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Optimisations to lcd_yuv_blit by Tom Meyer - speeds up mpegplayer by about 10-15%

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@10627 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Dave Chapman 2006-08-17 08:37:35 +00:00
parent 10af966be2
commit b80266c456
2 changed files with 93 additions and 68 deletions
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1
docs/CREDITS
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@ -225,3 +225,4 @@ Lars van de Klomp
Philippe Miossec
Jochen Kemnade
Corry Lazarowitz
Tom Meyer

160
firmware/drivers/lcd-ipodvideo.c
View file

@ -209,14 +209,15 @@ void lcd_update(void)
#define CSUB_Y 2
#define RYFAC (31*257)
#define GYFAC (63*257)
#define GYFAC (31*257)
#define BYFAC (31*257)
#define RVFAC 11170 /* 31 * 257 * 1.402 */
#define GVFAC (-11563) /* 63 * 257 * -0.714136 */
#define GUFAC (-5572) /* 63 * 257 * -0.344136 */
#define GVFAC (-5690) /* 31 * 257 * -0.714136 */
#define GUFAC (-2742) /* 31 * 257 * -0.344136 */
#define BUFAC 14118 /* 31 * 257 * 1.772 */
#define ROUNDOFFS (127*257)
#define ROUNDOFFSG (63*257)
/* Performance function to blit a YUV bitmap directly to the LCD */
void lcd_yuv_blit(unsigned char * const src[3],
@ -230,11 +231,12 @@ void lcd_yuv_blit(unsigned char * const src[3],
if (finishup_needed) {
unsigned int data;
/* Bottom-half of original lcd_bcm_finishup() function */
do {
/* This function takes about 14ms to execute - so we yield() */
data = lcd_bcm_read32(0x1F8);
while (data == 0xFFFA0005 || data == 0xFFFF) {
/* This loop can wait for up to 14ms - so we yield() */
yield();
data = lcd_bcm_read32(0x1F8);
} while (data == 0xFFFA0005 || data == 0xFFFF);
}
}
lcd_bcm_read32(0x1FC);
@ -261,18 +263,23 @@ void lcd_yuv_blit(unsigned char * const src[3],
ymax = y + height - 1 ;
const int stride_div_csub_x = stride/CSUB_X;
for (; y <= ymax ; y++)
{
/* upsampling, YUV->RGB conversion and reduction to RGB565 in one go */
const unsigned char *ysrc = src[0] + stride * src_y + src_x;
const unsigned char *usrc = src[1] + (stride/CSUB_X) * (src_y/CSUB_Y)
+ (src_x/CSUB_X);
const unsigned char *vsrc = src[2] + (stride/CSUB_X) * (src_y/CSUB_Y)
+ (src_x/CSUB_X);
const int uvoffset = stride_div_csub_x * (src_y/CSUB_Y) +
(src_x/CSUB_X);
const unsigned char *usrc = src[1] + uvoffset;
const unsigned char *vsrc = src[2] + uvoffset;
const unsigned char *row_end = ysrc + width;
int y, u, v;
int red, green, blue;
int red1, green1, blue1;
int red2, green2, blue2;
unsigned rbits, gbits, bbits;
int rc, gc, bc;
@ -282,73 +289,90 @@ void lcd_yuv_blit(unsigned char * const src[3],
u = *usrc++ - 128;
v = *vsrc++ - 128;
rc = RVFAC * v + ROUNDOFFS;
gc = GVFAC * v + GUFAC * u + ROUNDOFFS;
gc = GVFAC * v + GUFAC * u + ROUNDOFFSG;
