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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 
32 /*****************************************************************************
33 * Pitch analyser function
34 ******************************************************************************/
35 #include "SigProc_FLP.h"
36 #include "SigProc_FIX.h"
37 #include "pitch_est_defines.h"
38 #include "pitch.h"
39 
40 #define SCRATCH_SIZE        22
41 
42 /************************************************************/
43 /* Internally used functions                                */
44 /************************************************************/
45 static void silk_P_Ana_calc_corr_st3(
46     silk_float cross_corr_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ], /* O 3 DIM correlation array */
47     const silk_float    frame[],            /* I vector to correlate                                            */
48     opus_int            start_lag,          /* I start lag                                                      */
49     opus_int            sf_length,          /* I sub frame length                                               */
50     opus_int            nb_subfr,           /* I number of subframes                                            */
51     opus_int            complexity          /* I Complexity setting                                             */
52 );
53 
54 static void silk_P_Ana_calc_energy_st3(
55     silk_float energies_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ], /* O 3 DIM correlation array */
56     const silk_float    frame[],            /* I vector to correlate                                            */
57     opus_int            start_lag,          /* I start lag                                                      */
58     opus_int            sf_length,          /* I sub frame length                                               */
59     opus_int            nb_subfr,           /* I number of subframes                                            */
60     opus_int            complexity          /* I Complexity setting                                             */
61 );
62 
63 /************************************************************/
64 /* CORE PITCH ANALYSIS FUNCTION                             */
65 /************************************************************/
silk_pitch_analysis_core_FLP(const silk_float * frame,opus_int * pitch_out,opus_int16 * lagIndex,opus_int8 * contourIndex,silk_float * LTPCorr,opus_int prevLag,const silk_float search_thres1,const silk_float search_thres2,const opus_int Fs_kHz,const opus_int complexity,const opus_int nb_subfr)66 opus_int silk_pitch_analysis_core_FLP(      /* O    Voicing estimate: 0 voiced, 1 unvoiced                      */
67     const silk_float    *frame,             /* I    Signal of length PE_FRAME_LENGTH_MS*Fs_kHz                  */
68     opus_int            *pitch_out,         /* O    Pitch lag values [nb_subfr]                                 */
69     opus_int16          *lagIndex,          /* O    Lag Index                                                   */
70     opus_int8           *contourIndex,      /* O    Pitch contour Index                                         */
71     silk_float          *LTPCorr,           /* I/O  Normalized correlation; input: value from previous frame    */
72     opus_int            prevLag,            /* I    Last lag of previous frame; set to zero is unvoiced         */
73     const silk_float    search_thres1,      /* I    First stage threshold for lag candidates 0 - 1              */
74     const silk_float    search_thres2,      /* I    Final threshold for lag candidates 0 - 1                    */
