82 lines
2.1 KiB
C
82 lines
2.1 KiB
C
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/* brrUtils - BRR audio codec utilities
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* Copyright (C) 2022 tildearrow
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#include "brrUtils.h"
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void brrEncode(short* buf, unsigned char* out, long len) {
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if (len==0) return;
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// TODO
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}
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#define DO_ONE_SAMPLE \
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if (next&8) next|=0xfff8; \
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\
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next<<=(buf[0]>>4); /* range */ \
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\
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switch (control&0xc) { /* filter */ \
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case 0: \
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break; \
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case 4: \
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next+=(last1*15)/16; \
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break; \
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case 8: \
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next+=(last1*61)/32-(last2*15)/16; \
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break; \
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case 12: \
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next+=(last1*115)/64-(last2*13)/16; \
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break; \
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} \
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\
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if (next>32767) next=32767; \
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if (next<-32768) next=-32768; \
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\
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last2=last1; \
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last1=next; \
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*out=next; \
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out++;
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void brrDecode(unsigned char* buf, short* out, long len) {
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if (len==0) return;
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int last1=0;
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int last2=0;
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int next=0;
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// don't read out of bounds
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len-=8;
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for (long i=0; i<len; i+=9) {
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unsigned char control=buf[0];
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for (unsigned char j=1; j<9; j++) {
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next=buf[j]&15;
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DO_ONE_SAMPLE;
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next=buf[j]>>4;
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DO_ONE_SAMPLE;
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}
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// end bit
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if (control&1) break;
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buf+=9;
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}
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}
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