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jpg: handle progressive non-interleaved mode

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This commit is contained in:
cinap_lenrek 2015-02-23 01:20:42 +01:00
parent ccb624e2bb
commit d7a4fdee99
1 changed files with 19 additions and 16 deletions
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35
sys/src/cmd/jpg/readjpg.c
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@ -632,7 +632,7 @@ baselinescan(Header *h, int colorspace)
ss = h->ss; ss = h->ss;
Ns = ss[0]; Ns = ss[0];
if((Ns!=3 && Ns!=1) || Ns!=h->Nf) if((Ns!=3 && Ns!=1) || Ns!=h->Nf)
jpgerror(h, "ReadJPG: can't handle scan not 3 components"); jpgerror(h, "ReadJPG: can't handle scan not 1 or 3 components");
image = jpgmalloc(h, sizeof(Rawimage), 1); image = jpgmalloc(h, sizeof(Rawimage), 1);
h->image = image; h->image = image;
@ -843,7 +843,7 @@ progressiveinit(Header *h, int colorspace)
ss = h->ss; ss = h->ss;
Ns = ss[0]; Ns = ss[0];
Nf = h->Nf; Nf = h->Nf;
if((Ns!=3 && Ns!=1) || Ns!=Nf) if(Ns!=3 && Ns!=1)
jpgerror(h, "ReadJPG: image must have 1 or 3 components"); jpgerror(h, "ReadJPG: image must have 1 or 3 components");
image = jpgmalloc(h, sizeof(Rawimage), 1); image = jpgmalloc(h, sizeof(Rawimage), 1);
@ -897,25 +897,26 @@ progressivedc(Header *h, int comp, int Ah, int Al)
int block, t, diff, qt, *dc, bn; int block, t, diff, qt, *dc, bn;
Huffman *dcht; Huffman *dcht;
uchar *ss; uchar *ss;
int Td[3], DC[3], blockno[3]; int i, Td[3], DC[3], blockno[3];
ss= h->ss; ss= h->ss;
Ns = ss[0]; Ns = ss[0];
if(Ns!=h->Nf) if(Ns!=1 && Ns!=h->Nf)
jpgerror(h, "ReadJPG: can't handle progressive with Nf!=Ns in DC scan"); jpgerror(h, "ReadJPG: can't handle progressive with Ns!=1 and Nf!=Ns in DC scan");
/* initialize data structures */ /* initialize data structures */
h->cnt = 0; h->cnt = 0;
h->sr = 0; h->sr = 0;
h->peek = -1; h->peek = -1;
for(comp=0; comp<Ns; comp++){
for(i=0; i<Ns; i++){
/* /*
* JPEG requires scan components to be in same order as in frame, * JPEG requires scan components to be in same order as in frame,
* so if both have 3 we know scan is Y Cb Cr and there's no need to * so if both have 3 we know scan is Y Cb Cr and there's no need to
* reorder * reorder
*/ */
nibbles(ss[2+2*comp], &Td[comp], &z); /* z is ignored */ nibbles(ss[2+2*i], &Td[i], &z); /* z is ignored */
DC[comp] = 0; DC[i] = 0;
} }
ri = h->ri; ri = h->ri;
@ -923,31 +924,33 @@ progressivedc(Header *h, int comp, int Ah, int Al)
nmcu = h->nacross*h->ndown; nmcu = h->nacross*h->ndown;
memset(blockno, 0, sizeof blockno); memset(blockno, 0, sizeof blockno);
for(mcu=0; mcu<nmcu; ){ for(mcu=0; mcu<nmcu; ){
for(comp=0; comp<Ns; comp++){ for(i=0; i<Ns; i++){
dcht = &h->dcht[Td[comp]]; if(Ns != 1) comp = i;
dcht = &h->dcht[Td[i]];
qt = h->qt[h->comp[comp].Tq][0]; qt = h->qt[h->comp[comp].Tq][0];
dc = h->dccoeff[comp]; dc = h->dccoeff[comp];
bn = blockno[comp]; bn = blockno[i];
for(block=0; block<h->nblock[comp]; block++){ for(block=0; block<h->nblock[comp]; block++){
if(Ah == 0){ if(Ah == 0){
t = decode(h, dcht); t = decode(h, dcht);
diff = receive(h, t); diff = receive(h, t);
DC[comp] += diff; DC[i] += diff;
dc[bn] = qt*DC[comp]<<Al; dc[bn] = qt*DC[i]<<Al;
}else }else
dc[bn] |= qt*receivebit(h)<<Al; dc[bn] |= qt*receivebit(h)<<Al;
bn++; bn++;
} }
blockno[comp] = bn; blockno[i] = bn;
} }
/* process restart marker, if present */ /* process restart marker, if present */
mcu++; mcu++;
if(ri>0 && mcu<nmcu && mcu%ri==0){ if(ri>0 && mcu<nmcu && mcu%ri==0){
restart(h, mcu); restart(h, mcu);
for(comp=0; comp<Ns; comp++) for(i=0; i<Ns; i++)
DC[comp] = 0; DC[i] = 0;
} }
} }
} }