Add copy of opus library in deps/third_party.

opus/silk/float/warped_autocorrelation_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
+
+#include "main_FLP.h"
+
+/* Autocorrelations for a warped frequency axis */
+void silk_warped_autocorrelation_FLP(
+    silk_float                      *corr,                              /* O    Result [order + 1]                          */
+    const silk_float                *input,                             /* I    Input data to correlate                     */
+    const silk_float                warping,                            /* I    Warping coefficient                         */
+    const opus_int                  length,                             /* I    Length of input                             */
+    const opus_int                  order                               /* I    Correlation order (even)                    */
+)
+{
+    opus_int    n, i;
+    double      tmp1, tmp2;
+    double      state[ MAX_SHAPE_LPC_ORDER + 1 ] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };
+    double      C[     MAX_SHAPE_LPC_ORDER + 1 ] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };
+
+    /* Order must be even */
+    silk_assert( ( order & 1 ) == 0 );
+
+    /* Loop over samples */
+    for( n = 0; n < length; n++ ) {
+        tmp1 = input[ n ];
+        /* Loop over allpass sections */
+        for( i = 0; i < order; i += 2 ) {
+            /* Output of allpass section */
+            tmp2 = state[ i ] + warping * ( state[ i + 1 ] - tmp1 );
+            state[ i ] = tmp1;
+            C[ i ] += state[ 0 ] * tmp1;
+            /* Output of allpass section */
+            tmp1 = state[ i + 1 ] + warping * ( state[ i + 2 ] - tmp2 );
+            state[ i + 1 ] = tmp2;
+            C[ i + 1 ] += state[ 0 ] * tmp2;
+        }
+        state[ order ] = tmp1;
+        C[ order ] += state[ 0 ] * tmp1;
+    }
+
+    /* Copy correlations in silk_float output format */
+    for( i = 0; i < order + 1; i++ ) {
+        corr[ i ] = ( silk_float )C[ i ];
+    }
+}