1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
|
/***********************************************************************
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
/*
* Matrix of resampling methods used:
* Fs_out (kHz)
* 8 12 16 24 48
*
* 8 C UF U UF UF
* 12 AF C UF U UF
* Fs_in (kHz) 16 D AF C UF UF
* 24 AF D AF C U
* 48 AF AF AF D C
*
* C -> Copy (no resampling)
* D -> Allpass-based 2x downsampling
* U -> Allpass-based 2x upsampling
* UF -> Allpass-based 2x upsampling followed by FIR interpolation
* AF -> AR2 filter followed by FIR interpolation
*/
#include "resampler_private.h"
/* Tables with delay compensation values to equalize total delay for different modes */
static const opus_int8 delay_matrix_enc[ 5 ][ 3 ] = {
/* in \ out 8 12 16 */
/* 8 */ { 6, 0, 3 },
/* 12 */ { 0, 7, 3 },
/* 16 */ { 0, 1, 10 },
/* 24 */ { 0, 2, 6 },
/* 48 */ { 18, 10, 12 }
};
static const opus_int8 delay_matrix_dec[ 3 ][ 5 ] = {
/* in \ out 8 12 16 24 48 */
/* 8 */ { 4, 0, 2, 0, 0 },
/* 12 */ { 0, 9, 4, 7, 4 },
/* 16 */ { 0, 3, 12, 7, 7 }
};
/* Simple way to make [8000, 12000, 16000, 24000, 48000] to [0, 1, 2, 3, 4] */
#define rateID(R) ( ( ( ((R)>>12) - ((R)>16000) ) >> ((R)>24000) ) - 1 )
#define USE_silk_resampler_copy (0)
#define USE_silk_resampler_private_up2_HQ_wrapper (1)
#define USE_silk_resampler_private_IIR_FIR (2)
#define USE_silk_resampler_private_down_FIR (3)
/* Initialize/reset the resampler state for a given pair of input/output sampling rates */
opus_int silk_resampler_init(
silk_resampler_state_struct *S, /* I/O Resampler state */
opus_int32 Fs_Hz_in, /* I Input sampling rate (Hz) */
opus_int32 Fs_Hz_out, /* I Output sampling rate (Hz) */
opus_int forEnc /* I If 1: encoder; if 0: decoder */
)
{
opus_int up2x;
/* Clear state */
silk_memset( S, 0, sizeof( silk_resampler_state_struct ) );
/* Input checking */
if( forEnc ) {
if( ( Fs_Hz_in != 8000 && Fs_Hz_in != 12000 && Fs_Hz_in != 16000 && Fs_Hz_in != 24000 && Fs_Hz_in != 48000 ) ||
( Fs_Hz_out != 8000 && Fs_Hz_out != 12000 && Fs_Hz_out != 16000 ) ) {
silk_assert( 0 );
return -1;
}
S->inputDelay = delay_matrix_enc[ rateID( Fs_Hz_in ) ][ rateID( Fs_Hz_out ) ];
} else {
if( ( Fs_Hz_in != 8000 && Fs_Hz_in != 12000 && Fs_Hz_in != 16000 ) ||
( Fs_Hz_out != 8000 && Fs_Hz_out != 12000 && Fs_Hz_out != 16000 && Fs_Hz_out != 24000 && Fs_Hz_out != 48000 ) ) {
silk_assert( 0 );
return -1;
}
S->inputDelay = delay_matrix_dec[ rateID( Fs_Hz_in ) ][ rateID( Fs_Hz_out ) ];
}
S->Fs_in_kHz = silk_DIV32_16( Fs_Hz_in, 1000 );
S->Fs_out_kHz = silk_DIV32_16( Fs_Hz_out, 1000 );
/* Number of samples processed per batch */
S->batchSize = S->Fs_in_kHz * RESAMPLER_MAX_BATCH_SIZE_MS;
/* Find resampler with the right sampling ratio */
up2x = 0;
if( Fs_Hz_out > Fs_Hz_in ) {
/* Upsample */
if( Fs_Hz_out == silk_MUL( Fs_Hz_in, 2 ) ) { /* Fs_out : Fs_in = 2 : 1 */
/* Special case: directly use 2x upsampler */
S->resampler_function = USE_silk_resampler_private_up2_HQ_wrapper;
} else {
/* Default resampler */
S->resampler_function = USE_silk_resampler_private_IIR_FIR;
up2x = 1;
}
} else if ( Fs_Hz_out < Fs_Hz_in ) {
/* Downsample */
S->resampler_function = USE_silk_resampler_private_down_FIR;
if( silk_MUL( Fs_Hz_out, 4 ) == silk_MUL( Fs_Hz_in, 3 ) ) { /* Fs_out : Fs_in = 3 : 4 */