75     const opus_int      Fs_kHz,             /* I    sample frequency (kHz)                                      */
76     const opus_int      complexity,         /* I    Complexity setting, 0-2, where 2 is highest                 */
77     const opus_int      nb_subfr            /* I    Number of 5 ms subframes                                    */
78 )
79 {
80     opus_int   i, k, d, j;
81     silk_float frame_8kHz[  PE_MAX_FRAME_LENGTH_MS * 8 ];
82     silk_float frame_4kHz[  PE_MAX_FRAME_LENGTH_MS * 4 ];
83     opus_int16 frame_8_FIX[ PE_MAX_FRAME_LENGTH_MS * 8 ];
84     opus_int16 frame_4_FIX[ PE_MAX_FRAME_LENGTH_MS * 4 ];
85     opus_int32 filt_state[ 6 ];
86     silk_float threshold, contour_bias;
87     silk_float C[ PE_MAX_NB_SUBFR][ (PE_MAX_LAG >> 1) + 5 ];
88     opus_val32 xcorr[ PE_MAX_LAG_MS * 4 - PE_MIN_LAG_MS * 4 + 1 ];
89     silk_float CC[ PE_NB_CBKS_STAGE2_EXT ];
90     const silk_float *target_ptr, *basis_ptr;
91     double    cross_corr, normalizer, energy, energy_tmp;
92     opus_int   d_srch[ PE_D_SRCH_LENGTH ];
93     opus_int16 d_comp[ (PE_MAX_LAG >> 1) + 5 ];
94     opus_int   length_d_srch, length_d_comp;
95     silk_float Cmax, CCmax, CCmax_b, CCmax_new_b, CCmax_new;
96     opus_int   CBimax, CBimax_new, lag, start_lag, end_lag, lag_new;
97     opus_int   cbk_size;
98     silk_float lag_log2, prevLag_log2, delta_lag_log2_sqr;
99     silk_float energies_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ];
100     silk_float cross_corr_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ];
101     opus_int   lag_counter;
102     opus_int   frame_length, frame_length_8kHz, frame_length_4kHz;
103     opus_int   sf_length, sf_length_8kHz, sf_length_4kHz;
104     opus_int   min_lag, min_lag_8kHz, min_lag_4kHz;
105     opus_int   max_lag, max_lag_8kHz, max_lag_4kHz;
106     opus_int   nb_cbk_search;
107     const opus_int8 *Lag_CB_ptr;
108 
109     /* Check for valid sampling frequency */
110     silk_assert( Fs_kHz == 8 || Fs_kHz == 12 || Fs_kHz == 16 );
111 
112     /* Check for valid complexity setting */
113     silk_assert( complexity >= SILK_PE_MIN_COMPLEX );
114     silk_assert( complexity <= SILK_PE_MAX_COMPLEX );
115 
116     silk_assert( search_thres1 >= 0.0f && search_thres1 <= 1.0f );
117     silk_assert( search_thres2 >= 0.0f && search_thres2 <= 1.0f );
118 
119     /* Set up frame lengths max / min lag for the sampling frequency */
120     frame_length      = ( PE_LTP_MEM_LENGTH_MS + nb_subfr * PE_SUBFR_LENGTH_MS ) * Fs_kHz;
121     frame_length_4kHz = ( PE_LTP_MEM_LENGTH_MS + nb_subfr * PE_SUBFR_LENGTH_MS ) * 4;
122     frame_length_8kHz = ( PE_LTP_MEM_LENGTH_MS + nb_subfr * PE_SUBFR_LENGTH_MS ) * 8;
123     sf_length         = PE_SUBFR_LENGTH_MS * Fs_kHz;
124     sf_length_4kHz    = PE_SUBFR_LENGTH_MS * 4;
125     sf_length_8kHz    = PE_SUBFR_LENGTH_MS * 8;
126     min_lag           = PE_MIN_LAG_MS * Fs_kHz;
127     min_lag_4kHz      = PE_MIN_LAG_MS * 4;
128     min_lag_8kHz      = PE_MIN_LAG_MS * 8;
129     max_lag           = PE_MAX_LAG_MS * Fs_kHz - 1;
130     max_lag_4kHz      = PE_MAX_LAG_MS * 4;
131     max_lag_8kHz      = PE_MAX_LAG_MS * 8 - 1;
132 
133     /* Resample from input sampled at Fs_kHz to 8 kHz */
134     if( Fs_kHz == 16 ) {
135         /* Resample to 16 -> 8 khz */
136         opus_int16 frame_16_FIX[ 16 * PE_MAX_FRAME_LENGTH_MS ];
137         silk_float2short_array( frame_16_FIX, frame, frame_length );
138         silk_memset( filt_state, 0, 2 * sizeof( opus_int32 ) );
139         silk_resampler_down2( filt_state, frame_8_FIX, frame_16_FIX, frame_length );
140         silk_short2float_array( frame_8kHz, frame_8_FIX, frame_length_8kHz );
141     } else if( Fs_kHz == 12 ) {
142         /* Resample to 12 -> 8 khz */
143         opus_int16 frame_12_FIX[ 12 * PE_MAX_FRAME_LENGTH_MS ];
