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 "main.h"
      33             : 
      34             : /* Quantize mid/side predictors */
      35           0 : void silk_stereo_quant_pred(
      36             :     opus_int32                  pred_Q13[],                     /* I/O  Predictors (out: quantized)                 */
      37             :     opus_int8                   ix[ 2 ][ 3 ]                    /* O    Quantization indices                        */
      38             : )
      39             : {
      40             :     opus_int   i, j, n;
      41           0 :     opus_int32 low_Q13, step_Q13, lvl_Q13, err_min_Q13, err_Q13, quant_pred_Q13 = 0;
      42             : 
      43             :     /* Quantize */
      44           0 :     for( n = 0; n < 2; n++ ) {
      45             :         /* Brute-force search over quantization levels */
      46           0 :         err_min_Q13 = silk_int32_MAX;
      47           0 :         for( i = 0; i < STEREO_QUANT_TAB_SIZE - 1; i++ ) {
      48           0 :             low_Q13 = silk_stereo_pred_quant_Q13[ i ];
      49           0 :             step_Q13 = silk_SMULWB( silk_stereo_pred_quant_Q13[ i + 1 ] - low_Q13,
      50             :                 SILK_FIX_CONST( 0.5 / STEREO_QUANT_SUB_STEPS, 16 ) );
      51           0 :             for( j = 0; j < STEREO_QUANT_SUB_STEPS; j++ ) {
      52           0 :                 lvl_Q13 = silk_SMLABB( low_Q13, step_Q13, 2 * j + 1 );
      53           0 :                 err_Q13 = silk_abs( pred_Q13[ n ] - lvl_Q13 );
      54           0 :                 if( err_Q13 < err_min_Q13 ) {
      55           0 :                     err_min_Q13 = err_Q13;
      56           0 :                     quant_pred_Q13 = lvl_Q13;
      57           0 :                     ix[ n ][ 0 ] = i;
      58           0 :                     ix[ n ][ 1 ] = j;
      59             :                 } else {
      60             :                     /* Error increasing, so we're past the optimum */
      61           0 :                     goto done;
      62             :                 }
      63             :             }
      64             :         }
      65             :         done:
      66           0 :         ix[ n ][ 2 ]  = silk_DIV32_16( ix[ n ][ 0 ], 3 );
      67           0 :         ix[ n ][ 0 ] -= ix[ n ][ 2 ] * 3;
      68           0 :         pred_Q13[ n ] = quant_pred_Q13;
      69             :     }
      70             : 
      71             :     /* Subtract second from first predictor (helps when actually applying these) */
      72           0 :     pred_Q13[ 0 ] -= pred_Q13[ 1 ];
      73           0 : }