re-write BRR encoder

This commit is contained in:
tildearrow 2022-12-05 04:14:07 -05:00
parent 165774d136
commit 648851b5b5
1 changed files with 129 additions and 422 deletions

View File

@ -21,6 +21,8 @@
*/
#include "brrUtils.h"
#include <stdio.h>
#include <string.h>
#define NEXT_SAMPLE buf[j]-(buf[j]>>3)
@ -56,86 +58,86 @@
last2=last1; \
last1=nextDec; \
void brrEncodeBlock(const short* buf, unsigned char* out, unsigned char range, unsigned char filter, short* last1, short* last2) {
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
switch (filter) {
case 0:
for (int j=0; j<16; j++) {
}
break;
case 1:
for (int j=0; j<16; j++) {
int s=NEXT_SAMPLE;
unsigned char nibble=0;
short preOut=0;
int pred=0;
int nextDec=0;
int nextError=0;
*errorSum=0;
for (int j=0; j<16; j++) {
short s=NEXT_SAMPLE;
nibble<<=4;
switch (filter) {
case 0: // no filter
pred=s;
break;
case 1: // simple
pred=s-(((int)(*last1)*15)>>4);
break;
case 2: // complex
pred=s+(((int)(*last2)*15)>>4)-(((int)(*last1)*61)>>5);
break;
case 3:
pred=s+(((int)(*last2)*13)>>4)-(((int)(*last1)*115)>>6);
break;
}
pred1[j]=s-(((int)o1f1*15)>>4);
if (pred1[j]<-32768) pred1[j]=-32768;
if (pred1[j]>32767) pred1[j]=32767;
if (pred<-32768) pred=-32768;
if (pred>32767) pred=32767;
o0=pred1[j]>>range1;
if (range1) if (pred1[j]&(1<<(range1>>1))) o0++;
if (o0>7) o0=7;
if (o0<-8) o0=-8;
o=o0&15;
if (j&1) {
next1[j>>1]|=o;
} else {
next1[j>>1]=o<<4;
}
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;
nextDec=o;
DO_ONE_DEC(range1);
//o2f1=last2<<1;
o1f1=last1<<1;
}
break;
case 2:
for (int j=0; j<16; j++) {
int s=NEXT_SAMPLE;
pred2[j]=s+(((int)o2f2*15)>>4)-(((int)o1f2*61)>>5);
if (pred2[j]<-32768) pred2[j]=-32768;
if (pred2[j]>32767) pred2[j]=32767;
nibble=preOut&15;
if (j&1) {
out[j>>1]|=nibble;
} else {
out[j>>1]=nibble<<4;
}
o0=pred2[j]>>range2;
if (range2) if (pred2[j]&(1<<(range2>>1))) o0++;
if (o0>7) o0=7;
if (o0<-8) o0=-8;
o=o0&15;
if (j&1) {
next2[j>>1]|=o;
} else {
next2[j>>1]=o<<4;
}
// roll last1/last2
nextDec=nibble;
if (nextDec&8) nextDec|=0xfffffff0;
nextDec=o;
DO_ONE_DEC(range2);
o2f2=last2<<1;
o1f2=last1<<1;
}
break;
case 3:
for (int j=0; j<16; j++) {
int s=NEXT_SAMPLE;
pred3[j]=s+(((int)o2f3*13)>>4)-(((int)o1f3*115)>>6);
if (pred3[j]<-32768) pred3[j]=-32768;
if (pred3[j]>32767) pred3[j]=32767;
if (range>=13) { /* invalid shift */
nextDec=(nextDec<0)?0xfffff800:0;
} else {
nextDec<<=range; /* range */
nextDec>>=1;
}
o0=pred3[j]>>range3;
if (range3) if (pred3[j]&(1<<(range3>>1))) o0++;
if (o0>7) o0=7;
if (o0<-8) o0=-8;
o=o0&15;
if (j&1) {
next3[j>>1]|=o;
} else {
next3[j>>1]=o<<4;
}
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=o;
DO_ONE_DEC(range3);
o2f3=last2<<1;
o1f3=last1<<1;
}
break;
if (nextDec>32767) nextDec=32767;
if (nextDec<-32768) nextDec=-32768;
nextDec&=0x7fff;
if (nextDec&0x4000) nextDec|=0xffff8000;
nextError=s-(nextDec<<1);
if (nextError<0) nextError=-nextError;
*errorSum+=nextError;
*last2=*last1;
*last1=nextDec;
}
}
@ -146,375 +148,80 @@ long brrEncode(short* buf, unsigned char* out, long len, long loopStart) {
// 1. read next group of 16 samples
// 2. is this the first block?
