mirror of
https://github.com/Relintai/pandemonium_engine.git
synced 2024-12-22 11:56:49 +01:00
80 lines
4.3 KiB
C
80 lines
4.3 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 "main.h"
|
||
|
|
|
||
|
|
/* Find least-squares prediction gain for one signal based on another and quantize it */
|
||
|
|
opus_int32 silk_stereo_find_predictor( /* O Returns predictor in Q13 */
|
||
|
|
opus_int32 *ratio_Q14, /* O Ratio of residual and mid energies */
|
||
|
|
const opus_int16 x[], /* I Basis signal */
|
||
|
|
const opus_int16 y[], /* I Target signal */
|
||
|
|
opus_int32 mid_res_amp_Q0[], /* I/O Smoothed mid, residual norms */
|
||
|
|
opus_int length, /* I Number of samples */
|
||
|
|
opus_int smooth_coef_Q16 /* I Smoothing coefficient */
|
||
|
|
)
|
||
|
|
{
|
||
|
|
opus_int scale, scale1, scale2;
|
||
|
|
opus_int32 nrgx, nrgy, corr, pred_Q13, pred2_Q10;
|
||
|
|
|
||
|
|
/* Find predictor */
|
||
|
|
silk_sum_sqr_shift( &nrgx, &scale1, x, length );
|
||
|
|
silk_sum_sqr_shift( &nrgy, &scale2, y, length );
|
||
|
|
scale = silk_max_int( scale1, scale2 );
|
||
|
|
scale = scale + ( scale & 1 ); /* make even */
|
||
|
|
nrgy = silk_RSHIFT32( nrgy, scale - scale2 );
|
||
|
|
nrgx = silk_RSHIFT32( nrgx, scale - scale1 );
|
||
|
|
nrgx = silk_max_int( nrgx, 1 );
|
||
|
|
corr = silk_inner_prod_aligned_scale( x, y, scale, length );
|
||
|
|
pred_Q13 = silk_DIV32_varQ( corr, nrgx, 13 );
|
||
|
|
pred_Q13 = silk_LIMIT( pred_Q13, -(1 << 14), 1 << 14 );
|
||
|
|
pred2_Q10 = silk_SMULWB( pred_Q13, pred_Q13 );
|
||
|
|
|
||
|
|
/* Faster update for signals with large prediction parameters */
|
||
|
|
smooth_coef_Q16 = (opus_int)silk_max_int( smooth_coef_Q16, silk_abs( pred2_Q10 ) );
|
||
|
|
|
||
|
|
/* Smoothed mid and residual norms */
|
||
|
|
silk_assert( smooth_coef_Q16 < 32768 );
|
||
|
|
scale = silk_RSHIFT( scale, 1 );
|
||
|
|
mid_res_amp_Q0[ 0 ] = silk_SMLAWB( mid_res_amp_Q0[ 0 ], silk_LSHIFT( silk_SQRT_APPROX( nrgx ), scale ) - mid_res_amp_Q0[ 0 ],
|
||
|
|
smooth_coef_Q16 );
|
||
|
|
/* Residual energy = nrgy - 2 * pred * corr + pred^2 * nrgx */
|
||
|
|
nrgy = silk_SUB_LSHIFT32( nrgy, silk_SMULWB( corr, pred_Q13 ), 3 + 1 );
|
||
|
|
nrgy = silk_ADD_LSHIFT32( nrgy, silk_SMULWB( nrgx, pred2_Q10 ), 6 );
|
||
|
|
mid_res_amp_Q0[ 1 ] = silk_SMLAWB( mid_res_amp_Q0[ 1 ], silk_LSHIFT( silk_SQRT_APPROX( nrgy ), scale ) - mid_res_amp_Q0[ 1 ],
|
||
|
|
smooth_coef_Q16 );
|
||
|
|
|
||
|
|
/* Ratio of smoothed residual and mid norms */
|
||
|
|
*ratio_Q14 = silk_DIV32_varQ( mid_res_amp_Q0[ 1 ], silk_max( mid_res_amp_Q0[ 0 ], 1 ), 14 );
|
||
|
|
*ratio_Q14 = silk_LIMIT( *ratio_Q14, 0, 32767 );
|
||
|
|
|
||
|
|
return pred_Q13;
|
||
|
|
}
|