summaryrefslogtreecommitdiffstats
path: root/media/libopus/silk/fixed/schur64_FIX.c
diff options
context:
space:
mode:
Diffstat (limited to 'media/libopus/silk/fixed/schur64_FIX.c')
-rw-r--r--media/libopus/silk/fixed/schur64_FIX.c93
1 files changed, 93 insertions, 0 deletions
diff --git a/media/libopus/silk/fixed/schur64_FIX.c b/media/libopus/silk/fixed/schur64_FIX.c
new file mode 100644
index 0000000000..4b7e19ea59
--- /dev/null
+++ b/media/libopus/silk/fixed/schur64_FIX.c
@@ -0,0 +1,93 @@
+/***********************************************************************
+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_FIX.h"
+
+/* Slower than schur(), but more accurate. */
+/* Uses SMULL(), available on armv4 */
+opus_int32 silk_schur64( /* O returns residual energy */
+ opus_int32 rc_Q16[], /* O Reflection coefficients [order] Q16 */
+ const opus_int32 c[], /* I Correlations [order+1] */
+ opus_int32 order /* I Prediction order */
+)
+{
+ opus_int k, n;
+ opus_int32 C[ SILK_MAX_ORDER_LPC + 1 ][ 2 ];
+ opus_int32 Ctmp1_Q30, Ctmp2_Q30, rc_tmp_Q31;
+
+ celt_assert( order >= 0 && order <= SILK_MAX_ORDER_LPC );
+
+ /* Check for invalid input */
+ if( c[ 0 ] <= 0 ) {
+ silk_memset( rc_Q16, 0, order * sizeof( opus_int32 ) );
+ return 0;
+ }
+
+ k = 0;
+ do {
+ C[ k ][ 0 ] = C[ k ][ 1 ] = c[ k ];
+ } while( ++k <= order );
+
+ for( k = 0; k < order; k++ ) {
+ /* Check that we won't be getting an unstable rc, otherwise stop here. */
+ if (silk_abs_int32(C[ k + 1 ][ 0 ]) >= C[ 0 ][ 1 ]) {
+ if ( C[ k + 1 ][ 0 ] > 0 ) {
+ rc_Q16[ k ] = -SILK_FIX_CONST( .99f, 16 );
+ } else {
+ rc_Q16[ k ] = SILK_FIX_CONST( .99f, 16 );
+ }
+ k++;
+ break;
+ }
+
+ /* Get reflection coefficient: divide two Q30 values and get result in Q31 */
+ rc_tmp_Q31 = silk_DIV32_varQ( -C[ k + 1 ][ 0 ], C[ 0 ][ 1 ], 31 );
+
+ /* Save the output */
+ rc_Q16[ k ] = silk_RSHIFT_ROUND( rc_tmp_Q31, 15 );
+
+ /* Update correlations */
+ for( n = 0; n < order - k; n++ ) {
+ Ctmp1_Q30 = C[ n + k + 1 ][ 0 ];
+ Ctmp2_Q30 = C[ n ][ 1 ];
+
+ /* Multiply and add the highest int32 */
+ C[ n + k + 1 ][ 0 ] = Ctmp1_Q30 + silk_SMMUL( silk_LSHIFT( Ctmp2_Q30, 1 ), rc_tmp_Q31 );
+ C[ n ][ 1 ] = Ctmp2_Q30 + silk_SMMUL( silk_LSHIFT( Ctmp1_Q30, 1 ), rc_tmp_Q31 );
+ }
+ }
+
+ for(; k < order; k++ ) {
+ rc_Q16[ k ] = 0;
+ }
+
+ return silk_max_32( 1, C[ 0 ][ 1 ] );
+}