// - if yes, don't filter. output and then go to 1
// 3. is this the loop block?
// - if yes, don't filter. output and then go to 1
// 4. try encoding using 4 filters
// - perform linear prediction
// - calculate range
// - decode and apply correction to achieve low error
// 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. is this the last block?
// - if yes, mark end and finish
// 8. go to 1
// 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 next0[8];
unsigned char next1[8];
unsigned char next2[8];
unsigned char next3[8];
unsigned char filter=0;
unsigned char range0=0;
unsigned char range1=0;
unsigned char range2=0;
unsigned char range3=0;
unsigned char range=0;
unsigned char o=0;
int pred1[16];
int pred2[16];
int pred3[16];
short o1=0;
short o2=0;
short o0=0;
short o1f1=0;
short o1f2=0;
short o1f3=0;
//short o2f1=0;
short o2f2=0;
short o2f3=0;
int last1=0;
int last2=0;
int nextDec=0;
int maxError[4];
int avgError[4];
short in[16];
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);
len&=~15;
loopStart&=~15;
for (long i=0; i<len; i+=16) {
range0=0;
// encode with no filter
for (int j=0; j<16; j++) {
short s=NEXT_SAMPLE;
if (s<0) s=-s;
while (range0<12 && s>((8<<range0)-1)) range0++;
}
for (int j=0; j<16; j++) {
short s=NEXT_SAMPLE;
o0=s>>range0;
if (range0) if (s&(1<<(range1>>1))) o0++;
if (o0>7) o0=7;
if (o0<-8) o0=-8;
if (range0>=12) if (o0<-7) o0=-7;
o=o0&15;
if (j&1) {
next0[j>>1]|=o;
} else {
next0[j>>1]=o<<4;
memcpy(in,buf,16*sizeof(short));
// 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]);
}
}
// encode with filter
if (i /*&& i!=loopStart*/) {
// 1: x = o0 - o1 * 15/16
// 2: x = o0 + o2 * 15/16 - o1 * 61/32
// 3: x = o0 + o2 * 13/16 - o1 * 115/64
range1=0;
range2=0;
range3=0;
//o2f1=o2;
o2f2=o2;
o2f3=o2;
o1f1=o1;
o1f2=o1;
o1f3=o1;
// first pass
for (int j=0; j<16; j++) {
int s=NEXT_SAMPLE;
pred1[j]=s-(((int)o1*15)>>4);
if (pred1[j]<-32768) pred1[j]=-32768;
if (pred1[j]>32767) pred1[j]=32767;
pred2[j]=s+(((int)o2*15)>>4)-(((int)o1*61)>>5);
if (pred2[j]<-32768) pred2[j]=-32768;
if (pred2[j]>32767) pred2[j]=32767;
pred3[j]=s+(((int)o2*13)>>4)-(((int)o1*115)>>6);
if (pred3[j]<-32768) pred3[j]=-32768;
if (pred3[j]>32767) pred3[j]=32767;
o2=o1;
o1=s;
}
// calculate range of values
for (int j=0; j<16; j++) {
short s=pred1[j];
if (s<0) s=-s;
while (range1<12 && s>((8<<range1)-1)) range1++;
s=pred2[j];
if (s<0) s=-s;
while (range2<12 && s>((8<<range2)-1)) range2++;
s=pred3[j];
if (s<0) s=-s;
while (range3<12 && s>((8<<range3)-1)) range3++;
