[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

what's 32 bpp?



I see that X servers can be set to run at 8,16,24, or 32 BPP.  (also 2
and 4 but that's yuck!).

I know that the 8 bpp mode uses a map table to select 256 out of 2**16
or 2**18 colors, assuming that the card has 3 6 bit dac's, one for
each color.  In 16 or 15 bit mode the access to the dac's is direct. 
5 bits are used for each dac, with the lsb set to 0.  In 16 bbp mode
the extra bit is given to the green dac.  In 24bpp mode 8 bit dac's
are used, 8*3=24 bits.  

What happens in 32bpp??  I do not believe that video dac's are
available wider than 8 bits.  If they are, are 3 10 bit dac's used,
with the extra 2 bits thrown away?  Or is a 12 bit dac used for the
green????

Or is this only a maping thing, 24 bits are used, and a whole byte is
thrown away, but using 32bits per pixel cleans up the dma access some
how?




==
Amateur Radio, when all else fails!

http://www.qsl.net/wa2mze

Debian Gnu Linux, Live Free or .....


_________________________________________________________
DO YOU YAHOO!?
Get your free @yahoo.com address at http://mail.yahoo.com


Reply to: