1/***********************************************************************
2Copyright (c) 2006-2011, Skype Limited. All rights reserved.
3Redistribution and use in source and binary forms, with or without
4modification, are permitted provided that the following conditions
5are met:
6- Redistributions of source code must retain the above copyright notice,
7this list of conditions and the following disclaimer.
8- Redistributions in binary form must reproduce the above copyright
9notice, this list of conditions and the following disclaimer in the
10documentation and/or other materials provided with the distribution.
11- Neither the name of Internet Society, IETF or IETF Trust, nor the
12names of specific contributors, may be used to endorse or promote
13products derived from this software without specific prior written
14permission.
15THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
19LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25POSSIBILITY 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/************************************************************/
45static 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    int                 arch                /* I Run-time architecture                                          */
53);
54
55static void silk_P_Ana_calc_energy_st3(
56    silk_float energies_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ], /* O 3 DIM correlation array */
57    const silk_float    frame[],            /* I vector to correlate                                            */
58    opus_int            start_lag,          /* I start lag                                                      */
59    opus_int            sf_length,          /* I sub frame length                                               */
60    opus_int            nb_subfr,           /* I number of subframes                                            */
61    opus_int            complexity          /* I Complexity setting                                             */
62);
63
64/************************************************************/
65/* CORE PITCH ANALYSIS FUNCTION                             */
66/************************************************************/
67opus_int silk_pitch_analysis_core_FLP(      /* O    Voicing estimate: 0 voiced, 1 unvoiced                      */
68    const silk_float    *frame,             /* I    Signal of length PE_FRAME_LENGTH_MS*Fs_kHz                  */
69    opus_int            *pitch_out,         /* O    Pitch lag values [nb_subfr]                                 */
70    opus_int16          *lagIndex,          /* O    Lag Index                                                   */
71    opus_int8           *contourIndex,      /* O    Pitch contour Index                                         */
72    silk_float          *LTPCorr,           /* I/O  Normalized correlation; input: value from previous frame    */
73    opus_int            prevLag,            /* I    Last lag of previous frame; set to zero is unvoiced         */
74    const silk_float    search_thres1,      /* I    First stage threshold for lag candidates 0 - 1              */
75    const silk_float    search_thres2,      /* I    Final threshold for lag candidates 0 - 1                    */
76    const opus_int      Fs_kHz,             /* I    sample frequency (kHz)                                      */
77    const opus_int      complexity,         /* I    Complexity setting, 0-2, where 2 is highest                 */
78    const opus_int      nb_subfr,           /* I    Number of 5 ms subframes                                    */
