254         }
255         if( psEnc->state_Fxx[n].sCmn.first_frame_after_reset || transition ) {
256             for( i = 0; i < psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket; i++ ) {
257                 psEnc->state_Fxx[ n ].sCmn.LBRR_flags[ i ] = 0;
258             }
259         }
260         psEnc->state_Fxx[ n ].sCmn.inDTX = psEnc->state_Fxx[ n ].sCmn.useDTX;
261     }
262     celt_assert( encControl->nChannelsInternal == 1 || psEnc->state_Fxx[ 0 ].sCmn.fs_kHz == psEnc->state_Fxx[ 1 ].sCmn.fs_kHz );
263 
264     /* Input buffering/resampling and encoding */
265     nSamplesToBufferMax =
266         10 * nBlocksOf10ms * psEnc->state_Fxx[ 0 ].sCmn.fs_kHz;
267     nSamplesFromInputMax =
268         silk_DIV32_16( nSamplesToBufferMax *
269                            psEnc->state_Fxx[ 0 ].sCmn.API_fs_Hz,
270                        psEnc->state_Fxx[ 0 ].sCmn.fs_kHz * 1000 );
271     ALLOC( buf, nSamplesFromInputMax, opus_int16 );
272     while( 1 ) {
273         nSamplesToBuffer  = psEnc->state_Fxx[ 0 ].sCmn.frame_length - psEnc->state_Fxx[ 0 ].sCmn.inputBufIx;
274         nSamplesToBuffer  = silk_min( nSamplesToBuffer, nSamplesToBufferMax );
275         nSamplesFromInput = silk_DIV32_16( nSamplesToBuffer * psEnc->state_Fxx[ 0 ].sCmn.API_fs_Hz, psEnc->state_Fxx[ 0 ].sCmn.fs_kHz * 1000 );
276         /* Resample and write to buffer */
277         if( encControl->nChannelsAPI == 2 && encControl->nChannelsInternal == 2 ) {
278             opus_int id = psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded;
279             for( n = 0; n < nSamplesFromInput; n++ ) {
280                 buf[ n ] = samplesIn[ 2 * n ];
281             }
282             /* Making sure to start both resamplers from the same state when switching from mono to stereo */
283             if( psEnc->nPrevChannelsInternal == 1 && id==0 ) {
284                silk_memcpy( &psEnc->state_Fxx[ 1 ].sCmn.resampler_state, &psEnc->state_Fxx[ 0 ].sCmn.resampler_state, sizeof(psEnc->state_Fxx[ 1 ].sCmn.resampler_state));
285             }
286 
287             ret += silk_resampler( &psEnc->state_Fxx[ 0 ].sCmn.resampler_state,
288                 &psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.inputBufIx + 2 ], buf, nSamplesFromInput );
289             psEnc->state_Fxx[ 0 ].sCmn.inputBufIx += nSamplesToBuffer;
290 
291             nSamplesToBuffer  = psEnc->state_Fxx[ 1 ].sCmn.frame_length - psEnc->state_Fxx[ 1 ].sCmn.inputBufIx;
292             nSamplesToBuffer  = silk_min( nSamplesToBuffer, 10 * nBlocksOf10ms * psEnc->state_Fxx[ 1 ].sCmn.fs_kHz );
293             for( n = 0; n < nSamplesFromInput; n++ ) {
294                 buf[ n ] = samplesIn[ 2 * n + 1 ];
295             }
296             ret += silk_resampler( &psEnc->state_Fxx[ 1 ].sCmn.resampler_state,
297                 &psEnc->state_Fxx[ 1 ].sCmn.inputBuf[ psEnc->state_Fxx[ 1 ].sCmn.inputBufIx + 2 ], buf, nSamplesFromInput );
298 
299             psEnc->state_Fxx[ 1 ].sCmn.inputBufIx += nSamplesToBuffer;
300         } else if( encControl->nChannelsAPI == 2 && encControl->nChannelsInternal == 1 ) {
301             /* Combine left and right channels before resampling */
302             for( n = 0; n < nSamplesFromInput; n++ ) {
303                 sum = samplesIn[ 2 * n ] + samplesIn[ 2 * n + 1 ];
304                 buf[ n ] = (opus_int16)silk_RSHIFT_ROUND( sum,  1 );
305             }
306             ret += silk_resampler( &psEnc->state_Fxx[ 0 ].sCmn.resampler_state,
307                 &psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.inputBufIx + 2 ], buf, nSamplesFromInput );
308             /* On the first mono frame, average the results for the two resampler states  */
309             if( psEnc->nPrevChannelsInternal == 2 && psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded == 0 ) {
310                ret += silk_resampler( &psEnc->state_Fxx[ 1 ].sCmn.resampler_state,
311                    &psEnc->state_Fxx[ 1 ].sCmn.inputBuf[ psEnc->state_Fxx[ 1 ].sCmn.inputBufIx + 2 ], buf, nSamplesFromInput );
312                for( n = 0; n < psEnc->state_Fxx[ 0 ].sCmn.frame_length; n++ ) {