S->FIR_Fracs = 3;
S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR0;
S->Coefs = silk_Resampler_3_4_COEFS;
} else if( silk_MUL( Fs_Hz_out, 3 ) == silk_MUL( Fs_Hz_in, 2 ) ) { /* Fs_out : Fs_in = 2 : 3 */
S->FIR_Fracs = 2;
S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR0;
S->Coefs = silk_Resampler_2_3_COEFS;
} else if( silk_MUL( Fs_Hz_out, 2 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 2 */
S->FIR_Fracs = 1;
S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR1;
S->Coefs = silk_Resampler_1_2_COEFS;
} else if( silk_MUL( Fs_Hz_out, 3 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 3 */
S->FIR_Fracs = 1;
S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR2;
S->Coefs = silk_Resampler_1_3_COEFS;
} else if( silk_MUL( Fs_Hz_out, 4 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 4 */
S->FIR_Fracs = 1;
S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR2;
S->Coefs = silk_Resampler_1_4_COEFS;
} else if( silk_MUL( Fs_Hz_out, 6 ) == Fs_Hz_in ) { /* Fs_out : Fs_in = 1 : 6 */
S->FIR_Fracs = 1;
S->FIR_Order = RESAMPLER_DOWN_ORDER_FIR2;
S->Coefs = silk_Resampler_1_6_COEFS;
} else {
/* None available */
silk_assert( 0 );
return -1;
}
} else {
/* Input and output sampling rates are equal: copy */
S->resampler_function = USE_silk_resampler_copy;
}
/* Ratio of input/output samples */
S->invRatio_Q16 = silk_LSHIFT32( silk_DIV32( silk_LSHIFT32( Fs_Hz_in, 14 + up2x ), Fs_Hz_out ), 2 );
/* Make sure the ratio is rounded up */
while( silk_SMULWW( S->invRatio_Q16, Fs_Hz_out ) < silk_LSHIFT32( Fs_Hz_in, up2x ) ) {
S->invRatio_Q16++;
}
return 0;
}
/* Resampler: convert from one sampling rate to another */
/* Input and output sampling rate are at most 48000 Hz */
opus_int silk_resampler(
silk_resampler_state_struct *S, /* I/O Resampler state */
opus_int16 out[], /* O Output signal */
const opus_int16 in[], /* I Input signal */
opus_int32 inLen /* I Number of input samples */
)
{
opus_int nSamples;
/* Need at least 1 ms of input data */
silk_assert( inLen >= S->Fs_in_kHz );
/* Delay can't exceed the 1 ms of buffering */
silk_assert( S->inputDelay <= S->Fs_in_kHz );
nSamples = S->Fs_in_kHz - S->inputDelay;
/* Copy to delay buffer */
silk_memcpy( &S->delayBuf[ S->inputDelay ], in, nSamples * sizeof( opus_int16 ) );
switch( S->resampler_function ) {
case USE_silk_resampler_private_up2_HQ_wrapper:
silk_resampler_private_up2_HQ_wrapper( S, out, S->delayBuf, S->Fs_in_kHz );
silk_resampler_private_up2_HQ_wrapper( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz );
break;
case USE_silk_resampler_private_IIR_FIR:
silk_resampler_private_IIR_FIR( S, out, S->delayBuf, S->Fs_in_kHz );
silk_resampler_private_IIR_FIR( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz );
break;
case USE_silk_resampler_private_down_FIR:
silk_resampler_private_down_FIR( S, out, S->delayBuf, S->Fs_in_kHz );
silk_resampler_private_down_FIR( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz );
break;
default:
silk_memcpy( out, S->delayBuf, S->Fs_in_kHz * sizeof( opus_int16 ) );
silk_memcpy( &out[ S->Fs_out_kHz ], &in[ nSamples ], ( inLen - S->Fs_in_kHz ) * sizeof( opus_int16 ) );
}
/* Copy to delay buffer */
silk_memcpy( S->delayBuf, &in[ inLen - S->inputDelay ], S->inputDelay * sizeof( opus_int16 ) );
return 0;
}
|