1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libopus/silk/stereo_quant_pred.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,73 @@
1.4 +/***********************************************************************
1.5 +Copyright (c) 2006-2011, Skype Limited. All rights reserved.
1.6 +Redistribution and use in source and binary forms, with or without
1.7 +modification, are permitted provided that the following conditions
1.8 +are met:
1.9 +- Redistributions of source code must retain the above copyright notice,
1.10 +this list of conditions and the following disclaimer.
1.11 +- Redistributions in binary form must reproduce the above copyright
1.12 +notice, this list of conditions and the following disclaimer in the
1.13 +documentation and/or other materials provided with the distribution.
1.14 +- Neither the name of Internet Society, IETF or IETF Trust, nor the
1.15 +names of specific contributors, may be used to endorse or promote
1.16 +products derived from this software without specific prior written
1.17 +permission.
1.18 +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
1.19 +AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1.20 +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1.21 +ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
1.22 +LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
1.23 +CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
1.24 +SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
1.25 +INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
1.26 +CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
1.27 +ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
1.28 +POSSIBILITY OF SUCH DAMAGE.
1.29 +***********************************************************************/
1.30 +
1.31 +#ifdef HAVE_CONFIG_H
1.32 +#include "config.h"
1.33 +#endif
1.34 +
1.35 +#include "main.h"
1.36 +
1.37 +/* Quantize mid/side predictors */
1.38 +void silk_stereo_quant_pred(
1.39 + opus_int32 pred_Q13[], /* I/O Predictors (out: quantized) */
1.40 + opus_int8 ix[ 2 ][ 3 ] /* O Quantization indices */
1.41 +)
1.42 +{
1.43 + opus_int i, j, n;
1.44 + opus_int32 low_Q13, step_Q13, lvl_Q13, err_min_Q13, err_Q13, quant_pred_Q13 = 0;
1.45 +
1.46 + /* Quantize */
1.47 + for( n = 0; n < 2; n++ ) {
1.48 + /* Brute-force search over quantization levels */
1.49 + err_min_Q13 = silk_int32_MAX;
1.50 + for( i = 0; i < STEREO_QUANT_TAB_SIZE - 1; i++ ) {
1.51 + low_Q13 = silk_stereo_pred_quant_Q13[ i ];
1.52 + step_Q13 = silk_SMULWB( silk_stereo_pred_quant_Q13[ i + 1 ] - low_Q13,
1.53 + SILK_FIX_CONST( 0.5 / STEREO_QUANT_SUB_STEPS, 16 ) );
1.54 + for( j = 0; j < STEREO_QUANT_SUB_STEPS; j++ ) {
1.55 + lvl_Q13 = silk_SMLABB( low_Q13, step_Q13, 2 * j + 1 );
1.56 + err_Q13 = silk_abs( pred_Q13[ n ] - lvl_Q13 );
1.57 + if( err_Q13 < err_min_Q13 ) {
1.58 + err_min_Q13 = err_Q13;
1.59 + quant_pred_Q13 = lvl_Q13;
1.60 + ix[ n ][ 0 ] = i;
1.61 + ix[ n ][ 1 ] = j;
1.62 + } else {
1.63 + /* Error increasing, so we're past the optimum */
1.64 + goto done;
1.65 + }
1.66 + }
1.67 + }
1.68 + done:
1.69 + ix[ n ][ 2 ] = silk_DIV32_16( ix[ n ][ 0 ], 3 );
1.70 + ix[ n ][ 0 ] -= ix[ n ][ 2 ] * 3;
1.71 + pred_Q13[ n ] = quant_pred_Q13;
1.72 + }
1.73 +
1.74 + /* Subtract second from first predictor (helps when actually applying these) */
1.75 + pred_Q13[ 0 ] -= pred_Q13[ 1 ];
1.76 +}
