comparison src/opus-1.3/silk/sum_sqr_shift.c @ 69:7aeed7906520

Add Opus sources and macOS builds

+/***********************************************************************
+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"
+
+/* Compute number of bits to right shift the sum of squares of a vector */
+/* of int16s to make it fit in an int32                                 */
+void silk_sum_sqr_shift(
+    opus_int32                  *energy,            /* O   Energy of x, after shifting to the right                     */
+    opus_int                    *shift,             /* O   Number of bits right shift applied to energy                 */
+    const opus_int16            *x,                 /* I   Input vector                                                 */
+    opus_int                    len                 /* I   Length of input vector                                       */
+)
+{
+    opus_int   i, shft;
+    opus_uint32 nrg_tmp;
+    opus_int32 nrg;
+
+    /* Do a first run with the maximum shift we could have. */
+    shft = 31-silk_CLZ32(len);
+    /* Let's be conservative with rounding and start with nrg=len. */
+    nrg  = len;
+    for( i = 0; i < len - 1; i += 2 ) {
+        nrg_tmp = silk_SMULBB( x[ i ], x[ i ] );
+        nrg_tmp = silk_SMLABB_ovflw( nrg_tmp, x[ i + 1 ], x[ i + 1 ] );
+        nrg = (opus_int32)silk_ADD_RSHIFT_uint( nrg, nrg_tmp, shft );
+    }
+    if( i < len ) {
+        /* One sample left to process */
+        nrg_tmp = silk_SMULBB( x[ i ], x[ i ] );
+        nrg = (opus_int32)silk_ADD_RSHIFT_uint( nrg, nrg_tmp, shft );
+    }
+    silk_assert( nrg >= 0 );
+    /* Make sure the result will fit in a 32-bit signed integer with two bits
+       of headroom. */
+    shft = silk_max_32(0, shft+3 - silk_CLZ32(nrg));
+    nrg = 0;
+    for( i = 0 ; i < len - 1; i += 2 ) {
+        nrg_tmp = silk_SMULBB( x[ i ], x[ i ] );
+        nrg_tmp = silk_SMLABB_ovflw( nrg_tmp, x[ i + 1 ], x[ i + 1 ] );
+        nrg = (opus_int32)silk_ADD_RSHIFT_uint( nrg, nrg_tmp, shft );
+    }
+    if( i < len ) {
+        /* One sample left to process */
+        nrg_tmp = silk_SMULBB( x[ i ], x[ i ] );
+        nrg = (opus_int32)silk_ADD_RSHIFT_uint( nrg, nrg_tmp, shft );
+    }
+
+    silk_assert( nrg >= 0 );
+
+    /* Output arguments */
+    *shift  = shft;
+    *energy = nrg;
+}
+