control_SNR.c (5447B)
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 residual quantizer */ 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 }