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             : /* Autocorrelations for a warped frequency axis */
      35           0 : void silk_warped_autocorrelation_FLP(
      36             :     silk_float                      *corr,                              /* O    Result [order + 1]                          */
      37             :     const silk_float                *input,                             /* I    Input data to correlate                     */
      38             :     const silk_float                warping,                            /* I    Warping coefficient                         */
      39             :     const opus_int                  length,                             /* I    Length of input                             */
      40             :     const opus_int                  order                               /* I    Correlation order (even)                    */
      41             : )
      42             : {
      43             :     opus_int    n, i;
      44             :     double      tmp1, tmp2;
      45           0 :     double      state[ MAX_SHAPE_LPC_ORDER + 1 ] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };
      46           0 :     double      C[     MAX_SHAPE_LPC_ORDER + 1 ] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };
      47             : 
      48             :     /* Order must be even */
      49           0 :     silk_assert( ( order & 1 ) == 0 );
      50             : 
      51             :     /* Loop over samples */
      52           0 :     for( n = 0; n < length; n++ ) {
      53           0 :         tmp1 = input[ n ];
      54             :         /* Loop over allpass sections */
      55           0 :         for( i = 0; i < order; i += 2 ) {
      56             :             /* Output of allpass section */
      57           0 :             tmp2 = state[ i ] + warping * ( state[ i + 1 ] - tmp1 );
      58           0 :             state[ i ] = tmp1;
      59           0 :             C[ i ] += state[ 0 ] * tmp1;
      60             :             /* Output of allpass section */
      61           0 :             tmp1 = state[ i + 1 ] + warping * ( state[ i + 2 ] - tmp2 );
      62           0 :             state[ i + 1 ] = tmp2;
      63           0 :             C[ i + 1 ] += state[ 0 ] * tmp2;
      64             :         }
      65           0 :         state[ order ] = tmp1;
      66           0 :         C[ order ] += state[ 0 ] * tmp1;
      67             :     }
      68             : 
      69             :     /* Copy correlations in silk_float output format */
      70           0 :     for( i = 0; i < order + 1; i++ ) {
      71           0 :         corr[ i ] = ( silk_float )C[ i ];
      72             :     }
      73           0 : }