144         silk_float2short_array( frame_12_FIX, frame, frame_length );
145         silk_memset( filt_state, 0, 6 * sizeof( opus_int32 ) );
146         silk_resampler_down2_3( filt_state, frame_8_FIX, frame_12_FIX, frame_length );
147         silk_short2float_array( frame_8kHz, frame_8_FIX, frame_length_8kHz );
148     } else {
149         silk_assert( Fs_kHz == 8 );
150         silk_float2short_array( frame_8_FIX, frame, frame_length_8kHz );
151     }
152 
153     /* Decimate again to 4 kHz */
154     silk_memset( filt_state, 0, 2 * sizeof( opus_int32 ) );
155     silk_resampler_down2( filt_state, frame_4_FIX, frame_8_FIX, frame_length_8kHz );
156     silk_short2float_array( frame_4kHz, frame_4_FIX, frame_length_4kHz );
157 
158     /* Low-pass filter */
159     for( i = frame_length_4kHz - 1; i > 0; i-- ) {
160         frame_4kHz[ i ] += frame_4kHz[ i - 1 ];
161     }
162 
163     /******************************************************************************
164     * FIRST STAGE, operating in 4 khz
165     ******************************************************************************/
166     silk_memset(C, 0, sizeof(silk_float) * nb_subfr * ((PE_MAX_LAG >> 1) + 5));
167     target_ptr = &frame_4kHz[ silk_LSHIFT( sf_length_4kHz, 2 ) ];
168     for( k = 0; k < nb_subfr >> 1; k++ ) {
169         /* Check that we are within range of the array */
170         silk_assert( target_ptr >= frame_4kHz );
171         silk_assert( target_ptr + sf_length_8kHz <= frame_4kHz + frame_length_4kHz );
172 
173         basis_ptr = target_ptr - min_lag_4kHz;
174 
175         /* Check that we are within range of the array */
176         silk_assert( basis_ptr >= frame_4kHz );
177         silk_assert( basis_ptr + sf_length_8kHz <= frame_4kHz + frame_length_4kHz );
178 
179         celt_pitch_xcorr( target_ptr, target_ptr-max_lag_4kHz, xcorr, sf_length_8kHz, max_lag_4kHz - min_lag_4kHz + 1 );
180 
181         /* Calculate first vector products before loop */
182         cross_corr = xcorr[ max_lag_4kHz - min_lag_4kHz ];
183         normalizer = silk_energy_FLP( target_ptr, sf_length_8kHz ) +
184                      silk_energy_FLP( basis_ptr,  sf_length_8kHz ) +
185                      sf_length_8kHz * 4000.0f;
186 
187         C[ 0 ][ min_lag_4kHz ] += (silk_float)( 2 * cross_corr / normalizer );
188 
189         /* From now on normalizer is computed recursively */
190         for( d = min_lag_4kHz + 1; d <= max_lag_4kHz; d++ ) {
191             basis_ptr--;
192 
193             /* Check that we are within range of the array */
194             silk_assert( basis_ptr >= frame_4kHz );
195             silk_assert( basis_ptr + sf_length_8kHz <= frame_4kHz + frame_length_4kHz );
196 
197             cross_corr = xcorr[ max_lag_4kHz - d ];
198 
199             /* Add contribution of new sample and remove contribution from oldest sample */
200             normalizer +=
201                 basis_ptr[ 0 ] * (double)basis_ptr[ 0 ] -
202                 basis_ptr[ sf_length_8kHz ] * (double)basis_ptr[ sf_length_8kHz ];
203             C[ 0 ][ d ] += (silk_float)( 2 * cross_corr / normalizer );
204         }
205         /* Update target pointer */
206         target_ptr += sf_length_8kHz;
207     }
208 
209     /* Apply short-lag bias */
210     for( i = max_lag_4kHz; i >= min_lag_4kHz; i-- ) {
211         C[ 0 ][ i ] -= C[ 0 ][ i ] * i / 4096.0f;
212     }
213 
214     /* Sort */
215     length_d_srch = 4 + 2 * complexity;
216     silk_assert( 3 * length_d_srch <= PE_D_SRCH_LENGTH );
217     silk_insertion_sort_decreasing_FLP( &C[ 0 ][ min_lag_4kHz ], d_srch, max_lag_4kHz - min_lag_4kHz + 1, length_d_srch );
218 
219     /* Escape if correlation is very low already here */
220     Cmax = C[ 0 ][ min_lag_4kHz ];
