Create local copy of Opus v1.1.2

webrtc/modules/audio_coding/codecs/opus/opus/src/silk/float/pitch_analysis_core_FLP.c

Index: webrtc/modules/audio_coding/codecs/opus/opus/src/silk/float/pitch_analysis_core_FLP.c
diff --git a/webrtc/modules/audio_coding/codecs/opus/opus/src/silk/float/pitch_analysis_core_FLP.c b/webrtc/modules/audio_coding/codecs/opus/opus/src/silk/float/pitch_analysis_core_FLP.c
new file mode 100644
index 0000000000000000000000000000000000000000..d0e637a29dc95d5e63ade14d98f9e3f4ce7e0bd8
--- /dev/null
+++ b/webrtc/modules/audio_coding/codecs/opus/opus/src/silk/float/pitch_analysis_core_FLP.c
@@ -0,0 +1,630 @@
+/***********************************************************************
+Copyright (c) 2006-2011, Skype Limited. All rights reserved.
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+- Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+- Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in the
+documentation and/or other materials provided with the distribution.
+- Neither the name of Internet Society, IETF or IETF Trust, nor the
+names of specific contributors, may be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+***********************************************************************/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+/*****************************************************************************
+* Pitch analyser function
+******************************************************************************/
+#include "SigProc_FLP.h"
+#include "SigProc_FIX.h"
+#include "pitch_est_defines.h"
+#include "pitch.h"
+
+#define SCRATCH_SIZE        22
+
+/************************************************************/
+/* Internally used functions                                */
+/************************************************************/
+static void silk_P_Ana_calc_corr_st3(
+    silk_float cross_corr_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ], /* O 3 DIM correlation array */
+    const silk_float    frame[],            /* I vector to correlate                                            */
+    opus_int            start_lag,          /* I start lag                                                      */
+    opus_int            sf_length,          /* I sub frame length                                               */
+    opus_int            nb_subfr,           /* I number of subframes                                            */
+    opus_int            complexity,         /* I Complexity setting                                             */
+    int                 arch                /* I Run-time architecture                                          */
+);
+
+static void silk_P_Ana_calc_energy_st3(
+    silk_float energies_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ], /* O 3 DIM correlation array */
+    const silk_float    frame[],            /* I vector to correlate                                            */
+    opus_int            start_lag,          /* I start lag                                                      */
+    opus_int            sf_length,          /* I sub frame length                                               */
+    opus_int            nb_subfr,           /* I number of subframes                                            */
+    opus_int            complexity          /* I Complexity setting                                             */
+);
+
+/************************************************************/
+/* CORE PITCH ANALYSIS FUNCTION                             */
+/************************************************************/
+opus_int silk_pitch_analysis_core_FLP(      /* O    Voicing estimate: 0 voiced, 1 unvoiced                      */