}
// second pass
int prevLast1=last1;
int prevLast2=last2;
filter=1;
for (int j=0; j<16; j++) {
int s=NEXT_SAMPLE;
pred1[j]=s-(((int)o1f1*15)>>4);
if (pred1[j]<-32768) pred1[j]=-32768;
if (pred1[j]>32767) pred1[j]=32767;
o0=pred1[j]>>range1;
if (range1) if (pred1[j]&(1<<(range1>>1))) o0++;
if (o0>7) o0=7;
if (o0<-8) o0=-8;
o=o0&15;
if (j&1) {
next1[j>>1]|=o;
} else {
next1[j>>1]=o<<4;
}
nextDec=o;
DO_ONE_DEC(range1);
//o2f1=last2<<1;
o1f1=last1<<1;
}
last1=prevLast1;
last2=prevLast2;
filter=2;
for (int j=0; j<16; j++) {
int s=NEXT_SAMPLE;
pred2[j]=s+(((int)o2f2*15)>>4)-(((int)o1f2*61)>>5);
if (pred2[j]<-32768) pred2[j]=-32768;
if (pred2[j]>32767) pred2[j]=32767;
o0=pred2[j]>>range2;
if (range2) if (pred2[j]&(1<<(range2>>1))) o0++;
if (o0>7) o0=7;
if (o0<-8) o0=-8;
o=o0&15;
if (j&1) {
next2[j>>1]|=o;
} else {
next2[j>>1]=o<<4;
}
nextDec=o;
DO_ONE_DEC(range2);
o2f2=last2<<1;
o1f2=last1<<1;
}
last1=prevLast1;
last2=prevLast2;
filter=3;
for (int j=0; j<16; j++) {
int s=NEXT_SAMPLE;
pred3[j]=s+(((int)o2f3*13)>>4)-(((int)o1f3*115)>>6);
if (pred3[j]<-32768) pred3[j]=-32768;
if (pred3[j]>32767) pred3[j]=32767;
o0=pred3[j]>>range3;
if (range3) if (pred3[j]&(1<<(range3>>1))) o0++;
if (o0>7) o0=7;
if (o0<-8) o0=-8;
o=o0&15;
if (j&1) {
next3[j>>1]|=o;
} else {
next3[j>>1]=o<<4;
}
nextDec=o;
DO_ONE_DEC(range3);
o2f3=last2<<1;
o1f3=last1<<1;
}
last1=prevLast1;
last2=prevLast2;
// find best filter
int error=0;
maxError[0]=0;
maxError[1]=0;
maxError[2]=0;
maxError[3]=0;
avgError[0]=0;
avgError[1]=0;
avgError[2]=0;
avgError[3]=0;
// test filter 0
// find best filter/range
int candError=0x7fffffff;
if (i==0) {
filter=0;
for (int j=0; j<16; j++) {
int s=NEXT_SAMPLE;
if (j&1) {
nextDec=next0[j>>1]&15;
} else {
nextDec=next0[j>>1]>>4;
}
DO_ONE_DEC(range0);
error=s-(nextDec<<1);
if (error<0) error=-error;
avgError[0]+=error;
if (error>maxError[0]) maxError[0]=error;
}
last1=prevLast1;
last2=prevLast2;
// test filter 1
filter=1;
for (int j=0; j<16; j++) {
int s=NEXT_SAMPLE;
if (j&1) {
nextDec=next1[j>>1]&15;
} else {
nextDec=next1[j>>1]>>4;
}
DO_ONE_DEC(range1);
error=s-(nextDec<<1);
if (error<0) error=-error;
avgError[1]+=error;
if (error>maxError[1]) maxError[1]=error;
}
last1=prevLast1;
last2=prevLast2;
// test filter 2
filter=2;
for (int j=0; j<16; j++) {
int s=NEXT_SAMPLE;
if (j&1) {
nextDec=next2[j>>1]&15;
} else {
nextDec=next2[j>>1]>>4;
}
DO_ONE_DEC(range2);
error=s-(nextDec<<1);
if (error<0) error=-error;
avgError[2]+=error;
if (error>maxError[2]) maxError[2]=error;
}
