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jpg: ignore sampling factors for grayscale as colormap1() doesnt handle it

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cinap_lenrek 2012-08-14 05:36:05 +02:00
parent a8d7bbeeb3
commit 21b5efe962
1 changed files with 5 additions and 2 deletions
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7
sys/src/cmd/jpg/readjpg.c
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@ -7,7 +7,7 @@
enum {
/* Constants, all preceded by byte 0xFF */
SOF =0xC0, /* Start of Frame */
SOF2=0xC2, /* Start of Frame; progressive Huffman */
SOF2 =0xC2, /* Start of Frame; progressive Huffman */
JPG =0xC8, /* Reserved for JPEG extensions */
DHT =0xC4, /* Define Huffman Tables */
DAC =0xCC, /* Arithmetic coding conditioning */
@ -322,12 +322,15 @@ readslave(Header *header, int colorspace)
case SOF2:
header->Y = int2(b, 1);
header->X = int2(b, 3);
header->Nf =b[5];
header->Nf = b[5];
for(i=0; i<header->Nf; i++){
header->comp[i].C = b[6+3*i+0];
nibbles(b[6+3*i+1], &H, &V);
if(H<=0 || V<=0)
jpgerror(header, "non-positive sampling factor (Hsamp or Vsamp)");
/* hack: colormap1() doesnt handle resampling */
if(header->Nf == 1)
H = V = 1;
header->comp[i].H = H;
header->comp[i].V = V;
header->comp[i].Tq = b[6+3*i+2];