1 files changed, 53 insertions, 0 deletions
diff --git a/media/libopus/silk/float/k2a_FLP.c b/media/libopus/silk/float/k2a_FLP.c
new file mode 100644
index 000000000..12af4e766
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+++ b/media/libopus/silk/float/k2a_FLP.c
@@ -0,0 +1,53 @@
+/***********************************************************************
+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"
+
+/* step up function, converts reflection coefficients to prediction coefficients */
+void silk_k2a_FLP(
+    silk_float          *A,                 /* O     prediction coefficients [order]                            */
+    const silk_float    *rc,                /* I     reflection coefficients [order]                            */
+    opus_int32          order               /* I     prediction order                                           */
+)
+{
+    opus_int   k, n;
+    silk_float Atmp[ SILK_MAX_ORDER_LPC ];
+
+    for( k = 0; k < order; k++ ) {
+        for( n = 0; n < k; n++ ) {
+            Atmp[ n ] = A[ n ];
+        }
+        for( n = 0; n < k; n++ ) {
+            A[ n ] += Atmp[ k - n - 1 ] * rc[ k ];
+        }
+        A[ k ] = -rc[ k ];
+    }
+}