problem with overlay (XVideo) on ATI Rage Pro (mach64)

[Alexander Polyakov]

Hello,
 
I have following problem: video playback through XVideo on AIW Pro  works only
when X-resolution of video does not exceed 720 pixels, otherwise all I see is
rectangle filled with key color.
 
My setup: Mandriva Linux 2006.0, Xorg 6.9 cvs20050915, All-in-Wonder Pro
(mach64, 8 MB of memory).
 
There was no such problem in Mandrake Linux 10.0 (XFree 4.3.0) on the same
hardware, so I decided to look at the sources (Xorg 6.9.0 final). It turned
out 720 is hardcoded several times in atimach64xv.c and one time in
atiscreen.c.
 
I didn't want to compile everything from scratch, so I patched atimisc_drv.so
(replaced 720*480 with 768*576 and 720 with 768; 768 is the max. resolution I
need). And now it works.
 
However, I'm curious to know why this restriction (720 max.) was imposed
(bug/feature)?
 
Thanks!