+    const silk_float    *frame,             /* I    Signal of length PE_FRAME_LENGTH_MS*Fs_kHz                  */
+    opus_int            *pitch_out,         /* O    Pitch lag values [nb_subfr]                                 */
+    opus_int16          *lagIndex,          /* O    Lag Index                                                   */
+    opus_int8           *contourIndex,      /* O    Pitch contour Index                                         */
+    silk_float          *LTPCorr,           /* I/O  Normalized correlation; input: value from previous frame    */
+    opus_int            prevLag,            /* I    Last lag of previous frame; set to zero is unvoiced         */
+    const silk_float    search_thres1,      /* I    First stage threshold for lag candidates 0 - 1              */
+    const silk_float    search_thres2,      /* I    Final threshold for lag candidates 0 - 1                    */
+    const opus_int      Fs_kHz,             /* I    sample frequency (kHz)                                      */
+    const opus_int      complexity,         /* I    Complexity setting, 0-2, where 2 is highest                 */
+    const opus_int      nb_subfr,           /* I    Number of 5 ms subframes                                    */
+    int                 arch                /* I    Run-time architecture                                       */
+)
+{
+    opus_int   i, k, d, j;
+    silk_float frame_8kHz[  PE_MAX_FRAME_LENGTH_MS * 8 ];
+    silk_float frame_4kHz[  PE_MAX_FRAME_LENGTH_MS * 4 ];
+    opus_int16 frame_8_FIX[ PE_MAX_FRAME_LENGTH_MS * 8 ];
+    opus_int16 frame_4_FIX[ PE_MAX_FRAME_LENGTH_MS * 4 ];
+    opus_int32 filt_state[ 6 ];
+    silk_float threshold, contour_bias;
+    silk_float C[ PE_MAX_NB_SUBFR][ (PE_MAX_LAG >> 1) + 5 ];
+    opus_val32 xcorr[ PE_MAX_LAG_MS * 4 - PE_MIN_LAG_MS * 4 + 1 ];
+    silk_float CC[ PE_NB_CBKS_STAGE2_EXT ];
+    const silk_float *target_ptr, *basis_ptr;
+    double    cross_corr, normalizer, energy, energy_tmp;
+    opus_int   d_srch[ PE_D_SRCH_LENGTH ];
+    opus_int16 d_comp[ (PE_MAX_LAG >> 1) + 5 ];
+    opus_int   length_d_srch, length_d_comp;
+    silk_float Cmax, CCmax, CCmax_b, CCmax_new_b, CCmax_new;
+    opus_int   CBimax, CBimax_new, lag, start_lag, end_lag, lag_new;
+    opus_int   cbk_size;
+    silk_float lag_log2, prevLag_log2, delta_lag_log2_sqr;
+    silk_float energies_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ];
+    silk_float cross_corr_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ];
+    opus_int   lag_counter;
+    opus_int   frame_length, frame_length_8kHz, frame_length_4kHz;
+    opus_int   sf_length, sf_length_8kHz, sf_length_4kHz;
+    opus_int   min_lag, min_lag_8kHz, min_lag_4kHz;
+    opus_int   max_lag, max_lag_8kHz, max_lag_4kHz;
+    opus_int   nb_cbk_search;
+    const opus_int8 *Lag_CB_ptr;
+
+    /* Check for valid sampling frequency */
+    silk_assert( Fs_kHz == 8 || Fs_kHz == 12 || Fs_kHz == 16 );
+
+    /* Check for valid complexity setting */
+    silk_assert( complexity >= SILK_PE_MIN_COMPLEX );
+    silk_assert( complexity <= SILK_PE_MAX_COMPLEX );
+
+    silk_assert( search_thres1 >= 0.0f && search_thres1 <= 1.0f );
+    silk_assert( search_thres2 >= 0.0f && search_thres2 <= 1.0f );
+
+    /* Set up frame lengths max / min lag for the sampling frequency */
+    frame_length      = ( PE_LTP_MEM_LENGTH_MS + nb_subfr * PE_SUBFR_LENGTH_MS ) * Fs_kHz;
+    frame_length_4kHz = ( PE_LTP_MEM_LENGTH_MS + nb_subfr * PE_SUBFR_LENGTH_MS ) * 4;
+    frame_length_8kHz = ( PE_LTP_MEM_LENGTH_MS + nb_subfr * PE_SUBFR_LENGTH_MS ) * 8;
+    sf_length         = PE_SUBFR_LENGTH_MS * Fs_kHz;
+    sf_length_4kHz    = PE_SUBFR_LENGTH_MS * 4;
+    sf_length_8kHz    = PE_SUBFR_LENGTH_MS * 8;