79    int                 arch                /* I    Run-time architecture                                       */
80)
81{
82    opus_int   i, k, d, j;
83    silk_float frame_8kHz[  PE_MAX_FRAME_LENGTH_MS * 8 ];
84    silk_float frame_4kHz[  PE_MAX_FRAME_LENGTH_MS * 4 ];
85    opus_int16 frame_8_FIX[ PE_MAX_FRAME_LENGTH_MS * 8 ];
86    opus_int16 frame_4_FIX[ PE_MAX_FRAME_LENGTH_MS * 4 ];
87    opus_int32 filt_state[ 6 ];
88    silk_float threshold, contour_bias;
89    silk_float C[ PE_MAX_NB_SUBFR][ (PE_MAX_LAG >> 1) + 5 ];
90    opus_val32 xcorr[ PE_MAX_LAG_MS * 4 - PE_MIN_LAG_MS * 4 + 1 ];
91    silk_float CC[ PE_NB_CBKS_STAGE2_EXT ];
92    const silk_float *target_ptr, *basis_ptr;
93    double    cross_corr, normalizer, energy, energy_tmp;
94    opus_int   d_srch[ PE_D_SRCH_LENGTH ];
95    opus_int16 d_comp[ (PE_MAX_LAG >> 1) + 5 ];
96    opus_int   length_d_srch, length_d_comp;
97    silk_float Cmax, CCmax, CCmax_b, CCmax_new_b, CCmax_new;
98    opus_int   CBimax, CBimax_new, lag, start_lag, end_lag, lag_new;
99    opus_int   cbk_size;
100    silk_float lag_log2, prevLag_log2, delta_lag_log2_sqr;
101    silk_float energies_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ];
102    silk_float cross_corr_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ];
103    opus_int   lag_counter;
104    opus_int   frame_length, frame_length_8kHz, frame_length_4kHz;
105    opus_int   sf_length, sf_length_8kHz, sf_length_4kHz;
106    opus_int   min_lag, min_lag_8kHz, min_lag_4kHz;
107    opus_int   max_lag, max_lag_8kHz, max_lag_4kHz;
108    opus_int   nb_cbk_search;
109    const opus_int8 *Lag_CB_ptr;
110
111    /* Check for valid sampling frequency */
112    silk_assert( Fs_kHz == 8 || Fs_kHz == 12 || Fs_kHz == 16 );
113
114    /* Check for valid complexity setting */
115    silk_assert( complexity >= SILK_PE_MIN_COMPLEX );
116    silk_assert( complexity <= SILK_PE_MAX_COMPLEX );
117
118    silk_assert( search_thres1 >= 0.0f && search_thres1 <= 1.0f );
119    silk_assert( search_thres2 >= 0.0f && search_thres2 <= 1.0f );
120
121    /* Set up frame lengths max / min lag for the sampling frequency */
122    frame_length      = ( PE_LTP_MEM_LENGTH_MS + nb_subfr * PE_SUBFR_LENGTH_MS ) * Fs_kHz;
123    frame_length_4kHz = ( PE_LTP_MEM_LENGTH_MS + nb_subfr * PE_SUBFR_LENGTH_MS ) * 4;
124    frame_length_8kHz = ( PE_LTP_MEM_LENGTH_MS + nb_subfr * PE_SUBFR_LENGTH_MS ) * 8;
125    sf_length         = PE_SUBFR_LENGTH_MS * Fs_kHz;
126    sf_length_4kHz    = PE_SUBFR_LENGTH_MS * 4;
127    sf_length_8kHz    = PE_SUBFR_LENGTH_MS * 8;
128    min_lag           = PE_MIN_LAG_MS * Fs_kHz;
129    min_lag_4kHz      = PE_MIN_LAG_MS * 4;
130    min_lag_8kHz      = PE_MIN_LAG_MS * 8;
131    max_lag           = PE_MAX_LAG_MS * Fs_kHz - 1;
132    max_lag_4kHz      = PE_MAX_LAG_MS * 4;
133    max_lag_8kHz      = PE_MAX_LAG_MS * 8 - 1;
134
135    /* Resample from input sampled at Fs_kHz to 8 kHz */
136    if( Fs_kHz == 16 ) {
137        /* Resample to 16 -> 8 khz */
138        opus_int16 frame_16_FIX[ 16 * PE_MAX_FRAME_LENGTH_MS ];
139        silk_float2short_array( frame_16_FIX, frame, frame_length );
140        silk_memset( filt_state, 0, 2 * sizeof( opus_int32 ) );
141        silk_resampler_down2( filt_state, frame_8_FIX, frame_16_FIX, frame_length );
142        silk_short2float_array( frame_8kHz, frame_8_FIX, frame_length_8kHz );
143    } else if( Fs_kHz == 12 ) {
144        /* Resample to 12 -> 8 khz */
145        opus_int16 frame_12_FIX[ 12 * PE_MAX_FRAME_LENGTH_MS ];
146        silk_float2short_array( frame_12_FIX, frame, frame_length );
147        silk_memset( filt_state, 0, 6 * sizeof( opus_int32 ) );