last1=prevLast1;
last2=prevLast2;
// test filter 3
filter=3;
for (int j=0; j<16; j++) {
int s=NEXT_SAMPLE;
if (j&1) {
nextDec=next3[j>>1]&15;
} else {
nextDec=next3[j>>1]>>4;
}
DO_ONE_DEC(range3);
error=s-(nextDec<<1);
if (error<0) error=-error;
avgError[3]+=error;
if (error>maxError[3]) maxError[3]=error;
}
last1=prevLast1;
last2=prevLast2;
// pick best filter
int candError=0x7fffffff;
for (int j=0; j<4; j++) {
if (avgError[j]<candError) {
candError=avgError[j];
filter=j;
for (int k=0; k<13; k++) {
if (avgError[0][k]<candError) {
candError=avgError[0][k];
range=k;
}
}
//printf("block %ld: %8d %8d %8d %8d -> %d\n",i>>4,avgError[0],avgError[1],avgError[2],avgError[3],filter);
} else {
// don't filter on the first or loop block
filter=0;
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;
}
}
}
}
printf("%d: %d/%d\n",(int)i,filter,range);
// write
out[0]=(range<<4)|(filter<<2)|((i+16>=len)?((loopStart>=0)?3:1):0);
for (int j=0; j<8; j++) {
out[j+1]=possibleOut[filter][range][j];
}
switch (filter) {
case 0:
for (int j=0; j<8; j++) {
nextDec=next0[j]>>4;
DO_ONE_DEC(range0);
nextDec=next0[j]&15;
DO_ONE_DEC(range0);
}
o2=last2<<1;
o1=last1<<1;
out[0]=(range0<<4)|(filter<<2)|((i+16>=len)?((loopStart>=0)?3:1):0);
out[1]=next0[0];
out[2]=next0[1];
out[3]=next0[2];
out[4]=next0[3];
out[5]=next0[4];
out[6]=next0[5];
out[7]=next0[6];
out[8]=next0[7];
break;
case 1:
for (int j=0; j<8; j++) {
nextDec=next1[j]>>4;
DO_ONE_DEC(range1);
nextDec=next1[j]&15;
DO_ONE_DEC(range1);
}
o2=last2<<1;
o1=last1<<1;
out[0]=(range1<<4)|(filter<<2)|((i+16>=len)?((loopStart>=0)?3:1):0);
out[1]=next1[0];
out[2]=next1[1];
out[3]=next1[2];
out[4]=next1[3];
out[5]=next1[4];
out[6]=next1[5];
out[7]=next1[6];
out[8]=next1[7];
break;
case 2:
for (int j=0; j<8; j++) {
nextDec=next2[j]>>4;
DO_ONE_DEC(range2);
nextDec=next2[j]&15;
DO_ONE_DEC(range2);
}
o2=last2<<1;
o1=last1<<1;
out[0]=(range2<<4)|(filter<<2)|((i+16>=len)?((loopStart>=0)?3:1):0);
out[1]=next2[0];
out[2]=next2[1];
out[3]=next2[2];
out[4]=next2[3];
out[5]=next2[4];
out[6]=next2[5];
out[7]=next2[6];
out[8]=next2[7];
break;
case 3:
for (int j=0; j<8; j++) {
nextDec=next3[j]>>4;
DO_ONE_DEC(range3);
nextDec=next3[j]&15;
DO_ONE_DEC(range3);
}
o2=last2<<1;
o1=last1<<1;
out[0]=(range3<<4)|(filter<<2)|((i+16>=len)?((loopStart>=0)?3:1):0);
out[1]=next3[0];
out[2]=next3[1];
out[3]=next3[2];
out[4]=next3[3];
out[5]=next3[4];
out[6]=next3[5];
out[7]=next3[6];
out[8]=next3[7];
break;
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];
}
}
buf+=16;
out+=9;