+    min_lag           = PE_MIN_LAG_MS * Fs_kHz;
+    min_lag_4kHz      = PE_MIN_LAG_MS * 4;
+    min_lag_8kHz      = PE_MIN_LAG_MS * 8;
+    max_lag           = PE_MAX_LAG_MS * Fs_kHz - 1;
+    max_lag_4kHz      = PE_MAX_LAG_MS * 4;
+    max_lag_8kHz      = PE_MAX_LAG_MS * 8 - 1;
+
+    /* Resample from input sampled at Fs_kHz to 8 kHz */
+    if( Fs_kHz == 16 ) {
+        /* Resample to 16 -> 8 khz */
+        opus_int16 frame_16_FIX[ 16 * PE_MAX_FRAME_LENGTH_MS ];
+        silk_float2short_array( frame_16_FIX, frame, frame_length );
+        silk_memset( filt_state, 0, 2 * sizeof( opus_int32 ) );
+        silk_resampler_down2( filt_state, frame_8_FIX, frame_16_FIX, frame_length );
+        silk_short2float_array( frame_8kHz, frame_8_FIX, frame_length_8kHz );
+    } else if( Fs_kHz == 12 ) {
+        /* Resample to 12 -> 8 khz */
+        opus_int16 frame_12_FIX[ 12 * PE_MAX_FRAME_LENGTH_MS ];
+        silk_float2short_array( frame_12_FIX, frame, frame_length );
+        silk_memset( filt_state, 0, 6 * sizeof( opus_int32 ) );
+        silk_resampler_down2_3( filt_state, frame_8_FIX, frame_12_FIX, frame_length );
+        silk_short2float_array( frame_8kHz, frame_8_FIX, frame_length_8kHz );
+    } else {
+        silk_assert( Fs_kHz == 8 );
+        silk_float2short_array( frame_8_FIX, frame, frame_length_8kHz );
+    }
+
+    /* Decimate again to 4 kHz */
+    silk_memset( filt_state, 0, 2 * sizeof( opus_int32 ) );
+    silk_resampler_down2( filt_state, frame_4_FIX, frame_8_FIX, frame_length_8kHz );
+    silk_short2float_array( frame_4kHz, frame_4_FIX, frame_length_4kHz );
+
+    /* Low-pass filter */
+    for( i = frame_length_4kHz - 1; i > 0; i-- ) {
+        frame_4kHz[ i ] += frame_4kHz[ i - 1 ];
+    }
+
+    /******************************************************************************
+    * FIRST STAGE, operating in 4 khz
+    ******************************************************************************/
+    silk_memset(C, 0, sizeof(silk_float) * nb_subfr * ((PE_MAX_LAG >> 1) + 5));
+    target_ptr = &frame_4kHz[ silk_LSHIFT( sf_length_4kHz, 2 ) ];
+    for( k = 0; k < nb_subfr >> 1; k++ ) {
+        /* Check that we are within range of the array */
+        silk_assert( target_ptr >= frame_4kHz );
+        silk_assert( target_ptr + sf_length_8kHz <= frame_4kHz + frame_length_4kHz );
+
+        basis_ptr = target_ptr - min_lag_4kHz;
+
+        /* Check that we are within range of the array */
+        silk_assert( basis_ptr >= frame_4kHz );
+        silk_assert( basis_ptr + sf_length_8kHz <= frame_4kHz + frame_length_4kHz );
+
+        celt_pitch_xcorr( target_ptr, target_ptr-max_lag_4kHz, xcorr, sf_length_8kHz, max_lag_4kHz - min_lag_4kHz + 1, arch );
+
+        /* Calculate first vector products before loop */
+        cross_corr = xcorr[ max_lag_4kHz - min_lag_4kHz ];
+        normalizer = silk_energy_FLP( target_ptr, sf_length_8kHz ) +
+                     silk_energy_FLP( basis_ptr,  sf_length_8kHz ) +
+                     sf_length_8kHz * 4000.0f;
+
+        C[ 0 ][ min_lag_4kHz ] += (silk_float)( 2 * cross_corr / normalizer );
+
+        /* From now on normalizer is computed recursively */
+        for( d = min_lag_4kHz + 1; d <= max_lag_4kHz; d++ ) {
+            basis_ptr--;
+
+            /* Check that we are within range of the array */
+            silk_assert( basis_ptr >= frame_4kHz );
+            silk_assert( basis_ptr + sf_length_8kHz <= frame_4kHz + frame_length_4kHz );
+
+            cross_corr = xcorr[ max_lag_4kHz - d ];
+
+            /* Add contribution of new sample and remove contribution from oldest sample */
+            normalizer +=
+                basis_ptr[ 0 ] * (double)basis_ptr[ 0 ] -