148        silk_resampler_down2_3( filt_state, frame_8_FIX, frame_12_FIX, frame_length );
149        silk_short2float_array( frame_8kHz, frame_8_FIX, frame_length_8kHz );
150    } else {
151        silk_assert( Fs_kHz == 8 );
152        silk_float2short_array( frame_8_FIX, frame, frame_length_8kHz );
153    }
154
155    /* Decimate again to 4 kHz */
156    silk_memset( filt_state, 0, 2 * sizeof( opus_int32 ) );
157    silk_resampler_down2( filt_state, frame_4_FIX, frame_8_FIX, frame_length_8kHz );
158    silk_short2float_array( frame_4kHz, frame_4_FIX, frame_length_4kHz );
159
160    /* Low-pass filter */
161    for( i = frame_length_4kHz - 1; i > 0; i-- ) {
162        frame_4kHz[ i ] += frame_4kHz[ i - 1 ];
163    }
164
165    /******************************************************************************
166    * FIRST STAGE, operating in 4 khz
167    ******************************************************************************/
168    silk_memset(C, 0, sizeof(silk_float) * nb_subfr * ((PE_MAX_LAG >> 1) + 5));
169    target_ptr = &frame_4kHz[ silk_LSHIFT( sf_length_4kHz, 2 ) ];
170    for( k = 0; k < nb_subfr >> 1; k++ ) {
171        /* Check that we are within range of the array */
172        silk_assert( target_ptr >= frame_4kHz );
173        silk_assert( target_ptr + sf_length_8kHz <= frame_4kHz + frame_length_4kHz );
174
175        basis_ptr = target_ptr - min_lag_4kHz;
176
177        /* Check that we are within range of the array */
178        silk_assert( basis_ptr >= frame_4kHz );
179        silk_assert( basis_ptr + sf_length_8kHz <= frame_4kHz + frame_length_4kHz );
180
181        celt_pitch_xcorr( target_ptr, target_ptr-max_lag_4kHz, xcorr, sf_length_8kHz, max_lag_4kHz - min_lag_4kHz + 1, arch );
182
183        /* Calculate first vector products before loop */
184        cross_corr = xcorr[ max_lag_4kHz - min_lag_4kHz ];
185        normalizer = silk_energy_FLP( target_ptr, sf_length_8kHz ) +
186                     silk_energy_FLP( basis_ptr,  sf_length_8kHz ) +
187                     sf_length_8kHz * 4000.0f;
188
189        C[ 0 ][ min_lag_4kHz ] += (silk_float)( 2 * cross_corr / normalizer );
190
191        /* From now on normalizer is computed recursively */
192        for( d = min_lag_4kHz + 1; d <= max_lag_4kHz; d++ ) {
193            basis_ptr--;
194
195            /* Check that we are within range of the array */
196            silk_assert( basis_ptr >= frame_4kHz );
197            silk_assert( basis_ptr + sf_length_8kHz <= frame_4kHz + frame_length_4kHz );
198
199            cross_corr = xcorr[ max_lag_4kHz - d ];
200
201            /* Add contribution of new sample and remove contribution from oldest sample */
202            normalizer +=
203                basis_ptr[ 0 ] * (double)basis_ptr[ 0 ] -
204                basis_ptr[ sf_length_8kHz ] * (double)basis_ptr[ sf_length_8kHz ];
205            C[ 0 ][ d ] += (silk_float)( 2 * cross_corr / normalizer );
206        }
207        /* Update target pointer */
208        target_ptr += sf_length_8kHz;
209    }
210
211    /* Apply short-lag bias */
212    for( i = max_lag_4kHz; i >= min_lag_4kHz; i-- ) {
213        C[ 0 ][ i ] -= C[ 0 ][ i ] * i / 4096.0f;
214    }
215
216    /* Sort */
217    length_d_srch = 4 + 2 * complexity;
218    silk_assert( 3 * length_d_srch <= PE_D_SRCH_LENGTH );
219    silk_insertion_sort_decreasing_FLP( &C[ 0 ][ min_lag_4kHz ], d_srch, max_lag_4kHz - min_lag_4kHz + 1, length_d_srch );
220
221    /* Escape if correlation is very low already here */
222    Cmax = C[ 0 ][ min_lag_4kHz ];
223    if( Cmax < 0.2f ) {
224        silk_memset( pitch_out, 0, nb_subfr * sizeof( opus_int ) );
225        *LTPCorr      = 0.0f;
