mirror of
https://github.com/tildearrow/furnace.git
synced 2024-12-01 00:43:02 +00:00
399 lines
9.3 KiB
C
399 lines
9.3 KiB
C
/* brrUtils - BRR audio codec utilities
|
|
* Copyright (C) 2022 tildearrow
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in all
|
|
* copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
* SOFTWARE.
|
|
*/
|
|
|
|
#include "brrUtils.h"
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
|
|
#define NEXT_SAMPLE buf[j]-(buf[j]>>3)
|
|
|
|
#define DO_ONE_DEC(r) \
|
|
if (nextDec&8) nextDec|=0xfffffff0; \
|
|
\
|
|
if (r>=13) { /* invalid shift */ \
|
|
nextDec=(nextDec<0)?0xfffff800:0; \
|
|
} else { \
|
|
nextDec<<=r; /* range */ \
|
|
nextDec>>=1; \
|
|
} \
|
|
\
|
|
switch (filter) { /* filter */ \
|
|
case 0: \
|
|
break; \
|
|
case 1: \
|
|
nextDec+=last1+((-last1)>>4); \
|
|
break; \
|
|
case 2: \
|
|
nextDec+=last1*2+((-last1*3)>>5)-last2+(last2>>4); \
|
|
break; \
|
|
case 3: \
|
|
nextDec+=last1*2+((-last1*13)>>6)-last2+((last2*3)>>4); \
|
|
break; \
|
|
} \
|
|
\
|
|
if (nextDec>32767) nextDec=32767; \
|
|
if (nextDec<-32768) nextDec=-32768; \
|
|
nextDec&=0x7fff; \
|
|
if (nextDec&0x4000) nextDec|=0xffff8000; \
|
|
\
|
|
last2=last1; \
|
|
last1=nextDec; \
|
|
|
|
void brrEncodeBlock(const short* buf, unsigned char* out, unsigned char range, unsigned char filter, short* last1, short* last2, int* errorSum) {
|
|
// encode one block using BRR
|
|
unsigned char nibble=0;
|
|
int preOut=0;
|
|
int pred=0;
|
|
int nextDec=0;
|
|
int nextError=0;
|
|
*errorSum=0;
|
|
for (int j=0; j<16; j++) {
|
|
short s=NEXT_SAMPLE;
|
|
switch (filter) {
|
|
case 0: // no filter
|
|
pred=s;
|
|
break;
|
|
case 1: // simple
|
|
pred=s-(((int)(*last1*2)*15)>>4);
|
|
break;
|
|
case 2: // complex
|
|
pred=s+(((int)(*last2*2)*15)>>4)-(((int)(*last1*2)*61)>>5);
|
|
break;
|
|
case 3:
|
|
pred=s+(((int)(*last2*2)*13)>>4)-(((int)(*last1*2)*115)>>6);
|
|
break;
|
|
}
|
|
|
|
if (pred<-32768) pred=-32768;
|
|
if (pred>32767) pred=32767;
|
|
|
|
preOut=pred>>range;
|
|
if (range) {
|
|
if (pred&(1<<(range>>1))) preOut++;
|
|
if (filter==0 && range>=12) if (preOut<-7) preOut=-7;
|
|
}
|
|
if (preOut>7) preOut=7;
|
|
if (preOut<-8) preOut=-8;
|
|
|
|
nibble=preOut&15;
|
|
if (j&1) {
|
|
out[j>>1]|=nibble;
|
|
} else {
|
|
out[j>>1]=nibble<<4;
|
|
}
|
|
|
|
// roll last1/last2
|
|
nextDec=nibble;
|
|
if (nextDec&8) nextDec|=0xfffffff0;
|
|
|
|
if (range>=13) { /* invalid shift */
|
|
nextDec=(nextDec<0)?0xfffff800:0;
|
|
} else {
|
|
nextDec<<=range; /* range */
|
|
nextDec>>=1;
|
|
}
|
|
|
|
switch (filter) { /* filter */
|
|
case 0:
|
|
break;
|
|
case 1:
|
|
nextDec+=(*last1)+((-(*last1))>>4);
|
|
break;
|
|
case 2:
|
|
nextDec+=(*last1)*2+((-(*last1)*3)>>5)-(*last2)+((*last2)>>4);
|
|
break;
|
|
case 3:
|
|
nextDec+=(*last1)*2+((-(*last1)*13)>>6)-(*last2)+(((*last2)*3)>>4);
|
|
break;
|
|
}
|
|
|
|
nextDec&=0x7fff;
|
|
if (nextDec&0x4000) nextDec|=0xffff8000;
|
|
|
|
nextError=s-(nextDec<<1);
|
|
if (nextError<0) nextError=-nextError;
|
|
*errorSum+=nextError;
|
|
|
|
*last2=*last1;
|
|
*last1=nextDec;
|
|
}
|
|
}
|
|
|
|
long brrEncode(short* buf, unsigned char* out, long len, long loopStart, unsigned char emphasis) {
|
|
if (len==0) return 0;
|
|
|
|
// encoding process:
|
|
// 1. read next group of 16 samples
|
|
// 2. is this the first block?