+                basis_ptr[ sf_length_8kHz ] * (double)basis_ptr[ sf_length_8kHz ];
+            C[ 0 ][ d ] += (silk_float)( 2 * cross_corr / normalizer );
+        }
+        /* Update target pointer */
+        target_ptr += sf_length_8kHz;
+    }
+
+    /* Apply short-lag bias */
+    for( i = max_lag_4kHz; i >= min_lag_4kHz; i-- ) {
+        C[ 0 ][ i ] -= C[ 0 ][ i ] * i / 4096.0f;
+    }
+
+    /* Sort */
+    length_d_srch = 4 + 2 * complexity;
+    silk_assert( 3 * length_d_srch <= PE_D_SRCH_LENGTH );
+    silk_insertion_sort_decreasing_FLP( &C[ 0 ][ min_lag_4kHz ], d_srch, max_lag_4kHz - min_lag_4kHz + 1, length_d_srch );
+
+    /* Escape if correlation is very low already here */
+    Cmax = C[ 0 ][ min_lag_4kHz ];
+    if( Cmax < 0.2f ) {
+        silk_memset( pitch_out, 0, nb_subfr * sizeof( opus_int ) );
+        *LTPCorr      = 0.0f;
+        *lagIndex     = 0;
+        *contourIndex = 0;
+        return 1;
+    }
+
+    threshold = search_thres1 * Cmax;
+    for( i = 0; i < length_d_srch; i++ ) {
+        /* Convert to 8 kHz indices for the sorted correlation that exceeds the threshold */
+        if( C[ 0 ][ min_lag_4kHz + i ] > threshold ) {
+            d_srch[ i ] = silk_LSHIFT( d_srch[ i ] + min_lag_4kHz, 1 );
+        } else {
+            length_d_srch = i;
+            break;
+        }
+    }
+    silk_assert( length_d_srch > 0 );
+
+    for( i = min_lag_8kHz - 5; i < max_lag_8kHz + 5; i++ ) {
+        d_comp[ i ] = 0;
+    }
+    for( i = 0; i < length_d_srch; i++ ) {
+        d_comp[ d_srch[ i ] ] = 1;
+    }
+
+    /* Convolution */
+    for( i = max_lag_8kHz + 3; i >= min_lag_8kHz; i-- ) {
+        d_comp[ i ] += d_comp[ i - 1 ] + d_comp[ i - 2 ];
+    }
+
+    length_d_srch = 0;
+    for( i = min_lag_8kHz; i < max_lag_8kHz + 1; i++ ) {
+        if( d_comp[ i + 1 ] > 0 ) {
+            d_srch[ length_d_srch ] = i;
+            length_d_srch++;
+        }
+    }
+
+    /* Convolution */
+    for( i = max_lag_8kHz + 3; i >= min_lag_8kHz; i-- ) {
+        d_comp[ i ] += d_comp[ i - 1 ] + d_comp[ i - 2 ] + d_comp[ i - 3 ];
+    }
+
+    length_d_comp = 0;
+    for( i = min_lag_8kHz; i < max_lag_8kHz + 4; i++ ) {
+        if( d_comp[ i ] > 0 ) {
+            d_comp[ length_d_comp ] = (opus_int16)( i - 2 );
+            length_d_comp++;
+        }
+    }
+
+    /**********************************************************************************
+    ** SECOND STAGE, operating at 8 kHz, on lag sections with high correlation
+    *************************************************************************************/
+    /*********************************************************************************
+    * Find energy of each subframe projected onto its history, for a range of delays
+    *********************************************************************************/
+    silk_memset( C, 0, PE_MAX_NB_SUBFR*((PE_MAX_LAG >> 1) + 5) * sizeof(silk_float));
+
+    if( Fs_kHz == 8 ) {
+        target_ptr = &frame[ PE_LTP_MEM_LENGTH_MS * 8 ];
+    } else {
+        target_ptr = &frame_8kHz[ PE_LTP_MEM_LENGTH_MS * 8 ];
+    }
+    for( k = 0; k < nb_subfr; k++ ) {
+        energy_tmp = silk_energy_FLP( target_ptr, sf_length_8kHz ) + 1.0;
+        for( j = 0; j < length_d_comp; j++ ) {
+            d = d_comp[ j ];
+            basis_ptr = target_ptr - d;
+            cross_corr = silk_inner_product_FLP( basis_ptr, target_ptr, sf_length_8kHz );
+            if( cross_corr > 0.0f ) {
+                energy = silk_energy_FLP( basis_ptr, sf_length_8kHz );
+                C[ k ][ d ] = (silk_float)( 2 * cross_corr / ( energy + energy_tmp ) );
+            } else {
+                C[ k ][ d ] = 0.0f;
+            }
+        }
+        target_ptr += sf_length_8kHz;
+    }
+
