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annotate src/opus-1.3/silk/gain_quant.c @ 77:4edcd14160a5 pa_catalina

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Duplicate for patch testing
author Chris Cannam
date Wed, 30 Oct 2019 11:25:10 +0000
parents 7aeed7906520
children
rev   line source
Chris@69 1 /***********************************************************************
Chris@69 2 Copyright (c) 2006-2011, Skype Limited. All rights reserved.
Chris@69 3 Redistribution and use in source and binary forms, with or without
Chris@69 4 modification, are permitted provided that the following conditions
Chris@69 5 are met:
Chris@69 6 - Redistributions of source code must retain the above copyright notice,
Chris@69 7 this list of conditions and the following disclaimer.
Chris@69 8 - Redistributions in binary form must reproduce the above copyright
Chris@69 9 notice, this list of conditions and the following disclaimer in the
Chris@69 10 documentation and/or other materials provided with the distribution.
Chris@69 11 - Neither the name of Internet Society, IETF or IETF Trust, nor the
Chris@69 12 names of specific contributors, may be used to endorse or promote
Chris@69 13 products derived from this software without specific prior written
Chris@69 14 permission.
Chris@69 15 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
Chris@69 16 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
Chris@69 17 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
Chris@69 18 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
Chris@69 19 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
Chris@69 20 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
Chris@69 21 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
Chris@69 22 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
Chris@69 23 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
Chris@69 24 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
Chris@69 25 POSSIBILITY OF SUCH DAMAGE.
Chris@69 26 ***********************************************************************/
Chris@69 27
Chris@69 28 #ifdef HAVE_CONFIG_H
Chris@69 29 #include "config.h"
Chris@69 30 #endif
Chris@69 31
Chris@69 32 #include "main.h"
Chris@69 33
Chris@69 34 #define OFFSET ( ( MIN_QGAIN_DB * 128 ) / 6 + 16 * 128 )
Chris@69 35 #define SCALE_Q16 ( ( 65536 * ( N_LEVELS_QGAIN - 1 ) ) / ( ( ( MAX_QGAIN_DB - MIN_QGAIN_DB ) * 128 ) / 6 ) )
Chris@69 36 #define INV_SCALE_Q16 ( ( 65536 * ( ( ( MAX_QGAIN_DB - MIN_QGAIN_DB ) * 128 ) / 6 ) ) / ( N_LEVELS_QGAIN - 1 ) )
Chris@69 37
Chris@69 38 /* Gain scalar quantization with hysteresis, uniform on log scale */
Chris@69 39 void silk_gains_quant(
Chris@69 40 opus_int8 ind[ MAX_NB_SUBFR ], /* O gain indices */
Chris@69 41 opus_int32 gain_Q16[ MAX_NB_SUBFR ], /* I/O gains (quantized out) */
Chris@69 42 opus_int8 *prev_ind, /* I/O last index in previous frame */
Chris@69 43 const opus_int conditional, /* I first gain is delta coded if 1 */
Chris@69 44 const opus_int nb_subfr /* I number of subframes */
Chris@69 45 )
Chris@69 46 {
Chris@69 47 opus_int k, double_step_size_threshold;
Chris@69 48
Chris@69 49 for( k = 0; k < nb_subfr; k++ ) {
Chris@69 50 /* Convert to log scale, scale, floor() */
Chris@69 51 ind[ k ] = silk_SMULWB( SCALE_Q16, silk_lin2log( gain_Q16[ k ] ) - OFFSET );
Chris@69 52
Chris@69 53 /* Round towards previous quantized gain (hysteresis) */
Chris@69 54 if( ind[ k ] < *prev_ind ) {
Chris@69 55 ind[ k ]++;
Chris@69 56 }
Chris@69 57 ind[ k ] = silk_LIMIT_int( ind[ k ], 0, N_LEVELS_QGAIN - 1 );
Chris@69 58
Chris@69 59 /* Compute delta indices and limit */
Chris@69 60 if( k == 0 && conditional == 0 ) {
Chris@69 61 /* Full index */