313                   psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.inputBufIx+n+2 ] =
314                         silk_RSHIFT(psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.inputBufIx+n+2 ]
315                                   + psEnc->state_Fxx[ 1 ].sCmn.inputBuf[ psEnc->state_Fxx[ 1 ].sCmn.inputBufIx+n+2 ], 1);
316                }
317             }
318             psEnc->state_Fxx[ 0 ].sCmn.inputBufIx += nSamplesToBuffer;
319         } else {
320             celt_assert( encControl->nChannelsAPI == 1 && encControl->nChannelsInternal == 1 );
321             silk_memcpy(buf, samplesIn, nSamplesFromInput*sizeof(opus_int16));
322             ret += silk_resampler( &psEnc->state_Fxx[ 0 ].sCmn.resampler_state,
323                 &psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.inputBufIx + 2 ], buf, nSamplesFromInput );
324             psEnc->state_Fxx[ 0 ].sCmn.inputBufIx += nSamplesToBuffer;
325         }
326 
327         samplesIn  += nSamplesFromInput * encControl->nChannelsAPI;
328         nSamplesIn -= nSamplesFromInput;
329 
330         /* Default */
331         psEnc->allowBandwidthSwitch = 0;
332 
333         /* Silk encoder */
334         if( psEnc->state_Fxx[ 0 ].sCmn.inputBufIx >= psEnc->state_Fxx[ 0 ].sCmn.frame_length ) {
335             /* Enough data in input buffer, so encode */
336             celt_assert( psEnc->state_Fxx[ 0 ].sCmn.inputBufIx == psEnc->state_Fxx[ 0 ].sCmn.frame_length );
337             celt_assert( encControl->nChannelsInternal == 1 || psEnc->state_Fxx[ 1 ].sCmn.inputBufIx == psEnc->state_Fxx[ 1 ].sCmn.frame_length );
338 
339             /* Deal with LBRR data */
340             if( psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded == 0 && !prefillFlag ) {
341                 /* Create space at start of payload for VAD and FEC flags */
342                 opus_uint8 iCDF[ 2 ] = { 0, 0 };
343                 iCDF[ 0 ] = 256 - silk_RSHIFT( 256, ( psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket + 1 ) * encControl->nChannelsInternal );
344                 ec_enc_icdf( psRangeEnc, 0, iCDF, 8 );
345 
346                 /* Encode any LBRR data from previous packet */
347                 /* Encode LBRR flags */
348                 for( n = 0; n < encControl->nChannelsInternal; n++ ) {
349                     LBRR_symbol = 0;
350                     for( i = 0; i < psEnc->state_Fxx[ n ].sCmn.nFramesPerPacket; i++ ) {
351                         LBRR_symbol |= silk_LSHIFT( psEnc->state_Fxx[ n ].sCmn.LBRR_flags[ i ], i );
352                     }
353                     psEnc->state_Fxx[ n ].sCmn.LBRR_flag = LBRR_symbol > 0 ? 1 : 0;
354                     if( LBRR_symbol && psEnc->state_Fxx[ n ].sCmn.nFramesPerPacket > 1 ) {
355                         ec_enc_icdf( psRangeEnc, LBRR_symbol - 1, silk_LBRR_flags_iCDF_ptr[ psEnc->state_Fxx[ n ].sCmn.nFramesPerPacket - 2 ], 8 );
356                     }
357                 }
358 
359                 /* Code LBRR indices and excitation signals */
360                 for( i = 0; i < psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket; i++ ) {
361                     for( n = 0; n < encControl->nChannelsInternal; n++ ) {
362                         if( psEnc->state_Fxx[ n ].sCmn.LBRR_flags[ i ] ) {
363                             opus_int condCoding;
364 
365                             if( encControl->nChannelsInternal == 2 && n == 0 ) {
366                                 silk_stereo_encode_pred( psRangeEnc, psEnc->sStereo.predIx[ i ] );
367                                 /* For LBRR data there's no need to code the mid-only flag if the side-channel LBRR flag is set */
368                                 if( psEnc->state_Fxx[ 1 ].sCmn.LBRR_flags[ i ] == 0 ) {
369                                     silk_stereo_encode_mid_only( psRangeEnc, psEnc->sStereo.mid_only_flags[ i ] );
370                                 }
371                             }
372                             /* Use conditional coding if previous frame available */
373                             if( i > 0 && psEnc->state_Fxx[ n ].sCmn.LBRR_flags[ i - 1 ] ) {
374                                 condCoding = CODE_CONDITIONALLY;