+    /* search over lag range and lags codebook */
+    /* scale factor for lag codebook, as a function of center lag */
+
+    CCmax   = 0.0f; /* This value doesn't matter */
+    CCmax_b = -1000.0f;
+
+    CBimax = 0; /* To avoid returning undefined lag values */
+    lag = -1;   /* To check if lag with strong enough correlation has been found */
+
+    if( prevLag > 0 ) {
+        if( Fs_kHz == 12 ) {
+            prevLag = silk_LSHIFT( prevLag, 1 ) / 3;
+        } else if( Fs_kHz == 16 ) {
+            prevLag = silk_RSHIFT( prevLag, 1 );
+        }
+        prevLag_log2 = silk_log2( (silk_float)prevLag );
+    } else {
+        prevLag_log2 = 0;
+    }
+
+    /* Set up stage 2 codebook based on number of subframes */
+    if( nb_subfr == PE_MAX_NB_SUBFR ) {
+        cbk_size   = PE_NB_CBKS_STAGE2_EXT;
+        Lag_CB_ptr = &silk_CB_lags_stage2[ 0 ][ 0 ];
+        if( Fs_kHz == 8 && complexity > SILK_PE_MIN_COMPLEX ) {
+            /* If input is 8 khz use a larger codebook here because it is last stage */
+            nb_cbk_search = PE_NB_CBKS_STAGE2_EXT;
+        } else {
+            nb_cbk_search = PE_NB_CBKS_STAGE2;
+        }
+    } else {
+        cbk_size       = PE_NB_CBKS_STAGE2_10MS;
+        Lag_CB_ptr     = &silk_CB_lags_stage2_10_ms[ 0 ][ 0 ];
+        nb_cbk_search  = PE_NB_CBKS_STAGE2_10MS;
+    }
+
+    for( k = 0; k < length_d_srch; k++ ) {
+        d = d_srch[ k ];
+        for( j = 0; j < nb_cbk_search; j++ ) {
+            CC[j] = 0.0f;
+            for( i = 0; i < nb_subfr; i++ ) {
+                /* Try all codebooks */
+                CC[ j ] += C[ i ][ d + matrix_ptr( Lag_CB_ptr, i, j, cbk_size )];
+            }
+        }
+        /* Find best codebook */
+        CCmax_new  = -1000.0f;
+        CBimax_new = 0;
+        for( i = 0; i < nb_cbk_search; i++ ) {
+            if( CC[ i ] > CCmax_new ) {
+                CCmax_new = CC[ i ];
+                CBimax_new = i;
+            }
+        }
+
+        /* Bias towards shorter lags */
+        lag_log2 = silk_log2( (silk_float)d );
+        CCmax_new_b = CCmax_new - PE_SHORTLAG_BIAS * nb_subfr * lag_log2;
+
+        /* Bias towards previous lag */
+        if( prevLag > 0 ) {
+            delta_lag_log2_sqr = lag_log2 - prevLag_log2;
+            delta_lag_log2_sqr *= delta_lag_log2_sqr;
+            CCmax_new_b -= PE_PREVLAG_BIAS * nb_subfr * (*LTPCorr) * delta_lag_log2_sqr / ( delta_lag_log2_sqr + 0.5f );
+        }
+
+        if( CCmax_new_b > CCmax_b &&                /* Find maximum biased correlation                  */
+            CCmax_new > nb_subfr * search_thres2    /* Correlation needs to be high enough to be voiced */
+        ) {
+            CCmax_b = CCmax_new_b;
+            CCmax   = CCmax_new;
+            lag     = d;
+            CBimax  = CBimax_new;
+        }
+    }
+
+    if( lag == -1 ) {
+        /* No suitable candidate found */
+        silk_memset( pitch_out, 0, PE_MAX_NB_SUBFR * sizeof(opus_int) );
+        *LTPCorr      = 0.0f;
+        *lagIndex     = 0;
+        *contourIndex = 0;
+        return 1;
+    }
+
+    /* Output normalized correlation */
+    *LTPCorr = (silk_float)( CCmax / nb_subfr );
+    silk_assert( *LTPCorr >= 0.0f );
+
+    if( Fs_kHz > 8 ) {
+        /* Search in original signal */
+
+        /* Compensate for decimation */
+        silk_assert( lag == silk_SAT16( lag ) );
+        if( Fs_kHz == 12 ) {
+            lag = silk_RSHIFT_ROUND( silk_SMULBB( lag, 3 ), 1 );
+        } else { /* Fs_kHz == 16 */
+            lag = silk_LSHIFT( lag, 1 );
+        }
+
+        lag = silk_LIMIT_int( lag, min_lag, max_lag );
+        start_lag = silk_max_int( lag - 2, min_lag );
+        end_lag   = silk_min_int( lag + 2, max_lag );