226        *lagIndex     = 0;
227        *contourIndex = 0;
228        return 1;
229    }
230
231    threshold = search_thres1 * Cmax;
232    for( i = 0; i < length_d_srch; i++ ) {
233        /* Convert to 8 kHz indices for the sorted correlation that exceeds the threshold */
234        if( C[ 0 ][ min_lag_4kHz + i ] > threshold ) {
235            d_srch[ i ] = silk_LSHIFT( d_srch[ i ] + min_lag_4kHz, 1 );
236        } else {
237            length_d_srch = i;
238            break;
239        }
240    }
241    silk_assert( length_d_srch > 0 );
242
243    for( i = min_lag_8kHz - 5; i < max_lag_8kHz + 5; i++ ) {
244        d_comp[ i ] = 0;
245    }
246    for( i = 0; i < length_d_srch; i++ ) {
247        d_comp[ d_srch[ i ] ] = 1;
248    }
249
250    /* Convolution */
251    for( i = max_lag_8kHz + 3; i >= min_lag_8kHz; i-- ) {
252        d_comp[ i ] += d_comp[ i - 1 ] + d_comp[ i - 2 ];
253    }
254
255    length_d_srch = 0;
256    for( i = min_lag_8kHz; i < max_lag_8kHz + 1; i++ ) {
257        if( d_comp[ i + 1 ] > 0 ) {
258            d_srch[ length_d_srch ] = i;
259            length_d_srch++;
260        }
261    }
262
263    /* Convolution */
264    for( i = max_lag_8kHz + 3; i >= min_lag_8kHz; i-- ) {
265        d_comp[ i ] += d_comp[ i - 1 ] + d_comp[ i - 2 ] + d_comp[ i - 3 ];
266    }
267
268    length_d_comp = 0;
269    for( i = min_lag_8kHz; i < max_lag_8kHz + 4; i++ ) {
270        if( d_comp[ i ] > 0 ) {
271            d_comp[ length_d_comp ] = (opus_int16)( i - 2 );
272            length_d_comp++;
273        }
274    }
275
276    /**********************************************************************************
277    ** SECOND STAGE, operating at 8 kHz, on lag sections with high correlation
278    *************************************************************************************/
279    /*********************************************************************************
280    * Find energy of each subframe projected onto its history, for a range of delays
281    *********************************************************************************/
282    silk_memset( C, 0, PE_MAX_NB_SUBFR*((PE_MAX_LAG >> 1) + 5) * sizeof(silk_float));
283
284    if( Fs_kHz == 8 ) {
285        target_ptr = &frame[ PE_LTP_MEM_LENGTH_MS * 8 ];
286    } else {
287        target_ptr = &frame_8kHz[ PE_LTP_MEM_LENGTH_MS * 8 ];
288    }
289    for( k = 0; k < nb_subfr; k++ ) {
290        energy_tmp = silk_energy_FLP( target_ptr, sf_length_8kHz ) + 1.0;
291        for( j = 0; j < length_d_comp; j++ ) {
292            d = d_comp[ j ];
293            basis_ptr = target_ptr - d;
294            cross_corr = silk_inner_product_FLP( basis_ptr, target_ptr, sf_length_8kHz );
295            if( cross_corr > 0.0f ) {
296                energy = silk_energy_FLP( basis_ptr, sf_length_8kHz );
297                C[ k ][ d ] = (silk_float)( 2 * cross_corr / ( energy + energy_tmp ) );
298            } else {
299                C[ k ][ d ] = 0.0f;
300            }
301        }
302        target_ptr += sf_length_8kHz;
303    }
304
305    /* search over lag range and lags codebook */
306    /* scale factor for lag codebook, as a function of center lag */
307
308    CCmax   = 0.0f; /* This value doesn't matter */
309    CCmax_b = -1000.0f;
310
311    CBimax = 0; /* To avoid returning undefined lag values */
312    lag = -1;   /* To check if lag with strong enough correlation has been found */
313
314    if( prevLag > 0 ) {
315        if( Fs_kHz == 12 ) {
316            prevLag = silk_LSHIFT( prevLag, 1 ) / 3;
317        } else if( Fs_kHz == 16 ) {
318            prevLag = silk_RSHIFT( prevLag, 1 );
