On Tue, 2003-01-21 at 16:26, James Su wrote: > Hi, > Due to the physical limit of our LCD display, I can only use 4bpp pixel > format. I tried grayscale 4bpp and found that the display effect is > worse than the lut version, I don't know why. I use (red + green * 2 + > blue) >> 6 to convert RGB into grayscale, but I have no good idea to > convert back, so I just let red = green = blue = (grayscale * 16) in Sop > to Dacc operations.
If you are limited at 4bpp, then you have not choice but to use LUT modes. Blits at this bit depths are typically very fast, unless you need special effects (alpha blending, colorkeying, etc) > And the 4bpp lut speed of DirectFB 0.9.15 is fast enough for our > embedded system, but I cannot find any obvious difference between 0.9.16 > and 0.9.15 that can cause such big performance drop. > On the contrary, I experience a very slight speed-up at LUT8 using VESA on a very old PCI card. Tony DirectFB-0.9.15 Anti-aliased Text 3.37 secs ( 4.28 KChars/sec) Fill Rectangles 3.02 secs ( 93.34 MPixel/sec) Fill Rectangles (blend) 22.59 secs ( 0.29 MPixel/sec) Fill Triangles 3.02 secs ( 85.80 MPixel/sec) Fill Triangles (blend) 11.24 secs ( 0.29 MPixel/sec) Draw Rectangles 3.01 secs ( 13.27 KRects/sec) Draw Rectangles (blend) 3.40 secs ( 0.23 KRects/sec) Draw Lines 3.00 secs ( 44.98 KLines/sec) Draw Lines (blend) 3.09 secs ( 1.29 KLines/sec) Blit 3.01 secs ( 91.38 MPixel/sec) Blit colorkeyed 3.03 secs ( 93.13 MPixel/sec) Blit with format conversion 24.42 secs ( 0.27 MPixel/sec) Blit from 32bit (alphachannel blend) 61.30 secs ( 0.11 MPixel/sec) Blit from 8bit palette 3.07 secs ( 91.85 MPixel/sec) Blit from 8bit palette (alphachannel blend) 39.68 secs ( 0.17 MPixel/sec) Stretch Blit 3.05 secs ( 100.56 MPixel/sec) Stretch Blit colorkeyed 3.34 secs ( 73.59 MPixel/sec) DirectFB-0.9.16 Anti-aliased Text 3.65 secs ( 4.93 KChars/sec) Fill Rectangles 3.00 secs ( 93.90 MPixel/sec) Fill Rectangles (blend) 22.56 secs ( 0.29 MPixel/sec) Fill Triangles 3.03 secs ( 86.60 MPixel/sec) Fill Triangles (blend) 11.24 secs ( 0.29 MPixel/sec) Draw Rectangles 3.00 secs ( 13.78 KRects/sec) Draw Rectangles (blend) 3.32 secs ( 0.24 KRects/sec) Draw Lines 3.01 secs ( 45.82 KLines/sec) Draw Lines (blend) 3.78 secs ( 1.32 KLines/sec) Blit 3.06 secs ( 91.94 MPixel/sec) Blit colorkeyed 3.03 secs ( 95.23 MPixel/sec) Blit with format conversion 23.22 secs ( 0.28 MPixel/sec) Blit from 32bit (alphachannel blend) 59.04 secs ( 0.11 MPixel/sec) Blit from 8bit palette 3.06 secs ( 91.94 MPixel/sec) Blit from 8bit palette (alphachannel blend) 37.44 secs ( 0.17 MPixel/sec) Stretch Blit 3.11 secs ( 111.93 MPixel/sec) Stretch Blit colorkeyed 3.33 secs ( 73.90 MPixel/sec) -- Info: To unsubscribe send a mail to [EMAIL PROTECTED] with "unsubscribe directfb-dev" as subject.