bc = BUFAC * u + ROUNDOFFS;
/* Pixel 1 */
y = *ysrc++;
red = RYFAC * y + rc;
green = GYFAC * y + gc;
blue = BYFAC * y + bc;
if ((unsigned)red > (RYFAC*255+ROUNDOFFS))
{
if (red < 0)
red = 0;
else
red = (RYFAC*255+ROUNDOFFS);
}
if ((unsigned)green > (GYFAC*255+ROUNDOFFS))
{
if (green < 0)
green = 0;
else
green = (GYFAC*255+ROUNDOFFS);
}
if ((unsigned)blue > (BYFAC*255+ROUNDOFFS))
{
if (blue < 0)
blue = 0;
else
blue = (BYFAC*255+ROUNDOFFS);
}
rbits = ((unsigned)red) >> 16 ;
gbits = ((unsigned)green) >> 16 ;
bbits = ((unsigned)blue) >> 16 ;
outw((rbits << 11) | (gbits << 5) | bbits, 0x30000000);
red1 = RYFAC * y + rc;
green1 = GYFAC * y + gc;
blue1 = BYFAC * y + bc;
/* Pixel 2 */
y = *ysrc++;
red = RYFAC * y + rc;
green = GYFAC * y + gc;
blue = BYFAC * y + bc;
red2 = RYFAC * y + rc;
green2 = GYFAC * y + gc;
blue2 = BYFAC * y + bc;
if ((unsigned)red > (RYFAC*255+ROUNDOFFS))
{
if (red < 0)
red = 0;
else
red = (RYFAC*255+ROUNDOFFS);
}
if ((unsigned)green > (GYFAC*255+ROUNDOFFS))
{
if (green < 0)
green = 0;
else
green = (GYFAC*255+ROUNDOFFS);
}
if ((unsigned)blue > (BYFAC*255+ROUNDOFFS))
{
if (blue < 0)
blue = 0;
else
blue = (BYFAC*255+ROUNDOFFS);
}
rbits = ((unsigned)red) >> 16 ;
gbits = ((unsigned)green) >> 16 ;
bbits = ((unsigned)blue) >> 16 ;
/* Since out of bounds errors are relatively rare, we check two
pixels at once to see if any components are out of bounds, and
then fix whichever is broken. This works due to high values and
negative values both becoming larger than the cutoff when
casted to unsigned. And ORing them together checks all of them
simultaneously. */
if (((unsigned)(red1 | green1 | blue1 |
red2 | green2 | blue2)) > (RYFAC*255+ROUNDOFFS)) {
if (((unsigned)(red1 | green1 | blue1)) >
(RYFAC*255+ROUNDOFFS)) {
if ((unsigned)red1 > (RYFAC*255+ROUNDOFFS))
{
if (red1 < 0)
red1 = 0;
else
red1 = (RYFAC*255+ROUNDOFFS);
}
if ((unsigned)green1 > (GYFAC*255+ROUNDOFFSG))
{
if (green1 < 0)
green1 = 0;
else
green1 = (GYFAC*255+ROUNDOFFSG);
}
if ((unsigned)blue1 > (BYFAC*255+ROUNDOFFS))
{
if (blue1 < 0)
blue1 = 0;
else
blue1 = (BYFAC*255+ROUNDOFFS);
}
}
if (((unsigned)(red2 | green2 | blue2)) >
(RYFAC*255+ROUNDOFFS)) {
if ((unsigned)red2 > (RYFAC*255+ROUNDOFFS))
{
if (red2 < 0)
red2 = 0;
else
red2 = (RYFAC*255+ROUNDOFFS);
}
if ((unsigned)green2 > (GYFAC*255+ROUNDOFFSG))
{
if (green2 < 0)
green2 = 0;
else
green2 = (GYFAC*255+ROUNDOFFSG);
}
if ((unsigned)blue2 > (BYFAC*255+ROUNDOFFS))
{
if (blue2 < 0)
blue2 = 0;
else
blue2 = (BYFAC*255+ROUNDOFFS);
}
}
}
rbits = red1 >> 16 ;
gbits = green1 >> 15 ;
bbits = blue1 >> 16 ;
outw((rbits << 11) | (gbits << 5) | bbits, 0x30000000);
rbits = red2 >> 16 ;
gbits = green2 >> 15 ;
bbits = blue2 >> 16 ;
outw((rbits << 11) | (gbits << 5) | bbits, 0x30000000);
}
while (ysrc < row_end);