123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142 |
- /***********************************************************************
- 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"
- #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;
- }
|