375                             } else {
376                                 condCoding = CODE_INDEPENDENTLY;
377                             }
378                             silk_encode_indices( &psEnc->state_Fxx[ n ].sCmn, psRangeEnc, i, 1, condCoding );
379                             silk_encode_pulses( psRangeEnc, psEnc->state_Fxx[ n ].sCmn.indices_LBRR[i].signalType, psEnc->state_Fxx[ n ].sCmn.indices_LBRR[i].quantOffsetType,
380                                 psEnc->state_Fxx[ n ].sCmn.pulses_LBRR[ i ], psEnc->state_Fxx[ n ].sCmn.frame_length );
381                         }
382                     }
383                 }
384 
385                 /* Reset LBRR flags */
386                 for( n = 0; n < encControl->nChannelsInternal; n++ ) {
387                     silk_memset( psEnc->state_Fxx[ n ].sCmn.LBRR_flags, 0, sizeof( psEnc->state_Fxx[ n ].sCmn.LBRR_flags ) );
388                 }
389 
390                 psEnc->nBitsUsedLBRR = ec_tell( psRangeEnc );
391             }
392 
393             silk_HP_variable_cutoff( psEnc->state_Fxx );
394 
395             /* Total target bits for packet */
396             nBits = silk_DIV32_16( silk_MUL( encControl->bitRate, encControl->payloadSize_ms ), 1000 );
397             /* Subtract bits used for LBRR */
398             if( !prefillFlag ) {
399                 nBits -= psEnc->nBitsUsedLBRR;
400             }
401             /* Divide by number of uncoded frames left in packet */
402             nBits = silk_DIV32_16( nBits, psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket );
403             /* Convert to bits/second */
404             if( encControl->payloadSize_ms == 10 ) {
405                 TargetRate_bps = silk_SMULBB( nBits, 100 );
406             } else {
407                 TargetRate_bps = silk_SMULBB( nBits, 50 );
408             }
409             /* Subtract fraction of bits in excess of target in previous frames and packets */
410             TargetRate_bps -= silk_DIV32_16( silk_MUL( psEnc->nBitsExceeded, 1000 ), BITRESERVOIR_DECAY_TIME_MS );
411             if( !prefillFlag && psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded > 0 ) {
412                 /* Compare actual vs target bits so far in this packet */
413                 opus_int32 bitsBalance = ec_tell( psRangeEnc ) - psEnc->nBitsUsedLBRR - nBits * psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded;
414                 TargetRate_bps -= silk_DIV32_16( silk_MUL( bitsBalance, 1000 ), BITRESERVOIR_DECAY_TIME_MS );
415             }
416             /* Never exceed input bitrate */
417             TargetRate_bps = silk_LIMIT( TargetRate_bps, encControl->bitRate, 5000 );
418 
419             /* Convert Left/Right to Mid/Side */
420             if( encControl->nChannelsInternal == 2 ) {
421                 silk_stereo_LR_to_MS( &psEnc->sStereo, &psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ 2 ], &psEnc->state_Fxx[ 1 ].sCmn.inputBuf[ 2 ],
422                     psEnc->sStereo.predIx[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ], &psEnc->sStereo.mid_only_flags[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ],
423                     MStargetRates_bps, TargetRate_bps, psEnc->state_Fxx[ 0 ].sCmn.speech_activity_Q8, encControl->toMono,
424                     psEnc->state_Fxx[ 0 ].sCmn.fs_kHz, psEnc->state_Fxx[ 0 ].sCmn.frame_length );
425                 if( psEnc->sStereo.mid_only_flags[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ] == 0 ) {
426                     /* Reset side channel encoder memory for first frame with side coding */
427                     if( psEnc->prev_decode_only_middle == 1 ) {
428                         silk_memset( &psEnc->state_Fxx[ 1 ].sShape,               0, sizeof( psEnc->state_Fxx[ 1 ].sShape ) );
429                         silk_memset( &psEnc->state_Fxx[ 1 ].sCmn.sNSQ,            0, sizeof( psEnc->state_Fxx[ 1 ].sCmn.sNSQ ) );
430                         silk_memset( psEnc->state_Fxx[ 1 ].sCmn.prev_NLSFq_Q15,   0, sizeof( psEnc->state_Fxx[ 1 ].sCmn.prev_NLSFq_Q15 ) );
431                         silk_memset( &psEnc->state_Fxx[ 1 ].sCmn.sLP.In_LP_State, 0, sizeof( psEnc->state_Fxx[ 1 ].sCmn.sLP.In_LP_State ) );
