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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 #include "main_FIX.h"
     33 #include "stack_alloc.h"
     34 #include "tuning_parameters.h"
     35 
     36 /* Find pitch lags */
     37 void silk_find_pitch_lags_FIX(
     38     silk_encoder_state_FIX          *psEnc,                                 /* I/O  encoder state                                                               */
     39     silk_encoder_control_FIX        *psEncCtrl,                             /* I/O  encoder control                                                             */
     40     opus_int16                      res[],                                  /* O    residual                                                                    */
     41     const opus_int16                x[],                                    /* I    Speech signal                                                               */
     42     int                             arch                                    /* I    Run-time architecture                                                       */
     43 )
     44 {
     45     opus_int   buf_len, i, scale;
     46     opus_int32 thrhld_Q13, res_nrg;
     47     const opus_int16 *x_buf, *x_buf_ptr;
     48     VARDECL( opus_int16, Wsig );
     49     opus_int16 *Wsig_ptr;
     50     opus_int32 auto_corr[ MAX_FIND_PITCH_LPC_ORDER + 1 ];
     51     opus_int16 rc_Q15[    MAX_FIND_PITCH_LPC_ORDER ];
     52     opus_int32 A_Q24[     MAX_FIND_PITCH_LPC_ORDER ];
     53     opus_int16 A_Q12[     MAX_FIND_PITCH_LPC_ORDER ];
     54     SAVE_STACK;
     55 
     56     /******************************************/
     57     /* Set up buffer lengths etc based on Fs  */
     58     /******************************************/
     59     buf_len = psEnc->sCmn.la_pitch + psEnc->sCmn.frame_length + psEnc->sCmn.ltp_mem_length;
     60 
     61     /* Safety check */
     62     silk_assert( buf_len >= psEnc->sCmn.pitch_LPC_win_length );
     63 
     64     x_buf = x - psEnc->sCmn.ltp_mem_length;
     65 
     66     /*************************************/
     67     /* Estimate LPC AR coefficients      */
     68     /*************************************/
     69 
     70     /* Calculate windowed signal */
     71 
     72     ALLOC( Wsig, psEnc->sCmn.pitch_LPC_win_length, opus_int16 );
     73 
     74     /* First LA_LTP samples */
     75     x_buf_ptr = x_buf + buf_len - psEnc->sCmn.pitch_LPC_win_length;
     76     Wsig_ptr  = Wsig;
     77     silk_apply_sine_window( Wsig_ptr, x_buf_ptr, 1, psEnc->sCmn.la_pitch );
     78 
     79     /* Middle un - windowed samples */
     80     Wsig_ptr  += psEnc->sCmn.la_pitch;
     81     x_buf_ptr += psEnc->sCmn.la_pitch;
     82     silk_memcpy( Wsig_ptr, x_buf_ptr, ( psEnc->sCmn.pitch_LPC_win_length - silk_LSHIFT( psEnc->sCmn.la_pitch, 1 ) ) * sizeof( opus_int16 ) );
     83 
     84     /* Last LA_LTP samples */
     85     Wsig_ptr  += psEnc->sCmn.pitch_LPC_win_length - silk_LSHIFT( psEnc->sCmn.la_pitch, 1 );
     86     x_buf_ptr += psEnc->sCmn.pitch_LPC_win_length - silk_LSHIFT( psEnc->sCmn.la_pitch, 1 );
     87     silk_apply_sine_window( Wsig_ptr, x_buf_ptr, 2, psEnc->sCmn.la_pitch );
     88 
     89     /* Calculate autocorrelation sequence */
