Add copy of opus library in deps/third_party.

opus/silk/float/sort_FLP.c

+/***********************************************************************
+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
+
+/* Insertion sort (fast for already almost sorted arrays):  */
+/* Best case:  O(n)   for an already sorted array           */
+/* Worst case: O(n^2) for an inversely sorted array         */
+
+#include "typedef.h"
+#include "SigProc_FLP.h"
+
+void silk_insertion_sort_decreasing_FLP(
+    silk_float          *a,                 /* I/O  Unsorted / Sorted vector                                    */
+    opus_int            *idx,               /* O    Index vector for the sorted elements                        */
+    const opus_int      L,                  /* I    Vector length                                               */
+    const opus_int      K                   /* I    Number of correctly sorted positions                        */
+)
+{
+    silk_float value;
+    opus_int   i, j;
+
+    /* Safety checks */
+    silk_assert( K >  0 );
+    silk_assert( L >  0 );
+    silk_assert( L >= K );
+
+    /* Write start indices in index vector */
+    for( i = 0; i < K; i++ ) {
+        idx[ i ] = i;
+    }
+
+    /* Sort vector elements by value, decreasing order */
+    for( i = 1; i < K; i++ ) {
+        value = a[ i ];
+        for( j = i - 1; ( j >= 0 ) && ( value > a[ j ] ); j-- ) {
+            a[ j + 1 ]   = a[ j ];      /* Shift value */
+            idx[ j + 1 ] = idx[ j ];    /* Shift index */
+        }
+        a[ j + 1 ]   = value;   /* Write value */
+        idx[ j + 1 ] = i;       /* Write index */
+    }
+
+    /* If less than L values are asked check the remaining values,      */
+    /* but only spend CPU to ensure that the K first values are correct */
+    for( i = K; i < L; i++ ) {
+        value = a[ i ];
+        if( value > a[ K - 1 ] ) {
+            for( j = K - 2; ( j >= 0 ) && ( value > a[ j ] ); j-- ) {
+                a[ j + 1 ]   = a[ j ];      /* Shift value */
+                idx[ j + 1 ] = idx[ j ];    /* Shift index */
+            }
+            a[ j + 1 ]   = value;   /* Write value */
+            idx[ j + 1 ] = i;       /* Write index */
+        }
+    }
+}