|
|
// - if yes, don't filter. output and then go to 1
|
|
// 4. try encoding using 3 filters and 12 ranges (besides no filter)
|
|
// 5. which one of these yields the least amount of error?
|
|
// 6. output the one which does
|
|
// 7. do we still have more to encode?
|
|
// - if so, go to 1
|
|
// 8. is loop point set?
|
|
// - if not, end process here
|
|
// 9. is transition between last block and loop block smooth?
|
|
// - if not, encode the loop block again and output it
|
|
long total=0;
|
|
unsigned char filter=0;
|
|
unsigned char range=0;
|
|
|
|
short x0=0;
|
|
short x1=0;
|
|
short x2=0;
|
|
int emphOut=0;
|
|
|
|
short in[17];
|
|
|
|
short last1[4][13];
|
|
short last2[4][13];
|
|
int avgError[4][13];
|
|
unsigned char possibleOut[4][13][8];
|
|
|
|
memset(in,0,16*sizeof(short));
|
|
memset(last1,0,4*13*sizeof(short));
|
|
memset(last2,0,4*13*sizeof(short));
|
|
memset(avgError,0,4*13*sizeof(int));
|
|
memset(possibleOut,0,4*13*8);
|
|
|
|
for (long i=0; i<len; i+=16) {
|
|
if (i+17>len) {
|
|
long p=i;
|
|
for (int j=0; j<17; j++) {
|
|
if (p>=len) {
|
|
if (loopStart<0 || loopStart>=len) {
|
|
in[j]=0;
|
|
} else {
|
|
p=loopStart;
|
|
in[j]=buf[p++];
|
|
}
|
|
} else {
|
|
in[j]=buf[p++];
|
|
}
|
|
}
|
|
} else {
|
|
memcpy(in,&buf[i],17*sizeof(short));
|
|
}
|
|
|
|
// emphasis
|
|
if (emphasis) {
|
|
for (int j=0; j<17; j++) {
|
|
x0=x1;
|
|
x1=x2;
|
|
x2=in[j];
|
|
|
|
if (j==0) continue;
|
|
emphOut=((x1<<11)-x0*370-in[j]*374)/1305;
|
|
if (emphOut<-32768) emphOut=-32768;
|
|
if (emphOut>32767) emphOut=32767;
|
|
in[j-1]=emphOut;
|
|
}
|
|
}
|
|
|
|
// encode
|
|
for (int j=0; j<4; j++) {
|
|
for (int k=0; k<13; k++) {
|
|
brrEncodeBlock(in,possibleOut[j][k],k,j,&last1[j][k],&last2[j][k],&avgError[j][k]);
|
|
}
|
|
}
|
|
|
|
// find best filter/range
|
|
int candError=0x7fffffff;
|
|
if (i==0) {
|
|
filter=0;
|
|
for (int k=0; k<13; k++) {
|
|
if (avgError[0][k]<candError) {
|
|
candError=avgError[0][k];
|
|
range=k;
|
|
}
|
|
}
|
|
} else {
|
|
for (int j=0; j<4; j++) {
|
|
for (int k=0; k<13; k++) {
|
|
if (avgError[j][k]<candError) {
|
|
candError=avgError[j][k];
|
|
filter=j;
|
|
range=k;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// write
|
|
out[0]=(range<<4)|(filter<<2)|((i+16>=len && loopStart<0)?1:0);
|
|
for (int j=0; j<8; j++) {
|
|
out[j+1]=possibleOut[filter][range][j];
|
|
}
|
|
|
|
for (int j=0; j<4; j++) {
|
|
for (int k=0; k<13; k++) {
|
|
last1[j][k]=last1[filter][range];
|
|
last2[j][k]=last2[filter][range];
|
|
}
|
|
}
|
|
out+=9;
|
|
total+=9;
|
|
}
|
|
// encode loop block
|
|
if (loopStart>=0) {
|
|
long p=loopStart;
|
|
for (int i=0; i<17; i++) {
|
|
if (p>=len) {
|
|
