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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 
     35 void silk_find_pred_coefs_FIX(
     36     silk_encoder_state_FIX          *psEnc,                                 /* I/O  encoder state                                                               */
     37     silk_encoder_control_FIX        *psEncCtrl,                             /* I/O  encoder control                                                             */
     38     const opus_int16                res_pitch[],                            /* I    Residual from pitch analysis                                                */
     39     const opus_int16                x[],                                    /* I    Speech signal                                                               */
     40     opus_int                        condCoding                              /* I    The type of conditional coding to use                                       */
     41 )
     42 {
     43     opus_int         i;
     44     opus_int32       invGains_Q16[ MAX_NB_SUBFR ], local_gains[ MAX_NB_SUBFR ], Wght_Q15[ MAX_NB_SUBFR ];
     45     opus_int16       NLSF_Q15[ MAX_LPC_ORDER ];
     46     const opus_int16 *x_ptr;
     47     opus_int16       *x_pre_ptr;
     48     VARDECL( opus_int16, LPC_in_pre );
     49     opus_int32       tmp, min_gain_Q16, minInvGain_Q30;
     50     opus_int         LTP_corrs_rshift[ MAX_NB_SUBFR ];
     51     SAVE_STACK;
     52 
     53     /* weighting for weighted least squares */
     54     min_gain_Q16 = silk_int32_MAX >> 6;
     55     for( i = 0; i < psEnc->sCmn.nb_subfr; i++ ) {
     56         min_gain_Q16 = silk_min( min_gain_Q16, psEncCtrl->Gains_Q16[ i ] );
     57     }
     58     for( i = 0; i < psEnc->sCmn.nb_subfr; i++ ) {
     59         /* Divide to Q16 */
     60         silk_assert( psEncCtrl->Gains_Q16[ i ] > 0 );
     61         /* Invert and normalize gains, and ensure that maximum invGains_Q16 is within range of a 16 bit int */
     62         invGains_Q16[ i ] = silk_DIV32_varQ( min_gain_Q16, psEncCtrl->Gains_Q16[ i ], 16 - 2 );
     63 
     64         /* Ensure Wght_Q15 a minimum value 1 */
     65         invGains_Q16[ i ] = silk_max( invGains_Q16[ i ], 363 );
     66 
     67         /* Square the inverted gains */
     68         silk_assert( invGains_Q16[ i ] == silk_SAT16( invGains_Q16[ i ] ) );
     69         tmp = silk_SMULWB( invGains_Q16[ i ], invGains_Q16[ i ] );
     70         Wght_Q15[ i ] = silk_RSHIFT( tmp, 1 );
     71 
     72         /* Invert the inverted and normalized gains */
     73         local_gains[ i ] = silk_DIV32( ( (opus_int32)1 << 16 ), invGains_Q16[ i ] );
     74     }
     75 
     76     ALLOC( LPC_in_pre,
     77            psEnc->sCmn.nb_subfr * psEnc->sCmn.predictLPCOrder
     78                + psEnc->sCmn.frame_length, opus_int16 );
     79     if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
     80         VARDECL( opus_int32, WLTP );
     81 
     82         /**********/
     83         /* VOICED */
     84         /**********/
     85         silk_assert( psEnc->sCmn.ltp_mem_length - psEnc->sCmn.predictLPCOrder >= psEncCtrl->pitchL[ 0 ] + LTP_ORDER / 2 );
     86 
     87         ALLOC( WLTP, psEnc->sCmn.nb_subfr * LTP_ORDER * LTP_ORDER, opus_int32 );
     88 
     89         /* LTP analysis */
     90         silk_find_LTP_FIX( psEncCtrl->LTPCoef_Q14, WLTP, &psEncCtrl->LTPredCodGain_Q7,
