12bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian/***********************************************************************
22bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianCopyright (c) 2006-2011, Skype Limited. All rights reserved.
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52bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanianare met:
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72bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanianthis list of conditions and the following disclaimer.
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152bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianTHIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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172bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianIMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
182bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
192bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianLIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
202bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianCONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
212bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianSUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
222bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianINTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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242bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
252bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh VenkatasubramanianPOSSIBILITY OF SUCH DAMAGE.
262bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian***********************************************************************/
272bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian
282bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian#ifdef HAVE_CONFIG_H
292bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian#include "config.h"
302bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian#endif
312bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian
322bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian#include "SigProc_FIX.h"
332bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian
342bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian/* Compute number of bits to right shift the sum of squares of a vector */
352bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian/* of int16s to make it fit in an int32                                 */
362bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanianvoid silk_sum_sqr_shift(
372bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    opus_int32                  *energy,            /* O   Energy of x, after shifting to the right                     */
382bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    opus_int                    *shift,             /* O   Number of bits right shift applied to energy                 */
392bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    const opus_int16            *x,                 /* I   Input vector                                                 */
402bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    opus_int                    len                 /* I   Length of input vector                                       */
412bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian)
422bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian{
432bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    opus_int   i, shft;
442bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    opus_int32 nrg_tmp, nrg;
452bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian
462bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    nrg  = 0;
472bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    shft = 0;
482bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    len--;
492bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    for( i = 0; i < len; i += 2 ) {
502bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        nrg = silk_SMLABB_ovflw( nrg, x[ i ], x[ i ] );
512bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        nrg = silk_SMLABB_ovflw( nrg, x[ i + 1 ], x[ i + 1 ] );
522bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        if( nrg < 0 ) {
532bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian            /* Scale down */
542bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian            nrg = (opus_int32)silk_RSHIFT_uint( (opus_uint32)nrg, 2 );
552bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian            shft = 2;
562bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian            break;
572bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        }
582bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    }
592bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    for( ; i < len; i += 2 ) {
602bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        nrg_tmp = silk_SMULBB( x[ i ], x[ i ] );
612bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        nrg_tmp = silk_SMLABB_ovflw( nrg_tmp, x[ i + 1 ], x[ i + 1 ] );
622bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        nrg = (opus_int32)silk_ADD_RSHIFT_uint( nrg, (opus_uint32)nrg_tmp, shft );
632bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        if( nrg < 0 ) {
642bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian            /* Scale down */
652bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian            nrg = (opus_int32)silk_RSHIFT_uint( (opus_uint32)nrg, 2 );
662bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian            shft += 2;
672bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        }
682bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    }
692bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    if( i == len ) {
702bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        /* One sample left to process */
712bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        nrg_tmp = silk_SMULBB( x[ i ], x[ i ] );
722bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        nrg = (opus_int32)silk_ADD_RSHIFT_uint( nrg, nrg_tmp, shft );
732bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    }
742bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian
752bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    /* Make sure to have at least one extra leading zero (two leading zeros in total) */
762bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    if( nrg & 0xC0000000 ) {
772bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        nrg = silk_RSHIFT_uint( (opus_uint32)nrg, 2 );
782bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian        shft += 2;
792bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    }
802bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian
812bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    /* Output arguments */
822bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    *shift  = shft;
832bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian    *energy = nrg;
842bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian}
852bd8b54017b5320bc0c1df9bf86f4cdc9f8db242Vignesh Venkatasubramanian
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