+        lag_new   = lag;                                    /* to avoid undefined lag */
+        CBimax    = 0;                                      /* to avoid undefined lag */
+
+        CCmax = -1000.0f;
+
+        /* Calculate the correlations and energies needed in stage 3 */
+        silk_P_Ana_calc_corr_st3( cross_corr_st3, frame, start_lag, sf_length, nb_subfr, complexity, arch );
+        silk_P_Ana_calc_energy_st3( energies_st3, frame, start_lag, sf_length, nb_subfr, complexity );
+
+        lag_counter = 0;
+        silk_assert( lag == silk_SAT16( lag ) );
+        contour_bias = PE_FLATCONTOUR_BIAS / lag;
+
+        /* Set up cbk parameters according to complexity setting and frame length */
+        if( nb_subfr == PE_MAX_NB_SUBFR ) {
+            nb_cbk_search = (opus_int)silk_nb_cbk_searchs_stage3[ complexity ];
+            cbk_size      = PE_NB_CBKS_STAGE3_MAX;
+            Lag_CB_ptr    = &silk_CB_lags_stage3[ 0 ][ 0 ];
+        } else {
+            nb_cbk_search = PE_NB_CBKS_STAGE3_10MS;
+            cbk_size      = PE_NB_CBKS_STAGE3_10MS;
+            Lag_CB_ptr    = &silk_CB_lags_stage3_10_ms[ 0 ][ 0 ];
+        }
+
+        target_ptr = &frame[ PE_LTP_MEM_LENGTH_MS * Fs_kHz ];
+        energy_tmp = silk_energy_FLP( target_ptr, nb_subfr * sf_length ) + 1.0;
+        for( d = start_lag; d <= end_lag; d++ ) {
+            for( j = 0; j < nb_cbk_search; j++ ) {
+                cross_corr = 0.0;
+                energy = energy_tmp;
+                for( k = 0; k < nb_subfr; k++ ) {
+                    cross_corr += cross_corr_st3[ k ][ j ][ lag_counter ];
+                    energy     +=   energies_st3[ k ][ j ][ lag_counter ];
+                }
+                if( cross_corr > 0.0 ) {
+                    CCmax_new = (silk_float)( 2 * cross_corr / energy );
+                    /* Reduce depending on flatness of contour */
+                    CCmax_new *= 1.0f - contour_bias * j;
+                } else {
+                    CCmax_new = 0.0f;
+                }
+
+                if( CCmax_new > CCmax && ( d + (opus_int)silk_CB_lags_stage3[ 0 ][ j ] ) <= max_lag ) {
+                    CCmax   = CCmax_new;
+                    lag_new = d;
+                    CBimax  = j;
+                }
+            }
+            lag_counter++;
+        }
+
+        for( k = 0; k < nb_subfr; k++ ) {
+            pitch_out[ k ] = lag_new + matrix_ptr( Lag_CB_ptr, k, CBimax, cbk_size );
+            pitch_out[ k ] = silk_LIMIT( pitch_out[ k ], min_lag, PE_MAX_LAG_MS * Fs_kHz );
+        }
+        *lagIndex = (opus_int16)( lag_new - min_lag );
+        *contourIndex = (opus_int8)CBimax;
+    } else {        /* Fs_kHz == 8 */
+        /* Save Lags */
+        for( k = 0; k < nb_subfr; k++ ) {
+            pitch_out[ k ] = lag + matrix_ptr( Lag_CB_ptr, k, CBimax, cbk_size );
+            pitch_out[ k ] = silk_LIMIT( pitch_out[ k ], min_lag_8kHz, PE_MAX_LAG_MS * 8 );
+        }
+        *lagIndex = (opus_int16)( lag - min_lag_8kHz );
+        *contourIndex = (opus_int8)CBimax;
+    }
+    silk_assert( *lagIndex >= 0 );
+    /* return as voiced */
+    return 0;
+}
+
+/***********************************************************************
+ * Calculates the correlations used in stage 3 search. In order to cover
+ * the whole lag codebook for all the searched offset lags (lag +- 2),
+ * the following correlations are needed in each sub frame:
+ *
+ * sf1: lag range [-8,...,7] total 16 correlations
+ * sf2: lag range [-4,...,4] total 9 correlations
+ * sf3: lag range [-3,....4] total 8 correltions
+ * sf4: lag range [-6,....8] total 15 correlations
+ *
+ * In total 48 correlations. The direct implementation computed in worst
+ * case 4*12*5 = 240 correlations, but more likely around 120.
