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Diffstat (limited to 'lib/rbcodec/codecs/libopus/silk/gain_quant.c')
-rw-r--r-- | lib/rbcodec/codecs/libopus/silk/gain_quant.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libopus/silk/gain_quant.c b/lib/rbcodec/codecs/libopus/silk/gain_quant.c new file mode 100644 index 0000000000..e91ec937e1 --- /dev/null +++ b/lib/rbcodec/codecs/libopus/silk/gain_quant.c | |||
@@ -0,0 +1,141 @@ | |||
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. | ||
11 | - Neither the name of Internet Society, IETF or IETF Trust, nor the | ||
12 | names of specific contributors, may be used to endorse or promote | ||
13 | products derived from this software without specific prior written | ||
14 | permission. | ||
15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS” | ||
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 "opus_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 | } | ||