Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 1 | /*********************************************************************** |
| 2 | Copyright (c) 2006-2011, Skype Limited. All rights reserved. |
| 3 | Redistribution and use in source and binary forms, with or without |
| 4 | modification, are permitted provided that the following conditions |
| 5 | are met: |
| 6 | - Redistributions of source code must retain the above copyright notice, |
| 7 | this list of conditions and the following disclaimer. |
| 8 | - Redistributions in binary form must reproduce the above copyright |
| 9 | notice, this list of conditions and the following disclaimer in the |
| 10 | documentation and/or other materials provided with the distribution. |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 11 | - Neither the name of Internet Society, IETF or IETF Trust, nor the |
Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 12 | names of specific contributors, may be used to endorse or promote |
| 13 | products derived from this software without specific prior written |
| 14 | permission. |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 16 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 17 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 18 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| 19 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 20 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 21 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 22 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 23 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 24 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 25 | POSSIBILITY OF SUCH DAMAGE. |
| 26 | ***********************************************************************/ |
| 27 | |
| 28 | #ifdef HAVE_CONFIG_H |
| 29 | #include "config.h" |
| 30 | #endif |
| 31 | |
| 32 | #include "main.h" |
| 33 | |
| 34 | #define OFFSET ( ( MIN_QGAIN_DB * 128 ) / 6 + 16 * 128 ) |
| 35 | #define SCALE_Q16 ( ( 65536 * ( N_LEVELS_QGAIN - 1 ) ) / ( ( ( MAX_QGAIN_DB - MIN_QGAIN_DB ) * 128 ) / 6 ) ) |
| 36 | #define INV_SCALE_Q16 ( ( 65536 * ( ( ( MAX_QGAIN_DB - MIN_QGAIN_DB ) * 128 ) / 6 ) ) / ( N_LEVELS_QGAIN - 1 ) ) |
| 37 | |
| 38 | /* Gain scalar quantization with hysteresis, uniform on log scale */ |
| 39 | void silk_gains_quant( |
| 40 | opus_int8 ind[ MAX_NB_SUBFR ], /* O gain indices */ |
| 41 | opus_int32 gain_Q16[ MAX_NB_SUBFR ], /* I/O gains (quantized out) */ |
| 42 | opus_int8 *prev_ind, /* I/O last index in previous frame */ |
| 43 | const opus_int conditional, /* I first gain is delta coded if 1 */ |
| 44 | const opus_int nb_subfr /* I number of subframes */ |
| 45 | ) |
| 46 | { |
| 47 | opus_int k, double_step_size_threshold; |
| 48 | |
| 49 | for( k = 0; k < nb_subfr; k++ ) { |
| 50 | /* Convert to log scale, scale, floor() */ |
| 51 | ind[ k ] = silk_SMULWB( SCALE_Q16, silk_lin2log( gain_Q16[ k ] ) - OFFSET ); |
| 52 | |
| 53 | /* Round towards previous quantized gain (hysteresis) */ |
| 54 | if( ind[ k ] < *prev_ind ) { |
| 55 | ind[ k ]++; |
| 56 | } |
| 57 | ind[ k ] = silk_LIMIT_int( ind[ k ], 0, N_LEVELS_QGAIN - 1 ); |
| 58 | |
| 59 | /* Compute delta indices and limit */ |
| 60 | if( k == 0 && conditional == 0 ) { |
| 61 | /* Full index */ |