221     if( Cmax < 0.2f ) {
222         silk_memset( pitch_out, 0, nb_subfr * sizeof( opus_int ) );
223         *LTPCorr      = 0.0f;
224         *lagIndex     = 0;
225         *contourIndex = 0;
226         return 1;
227     }
228 
229     threshold = search_thres1 * Cmax;
230     for( i = 0; i < length_d_srch; i++ ) {
231         /* Convert to 8 kHz indices for the sorted correlation that exceeds the threshold */
232         if( C[ 0 ][ min_lag_4kHz + i ] > threshold ) {
233             d_srch[ i ] = silk_LSHIFT( d_srch[ i ] + min_lag_4kHz, 1 );
234         } else {
235             length_d_srch = i;
236             break;
237         }
238     }
239     silk_assert( length_d_srch > 0 );
240 
241     for( i = min_lag_8kHz - 5; i < max_lag_8kHz + 5; i++ ) {
242         d_comp[ i ] = 0;
243     }
244     for( i = 0; i < length_d_srch; i++ ) {
245         d_comp[ d_srch[ i ] ] = 1;
246     }
247 
248     /* Convolution */
249     for( i = max_lag_8kHz + 3; i >= min_lag_8kHz; i-- ) {
250         d_comp[ i ] += d_comp[ i - 1 ] + d_comp[ i - 2 ];
251     }
252 
253     length_d_srch = 0;
254     for( i = min_lag_8kHz; i < max_lag_8kHz + 1; i++ ) {
255         if( d_comp[ i + 1 ] > 0 ) {
256             d_srch[ length_d_srch ] = i;
257             length_d_srch++;
258         }
259     }
260 
261     /* Convolution */
262     for( i = max_lag_8kHz + 3; i >= min_lag_8kHz; i-- ) {
263         d_comp[ i ] += d_comp[ i - 1 ] + d_comp[ i - 2 ] + d_comp[ i - 3 ];
264     }
265 
266     length_d_comp = 0;
267     for( i = min_lag_8kHz; i < max_lag_8kHz + 4; i++ ) {
268         if( d_comp[ i ] > 0 ) {
269             d_comp[ length_d_comp ] = (opus_int16)( i - 2 );
270             length_d_comp++;
271         }
272     }
273 
274     /**********************************************************************************
275     ** SECOND STAGE, operating at 8 kHz, on lag sections with high correlation
276     *************************************************************************************/
277     /*********************************************************************************
278     * Find energy of each subframe projected onto its history, for a range of delays
279     *********************************************************************************/
280     silk_memset( C, 0, PE_MAX_NB_SUBFR*((PE_MAX_LAG >> 1) + 5) * sizeof(silk_float));
281 
282     if( Fs_kHz == 8 ) {
283         target_ptr = &frame[ PE_LTP_MEM_LENGTH_MS * 8 ];
284     } else {
285         target_ptr = &frame_8kHz[ PE_LTP_MEM_LENGTH_MS * 8 ];
286     }
287     for( k = 0; k < nb_subfr; k++ ) {
288         energy_tmp = silk_energy_FLP( target_ptr, sf_length_8kHz ) + 1.0;
289         for( j = 0; j < length_d_comp; j++ ) {
290             d = d_comp[ j ];
291             basis_ptr = target_ptr - d;
292             cross_corr = silk_inner_product_FLP( basis_ptr, target_ptr, sf_length_8kHz );
293             if( cross_corr > 0.0f ) {
294                 energy = silk_energy_FLP( basis_ptr, sf_length_8kHz );
295                 C[ k ][ d ] = (silk_float)( 2 * cross_corr / ( energy + energy_tmp ) );
296             } else {
297                 C[ k ][ d ] = 0.0f;
298             }
299         }
300         target_ptr += sf_length_8kHz;
301     }
302 
303     /* search over lag range and lags codebook */
304     /* scale factor for lag codebook, as a function of center lag */
305 
306     CCmax   = 0.0f; /* This value doesn't matter */
307     CCmax_b = -1000.0f;
308 
309     CBimax = 0; /* To avoid returning undefined lag values */
310     lag = -1;   /* To check if lag with strong enough correlation has been found */
311 
312     if( prevLag > 0 ) {
313         if( Fs_kHz == 12 ) {
314             prevLag = silk_LSHIFT( prevLag, 1 ) / 3;
