Line data    Source code

       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
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      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_FLP.h"
      33             : 
      34           0 : void silk_LTP_analysis_filter_FLP(
      35             :     silk_float                      *LTP_res,                           /* O    LTP res MAX_NB_SUBFR*(pre_lgth+subfr_lngth) */
      36             :     const silk_float                *x,                                 /* I    Input signal, with preceding samples        */
      37             :     const silk_float                B[ LTP_ORDER * MAX_NB_SUBFR ],      /* I    LTP coefficients for each subframe          */
      38             :     const opus_int                  pitchL[   MAX_NB_SUBFR ],           /* I    Pitch lags                                  */
      39             :     const silk_float                invGains[ MAX_NB_SUBFR ],           /* I    Inverse quantization gains                  */
      40             :     const opus_int                  subfr_length,                       /* I    Length of each subframe                     */
      41             :     const opus_int                  nb_subfr,                           /* I    number of subframes                         */
      42             :     const opus_int                  pre_length                          /* I    Preceding samples for each subframe         */
      43             : )
      44             : {
      45             :     const silk_float *x_ptr, *x_lag_ptr;
      46             :     silk_float   Btmp[ LTP_ORDER ];
      47             :     silk_float   *LTP_res_ptr;
      48             :     silk_float   inv_gain;
      49             :     opus_int     k, i, j;
      50             : 
      51           0 :     x_ptr = x;
      52           0 :     LTP_res_ptr = LTP_res;
      53           0 :     for( k = 0; k < nb_subfr; k++ ) {
      54           0 :         x_lag_ptr = x_ptr - pitchL[ k ];
      55           0 :         inv_gain = invGains[ k ];
      56           0 :         for( i = 0; i < LTP_ORDER; i++ ) {
      57           0 :             Btmp[ i ] = B[ k * LTP_ORDER + i ];
      58             :         }
      59             : 
      60             :         /* LTP analysis FIR filter */
      61           0 :         for( i = 0; i < subfr_length + pre_length; i++ ) {
      62           0 :             LTP_res_ptr[ i ] = x_ptr[ i ];
      63             :             /* Subtract long-term prediction */
      64           0 :             for( j = 0; j < LTP_ORDER; j++ ) {
      65           0 :                 LTP_res_ptr[ i ] -= Btmp[ j ] * x_lag_ptr[ LTP_ORDER / 2 - j ];
      66             :             }
      67           0 :             LTP_res_ptr[ i ] *= inv_gain;
      68           0 :             x_lag_ptr++;
      69             :         }
      70             : 
      71             :         /* Update pointers */
      72           0 :         LTP_res_ptr += subfr_length + pre_length;
      73           0 :         x_ptr       += subfr_length;
      74             :     }
      75           0 : }