87 lines
3.6 KiB
C
87 lines
3.6 KiB
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 "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_int32 nrg_tmp, nrg;
|
||
|
|
|
||
|
|
nrg = 0;
|
||
|
|
shft = 0;
|
||
|
|
len--;
|
||
|
|
for( i = 0; i < len; i += 2 ) {
|
||
|
|
nrg = silk_SMLABB_ovflw( nrg, x[ i ], x[ i ] );
|
||
|
|
nrg = silk_SMLABB_ovflw( nrg, x[ i + 1 ], x[ i + 1 ] );
|
||
|
|
if( nrg < 0 ) {
|
||
|
|
/* Scale down */
|
||
|
|
nrg = (opus_int32)silk_RSHIFT_uint( (opus_uint32)nrg, 2 );
|
||
|
|
shft = 2;
|
||
|
|
i+=2;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
for( ; i < len; 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, (opus_uint32)nrg_tmp, shft );
|
||
|
|
if( nrg < 0 ) {
|
||
|
|
/* Scale down */
|
||
|
|
nrg = (opus_int32)silk_RSHIFT_uint( (opus_uint32)nrg, 2 );
|
||
|
|
shft += 2;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
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 );
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Make sure to have at least one extra leading zero (two leading zeros in total) */
|
||
|
|
if( nrg & 0xC0000000 ) {
|
||
|
|
nrg = silk_RSHIFT_uint( (opus_uint32)nrg, 2 );
|
||
|
|
shft += 2;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Output arguments */
|
||
|
|
*shift = shft;
|
||
|
|
*energy = nrg;
|
||
|
|
}
|
||
|
|
|