Chris@69 62 ind[ k ] = silk_LIMIT_int( ind[ k ], *prev_ind + MIN_DELTA_GAIN_QUANT, N_LEVELS_QGAIN - 1 );
Chris@69 63 *prev_ind = ind[ k ];
Chris@69 64 } else {
Chris@69 65 /* Delta index */
Chris@69 66 ind[ k ] = ind[ k ] - *prev_ind;
Chris@69 67
Chris@69 68 /* Double the quantization step size for large gain increases, so that the max gain level can be reached */
Chris@69 69 double_step_size_threshold = 2 * MAX_DELTA_GAIN_QUANT - N_LEVELS_QGAIN + *prev_ind;
Chris@69 70 if( ind[ k ] > double_step_size_threshold ) {
Chris@69 71 ind[ k ] = double_step_size_threshold + silk_RSHIFT( ind[ k ] - double_step_size_threshold + 1, 1 );
Chris@69 72 }
Chris@69 73
Chris@69 74 ind[ k ] = silk_LIMIT_int( ind[ k ], MIN_DELTA_GAIN_QUANT, MAX_DELTA_GAIN_QUANT );
Chris@69 75
Chris@69 76 /* Accumulate deltas */
Chris@69 77 if( ind[ k ] > double_step_size_threshold ) {
Chris@69 78 *prev_ind += silk_LSHIFT( ind[ k ], 1 ) - double_step_size_threshold;
Chris@69 79 *prev_ind = silk_min_int( *prev_ind, N_LEVELS_QGAIN - 1 );
Chris@69 80 } else {
Chris@69 81 *prev_ind += ind[ k ];
Chris@69 82 }
Chris@69 83
Chris@69 84 /* Shift to make non-negative */
Chris@69 85 ind[ k ] -= MIN_DELTA_GAIN_QUANT;
Chris@69 86 }
Chris@69 87
Chris@69 88 /* Scale and convert to linear scale */
Chris@69 89 gain_Q16[ k ] = silk_log2lin( silk_min_32( silk_SMULWB( INV_SCALE_Q16, *prev_ind ) + OFFSET, 3967 ) ); /* 3967 = 31 in Q7 */
Chris@69 90 }
Chris@69 91 }
Chris@69 92
Chris@69 93 /* Gains scalar dequantization, uniform on log scale */
Chris@69 94 void silk_gains_dequant(
Chris@69 95 opus_int32 gain_Q16[ MAX_NB_SUBFR ], /* O quantized gains */
Chris@69 96 const opus_int8 ind[ MAX_NB_SUBFR ], /* I gain indices */
Chris@69 97 opus_int8 *prev_ind, /* I/O last index in previous frame */
Chris@69 98 const opus_int conditional, /* I first gain is delta coded if 1 */
Chris@69 99 const opus_int nb_subfr /* I number of subframes */
Chris@69 100 )
Chris@69 101 {
Chris@69 102 opus_int k, ind_tmp, double_step_size_threshold;
Chris@69 103
Chris@69 104 for( k = 0; k < nb_subfr; k++ ) {
Chris@69 105 if( k == 0 && conditional == 0 ) {
Chris@69 106 /* Gain index is not allowed to go down more than 16 steps (~21.8 dB) */
Chris@69 107 *prev_ind = silk_max_int( ind[ k ], *prev_ind - 16 );
Chris@69 108 } else {
Chris@69 109 /* Delta index */
Chris@69 110 ind_tmp = ind[ k ] + MIN_DELTA_GAIN_QUANT;
Chris@69 111
Chris@69 112 /* Accumulate deltas */
Chris@69 113 double_step_size_threshold = 2 * MAX_DELTA_GAIN_QUANT - N_LEVELS_QGAIN + *prev_ind;
Chris@69 114 if( ind_tmp > double_step_size_threshold ) {
Chris@69 115 *prev_ind += silk_LSHIFT( ind_tmp, 1 ) - double_step_size_threshold;
Chris@69 116 } else {
Chris@69 117 *prev_ind += ind_tmp;
Chris@69 118 }
Chris@69 119 }
Chris@69 120 *prev_ind = silk_LIMIT_int( *prev_ind, 0, N_LEVELS_QGAIN - 1 );
Chris@69 121
Chris@69 122 /* Scale and convert to linear scale */
Chris@69 123 gain_Q16[ k ] = silk_log2lin( silk_min_32( silk_SMULWB( INV_SCALE_Q16, *prev_ind ) + OFFSET, 3967 ) ); /* 3967 = 31 in Q7 */
Chris@69 124 }
Chris@69 125 }
Chris@69 126
Chris@69 127 /* Compute unique identifier of gain indices vector */
Chris@69 128 opus_int32 silk_gains_ID( /* O returns unique identifier of gains */
Chris@69 129 const opus_int8 ind[ MAX_NB_SUBFR ], /* I gain indices */
Chris@69 130 const opus_int nb_subfr /* I number of subframes */
Chris@69 131 )
Chris@69 132 {
Chris@69 133 opus_int k;
Chris@69 134 opus_int32 gainsID;
Chris@69 135
Chris@69 136 gainsID = 0;
Chris@69 137 for( k = 0; k < nb_subfr; k++ ) {
Chris@69 138 gainsID = silk_ADD_LSHIFT32( ind[ k ], gainsID, 8 );
Chris@69 139 }
Chris@69 140
Chris@69 141 return gainsID;
Chris@69 142 }