315         } else if( Fs_kHz == 16 ) {
316             prevLag = silk_RSHIFT( prevLag, 1 );
317         }
318         prevLag_log2 = silk_log2( (silk_float)prevLag );
319     } else {
320         prevLag_log2 = 0;
321     }
322 
323     /* Set up stage 2 codebook based on number of subframes */
324     if( nb_subfr == PE_MAX_NB_SUBFR ) {
325         cbk_size   = PE_NB_CBKS_STAGE2_EXT;
326         Lag_CB_ptr = &silk_CB_lags_stage2[ 0 ][ 0 ];
327         if( Fs_kHz == 8 && complexity > SILK_PE_MIN_COMPLEX ) {
328             /* If input is 8 khz use a larger codebook here because it is last stage */
329             nb_cbk_search = PE_NB_CBKS_STAGE2_EXT;
330         } else {
331             nb_cbk_search = PE_NB_CBKS_STAGE2;
332         }
333     } else {
334         cbk_size       = PE_NB_CBKS_STAGE2_10MS;
335         Lag_CB_ptr     = &silk_CB_lags_stage2_10_ms[ 0 ][ 0 ];
336         nb_cbk_search  = PE_NB_CBKS_STAGE2_10MS;
337     }
338 
339     for( k = 0; k < length_d_srch; k++ ) {
340         d = d_srch[ k ];
341         for( j = 0; j < nb_cbk_search; j++ ) {
342             CC[j] = 0.0f;
343             for( i = 0; i < nb_subfr; i++ ) {
344                 /* Try all codebooks */
345                 CC[ j ] += C[ i ][ d + matrix_ptr( Lag_CB_ptr, i, j, cbk_size )];
346             }
347         }
348         /* Find best codebook */
349         CCmax_new  = -1000.0f;
350         CBimax_new = 0;
351         for( i = 0; i < nb_cbk_search; i++ ) {
352             if( CC[ i ] > CCmax_new ) {
353                 CCmax_new = CC[ i ];
354                 CBimax_new = i;
355             }
356         }
357 
358         /* Bias towards shorter lags */
359         lag_log2 = silk_log2( (silk_float)d );
360         CCmax_new_b = CCmax_new - PE_SHORTLAG_BIAS * nb_subfr * lag_log2;
361 
362         /* Bias towards previous lag */
363         if( prevLag > 0 ) {
364             delta_lag_log2_sqr = lag_log2 - prevLag_log2;
365             delta_lag_log2_sqr *= delta_lag_log2_sqr;
366             CCmax_new_b -= PE_PREVLAG_BIAS * nb_subfr * (*LTPCorr) * delta_lag_log2_sqr / ( delta_lag_log2_sqr + 0.5f );
367         }
368 
369         if( CCmax_new_b > CCmax_b &&                /* Find maximum biased correlation                  */
370             CCmax_new > nb_subfr * search_thres2    /* Correlation needs to be high enough to be voiced */
371         ) {
372             CCmax_b = CCmax_new_b;
373             CCmax   = CCmax_new;
374             lag     = d;
375             CBimax  = CBimax_new;
376         }
377     }
378 
379     if( lag == -1 ) {
380         /* No suitable candidate found */
381         silk_memset( pitch_out, 0, PE_MAX_NB_SUBFR * sizeof(opus_int) );
382         *LTPCorr      = 0.0f;
383         *lagIndex     = 0;
384         *contourIndex = 0;
385         return 1;
386     }
387 
388     /* Output normalized correlation */
389     *LTPCorr = (silk_float)( CCmax / nb_subfr );
390     silk_assert( *LTPCorr >= 0.0f );
391 
392     if( Fs_kHz > 8 ) {
393         /* Search in original signal */
394 
395         /* Compensate for decimation */
396         silk_assert( lag == silk_SAT16( lag ) );
397         if( Fs_kHz == 12 ) {
398             lag = silk_RSHIFT_ROUND( silk_SMULBB( lag, 3 ), 1 );
399         } else { /* Fs_kHz == 16 */
400             lag = silk_LSHIFT( lag, 1 );
401         }
402 
403         lag = silk_LIMIT_int( lag, min_lag, max_lag );
404         start_lag = silk_max_int( lag - 2, min_lag );
405         end_lag   = silk_min_int( lag + 2, max_lag );
406         lag_new   = lag;                                    /* to avoid undefined lag */
407         CBimax    = 0;                                      /* to avoid undefined lag */
408 
409         CCmax = -1000.0f;
410 
