Simplify tiff decoder by merging two functions.

This commit is contained in:
Carl Eugen Hoyos 2011-12-31 01:58:16 +01:00
parent b46fb615c4
commit e767968c6e

View File

@ -106,21 +106,19 @@ static void av_always_inline horizontal_fill(unsigned int bpp, uint8_t* dst,
int usePtr, const uint8_t *src,
uint8_t c, int width, int offset)
{
int i;
switch (bpp) {
case 2:
for (i = 0; i < width; i++) {
dst[(i+offset)*4+0] = (usePtr ? src[i] : c) >> 6;
dst[(i+offset)*4+1] = (usePtr ? src[i] : c) >> 4 & 0x3;
dst[(i+offset)*4+2] = (usePtr ? src[i] : c) >> 2 & 0x3;
dst[(i+offset)*4+3] = (usePtr ? src[i] : c) & 0x3;
while (--width >= 0) {
dst[(width+offset)*4+3] = (usePtr ? src[width] : c) & 0x3;
dst[(width+offset)*4+2] = (usePtr ? src[width] : c) >> 2 & 0x3;
dst[(width+offset)*4+1] = (usePtr ? src[width] : c) >> 4 & 0x3;
dst[(width+offset)*4+0] = (usePtr ? src[width] : c) >> 6;
}
break;
case 4:
for (i = 0; i < width; i++) {
dst[(i+offset)*2+0] = (usePtr ? src[i] : c) >> 4;
dst[(i+offset)*2+1] = (usePtr ? src[i] : c) & 0xF;
while (--width >= 0) {
dst[(width+offset)*2+1] = (usePtr ? src[width] : c) & 0xF;
dst[(width+offset)*2+0] = (usePtr ? src[width] : c) >> 4;
}
break;
default:
@ -132,16 +130,6 @@ static void av_always_inline horizontal_fill(unsigned int bpp, uint8_t* dst,
}
}
static void av_always_inline split_nibbles(uint8_t *dst, const uint8_t *src,
int width)
{
while (--width >= 0) {
// src == dst for LZW
dst[width * 2 + 1] = src[width] & 0xF;
dst[width * 2 + 0] = src[width] >> 4;
}
}
static int tiff_unpack_strip(TiffContext *s, uint8_t* dst, int stride, const uint8_t *src, int size, int lines){
int c, line, pixels, code;
const uint8_t *ssrc = src;
@ -162,7 +150,7 @@ static int tiff_unpack_strip(TiffContext *s, uint8_t* dst, int stride, const uin
src = zbuf;
for(line = 0; line < lines; line++){
if(s->bpp == 4){
split_nibbles(dst, src, width);
horizontal_fill(s->bpp, dst, 1, src, 0, width, 0);
}else{
memcpy(dst, src, width);
}
@ -258,7 +246,7 @@ static int tiff_unpack_strip(TiffContext *s, uint8_t* dst, int stride, const uin
return -1;
}
if(s->bpp == 4)
split_nibbles(dst, dst, width);
horizontal_fill(s->bpp, dst, 1, dst, 0, width, 0);
break;
}
dst += stride;