1 /* 2 * Copyright (C) 2016 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 /* 39 * btstack_sbc_plc.c 40 * 41 */ 42 43 #include <stdint.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <fcntl.h> 48 #include <unistd.h> 49 #include <math.h> 50 51 #include "btstack_sbc_plc.h" 52 53 static uint8_t indices0[] = { 0xad, 0x00, 0x00, 0xc5, 0x00, 0x00, 0x00, 0x00, 0x77, 0x6d, 54 0xb6, 0xdd, 0xdb, 0x6d, 0xb7, 0x76, 0xdb, 0x6d, 0xdd, 0xb6, 0xdb, 0x77, 0x6d, 55 0xb6, 0xdd, 0xdb, 0x6d, 0xb7, 0x76, 0xdb, 0x6d, 0xdd, 0xb6, 0xdb, 0x77, 0x6d, 56 0xb6, 0xdd, 0xdb, 0x6d, 0xb7, 0x76, 0xdb, 0x6d, 0xdd, 0xb6, 0xdb, 0x77, 0x6d, 57 0xb6, 0xdd, 0xdb, 0x6d, 0xb7, 0x76, 0xdb, 0x6c}; 58 59 /* Raised COSine table for OLA */ 60 static float rcos[OLAL] = { 61 0.99148655f,0.96623611f,0.92510857f,0.86950446f, 62 0.80131732f,0.72286918f,0.63683150f,0.54613418f, 63 0.45386582f,0.36316850f,0.27713082f,0.19868268f, 64 0.13049554f,0.07489143f,0.03376389f,0.00851345f}; 65 66 static float CrossCorrelation(int16_t *x, int16_t *y); 67 static int PatternMatch(int16_t *y); 68 static float AmplitudeMatch(int16_t *y, int16_t bestmatch); 69 70 uint8_t * btstack_sbc_plc_zero_signal_frame(void){ 71 return (uint8_t *)&indices0; 72 } 73 74 void btstack_sbc_plc_init(btstack_sbc_plc_state_t *plc_state){ 75 int i; 76 plc_state->nbf=0; 77 plc_state->bestlag=0; 78 // for (i=0;i<LHIST+FS+CVSDRT+OLAL;i++){ 79 // plc_state->hist[i] = 0; 80 // } 81 memset(plc_state->hist,0,sizeof(plc_state->hist)); 82 83 } 84 85 void btstack_sbc_plc_bad_frame(btstack_sbc_plc_state_t *plc_state, int16_t *ZIRbuf, int16_t *out){ 86 int i; 87 float val; 88 float sf; 89 plc_state->nbf++; 90 sf=1.0f; 91 92 i=0; 93 if (plc_state->nbf==1){ 94 /* Perform pattern matching to find where to replicate */ 95 plc_state->bestlag = PatternMatch(plc_state->hist); 96 /* the replication begins after the template match */ 97 plc_state->bestlag += M; 98 99 /* Compute Scale Factor to Match Amplitude of Substitution Packet to that of Preceding Packet */ 100 sf = AmplitudeMatch(plc_state->hist, plc_state->bestlag); 101 for (i=0;i<OLAL;i++){ 102 val = ZIRbuf[i]*rcos[i] + sf*plc_state->hist[plc_state->bestlag+i]*rcos[OLAL-i-1]; 103 if (val > 32767.0) val= 32767.0; 104 if (val < -32768.0) val=-32768.0; 105 plc_state->hist[LHIST+i] = (int16_t)val; 106 } 107 108 for (;i<FS;i++){ 109 val = sf*plc_state->hist[plc_state->bestlag+i]; if (val > 32767.0) val= 32767.0; 110 if (val < -32768.0) val=-32768.0; plc_state->hist[LHIST+i] = (int16_t)val; 111 } 112 113 for (;i<FS+OLAL;i++){ 114 val = sf*plc_state->hist[plc_state->bestlag+i]*rcos[i-FS]+plc_state->hist[plc_state->bestlag+i]*rcos[OLAL-1-i+FS]; 115 if (val > 32767.0) val= 32767.0; 116 if (val < -32768.0) val=-32768.0; 117 plc_state->hist[LHIST+i] = (int16_t)val; 118 } 119 120 for (;i<FS+SBCRT+OLAL;i++) 121 plc_state->hist[LHIST+i] = plc_state->hist[plc_state->bestlag+i]; 122 } else { 123 for (;i<FS;i++) 124 plc_state->hist[LHIST+i] = plc_state->hist[plc_state->bestlag+i]; 125 for (;i<FS+SBCRT+OLAL;i++) 126 plc_state->hist[LHIST+i] = plc_state->hist[plc_state->bestlag+i]; 127 } 128 for (i=0;i<FS;i++) 129 out[i] = plc_state->hist[LHIST+i]; 130 131 /* shift the history buffer */ 132 for (i=0;i<LHIST+SBCRT+OLAL;i++) 133 plc_state->hist[i] = plc_state->hist[i+FS]; 134 135 } 136 137 void btstack_sbc_plc_good_frame(btstack_sbc_plc_state_t *plc_state, int16_t *in, int16_t *out){ 138 int i; 139 i=0; 140 if (plc_state->nbf>0){ 141 for (i=0;i<SBCRT;i++) 142 out[i] = plc_state->hist[LHIST+i]; 143 for (;i<SBCRT+OLAL;i++) 144 out[i] = (int16_t)(plc_state->hist[LHIST+i]*rcos[i-SBCRT] + in[i]*rcos[OLAL-1-i+SBCRT]); 145 } 146 for (;i<FS;i++) 147 out[i] = in[i]; 148 /*Copy the output to the history buffer */ 149 for (i=0;i<FS;i++) 150 plc_state->hist[LHIST+i] = out[i]; 151 /* shift the history buffer */ 152 for (i=0;i<LHIST;i++) 153 plc_state->hist[i] = plc_state->hist[i+FS]; 154 plc_state->nbf=0; 155 } 156 157 158 float CrossCorrelation(int16_t *x, int16_t *y){ 159 int m; 160 float num; 161 float den; 162 float Cn; 163 float x2, y2; 164 num=0; 165 den=0; 166 x2=0.0; 167 y2=0.0; 168 for (m=0;m<M;m++){ 169 num+=((float)x[m])*y[m]; 170 x2+=((float)x[m])*x[m]; 171 y2+=((float)y[m])*y[m]; 172 } 173 den = (float)sqrt(x2*y2); 174 Cn = num/den; 175 return(Cn); 176 } 177 178 int PatternMatch(int16_t *y){ 179 int n; 180 float maxCn; 181 float Cn; 182 int bestmatch; 183 maxCn=-999999.0; /* large negative number */ 184 bestmatch=0; 185 for (n=0;n<N;n++){ 186 Cn = CrossCorrelation(&y[LHIST-M] /* x */, &y[n]); 187 if (Cn>maxCn){ 188 bestmatch=n; 189 maxCn = Cn; 190 } 191 } 192 return(bestmatch); 193 } 194 195 196 float AmplitudeMatch(int16_t *y, int16_t bestmatch) { 197 int i; 198 float sumx; 199 float sumy; 200 float sf; 201 sumx = 0.0; 202 sumy = 0.000001f; 203 for (i=0;i<FS;i++){ 204 sumx += abs(y[LHIST-FS+i]); 205 sumy += abs(y[bestmatch+i]); 206 } 207 sf = sumx/sumy; 208 /* This is not in the paper, but limit the scaling factor to something reasonable to avoid creating artifacts */ 209 if (sf<0.75f) sf=0.75f; 210 if (sf>1.2f) sf=1.2f; 211 return(sf); 212 }