diff src/opus-1.3/silk/float/k2a_FLP.c @ 154:4664ac0c1032

Add Opus sources and macOS builds

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/opus-1.3/silk/float/k2a_FLP.c	Wed Jan 23 13:48:08 2019 +0000
@@ -0,0 +1,54 @@
+/***********************************************************************
+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 rck, tmp1, tmp2;
+
+    for( k = 0; k < order; k++ ) {
+        rck = rc[ k ];
+        for( n = 0; n < (k + 1) >> 1; n++ ) {
+            tmp1 = A[ n ];
+            tmp2 = A[ k - n - 1 ];
+            A[ n ]         = tmp1 + tmp2 * rck;
+            A[ k - n - 1 ] = tmp2 + tmp1 * rck;
+        }
+        A[ k ] = -rck;
+    }
+}