432                         psEnc->state_Fxx[ 1 ].sCmn.prevLag                 = 100;
433                         psEnc->state_Fxx[ 1 ].sCmn.sNSQ.lagPrev            = 100;
434                         psEnc->state_Fxx[ 1 ].sShape.LastGainIndex         = 10;
435                         psEnc->state_Fxx[ 1 ].sCmn.prevSignalType          = TYPE_NO_VOICE_ACTIVITY;
436                         psEnc->state_Fxx[ 1 ].sCmn.sNSQ.prev_gain_Q16      = 65536;
437                         psEnc->state_Fxx[ 1 ].sCmn.first_frame_after_reset = 1;
438                     }
439                     silk_encode_do_VAD_Fxx( &psEnc->state_Fxx[ 1 ], activity );
440                 } else {
441                     psEnc->state_Fxx[ 1 ].sCmn.VAD_flags[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ] = 0;
442                 }
443                 if( !prefillFlag ) {
444                     silk_stereo_encode_pred( psRangeEnc, psEnc->sStereo.predIx[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ] );
445                     if( psEnc->state_Fxx[ 1 ].sCmn.VAD_flags[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ] == 0 ) {
446                         silk_stereo_encode_mid_only( psRangeEnc, psEnc->sStereo.mid_only_flags[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded ] );
447                     }
448                 }
449             } else {
450                 /* Buffering */
451                 silk_memcpy( psEnc->state_Fxx[ 0 ].sCmn.inputBuf, psEnc->sStereo.sMid, 2 * sizeof( opus_int16 ) );
452                 silk_memcpy( psEnc->sStereo.sMid, &psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.frame_length ], 2 * sizeof( opus_int16 ) );
453             }
454             silk_encode_do_VAD_Fxx( &psEnc->state_Fxx[ 0 ], activity );
455 
456             /* Encode */
457             for( n = 0; n < encControl->nChannelsInternal; n++ ) {
458                 opus_int maxBits, useCBR;
459 
460                 /* Handling rate constraints */
461                 maxBits = encControl->maxBits;
462                 if( tot_blocks == 2 && curr_block == 0 ) {
463                     maxBits = maxBits * 3 / 5;
464                 } else if( tot_blocks == 3 ) {
465                     if( curr_block == 0 ) {
466                         maxBits = maxBits * 2 / 5;
467                     } else if( curr_block == 1 ) {
468                         maxBits = maxBits * 3 / 4;
469                     }
470                 }
471                 useCBR = encControl->useCBR && curr_block == tot_blocks - 1;
472 
473                 if( encControl->nChannelsInternal == 1 ) {
474                     channelRate_bps = TargetRate_bps;
475                 } else {
476                     channelRate_bps = MStargetRates_bps[ n ];
477                     if( n == 0 && MStargetRates_bps[ 1 ] > 0 ) {
478                         useCBR = 0;
479                         /* Give mid up to 1/2 of the max bits for that frame */
480                         maxBits -= encControl->maxBits / ( tot_blocks * 2 );
481                     }
482                 }
483 
484                 if( channelRate_bps > 0 ) {
485                     opus_int condCoding;
486 
487                     silk_control_SNR( &psEnc->state_Fxx[ n ].sCmn, channelRate_bps );
488 
489                     /* Use independent coding if no previous frame available */
490                     if( psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded - n <= 0 ) {
491                         condCoding = CODE_INDEPENDENTLY;
492                     } else if( n > 0 && psEnc->prev_decode_only_middle ) {
493                         /* If we skipped a side frame in this packet, we don't
494                            need LTP scaling; the LTP state is well-defined. */
495                         condCoding = CODE_INDEPENDENTLY_NO_LTP_SCALING;
496                     } else {
497                         condCoding = CODE_CONDITIONALLY;
498                     }
499                     if( ( ret = silk_encode_frame_Fxx( &psEnc->state_Fxx[ n ], nBytesOut, psRangeEnc, condCoding, maxBits, useCBR ) ) != 0 ) {