411         /* Calculate the correlations and energies needed in stage 3 */
412         silk_P_Ana_calc_corr_st3( cross_corr_st3, frame, start_lag, sf_length, nb_subfr, complexity );
413         silk_P_Ana_calc_energy_st3( energies_st3, frame, start_lag, sf_length, nb_subfr, complexity );
414 
415         lag_counter = 0;
416         silk_assert( lag == silk_SAT16( lag ) );
417         contour_bias = PE_FLATCONTOUR_BIAS / lag;
418 
419         /* Set up cbk parameters according to complexity setting and frame length */
420         if( nb_subfr == PE_MAX_NB_SUBFR ) {
421             nb_cbk_search = (opus_int)silk_nb_cbk_searchs_stage3[ complexity ];
422             cbk_size      = PE_NB_CBKS_STAGE3_MAX;
423             Lag_CB_ptr    = &silk_CB_lags_stage3[ 0 ][ 0 ];
424         } else {
425             nb_cbk_search = PE_NB_CBKS_STAGE3_10MS;
426             cbk_size      = PE_NB_CBKS_STAGE3_10MS;
427             Lag_CB_ptr    = &silk_CB_lags_stage3_10_ms[ 0 ][ 0 ];
428         }
429 
430         target_ptr = &frame[ PE_LTP_MEM_LENGTH_MS * Fs_kHz ];
431         energy_tmp = silk_energy_FLP( target_ptr, nb_subfr * sf_length ) + 1.0;
432         for( d = start_lag; d <= end_lag; d++ ) {
433             for( j = 0; j < nb_cbk_search; j++ ) {
434                 cross_corr = 0.0;
435                 energy = energy_tmp;
436                 for( k = 0; k < nb_subfr; k++ ) {
437                     cross_corr += cross_corr_st3[ k ][ j ][ lag_counter ];
438                     energy     +=   energies_st3[ k ][ j ][ lag_counter ];
439                 }
440                 if( cross_corr > 0.0 ) {
441                     CCmax_new = (silk_float)( 2 * cross_corr / energy );
442                     /* Reduce depending on flatness of contour */
443                     CCmax_new *= 1.0f - contour_bias * j;
444                 } else {
445                     CCmax_new = 0.0f;
446                 }
447 
448                 if( CCmax_new > CCmax && ( d + (opus_int)silk_CB_lags_stage3[ 0 ][ j ] ) <= max_lag ) {
449                     CCmax   = CCmax_new;
450                     lag_new = d;
451                     CBimax  = j;
452                 }
453             }
454             lag_counter++;
455         }
456 
457         for( k = 0; k < nb_subfr; k++ ) {
458             pitch_out[ k ] = lag_new + matrix_ptr( Lag_CB_ptr, k, CBimax, cbk_size );
459             pitch_out[ k ] = silk_LIMIT( pitch_out[ k ], min_lag, PE_MAX_LAG_MS * Fs_kHz );
460         }
461         *lagIndex = (opus_int16)( lag_new - min_lag );
462         *contourIndex = (opus_int8)CBimax;
463     } else {        /* Fs_kHz == 8 */
464         /* Save Lags */
465         for( k = 0; k < nb_subfr; k++ ) {
466             pitch_out[ k ] = lag + matrix_ptr( Lag_CB_ptr, k, CBimax, cbk_size );
467             pitch_out[ k ] = silk_LIMIT( pitch_out[ k ], min_lag_8kHz, PE_MAX_LAG_MS * 8 );
468         }
469         *lagIndex = (opus_int16)( lag - min_lag_8kHz );
470         *contourIndex = (opus_int8)CBimax;
471     }
472     silk_assert( *lagIndex >= 0 );
473     /* return as voiced */
474     return 0;
475 }
476 
477 /***********************************************************************
478  * Calculates the correlations used in stage 3 search. In order to cover
479  * the whole lag codebook for all the searched offset lags (lag +- 2),
480  * the following correlations are needed in each sub frame:
481  *
482  * sf1: lag range [-8,...,7] total 16 correlations
483  * sf2: lag range [-4,...,4] total 9 correlations
484  * sf3: lag range [-3,....4] total 8 correltions
485  * sf4: lag range [-6,....8] total 15 correlations
486  *
487  * In total 48 correlations. The direct implementation computed in worst
488  * case 4*12*5 = 240 correlations, but more likely around 120.