319        }
320        prevLag_log2 = silk_log2( (silk_float)prevLag );
321    } else {
322        prevLag_log2 = 0;
323    }
324
325    /* Set up stage 2 codebook based on number of subframes */
326    if( nb_subfr == PE_MAX_NB_SUBFR ) {
327        cbk_size   = PE_NB_CBKS_STAGE2_EXT;
328        Lag_CB_ptr = &silk_CB_lags_stage2[ 0 ][ 0 ];
329        if( Fs_kHz == 8 && complexity > SILK_PE_MIN_COMPLEX ) {
330            /* If input is 8 khz use a larger codebook here because it is last stage */
331            nb_cbk_search = PE_NB_CBKS_STAGE2_EXT;
332        } else {
333            nb_cbk_search = PE_NB_CBKS_STAGE2;
334        }
335    } else {
336        cbk_size       = PE_NB_CBKS_STAGE2_10MS;
337        Lag_CB_ptr     = &silk_CB_lags_stage2_10_ms[ 0 ][ 0 ];
338        nb_cbk_search  = PE_NB_CBKS_STAGE2_10MS;
339    }
340
341    for( k = 0; k < length_d_srch; k++ ) {
342        d = d_srch[ k ];
343        for( j = 0; j < nb_cbk_search; j++ ) {
344            CC[j] = 0.0f;
345            for( i = 0; i < nb_subfr; i++ ) {
346                /* Try all codebooks */
347                CC[ j ] += C[ i ][ d + matrix_ptr( Lag_CB_ptr, i, j, cbk_size )];
348            }
349        }
350        /* Find best codebook */
351        CCmax_new  = -1000.0f;
352        CBimax_new = 0;
353        for( i = 0; i < nb_cbk_search; i++ ) {
354            if( CC[ i ] > CCmax_new ) {
355                CCmax_new = CC[ i ];
356                CBimax_new = i;
357            }
358        }
359
360        /* Bias towards shorter lags */
361        lag_log2 = silk_log2( (silk_float)d );
362        CCmax_new_b = CCmax_new - PE_SHORTLAG_BIAS * nb_subfr * lag_log2;
363
364        /* Bias towards previous lag */
365        if( prevLag > 0 ) {
366            delta_lag_log2_sqr = lag_log2 - prevLag_log2;
367            delta_lag_log2_sqr *= delta_lag_log2_sqr;
368            CCmax_new_b -= PE_PREVLAG_BIAS * nb_subfr * (*LTPCorr) * delta_lag_log2_sqr / ( delta_lag_log2_sqr + 0.5f );
369        }
370
371        if( CCmax_new_b > CCmax_b &&                /* Find maximum biased correlation                  */
372            CCmax_new > nb_subfr * search_thres2    /* Correlation needs to be high enough to be voiced */
373        ) {
374            CCmax_b = CCmax_new_b;
375            CCmax   = CCmax_new;
376            lag     = d;
377            CBimax  = CBimax_new;
378        }
379    }
380
381    if( lag == -1 ) {
382        /* No suitable candidate found */
383        silk_memset( pitch_out, 0, PE_MAX_NB_SUBFR * sizeof(opus_int) );
384        *LTPCorr      = 0.0f;
385        *lagIndex     = 0;
386        *contourIndex = 0;
387        return 1;
388    }
389
390    /* Output normalized correlation */
391    *LTPCorr = (silk_float)( CCmax / nb_subfr );
392    silk_assert( *LTPCorr >= 0.0f );
393
394    if( Fs_kHz > 8 ) {
395        /* Search in original signal */
396
397        /* Compensate for decimation */
398        silk_assert( lag == silk_SAT16( lag ) );
399        if( Fs_kHz == 12 ) {
400            lag = silk_RSHIFT_ROUND( silk_SMULBB( lag, 3 ), 1 );
401        } else { /* Fs_kHz == 16 */
402            lag = silk_LSHIFT( lag, 1 );
403        }
404
405        lag = silk_LIMIT_int( lag, min_lag, max_lag );
406        start_lag = silk_max_int( lag - 2, min_lag );
407        end_lag   = silk_min_int( lag + 2, max_lag );
408        lag_new   = lag;                                    /* to avoid undefined lag */
409        CBimax    = 0;                                      /* to avoid undefined lag */
410
411        CCmax = -1000.0f;
412
413        /* Calculate the correlations and energies needed in stage 3 */
