summaryrefslogtreecommitdiffstats
path: root/media/libopus/silk/float/schur_FLP.c
diff options
context:
space:
mode:
Diffstat (limited to 'media/libopus/silk/float/schur_FLP.c')
-rw-r--r--media/libopus/silk/float/schur_FLP.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/media/libopus/silk/float/schur_FLP.c b/media/libopus/silk/float/schur_FLP.c
new file mode 100644
index 000000000..ee436f835
--- /dev/null
+++ b/media/libopus/silk/float/schur_FLP.c
@@ -0,0 +1,70 @@
+/***********************************************************************
+Copyright (c) 2006-2011, Skype Limited. All rights reserved.
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+- Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+- Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in the
+documentation and/or other materials provided with the distribution.
+- Neither the name of Internet Society, IETF or IETF Trust, nor the
+names of specific contributors, may be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+***********************************************************************/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "SigProc_FLP.h"
+
+silk_float silk_schur_FLP( /* O returns residual energy */
+ silk_float refl_coef[], /* O reflection coefficients (length order) */
+ const silk_float auto_corr[], /* I autocorrelation sequence (length order+1) */
+ opus_int order /* I order */
+)
+{
+ opus_int k, n;
+ silk_float C[ SILK_MAX_ORDER_LPC + 1 ][ 2 ];
+ silk_float Ctmp1, Ctmp2, rc_tmp;
+
+ silk_assert( order==6||order==8||order==10||order==12||order==14||order==16 );
+
+ /* Copy correlations */
+ for( k = 0; k < order+1; k++ ) {
+ C[ k ][ 0 ] = C[ k ][ 1 ] = auto_corr[ k ];
+ }
+
+ for( k = 0; k < order; k++ ) {
+ /* Get reflection coefficient */
+ rc_tmp = -C[ k + 1 ][ 0 ] / silk_max_float( C[ 0 ][ 1 ], 1e-9f );
+
+ /* Save the output */
+ refl_coef[ k ] = rc_tmp;
+
+ /* Update correlations */
+ for( n = 0; n < order - k; n++ ) {
+ Ctmp1 = C[ n + k + 1 ][ 0 ];
+ Ctmp2 = C[ n ][ 1 ];
+ C[ n + k + 1 ][ 0 ] = Ctmp1 + Ctmp2 * rc_tmp;
+ C[ n ][ 1 ] = Ctmp2 + Ctmp1 * rc_tmp;
+ }
+ }
+
+ /* Return residual energy */
+ return C[ 0 ][ 1 ];
+}
+