489  ***********************************************************************/
silk_P_Ana_calc_corr_st3(silk_float cross_corr_st3[PE_MAX_NB_SUBFR][PE_NB_CBKS_STAGE3_MAX][PE_NB_STAGE3_LAGS],const silk_float frame[],opus_int start_lag,opus_int sf_length,opus_int nb_subfr,opus_int complexity)490 static void silk_P_Ana_calc_corr_st3(
491     silk_float cross_corr_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ], /* O 3 DIM correlation array */
492     const silk_float    frame[],            /* I vector to correlate                                            */
493     opus_int            start_lag,          /* I start lag                                                      */
494     opus_int            sf_length,          /* I sub frame length                                               */
495     opus_int            nb_subfr,           /* I number of subframes                                            */
496     opus_int            complexity          /* I Complexity setting                                             */
497 )
498 {
499     const silk_float *target_ptr, *basis_ptr;
500     opus_int   i, j, k, lag_counter, lag_low, lag_high;
501     opus_int   nb_cbk_search, delta, idx, cbk_size;
502     silk_float scratch_mem[ SCRATCH_SIZE ];
503     opus_val32 xcorr[ SCRATCH_SIZE ];
504     const opus_int8 *Lag_range_ptr, *Lag_CB_ptr;
505 
506     silk_assert( complexity >= SILK_PE_MIN_COMPLEX );
507     silk_assert( complexity <= SILK_PE_MAX_COMPLEX );
508 
509     if( nb_subfr == PE_MAX_NB_SUBFR ) {
510         Lag_range_ptr = &silk_Lag_range_stage3[ complexity ][ 0 ][ 0 ];
511         Lag_CB_ptr    = &silk_CB_lags_stage3[ 0 ][ 0 ];
512         nb_cbk_search = silk_nb_cbk_searchs_stage3[ complexity ];
513         cbk_size      = PE_NB_CBKS_STAGE3_MAX;
514     } else {
515         silk_assert( nb_subfr == PE_MAX_NB_SUBFR >> 1);
516         Lag_range_ptr = &silk_Lag_range_stage3_10_ms[ 0 ][ 0 ];
517         Lag_CB_ptr    = &silk_CB_lags_stage3_10_ms[ 0 ][ 0 ];
518         nb_cbk_search = PE_NB_CBKS_STAGE3_10MS;
519         cbk_size      = PE_NB_CBKS_STAGE3_10MS;
520     }
521 
522     target_ptr = &frame[ silk_LSHIFT( sf_length, 2 ) ]; /* Pointer to middle of frame */
523     for( k = 0; k < nb_subfr; k++ ) {
524         lag_counter = 0;
525 
526         /* Calculate the correlations for each subframe */
527         lag_low  = matrix_ptr( Lag_range_ptr, k, 0, 2 );
528         lag_high = matrix_ptr( Lag_range_ptr, k, 1, 2 );
529         silk_assert(lag_high-lag_low+1 <= SCRATCH_SIZE);
530         celt_pitch_xcorr( target_ptr, target_ptr - start_lag - lag_high, xcorr, sf_length, lag_high - lag_low + 1 );
531         for( j = lag_low; j <= lag_high; j++ ) {
532             basis_ptr = target_ptr - ( start_lag + j );
533             silk_assert( lag_counter < SCRATCH_SIZE );
534             scratch_mem[ lag_counter ] = xcorr[ lag_high - j ];
535             lag_counter++;
536         }
537 
538         delta = matrix_ptr( Lag_range_ptr, k, 0, 2 );
539         for( i = 0; i < nb_cbk_search; i++ ) {
540             /* Fill out the 3 dim array that stores the correlations for */
541             /* each code_book vector for each start lag */
542             idx = matrix_ptr( Lag_CB_ptr, k, i, cbk_size ) - delta;
543             for( j = 0; j < PE_NB_STAGE3_LAGS; j++ ) {
544                 silk_assert( idx + j < SCRATCH_SIZE );
545                 silk_assert( idx + j < lag_counter );
546                 cross_corr_st3[ k ][ i ][ j ] = scratch_mem[ idx + j ];
547             }
548         }
549         target_ptr += sf_length;
550     }
551 }
552 
553 /********************************************************************/
554 /* Calculate the energies for first two subframes. The energies are */
555 /* calculated recursively.                                          */
556 /********************************************************************/