+ ***********************************************************************/
+static void silk_P_Ana_calc_corr_st3(
+    silk_float cross_corr_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ], /* O 3 DIM correlation array */
+    const silk_float    frame[],            /* I vector to correlate                                            */
+    opus_int            start_lag,          /* I start lag                                                      */
+    opus_int            sf_length,          /* I sub frame length                                               */
+    opus_int            nb_subfr,           /* I number of subframes                                            */
+    opus_int            complexity,         /* I Complexity setting                                             */
+    int                 arch                /* I Run-time architecture                                          */
+)
+{
+    const silk_float *target_ptr;
+    opus_int   i, j, k, lag_counter, lag_low, lag_high;
+    opus_int   nb_cbk_search, delta, idx, cbk_size;
+    silk_float scratch_mem[ SCRATCH_SIZE ];
+    opus_val32 xcorr[ SCRATCH_SIZE ];
+    const opus_int8 *Lag_range_ptr, *Lag_CB_ptr;
+
+    silk_assert( complexity >= SILK_PE_MIN_COMPLEX );
+    silk_assert( complexity <= SILK_PE_MAX_COMPLEX );
+
+    if( nb_subfr == PE_MAX_NB_SUBFR ) {
+        Lag_range_ptr = &silk_Lag_range_stage3[ complexity ][ 0 ][ 0 ];
+        Lag_CB_ptr    = &silk_CB_lags_stage3[ 0 ][ 0 ];
+        nb_cbk_search = silk_nb_cbk_searchs_stage3[ complexity ];
+        cbk_size      = PE_NB_CBKS_STAGE3_MAX;
+    } else {
+        silk_assert( nb_subfr == PE_MAX_NB_SUBFR >> 1);
+        Lag_range_ptr = &silk_Lag_range_stage3_10_ms[ 0 ][ 0 ];
+        Lag_CB_ptr    = &silk_CB_lags_stage3_10_ms[ 0 ][ 0 ];
+        nb_cbk_search = PE_NB_CBKS_STAGE3_10MS;
+        cbk_size      = PE_NB_CBKS_STAGE3_10MS;
+    }
+
+    target_ptr = &frame[ silk_LSHIFT( sf_length, 2 ) ]; /* Pointer to middle of frame */
+    for( k = 0; k < nb_subfr; k++ ) {
+        lag_counter = 0;
+
+        /* Calculate the correlations for each subframe */
+        lag_low  = matrix_ptr( Lag_range_ptr, k, 0, 2 );
+        lag_high = matrix_ptr( Lag_range_ptr, k, 1, 2 );
+        silk_assert(lag_high-lag_low+1 <= SCRATCH_SIZE);
+        celt_pitch_xcorr( target_ptr, target_ptr - start_lag - lag_high, xcorr, sf_length, lag_high - lag_low + 1, arch );
+        for( j = lag_low; j <= lag_high; j++ ) {
+            silk_assert( lag_counter < SCRATCH_SIZE );
+            scratch_mem[ lag_counter ] = xcorr[ lag_high - j ];
+            lag_counter++;
+        }
+
+        delta = matrix_ptr( Lag_range_ptr, k, 0, 2 );
+        for( i = 0; i < nb_cbk_search; i++ ) {
+            /* Fill out the 3 dim array that stores the correlations for */
+            /* each code_book vector for each start lag */
+            idx = matrix_ptr( Lag_CB_ptr, k, i, cbk_size ) - delta;
+            for( j = 0; j < PE_NB_STAGE3_LAGS; j++ ) {
+                silk_assert( idx + j < SCRATCH_SIZE );
+                silk_assert( idx + j < lag_counter );
+                cross_corr_st3[ k ][ i ][ j ] = scratch_mem[ idx + j ];
+            }
+        }
+        target_ptr += sf_length;
+    }
+}
+
+/********************************************************************/
+/* Calculate the energies for first two subframes. The energies are */
+/* calculated recursively.                                          */
+/********************************************************************/