p=loopStart;
|
|
}
|
|
in[i]=buf[p++];
|
|
}
|
|
|
|
if (emphasis) {
|
|
for (int j=0; j<17; j++) {
|
|
x0=x1;
|
|
x1=x2;
|
|
x2=in[j];
|
|
|
|
if (j==0) continue;
|
|
emphOut=((x1<<11)-x0*370-in[j]*374)/1305;
|
|
if (emphOut<-32768) emphOut=-32768;
|
|
if (emphOut>32767) emphOut=32767;
|
|
in[j-1]=emphOut;
|
|
}
|
|
}
|
|
|
|
// encode (filter 0/1 only)
|
|
for (int j=0; j<2; j++) {
|
|
for (int k=0; k<13; k++) {
|
|
brrEncodeBlock(in,possibleOut[j][k],k,j,&last1[j][k],&last2[j][k],&avgError[j][k]);
|
|
}
|
|
}
|
|
|
|
// find best filter/range
|
|
int candError=0x7fffffff;
|
|
for (int j=0; j<2; j++) {
|
|
for (int k=0; k<13; k++) {
|
|
if (avgError[j][k]<candError) {
|
|
candError=avgError[j][k];
|
|
filter=j;
|
|
range=k;
|
|
}
|
|
}
|
|
}
|
|
|
|
// write
|
|
out[0]=(range<<4)|(filter<<2)|3;
|
|
for (int j=0; j<8; j++) {
|
|
out[j+1]=possibleOut[filter][range][j];
|
|
}
|
|
|
|
for (int j=0; j<4; j++) {
|
|
for (int k=0; k<13; k++) {
|
|
last1[j][k]=last1[filter][range];
|
|
last2[j][k]=last2[filter][range];
|
|
}
|
|
}
|
|
out+=9;
|
|
total+=9;
|
|
}
|
|
return total;
|
|
}
|
|
|
|
#define DO_ONE_SAMPLE \
|
|
if (next&8) next|=0xfffffff0; \
|
|
\
|
|
if (buf[0]>=0xd0) { /* invalid shift */ \
|
|
next=(next<0)?0xfffff800:0; \
|
|
} else { \
|
|
next<<=(buf[0]>>4); /* range */ \
|
|
next>>=1; \
|
|
} \
|
|
\
|
|
switch (control&0xc) { /* filter */ \
|
|
case 0: \
|
|
break; \
|
|
case 4: \
|
|
next+=last1+((-last1)>>4); \
|
|
break; \
|
|
case 8: \
|
|
next+=last1*2+((-last1*3)>>5)-last2+(last2>>4); \
|
|
break; \
|
|
case 12: \
|
|
next+=last1*2+((-last1*13)>>6)-last2+((last2*3)>>4); \
|
|
break; \
|
|
} \
|
|
\
|
|
if (next>32767) next=32767; \
|
|
if (next<-32768) next=-32768; \
|
|
next&=0x7fff; \
|
|
if (next&0x4000) next|=0xffff8000; \
|
|
\
|
|
last2=last1; \
|
|
last1=next; \
|
|
*out=next<<1; \
|
|
out++;
|
|
|
|
long brrDecode(unsigned char* buf, short* out, long len, unsigned char emphasis) {
|
|
if (len==0) return 0;
|
|
|
|
short* outOrig=out;
|
|
|
|
long total=0;
|
|
|
|
int last1=0;
|
|
int last2=0;
|
|
int next=0;
|
|
|
|
// don't read out of bounds
|
|
len-=8;
|
|
|
|
for (long i=0; i<len; i+=9) {
|
|
unsigned char control=buf[0];
|
|
|
|
for (unsigned char j=1; j<9; j++) {
|
|
next=buf[j]>>4;
|
|
DO_ONE_SAMPLE;
|
|
|
|
next=buf[j]&15;
|
|
DO_ONE_SAMPLE;
|
|
}
|
|
|
|
// end bit
|
|
total+=16;
|
|
if (control&1) break;
|
|
buf+=9;
|
|
}
|
|
|
|
if (emphasis) {
|
|
short x0=0;
|
|
short x1=0;
|
|
short x2=0;
|
|
for (long i=0; i<=total; i++) {
|
|
x0=x1;
|
|
x1=x2;
|
|
x2=(i>=total)?0:outOrig[i];
|
|
|
|
if (i==0) continue;
|
|
|
|
outOrig[i-1]=(x0*370+x1*1305+x2*374)>>11;
|
|
}
|
|
}
|
|
|
|
return total;
|
|
}
|