     91             res_pitch, psEncCtrl->pitchL, Wght_Q15, psEnc->sCmn.subfr_length,
     92             psEnc->sCmn.nb_subfr, psEnc->sCmn.ltp_mem_length, LTP_corrs_rshift );
     93 
     94         /* Quantize LTP gain parameters */
     95         silk_quant_LTP_gains( psEncCtrl->LTPCoef_Q14, psEnc->sCmn.indices.LTPIndex, &psEnc->sCmn.indices.PERIndex,
     96             &psEnc->sCmn.sum_log_gain_Q7, WLTP, psEnc->sCmn.mu_LTP_Q9, psEnc->sCmn.LTPQuantLowComplexity, psEnc->sCmn.nb_subfr);
     97 
     98         /* Control LTP scaling */
     99         silk_LTP_scale_ctrl_FIX( psEnc, psEncCtrl, condCoding );
    100 
    101         /* Create LTP residual */
    102         silk_LTP_analysis_filter_FIX( LPC_in_pre, x - psEnc->sCmn.predictLPCOrder, psEncCtrl->LTPCoef_Q14,
    103             psEncCtrl->pitchL, invGains_Q16, psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr, psEnc->sCmn.predictLPCOrder );
    104 
    105     } else {
    106         /************/
    107         /* UNVOICED */
    108         /************/
    109         /* Create signal with prepended subframes, scaled by inverse gains */
    110         x_ptr     = x - psEnc->sCmn.predictLPCOrder;
    111         x_pre_ptr = LPC_in_pre;
    112         for( i = 0; i < psEnc->sCmn.nb_subfr; i++ ) {
    113             silk_scale_copy_vector16( x_pre_ptr, x_ptr, invGains_Q16[ i ],
    114                 psEnc->sCmn.subfr_length + psEnc->sCmn.predictLPCOrder );
    115             x_pre_ptr += psEnc->sCmn.subfr_length + psEnc->sCmn.predictLPCOrder;
    116             x_ptr     += psEnc->sCmn.subfr_length;
    117         }
    118 
    119         silk_memset( psEncCtrl->LTPCoef_Q14, 0, psEnc->sCmn.nb_subfr * LTP_ORDER * sizeof( opus_int16 ) );
    120         psEncCtrl->LTPredCodGain_Q7 = 0;
    121 		psEnc->sCmn.sum_log_gain_Q7 = 0;
    122     }
    123 
    124     /* Limit on total predictive coding gain */
    125     if( psEnc->sCmn.first_frame_after_reset ) {
    126         minInvGain_Q30 = SILK_FIX_CONST( 1.0f / MAX_PREDICTION_POWER_GAIN_AFTER_RESET, 30 );
    127     } else {
    128         minInvGain_Q30 = silk_log2lin( silk_SMLAWB( 16 << 7, (opus_int32)psEncCtrl->LTPredCodGain_Q7, SILK_FIX_CONST( 1.0 / 3, 16 ) ) );      /* Q16 */
    129         minInvGain_Q30 = silk_DIV32_varQ( minInvGain_Q30,
    130             silk_SMULWW( SILK_FIX_CONST( MAX_PREDICTION_POWER_GAIN, 0 ),
    131                 silk_SMLAWB( SILK_FIX_CONST( 0.25, 18 ), SILK_FIX_CONST( 0.75, 18 ), psEncCtrl->coding_quality_Q14 ) ), 14 );
    132     }
    133 
    134     /* LPC_in_pre contains the LTP-filtered input for voiced, and the unfiltered input for unvoiced */
    135     silk_find_LPC_FIX( &psEnc->sCmn, NLSF_Q15, LPC_in_pre, minInvGain_Q30 );
    136 
    137     /* Quantize LSFs */
    138     silk_process_NLSFs( &psEnc->sCmn, psEncCtrl->PredCoef_Q12, NLSF_Q15, psEnc->sCmn.prev_NLSFq_Q15 );
    139 
    140     /* Calculate residual energy using quantized LPC coefficients */
    141     silk_residual_energy_FIX( psEncCtrl->ResNrg, psEncCtrl->ResNrgQ, LPC_in_pre, psEncCtrl->PredCoef_Q12, local_gains,
    142         psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr, psEnc->sCmn.predictLPCOrder );
    143 
    144     /* Copy to prediction struct for use in next frame for interpolation */
    145     silk_memcpy( psEnc->sCmn.prev_NLSFq_Q15, NLSF_Q15, sizeof( psEnc->sCmn.prev_NLSFq_Q15 ) );
    146     RESTORE_STACK;
    147 }
    148