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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 "config.h"
30 #endif
31 
32 #include "main.h"
33 #include "tuning_parameters.h"
34 
35 /* These tables hold SNR values divided by 21 (so they fit in 8 bits)
36    for different target bitrates spaced at 400 bps interval. The first
37    10 values are omitted (0-4 kb/s) because they're all zeros.
38    These tables were obtained by running different SNRs through the
39    encoder and measuring the active bitrate. */
40 static const unsigned char silk_TargetRate_NB_21[117 - 10] = {
41                                               0, 15, 39, 52, 61, 68,
42      74, 79, 84, 88, 92, 95, 99,102,105,108,111,114,117,119,122,124,
43     126,129,131,133,135,137,139,142,143,145,147,149,151,153,155,157,
44     158,160,162,163,165,167,168,170,171,173,174,176,177,179,180,182,
45     183,185,186,187,189,190,192,193,194,196,197,199,200,201,203,204,
46     205,207,208,209,211,212,213,215,216,217,219,220,221,223,224,225,
47     227,228,230,231,232,234,235,236,238,239,241,242,243,245,246,248,
48     249,250,252,253,255
49 };
50 
51 static const unsigned char silk_TargetRate_MB_21[165 - 10] = {
52                                               0,  0, 28, 43, 52, 59,
53      65, 70, 74, 78, 81, 85, 87, 90, 93, 95, 98,100,102,105,107,109,
54     111,113,115,116,118,120,122,123,125,127,128,130,131,133,134,136,
55     137,138,140,141,143,144,145,147,148,149,151,152,153,154,156,157,
56     158,159,160,162,163,164,165,166,167,168,169,171,172,173,174,175,
57     176,177,178,179,180,181,182,183,184,185,186,187,188,188,189,190,
58     191,192,193,194,195,196,197,198,199,200,201,202,203,203,204,205,
59     206,207,208,209,210,211,212,213,214,214,215,216,217,218,219,220,
60     221,222,223,224,224,225,226,227,228,229,230,231,232,233,234,235,
61     236,236,237,238,239,240,241,242,243,244,245,246,247,248,249,250,
62     251,252,253,254,255
63 };
64 
65 static const unsigned char silk_TargetRate_WB_21[201 - 10] = {
66                                               0,  0,  0,  8, 29, 41,
67      49, 56, 62, 66, 70, 74, 77, 80, 83, 86, 88, 91, 93, 95, 97, 99,
68     101,103,105,107,108,110,112,113,115,116,118,119,121,122,123,125,
69     126,127,129,130,131,132,134,135,136,137,138,140,141,142,143,144,
70     145,146,147,148,149,150,151,152,153,154,156,157,158,159,159,160,
71     161,162,163,164,165,166,167,168,169,170,171,171,172,173,174,175,
72     176,177,177,178,179,180,181,181,182,183,184,185,185,186,187,188,
73     189,189,190,191,192,192,193,194,195,195,196,197,198,198,199,200,
74     200,201,202,203,203,204,205,206,206,207,208,209,209,210,211,211,
75     212,213,214,214,215,216,216,217,218,219,219,220,221,221,222,223,
76     224,224,225,226,226,227,228,229,229,230,231,232,232,233,234,234,
77     235,236,237,237,238,239,240,240,241,242,243,243,244,245,246,246,
78     247,248,249,249,250,251,252,253,255
79 };
80 
81 /* Control SNR of redidual quantizer */
silk_control_SNR(silk_encoder_state * psEncC,opus_int32 TargetRate_bps)82 opus_int silk_control_SNR(
83     silk_encoder_state          *psEncC,                        /* I/O  Pointer to Silk encoder state               */
84     opus_int32                  TargetRate_bps                  /* I    Target max bitrate (bps)                    */
85 )
86 {
87     int id;
88     int bound;
89     const unsigned char *snr_table;
90 
91     psEncC->TargetRate_bps = TargetRate_bps;
92     if( psEncC->nb_subfr == 2 ) {
93         TargetRate_bps -= 2000 + psEncC->fs_kHz/16;
94     }
95     if( psEncC->fs_kHz == 8 ) {
96         bound = sizeof(silk_TargetRate_NB_21);
97         snr_table = silk_TargetRate_NB_21;
98     } else if( psEncC->fs_kHz == 12 ) {
99         bound = sizeof(silk_TargetRate_MB_21);
100         snr_table = silk_TargetRate_MB_21;
101     } else {
102         bound = sizeof(silk_TargetRate_WB_21);
103         snr_table = silk_TargetRate_WB_21;
104     }
105     id = (TargetRate_bps+200)/400;
106     id = silk_min(id - 10, bound-1);
107     if( id <= 0 ) {
108         psEncC->SNR_dB_Q7 = 0;
109     } else {
110         psEncC->SNR_dB_Q7 = snr_table[id]*21;
111     }
112     return SILK_NO_ERROR;
113 }
114