414        silk_P_Ana_calc_corr_st3( cross_corr_st3, frame, start_lag, sf_length, nb_subfr, complexity, arch );
415        silk_P_Ana_calc_energy_st3( energies_st3, frame, start_lag, sf_length, nb_subfr, complexity );
416
417        lag_counter = 0;
418        silk_assert( lag == silk_SAT16( lag ) );
419        contour_bias = PE_FLATCONTOUR_BIAS / lag;
420
421        /* Set up cbk parameters according to complexity setting and frame length */
422        if( nb_subfr == PE_MAX_NB_SUBFR ) {
423            nb_cbk_search = (opus_int)silk_nb_cbk_searchs_stage3[ complexity ];
424            cbk_size      = PE_NB_CBKS_STAGE3_MAX;
425            Lag_CB_ptr    = &silk_CB_lags_stage3[ 0 ][ 0 ];
426        } else {
427            nb_cbk_search = PE_NB_CBKS_STAGE3_10MS;
428            cbk_size      = PE_NB_CBKS_STAGE3_10MS;
429            Lag_CB_ptr    = &silk_CB_lags_stage3_10_ms[ 0 ][ 0 ];
430        }
431
432        target_ptr = &frame[ PE_LTP_MEM_LENGTH_MS * Fs_kHz ];
433        energy_tmp = silk_energy_FLP( target_ptr, nb_subfr * sf_length ) + 1.0;
434        for( d = start_lag; d <= end_lag; d++ ) {
435            for( j = 0; j < nb_cbk_search; j++ ) {
436                cross_corr = 0.0;
437                energy = energy_tmp;
438                for( k = 0; k < nb_subfr; k++ ) {
439                    cross_corr += cross_corr_st3[ k ][ j ][ lag_counter ];
440                    energy     +=   energies_st3[ k ][ j ][ lag_counter ];
441                }
442                if( cross_corr > 0.0 ) {
443                    CCmax_new = (silk_float)( 2 * cross_corr / energy );
444                    /* Reduce depending on flatness of contour */
445                    CCmax_new *= 1.0f - contour_bias * j;
446                } else {
447                    CCmax_new = 0.0f;
448                }
449
450                if( CCmax_new > CCmax && ( d + (opus_int)silk_CB_lags_stage3[ 0 ][ j ] ) <= max_lag ) {
451                    CCmax   = CCmax_new;
452                    lag_new = d;
453                    CBimax  = j;
454                }
455            }
456            lag_counter++;
457        }
458
459        for( k = 0; k < nb_subfr; k++ ) {
460            pitch_out[ k ] = lag_new + matrix_ptr( Lag_CB_ptr, k, CBimax, cbk_size );
461            pitch_out[ k ] = silk_LIMIT( pitch_out[ k ], min_lag, PE_MAX_LAG_MS * Fs_kHz );
462        }
463        *lagIndex = (opus_int16)( lag_new - min_lag );
464        *contourIndex = (opus_int8)CBimax;
465    } else {        /* Fs_kHz == 8 */
466        /* Save Lags */
467        for( k = 0; k < nb_subfr; k++ ) {
468            pitch_out[ k ] = lag + matrix_ptr( Lag_CB_ptr, k, CBimax, cbk_size );
469            pitch_out[ k ] = silk_LIMIT( pitch_out[ k ], min_lag_8kHz, PE_MAX_LAG_MS * 8 );
470        }
471        *lagIndex = (opus_int16)( lag - min_lag_8kHz );
472        *contourIndex = (opus_int8)CBimax;
473    }
474    silk_assert( *lagIndex >= 0 );
475    /* return as voiced */
476    return 0;
477}
478
479/***********************************************************************
480 * Calculates the correlations used in stage 3 search. In order to cover
481 * the whole lag codebook for all the searched offset lags (lag +- 2),
482 * the following correlations are needed in each sub frame:
483 *
484 * sf1: lag range [-8,...,7] total 16 correlations
485 * sf2: lag range [-4,...,4] total 9 correlations
486 * sf3: lag range [-3,....4] total 8 correltions
487 * sf4: lag range [-6,....8] total 15 correlations
488 *
489 * In total 48 correlations. The direct implementation computed in worst
490 * case 4*12*5 = 240 correlations, but more likely around 120.