     90     silk_autocorr( auto_corr, &scale, Wsig, psEnc->sCmn.pitch_LPC_win_length, psEnc->sCmn.pitchEstimationLPCOrder + 1, arch );
     91 
     92     /* Add white noise, as fraction of energy */
     93     auto_corr[ 0 ] = silk_SMLAWB( auto_corr[ 0 ], auto_corr[ 0 ], SILK_FIX_CONST( FIND_PITCH_WHITE_NOISE_FRACTION, 16 ) ) + 1;
     94 
     95     /* Calculate the reflection coefficients using schur */
     96     res_nrg = silk_schur( rc_Q15, auto_corr, psEnc->sCmn.pitchEstimationLPCOrder );
     97 
     98     /* Prediction gain */
     99     psEncCtrl->predGain_Q16 = silk_DIV32_varQ( auto_corr[ 0 ], silk_max_int( res_nrg, 1 ), 16 );
    100 
    101     /* Convert reflection coefficients to prediction coefficients */
    102     silk_k2a( A_Q24, rc_Q15, psEnc->sCmn.pitchEstimationLPCOrder );
    103 
    104     /* Convert From 32 bit Q24 to 16 bit Q12 coefs */
    105     for( i = 0; i < psEnc->sCmn.pitchEstimationLPCOrder; i++ ) {
    106         A_Q12[ i ] = (opus_int16)silk_SAT16( silk_RSHIFT( A_Q24[ i ], 12 ) );
    107     }
    108 
    109     /* Do BWE */
    110     silk_bwexpander( A_Q12, psEnc->sCmn.pitchEstimationLPCOrder, SILK_FIX_CONST( FIND_PITCH_BANDWIDTH_EXPANSION, 16 ) );
    111 
    112     /*****************************************/
    113     /* LPC analysis filtering                */
    114     /*****************************************/
    115     silk_LPC_analysis_filter( res, x_buf, A_Q12, buf_len, psEnc->sCmn.pitchEstimationLPCOrder, psEnc->sCmn.arch );
    116 
    117     if( psEnc->sCmn.indices.signalType != TYPE_NO_VOICE_ACTIVITY && psEnc->sCmn.first_frame_after_reset == 0 ) {
    118         /* Threshold for pitch estimator */
    119         thrhld_Q13 = SILK_FIX_CONST( 0.6, 13 );
    120         thrhld_Q13 = silk_SMLABB( thrhld_Q13, SILK_FIX_CONST( -0.004, 13 ), psEnc->sCmn.pitchEstimationLPCOrder );
    121         thrhld_Q13 = silk_SMLAWB( thrhld_Q13, SILK_FIX_CONST( -0.1,   21  ), psEnc->sCmn.speech_activity_Q8 );
    122         thrhld_Q13 = silk_SMLABB( thrhld_Q13, SILK_FIX_CONST( -0.15,  13 ), silk_RSHIFT( psEnc->sCmn.prevSignalType, 1 ) );
    123         thrhld_Q13 = silk_SMLAWB( thrhld_Q13, SILK_FIX_CONST( -0.1,   14 ), psEnc->sCmn.input_tilt_Q15 );
    124         thrhld_Q13 = silk_SAT16(  thrhld_Q13 );
    125 
    126         /*****************************************/
    127         /* Call pitch estimator                  */
    128         /*****************************************/
    129         if( silk_pitch_analysis_core( res, psEncCtrl->pitchL, &psEnc->sCmn.indices.lagIndex, &psEnc->sCmn.indices.contourIndex,
    130                 &psEnc->LTPCorr_Q15, psEnc->sCmn.prevLag, psEnc->sCmn.pitchEstimationThreshold_Q16,
    131                 (opus_int)thrhld_Q13, psEnc->sCmn.fs_kHz, psEnc->sCmn.pitchEstimationComplexity, psEnc->sCmn.nb_subfr,
    132                 psEnc->sCmn.arch) == 0 )
    133         {
    134             psEnc->sCmn.indices.signalType = TYPE_VOICED;
    135         } else {
    136             psEnc->sCmn.indices.signalType = TYPE_UNVOICED;
    137         }
    138     } else {
    139         silk_memset( psEncCtrl->pitchL, 0, sizeof( psEncCtrl->pitchL ) );
    140         psEnc->sCmn.indices.lagIndex = 0;
    141         psEnc->sCmn.indices.contourIndex = 0;
    142         psEnc->LTPCorr_Q15 = 0;
    143     }
    144     RESTORE_STACK;
    145 }
    146