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
      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 "SigProc_FIX.h"
      33             : #include "resampler_private.h"
      34             : 
      35             : /* Second order AR filter with single delay elements */
      36           0 : void silk_resampler_private_AR2(
      37             :     opus_int32                      S[],            /* I/O  State vector [ 2 ]          */
      38             :     opus_int32                      out_Q8[],       /* O    Output signal               */
      39             :     const opus_int16                in[],           /* I    Input signal                */
      40             :     const opus_int16                A_Q14[],        /* I    AR coefficients, Q14        */
      41             :     opus_int32                      len             /* I    Signal length               */
      42             : )
      43             : {
      44             :     opus_int32    k;
      45             :     opus_int32    out32;
      46             : 
      47           0 :     for( k = 0; k < len; k++ ) {
      48           0 :         out32       = silk_ADD_LSHIFT32( S[ 0 ], (opus_int32)in[ k ], 8 );
      49           0 :         out_Q8[ k ] = out32;
      50           0 :         out32       = silk_LSHIFT( out32, 2 );
      51           0 :         S[ 0 ]      = silk_SMLAWB( S[ 1 ], out32, A_Q14[ 0 ] );
      52           0 :         S[ 1 ]      = silk_SMULWB( out32, A_Q14[ 1 ] );
      53             :     }
      54           0 : }
      55             :