491 ***********************************************************************/
492static void silk_P_Ana_calc_corr_st3(
493    silk_float cross_corr_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ], /* O 3 DIM correlation array */
494    const silk_float    frame[],            /* I vector to correlate                                            */
495    opus_int            start_lag,          /* I start lag                                                      */
496    opus_int            sf_length,          /* I sub frame length                                               */
497    opus_int            nb_subfr,           /* I number of subframes                                            */
498    opus_int            complexity,         /* I Complexity setting                                             */
499    int                 arch                /* I Run-time architecture                                          */
500)
501{
502    const silk_float *target_ptr;
503    opus_int   i, j, k, lag_counter, lag_low, lag_high;
504    opus_int   nb_cbk_search, delta, idx, cbk_size;
505    silk_float scratch_mem[ SCRATCH_SIZE ];
506    opus_val32 xcorr[ SCRATCH_SIZE ];
507    const opus_int8 *Lag_range_ptr, *Lag_CB_ptr;
508
509    silk_assert( complexity >= SILK_PE_MIN_COMPLEX );
510    silk_assert( complexity <= SILK_PE_MAX_COMPLEX );
511
512    if( nb_subfr == PE_MAX_NB_SUBFR ) {
513        Lag_range_ptr = &silk_Lag_range_stage3[ complexity ][ 0 ][ 0 ];
514        Lag_CB_ptr    = &silk_CB_lags_stage3[ 0 ][ 0 ];
515        nb_cbk_search = silk_nb_cbk_searchs_stage3[ complexity ];
516        cbk_size      = PE_NB_CBKS_STAGE3_MAX;
517    } else {
518        silk_assert( nb_subfr == PE_MAX_NB_SUBFR >> 1);
519        Lag_range_ptr = &silk_Lag_range_stage3_10_ms[ 0 ][ 0 ];
520        Lag_CB_ptr    = &silk_CB_lags_stage3_10_ms[ 0 ][ 0 ];
521        nb_cbk_search = PE_NB_CBKS_STAGE3_10MS;
522        cbk_size      = PE_NB_CBKS_STAGE3_10MS;
523    }
524
525    target_ptr = &frame[ silk_LSHIFT( sf_length, 2 ) ]; /* Pointer to middle of frame */
526    for( k = 0; k < nb_subfr; k++ ) {
527        lag_counter = 0;
528
529        /* Calculate the correlations for each subframe */
530        lag_low  = matrix_ptr( Lag_range_ptr, k, 0, 2 );
531        lag_high = matrix_ptr( Lag_range_ptr, k, 1, 2 );
532        silk_assert(lag_high-lag_low+1 <= SCRATCH_SIZE);
533        celt_pitch_xcorr( target_ptr, target_ptr - start_lag - lag_high, xcorr, sf_length, lag_high - lag_low + 1, arch );
534        for( j = lag_low; j <= lag_high; j++ ) {
535            silk_assert( lag_counter < SCRATCH_SIZE );
536            scratch_mem[ lag_counter ] = xcorr[ lag_high - j ];
537            lag_counter++;
538        }
539
540        delta = matrix_ptr( Lag_range_ptr, k, 0, 2 );
541        for( i = 0; i < nb_cbk_search; i++ ) {
542            /* Fill out the 3 dim array that stores the correlations for */
543            /* each code_book vector for each start lag */
544            idx = matrix_ptr( Lag_CB_ptr, k, i, cbk_size ) - delta;
545            for( j = 0; j < PE_NB_STAGE3_LAGS; j++ ) {
546                silk_assert( idx + j < SCRATCH_SIZE );
547                silk_assert( idx + j < lag_counter );
548                cross_corr_st3[ k ][ i ][ j ] = scratch_mem[ idx + j ];
549            }
550        }
551        target_ptr += sf_length;
552    }
553}
554
555/********************************************************************/
556/* Calculate the energies for first two subframes. The energies are */
557/* calculated recursively.                                          */
558/********************************************************************/
