1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libopus/silk/fixed/schur64_FIX.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,92 @@
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 "SigProc_FIX.h"
1.36 +
1.37 +/* Slower than schur(), but more accurate. */
1.38 +/* Uses SMULL(), available on armv4 */
1.39 +opus_int32 silk_schur64( /* O returns residual energy */
1.40 + opus_int32 rc_Q16[], /* O Reflection coefficients [order] Q16 */
1.41 + const opus_int32 c[], /* I Correlations [order+1] */
1.42 + opus_int32 order /* I Prediction order */
1.43 +)
1.44 +{
1.45 + opus_int k, n;
1.46 + opus_int32 C[ SILK_MAX_ORDER_LPC + 1 ][ 2 ];
1.47 + opus_int32 Ctmp1_Q30, Ctmp2_Q30, rc_tmp_Q31;
1.48 +
1.49 + silk_assert( order==6||order==8||order==10||order==12||order==14||order==16 );
1.50 +
1.51 + /* Check for invalid input */
1.52 + if( c[ 0 ] <= 0 ) {
1.53 + silk_memset( rc_Q16, 0, order * sizeof( opus_int32 ) );
1.54 + return 0;
1.55 + }
1.56 +
1.57 + for( k = 0; k < order + 1; k++ ) {
1.58 + C[ k ][ 0 ] = C[ k ][ 1 ] = c[ k ];
1.59 + }
1.60 +
1.61 + for( k = 0; k < order; k++ ) {
1.62 + /* Check that we won't be getting an unstable rc, otherwise stop here. */
1.63 + if (silk_abs_int32(C[ k + 1 ][ 0 ]) >= C[ 0 ][ 1 ]) {
1.64 + if ( C[ k + 1 ][ 0 ] > 0 ) {
1.65 + rc_Q16[ k ] = -SILK_FIX_CONST( .99f, 16 );
1.66 + } else {
1.67 + rc_Q16[ k ] = SILK_FIX_CONST( .99f, 16 );
1.68 + }
1.69 + k++;
1.70 + break;
1.71 + }
1.72 +
1.73 + /* Get reflection coefficient: divide two Q30 values and get result in Q31 */
1.74 + rc_tmp_Q31 = silk_DIV32_varQ( -C[ k + 1 ][ 0 ], C[ 0 ][ 1 ], 31 );
1.75 +
1.76 + /* Save the output */
1.77 + rc_Q16[ k ] = silk_RSHIFT_ROUND( rc_tmp_Q31, 15 );
1.78 +
1.79 + /* Update correlations */
1.80 + for( n = 0; n < order - k; n++ ) {
1.81 + Ctmp1_Q30 = C[ n + k + 1 ][ 0 ];
1.82 + Ctmp2_Q30 = C[ n ][ 1 ];
1.83 +
1.84 + /* Multiply and add the highest int32 */
1.85 + C[ n + k + 1 ][ 0 ] = Ctmp1_Q30 + silk_SMMUL( silk_LSHIFT( Ctmp2_Q30, 1 ), rc_tmp_Q31 );
1.86 + C[ n ][ 1 ] = Ctmp2_Q30 + silk_SMMUL( silk_LSHIFT( Ctmp1_Q30, 1 ), rc_tmp_Q31 );
1.87 + }
1.88 + }
1.89 +
1.90 + for(; k < order; k++ ) {
1.91 + rc_Q16[ k ] = 0;
1.92 + }
1.93 +
1.94 + return silk_max_32( 1, C[ 0 ][ 1 ] );
1.95 +}