silk_P_Ana_calc_energy_st3(silk_float energies_st3[PE_MAX_NB_SUBFR][PE_NB_CBKS_STAGE3_MAX][PE_NB_STAGE3_LAGS],const silk_float frame[],opus_int start_lag,opus_int sf_length,opus_int nb_subfr,opus_int complexity)557 static void silk_P_Ana_calc_energy_st3(
558     silk_float energies_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ], /* O 3 DIM correlation array */
559     const silk_float    frame[],            /* I vector to correlate                                            */
560     opus_int            start_lag,          /* I start lag                                                      */
561     opus_int            sf_length,          /* I sub frame length                                               */
562     opus_int            nb_subfr,           /* I number of subframes                                            */
563     opus_int            complexity          /* I Complexity setting                                             */
564 )
565 {
566     const silk_float *target_ptr, *basis_ptr;
567     double    energy;
568     opus_int   k, i, j, lag_counter;
569     opus_int   nb_cbk_search, delta, idx, cbk_size, lag_diff;
570     silk_float scratch_mem[ SCRATCH_SIZE ];
571     const opus_int8 *Lag_range_ptr, *Lag_CB_ptr;
572 
573     silk_assert( complexity >= SILK_PE_MIN_COMPLEX );
574     silk_assert( complexity <= SILK_PE_MAX_COMPLEX );
575 
576     if( nb_subfr == PE_MAX_NB_SUBFR ) {
577         Lag_range_ptr = &silk_Lag_range_stage3[ complexity ][ 0 ][ 0 ];
578         Lag_CB_ptr    = &silk_CB_lags_stage3[ 0 ][ 0 ];
579         nb_cbk_search = silk_nb_cbk_searchs_stage3[ complexity ];
580         cbk_size      = PE_NB_CBKS_STAGE3_MAX;
581     } else {
582         silk_assert( nb_subfr == PE_MAX_NB_SUBFR >> 1);
583         Lag_range_ptr = &silk_Lag_range_stage3_10_ms[ 0 ][ 0 ];
584         Lag_CB_ptr    = &silk_CB_lags_stage3_10_ms[ 0 ][ 0 ];
585         nb_cbk_search = PE_NB_CBKS_STAGE3_10MS;
586         cbk_size      = PE_NB_CBKS_STAGE3_10MS;
587     }
588 
589     target_ptr = &frame[ silk_LSHIFT( sf_length, 2 ) ];
590     for( k = 0; k < nb_subfr; k++ ) {
591         lag_counter = 0;
592 
593         /* Calculate the energy for first lag */
594         basis_ptr = target_ptr - ( start_lag + matrix_ptr( Lag_range_ptr, k, 0, 2 ) );
595         energy = silk_energy_FLP( basis_ptr, sf_length ) + 1e-3;
596         silk_assert( energy >= 0.0 );
597         scratch_mem[lag_counter] = (silk_float)energy;
598         lag_counter++;
599 
600         lag_diff = ( matrix_ptr( Lag_range_ptr, k, 1, 2 ) -  matrix_ptr( Lag_range_ptr, k, 0, 2 ) + 1 );
601         for( i = 1; i < lag_diff; i++ ) {
602             /* remove part outside new window */
603             energy -= basis_ptr[sf_length - i] * (double)basis_ptr[sf_length - i];
604             silk_assert( energy >= 0.0 );
605 
606             /* add part that comes into window */
607             energy += basis_ptr[ -i ] * (double)basis_ptr[ -i ];
608             silk_assert( energy >= 0.0 );
609             silk_assert( lag_counter < SCRATCH_SIZE );
610             scratch_mem[lag_counter] = (silk_float)energy;
611             lag_counter++;
612         }
613 
614         delta = matrix_ptr( Lag_range_ptr, k, 0, 2 );
615         for( i = 0; i < nb_cbk_search; i++ ) {
616             /* Fill out the 3 dim array that stores the correlations for    */
617             /* each code_book vector for each start lag                     */
618             idx = matrix_ptr( Lag_CB_ptr, k, i, cbk_size ) - delta;
619             for( j = 0; j < PE_NB_STAGE3_LAGS; j++ ) {
620                 silk_assert( idx + j < SCRATCH_SIZE );
621                 silk_assert( idx + j < lag_counter );
622                 energies_st3[ k ][ i ][ j ] = scratch_mem[ idx + j ];
623                 silk_assert( energies_st3[ k ][ i ][ j ] >= 0.0f );
624             }
625         }
626         target_ptr += sf_length;
627     }
628 }
629