559static void silk_P_Ana_calc_energy_st3(
560    silk_float energies_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ], /* O 3 DIM correlation array */
561    const silk_float    frame[],            /* I vector to correlate                                            */
562    opus_int            start_lag,          /* I start lag                                                      */
563    opus_int            sf_length,          /* I sub frame length                                               */
564    opus_int            nb_subfr,           /* I number of subframes                                            */
565    opus_int            complexity          /* I Complexity setting                                             */
566)
567{
568    const silk_float *target_ptr, *basis_ptr;
569    double    energy;
570    opus_int   k, i, j, lag_counter;
571    opus_int   nb_cbk_search, delta, idx, cbk_size, lag_diff;
572    silk_float scratch_mem[ SCRATCH_SIZE ];
573    const opus_int8 *Lag_range_ptr, *Lag_CB_ptr;
574
575    silk_assert( complexity >= SILK_PE_MIN_COMPLEX );
576    silk_assert( complexity <= SILK_PE_MAX_COMPLEX );
577
578    if( nb_subfr == PE_MAX_NB_SUBFR ) {
579        Lag_range_ptr = &silk_Lag_range_stage3[ complexity ][ 0 ][ 0 ];
580        Lag_CB_ptr    = &silk_CB_lags_stage3[ 0 ][ 0 ];
581        nb_cbk_search = silk_nb_cbk_searchs_stage3[ complexity ];
582        cbk_size      = PE_NB_CBKS_STAGE3_MAX;
583    } else {
584        silk_assert( nb_subfr == PE_MAX_NB_SUBFR >> 1);
585        Lag_range_ptr = &silk_Lag_range_stage3_10_ms[ 0 ][ 0 ];
586        Lag_CB_ptr    = &silk_CB_lags_stage3_10_ms[ 0 ][ 0 ];
587        nb_cbk_search = PE_NB_CBKS_STAGE3_10MS;
588        cbk_size      = PE_NB_CBKS_STAGE3_10MS;
589    }
590
591    target_ptr = &frame[ silk_LSHIFT( sf_length, 2 ) ];
592    for( k = 0; k < nb_subfr; k++ ) {
593        lag_counter = 0;
594
595        /* Calculate the energy for first lag */
596        basis_ptr = target_ptr - ( start_lag + matrix_ptr( Lag_range_ptr, k, 0, 2 ) );
597        energy = silk_energy_FLP( basis_ptr, sf_length ) + 1e-3;
598        silk_assert( energy >= 0.0 );
599        scratch_mem[lag_counter] = (silk_float)energy;
600        lag_counter++;
601
602        lag_diff = ( matrix_ptr( Lag_range_ptr, k, 1, 2 ) -  matrix_ptr( Lag_range_ptr, k, 0, 2 ) + 1 );
603        for( i = 1; i < lag_diff; i++ ) {
604            /* remove part outside new window */
605            energy -= basis_ptr[sf_length - i] * (double)basis_ptr[sf_length - i];
606            silk_assert( energy >= 0.0 );
607
608            /* add part that comes into window */
609            energy += basis_ptr[ -i ] * (double)basis_ptr[ -i ];
610            silk_assert( energy >= 0.0 );
611            silk_assert( lag_counter < SCRATCH_SIZE );
612            scratch_mem[lag_counter] = (silk_float)energy;
613            lag_counter++;
614        }
615
616        delta = matrix_ptr( Lag_range_ptr, k, 0, 2 );
617        for( i = 0; i < nb_cbk_search; i++ ) {
618            /* Fill out the 3 dim array that stores the correlations for    */
619            /* each code_book vector for each start lag                     */
620            idx = matrix_ptr( Lag_CB_ptr, k, i, cbk_size ) - delta;
621            for( j = 0; j < PE_NB_STAGE3_LAGS; j++ ) {
622                silk_assert( idx + j < SCRATCH_SIZE );
623                silk_assert( idx + j < lag_counter );
624                energies_st3[ k ][ i ][ j ] = scratch_mem[ idx + j ];
625                silk_assert( energies_st3[ k ][ i ][ j ] >= 0.0f );
626            }
627        }
628        target_ptr += sf_length;
629    }
630}
631