74 lines
3.4 KiB
C
74 lines
3.4 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 OPUS_HAVE_CONFIG_H
|
|
#include "opus_config.h"
|
|
#endif
|
|
|
|
#include "silk_main.h"
|
|
|
|
/* Decode mid/side predictors */
|
|
void silk_stereo_decode_pred(
|
|
ec_dec *psRangeDec, /* I/O Compressor data structure */
|
|
opus_int32 pred_Q13[] /* O Predictors */
|
|
)
|
|
{
|
|
opus_int n, ix[ 2 ][ 3 ];
|
|
opus_int32 low_Q13, step_Q13;
|
|
|
|
/* Entropy decoding */
|
|
n = ec_dec_icdf( psRangeDec, silk_stereo_pred_joint_iCDF, 8 );
|
|
ix[ 0 ][ 2 ] = silk_DIV32_16( n, 5 );
|
|
ix[ 1 ][ 2 ] = n - 5 * ix[ 0 ][ 2 ];
|
|
for( n = 0; n < 2; n++ ) {
|
|
ix[ n ][ 0 ] = ec_dec_icdf( psRangeDec, silk_uniform3_iCDF, 8 );
|
|
ix[ n ][ 1 ] = ec_dec_icdf( psRangeDec, silk_uniform5_iCDF, 8 );
|
|
}
|
|
|
|
/* Dequantize */
|
|
for( n = 0; n < 2; n++ ) {
|
|
ix[ n ][ 0 ] += 3 * ix[ n ][ 2 ];
|
|
low_Q13 = silk_stereo_pred_quant_Q13[ ix[ n ][ 0 ] ];
|
|
step_Q13 = silk_SMULWB( silk_stereo_pred_quant_Q13[ ix[ n ][ 0 ] + 1 ] - low_Q13,
|
|
SILK_FIX_CONST( 0.5 / STEREO_QUANT_SUB_STEPS, 16 ) );
|
|
pred_Q13[ n ] = silk_SMLABB( low_Q13, step_Q13, 2 * ix[ n ][ 1 ] + 1 );
|
|
}
|
|
|
|
/* Subtract second from first predictor (helps when actually applying these) */
|
|
pred_Q13[ 0 ] -= pred_Q13[ 1 ];
|
|
}
|
|
|
|
/* Decode mid-only flag */
|
|
void silk_stereo_decode_mid_only(
|
|
ec_dec *psRangeDec, /* I/O Compressor data structure */
|
|
opus_int *decode_only_mid /* O Flag that only mid channel has been coded */
|
|
)
|
|
{
|
|
/* Decode flag that only mid channel is coded */
|
|
*decode_only_mid = ec_dec_icdf( psRangeDec, silk_stereo_only_code_mid_iCDF, 8 );
|
|
}
|