+static void silk_P_Ana_calc_energy_st3(
+    silk_float energies_st3[ PE_MAX_NB_SUBFR ][ PE_NB_CBKS_STAGE3_MAX ][ PE_NB_STAGE3_LAGS ], /* O 3 DIM correlation array */
+    const silk_float    frame[],            /* I vector to correlate                                            */
+    opus_int            start_lag,          /* I start lag                                                      */
+    opus_int            sf_length,          /* I sub frame length                                               */
+    opus_int            nb_subfr,           /* I number of subframes                                            */
+    opus_int            complexity          /* I Complexity setting                                             */
+)
+{
+    const silk_float *target_ptr, *basis_ptr;
+    double    energy;
+    opus_int   k, i, j, lag_counter;
+    opus_int   nb_cbk_search, delta, idx, cbk_size, lag_diff;
+    silk_float scratch_mem[ SCRATCH_SIZE ];
+    const opus_int8 *Lag_range_ptr, *Lag_CB_ptr;
+
+    silk_assert( complexity >= SILK_PE_MIN_COMPLEX );
+    silk_assert( complexity <= SILK_PE_MAX_COMPLEX );
+
+    if( nb_subfr == PE_MAX_NB_SUBFR ) {
+        Lag_range_ptr = &silk_Lag_range_stage3[ complexity ][ 0 ][ 0 ];
+        Lag_CB_ptr    = &silk_CB_lags_stage3[ 0 ][ 0 ];
+        nb_cbk_search = silk_nb_cbk_searchs_stage3[ complexity ];
+        cbk_size      = PE_NB_CBKS_STAGE3_MAX;
+    } else {
+        silk_assert( nb_subfr == PE_MAX_NB_SUBFR >> 1);
+        Lag_range_ptr = &silk_Lag_range_stage3_10_ms[ 0 ][ 0 ];
+        Lag_CB_ptr    = &silk_CB_lags_stage3_10_ms[ 0 ][ 0 ];
+        nb_cbk_search = PE_NB_CBKS_STAGE3_10MS;
+        cbk_size      = PE_NB_CBKS_STAGE3_10MS;
+    }
+
+    target_ptr = &frame[ silk_LSHIFT( sf_length, 2 ) ];
+    for( k = 0; k < nb_subfr; k++ ) {
+        lag_counter = 0;
+
+        /* Calculate the energy for first lag */
+        basis_ptr = target_ptr - ( start_lag + matrix_ptr( Lag_range_ptr, k, 0, 2 ) );
+        energy = silk_energy_FLP( basis_ptr, sf_length ) + 1e-3;
+        silk_assert( energy >= 0.0 );
+        scratch_mem[lag_counter] = (silk_float)energy;
+        lag_counter++;
+
+        lag_diff = ( matrix_ptr( Lag_range_ptr, k, 1, 2 ) -  matrix_ptr( Lag_range_ptr, k, 0, 2 ) + 1 );
+        for( i = 1; i < lag_diff; i++ ) {
+            /* remove part outside new window */
+            energy -= basis_ptr[sf_length - i] * (double)basis_ptr[sf_length - i];
+            silk_assert( energy >= 0.0 );
+
+            /* add part that comes into window */
+            energy += basis_ptr[ -i ] * (double)basis_ptr[ -i ];
+            silk_assert( energy >= 0.0 );
+            silk_assert( lag_counter < SCRATCH_SIZE );
+            scratch_mem[lag_counter] = (silk_float)energy;
+            lag_counter++;
+        }
+
+        delta = matrix_ptr( Lag_range_ptr, k, 0, 2 );
+        for( i = 0; i < nb_cbk_search; i++ ) {
+            /* Fill out the 3 dim array that stores the correlations for    */
+            /* each code_book vector for each start lag                     */
+            idx = matrix_ptr( Lag_CB_ptr, k, i, cbk_size ) - delta;
+            for( j = 0; j < PE_NB_STAGE3_LAGS; j++ ) {
+                silk_assert( idx + j < SCRATCH_SIZE );
+                silk_assert( idx + j < lag_counter );
+                energies_st3[ k ][ i ][ j ] = scratch_mem[ idx + j ];
+                silk_assert( energies_st3[ k ][ i ][ j ] >= 0.0f );
+            }
+        }
+        target_ptr += sf_length;
+    }
+}