| 62 | ind[ k ] = silk_LIMIT_int( ind[ k ], *prev_ind + MIN_DELTA_GAIN_QUANT, N_LEVELS_QGAIN - 1 ); |
| 63 | *prev_ind = ind[ k ]; |
| 64 | } else { |
| 65 | /* Delta index */ |
| 66 | ind[ k ] = ind[ k ] - *prev_ind; |
| 67 | |
| 68 | /* Double the quantization step size for large gain increases, so that the max gain level can be reached */ |
| 69 | double_step_size_threshold = 2 * MAX_DELTA_GAIN_QUANT - N_LEVELS_QGAIN + *prev_ind; |
| 70 | if( ind[ k ] > double_step_size_threshold ) { |
| 71 | ind[ k ] = double_step_size_threshold + silk_RSHIFT( ind[ k ] - double_step_size_threshold + 1, 1 ); |
| 72 | } |
| 73 | |
| 74 | ind[ k ] = silk_LIMIT_int( ind[ k ], MIN_DELTA_GAIN_QUANT, MAX_DELTA_GAIN_QUANT ); |
| 75 | |
| 76 | /* Accumulate deltas */ |
| 77 | if( ind[ k ] > double_step_size_threshold ) { |
| 78 | *prev_ind += silk_LSHIFT( ind[ k ], 1 ) - double_step_size_threshold; |
| 79 | } else { |
| 80 | *prev_ind += ind[ k ]; |
| 81 | } |
| 82 | |
| 83 | /* Shift to make non-negative */ |
| 84 | ind[ k ] -= MIN_DELTA_GAIN_QUANT; |
| 85 | } |
| 86 | |
| 87 | /* Scale and convert to linear scale */ |
| 88 | gain_Q16[ k ] = silk_log2lin( silk_min_32( silk_SMULWB( INV_SCALE_Q16, *prev_ind ) + OFFSET, 3967 ) ); /* 3967 = 31 in Q7 */ |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | /* Gains scalar dequantization, uniform on log scale */ |
| 93 | void silk_gains_dequant( |
| 94 | opus_int32 gain_Q16[ MAX_NB_SUBFR ], /* O quantized gains */ |
| 95 | const opus_int8 ind[ MAX_NB_SUBFR ], /* I gain indices */ |
| 96 | opus_int8 *prev_ind, /* I/O last index in previous frame */ |
| 97 | const opus_int conditional, /* I first gain is delta coded if 1 */ |
| 98 | const opus_int nb_subfr /* I number of subframes */ |
| 99 | ) |
| 100 | { |
| 101 | opus_int k, ind_tmp, double_step_size_threshold; |
| 102 | |
| 103 | for( k = 0; k < nb_subfr; k++ ) { |
| 104 | if( k == 0 && conditional == 0 ) { |
| 105 | /* Gain index is not allowed to go down more than 16 steps (~21.8 dB) */ |
| 106 | *prev_ind = silk_max_int( ind[ k ], *prev_ind - 16 ); |
| 107 | } else { |
| 108 | /* Delta index */ |
| 109 | ind_tmp = ind[ k ] + MIN_DELTA_GAIN_QUANT; |
| 110 | |
| 111 | /* Accumulate deltas */ |
| 112 | double_step_size_threshold = 2 * MAX_DELTA_GAIN_QUANT - N_LEVELS_QGAIN + *prev_ind; |
| 113 | if( ind_tmp > double_step_size_threshold ) { |
| 114 | *prev_ind += silk_LSHIFT( ind_tmp, 1 ) - double_step_size_threshold; |
| 115 | } else { |
| 116 | *prev_ind += ind_tmp; |
| 117 | } |
| 118 | } |
| 119 | *prev_ind = silk_LIMIT_int( *prev_ind, 0, N_LEVELS_QGAIN - 1 ); |
| 120 | |
| 121 | /* Scale and convert to linear scale */ |
| 122 | gain_Q16[ k ] = silk_log2lin( silk_min_32( silk_SMULWB( INV_SCALE_Q16, *prev_ind ) + OFFSET, 3967 ) ); /* 3967 = 31 in Q7 */ |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | /* Compute unique identifier of gain indices vector */ |
| 127 | opus_int32 silk_gains_ID( /* O returns unique identifier of gains */ |
| 128 | const opus_int8 ind[ MAX_NB_SUBFR ], /* I gain indices */ |
| 129 | const opus_int nb_subfr /* I number of subframes */ |
| 130 | ) |
| 131 | { |
| 132 | opus_int k; |
| 133 | opus_int32 gainsID; |
| 134 | |
| 135 | gainsID = 0; |
| 136 | for( k = 0; k < nb_subfr; k++ ) { |
| 137 | gainsID = silk_ADD_LSHIFT32( ind[ k ], gainsID, 8 ); |
| 138 | } |
| 139 | |
| 140 | return gainsID; |
| 141 | } |