142 lines
6.7 KiB
C
142 lines
6.7 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"
|
|
|
|
#define OFFSET ( ( MIN_QGAIN_DB * 128 ) / 6 + 16 * 128 )
|
|
#define SCALE_Q16 ( ( 65536 * ( N_LEVELS_QGAIN - 1 ) ) / ( ( ( MAX_QGAIN_DB - MIN_QGAIN_DB ) * 128 ) / 6 ) )
|
|
#define INV_SCALE_Q16 ( ( 65536 * ( ( ( MAX_QGAIN_DB - MIN_QGAIN_DB ) * 128 ) / 6 ) ) / ( N_LEVELS_QGAIN - 1 ) )
|
|
|
|
/* Gain scalar quantization with hysteresis, uniform on log scale */
|
|
void silk_gains_quant(
|
|
opus_int8 ind[ MAX_NB_SUBFR ], /* O gain indices */
|
|
opus_int32 gain_Q16[ MAX_NB_SUBFR ], /* I/O gains (quantized out) */
|
|
opus_int8 *prev_ind, /* I/O last index in previous frame */
|
|
const opus_int conditional, /* I first gain is delta coded if 1 */
|
|
const opus_int nb_subfr /* I number of subframes */
|
|
)
|
|
{
|
|
opus_int k, double_step_size_threshold;
|
|
|
|
for( k = 0; k < nb_subfr; k++ ) {
|
|
/* Convert to log scale, scale, floor() */
|
|
ind[ k ] = silk_SMULWB( SCALE_Q16, silk_lin2log( gain_Q16[ k ] ) - OFFSET );
|
|
|
|
/* Round towards previous quantized gain (hysteresis) */
|
|
if( ind[ k ] < *prev_ind ) {
|
|
ind[ k ]++;
|
|
}
|
|
ind[ k ] = silk_LIMIT_int( ind[ k ], 0, N_LEVELS_QGAIN - 1 );
|
|
|
|
/* Compute delta indices and limit */
|
|
if( k == 0 && conditional == 0 ) {
|
|
/* Full index */
|
|
ind[ k ] = silk_LIMIT_int( ind[ k ], *prev_ind + MIN_DELTA_GAIN_QUANT, N_LEVELS_QGAIN - 1 );
|
|
*prev_ind = ind[ k ];
|
|
} else {
|
|
/* Delta index */
|
|
ind[ k ] = ind[ k ] - *prev_ind;
|
|
|
|
/* Double the quantization step size for large gain increases, so that the max gain level can be reached */
|
|
double_step_size_threshold = 2 * MAX_DELTA_GAIN_QUANT - N_LEVELS_QGAIN + *prev_ind;
|
|
if( ind[ k ] > double_step_size_threshold ) {
|
|
ind[ k ] = double_step_size_threshold + silk_RSHIFT( ind[ k ] - double_step_size_threshold + 1, 1 );
|
|
}
|
|
|
|
ind[ k ] = silk_LIMIT_int( ind[ k ], MIN_DELTA_GAIN_QUANT, MAX_DELTA_GAIN_QUANT );
|
|
|
|
/* Accumulate deltas */
|
|
if( ind[ k ] > double_step_size_threshold ) {
|
|
*prev_ind += silk_LSHIFT( ind[ k ], 1 ) - double_step_size_threshold;
|
|
} else {
|
|
*prev_ind += ind[ k ];
|
|
}
|
|
|
|
/* Shift to make non-negative */
|
|
ind[ k ] -= MIN_DELTA_GAIN_QUANT;
|
|
}
|
|
|
|
/* Scale and convert to linear scale */
|
|
gain_Q16[ k ] = silk_log2lin( silk_min_32( silk_SMULWB( INV_SCALE_Q16, *prev_ind ) + OFFSET, 3967 ) ); /* 3967 = 31 in Q7 */
|
|
}
|
|
}
|
|
|
|
/* Gains scalar dequantization, uniform on log scale */
|
|
void silk_gains_dequant(
|
|
opus_int32 gain_Q16[ MAX_NB_SUBFR ], /* O quantized gains */
|
|
const opus_int8 ind[ MAX_NB_SUBFR ], /* I gain indices */
|
|
opus_int8 *prev_ind, /* I/O last index in previous frame */
|
|
const opus_int conditional, /* I first gain is delta coded if 1 */
|
|
const opus_int nb_subfr /* I number of subframes */
|
|
)
|
|
{
|
|
opus_int k, ind_tmp, double_step_size_threshold;
|
|
|
|
for( k = 0; k < nb_subfr; k++ ) {
|
|
if( k == 0 && conditional == 0 ) {
|
|
/* Gain index is not allowed to go down more than 16 steps (~21.8 dB) */
|
|
*prev_ind = silk_max_int( ind[ k ], *prev_ind - 16 );
|
|
} else {
|
|
/* Delta index */
|
|
ind_tmp = ind[ k ] + MIN_DELTA_GAIN_QUANT;
|
|
|
|
/* Accumulate deltas */
|
|
double_step_size_threshold = 2 * MAX_DELTA_GAIN_QUANT - N_LEVELS_QGAIN + *prev_ind;
|
|
if( ind_tmp > double_step_size_threshold ) {
|
|
*prev_ind += silk_LSHIFT( ind_tmp, 1 ) - double_step_size_threshold;
|
|
} else {
|
|
*prev_ind += ind_tmp;
|
|
}
|
|
}
|
|
*prev_ind = silk_LIMIT_int( *prev_ind, 0, N_LEVELS_QGAIN - 1 );
|
|
|
|
/* Scale and convert to linear scale */
|
|
gain_Q16[ k ] = silk_log2lin( silk_min_32( silk_SMULWB( INV_SCALE_Q16, *prev_ind ) + OFFSET, 3967 ) ); /* 3967 = 31 in Q7 */
|
|
}
|
|
}
|
|
|
|
/* Compute unique identifier of gain indices vector */
|
|
opus_int32 silk_gains_ID( /* O returns unique identifier of gains */
|
|
const opus_int8 ind[ MAX_NB_SUBFR ], /* I gain indices */
|
|
const opus_int nb_subfr /* I number of subframes */
|
|
)
|
|
{
|
|
opus_int k;
|
|
opus_int32 gainsID;
|
|
|
|
gainsID = 0;
|
|
for( k = 0; k < nb_subfr; k++ ) {
|
|
gainsID = silk_ADD_LSHIFT32( ind[ k ], gainsID, 8 );
|
|
}
|
|
|
|
return gainsID;
|
|
}
|