500                         silk_assert( 0 );
501                     }
502                 }
503                 psEnc->state_Fxx[ n ].sCmn.controlled_since_last_payload = 0;
504                 psEnc->state_Fxx[ n ].sCmn.inputBufIx = 0;
505                 psEnc->state_Fxx[ n ].sCmn.nFramesEncoded++;
506             }
507             psEnc->prev_decode_only_middle = psEnc->sStereo.mid_only_flags[ psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded - 1 ];
508 
509             /* Insert VAD and FEC flags at beginning of bitstream */
510             if( *nBytesOut > 0 && psEnc->state_Fxx[ 0 ].sCmn.nFramesEncoded == psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket) {
511                 flags = 0;
512                 for( n = 0; n < encControl->nChannelsInternal; n++ ) {
513                     for( i = 0; i < psEnc->state_Fxx[ n ].sCmn.nFramesPerPacket; i++ ) {
514                         flags  = silk_LSHIFT( flags, 1 );
515                         flags |= psEnc->state_Fxx[ n ].sCmn.VAD_flags[ i ];
516                     }
517                     flags  = silk_LSHIFT( flags, 1 );
518                     flags |= psEnc->state_Fxx[ n ].sCmn.LBRR_flag;
519                 }
520                 if( !prefillFlag ) {
521                     ec_enc_patch_initial_bits( psRangeEnc, flags, ( psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket + 1 ) * encControl->nChannelsInternal );
522                 }
523 
524                 /* Return zero bytes if all channels DTXed */
525                 if( psEnc->state_Fxx[ 0 ].sCmn.inDTX && ( encControl->nChannelsInternal == 1 || psEnc->state_Fxx[ 1 ].sCmn.inDTX ) ) {
526                     *nBytesOut = 0;
527                 }
528 
529                 psEnc->nBitsExceeded += *nBytesOut * 8;
530                 psEnc->nBitsExceeded -= silk_DIV32_16( silk_MUL( encControl->bitRate, encControl->payloadSize_ms ), 1000 );
531                 psEnc->nBitsExceeded  = silk_LIMIT( psEnc->nBitsExceeded, 0, 10000 );
532 
533                 /* Update flag indicating if bandwidth switching is allowed */
534                 speech_act_thr_for_switch_Q8 = silk_SMLAWB( SILK_FIX_CONST( SPEECH_ACTIVITY_DTX_THRES, 8 ),
535                     SILK_FIX_CONST( ( 1 - SPEECH_ACTIVITY_DTX_THRES ) / MAX_BANDWIDTH_SWITCH_DELAY_MS, 16 + 8 ), psEnc->timeSinceSwitchAllowed_ms );
536                 if( psEnc->state_Fxx[ 0 ].sCmn.speech_activity_Q8 < speech_act_thr_for_switch_Q8 ) {
537                     psEnc->allowBandwidthSwitch = 1;
538                     psEnc->timeSinceSwitchAllowed_ms = 0;
539                 } else {
540                     psEnc->allowBandwidthSwitch = 0;
541                     psEnc->timeSinceSwitchAllowed_ms += encControl->payloadSize_ms;
542                 }
543             }
544 
545             if( nSamplesIn == 0 ) {
546                 break;
547             }
548         } else {
549             break;
550         }
551         curr_block++;
552     }
553 
554     psEnc->nPrevChannelsInternal = encControl->nChannelsInternal;
555 
556     encControl->allowBandwidthSwitch = psEnc->allowBandwidthSwitch;
557     encControl->inWBmodeWithoutVariableLP = psEnc->state_Fxx[ 0 ].sCmn.fs_kHz == 16 && psEnc->state_Fxx[ 0 ].sCmn.sLP.mode == 0;
558     encControl->internalSampleRate = silk_SMULBB( psEnc->state_Fxx[ 0 ].sCmn.fs_kHz, 1000 );
559     encControl->stereoWidth_Q14 = encControl->toMono ? 0 : psEnc->sStereo.smth_width_Q14;
560     if( prefillFlag ) {
561         encControl->payloadSize_ms = tmp_payloadSize_ms;
562         encControl->complexity = tmp_complexity;
563         for( n = 0; n < encControl->nChannelsInternal; n++ ) {
564             psEnc->state_Fxx[ n ].sCmn.controlled_since_last_payload = 0;
565             psEnc->state_Fxx[ n ].sCmn.prefillFlag = 0;
566         }
567     }
568 
569     encControl->signalType = psEnc->state_Fxx[0].sCmn.indices.signalType;
570     encControl->offset = silk_Quantization_Offsets_Q10
571                          [ psEnc->state_Fxx[0].sCmn.indices.signalType >> 1 ]
572                          [ psEnc->state_Fxx[0].sCmn.indices.quantOffsetType ];
573     RESTORE_STACK;
574     return ret;
575 }
576 
577