** Description changed:
Ubuntu 8.04, xserver-xorg-video-mga 1:1.4.8.dfsg.1-1.
Attempts to play *.avi from various sources in mplayer(1), vlc(1), etc.,
result in the same fault; two columns have been swapped with their
neighbours for every few columns through the frame. It doesn't happen
if I change
mplayer step.avi
for
mplayer -vo x11 step.avi
thereby switching mplayer from using the X server's XVideo extension to
a shared memory implementation. Based on this, and the same flaw occurs
in others players that use XVideo, I suspect it's a problem in package
xserver-xorg-video-mga's XVideo implementation as my /etc/X11/xorg.conf
uses the mga driver and I've a 16bpp X screen.
A sample frame called paraglider.png from a movie is attached. The dark
streak below him is a slightly off-vertical lamp post.
To help analyse the problem, I created a 64x64 pixel movie with 64
frames at 1fps. The first frame is all black, on each subsequent frame
the next column of 64 pixels is filled in from left to right until,
after 64 frames, only the rightmost column remains black. Playing it
with `mplayer' showed a regular corruption of the columns filled. I
repeatedly grabbed mplayer's window with xwd(1) whilst it was running
and then spliced this recording under the original so people with
working systems can see what I experience against what I should be
seeing. That's compare.avi, also attached.
Some frames in the movie don't cause any change on the screen, and some
cause two pixels to change. So if you consider each of the movie 64
frames be repesented by one line below then, instead of getting a
regular `triangle' of black changing to white,
1111111111111111111111111111111111111111111111111111111111111111
0111111111111111111111111111111111111111111111111111111111111111
0011111111111111111111111111111111111111111111111111111111111111
...58 rows snipped...
0000000000000000000000000000000000000000000000000000000000000111
0000000000000000000000000000000000000000000000000000000000000011
0000000000000000000000000000000000000000000000000000000000000001
you get this strange, regular, corruption. We start off with all black,
but then setting column 0 white results in #4 and #6 going white, #1
sets #5 and #7, and then setting #2 and #3 has no effect. Then we start
again, but this time setting #4-7 affects #0-3. This repeats for every
set of eight pixels.
1111111111111111111111111111111111111111111111111111111111111111
1111010111111111111111111111111111111111111111111111111111111111
1111000011111111111111111111111111111111111111111111111111111111
"
"
0101000011111111111111111111111111111111111111111111111111111111
0000000011111111111111111111111111111111111111111111111111111111
"
"
0000000011110101111111111111111111111111111111111111111111111111
0000000011110000111111111111111111111111111111111111111111111111
"
...lines snipped...
"
0000000000000000000000000000000000000000000000000101000011111111
0000000000000000000000000000000000000000000000000000000011111111
"
"
0000000000000000000000000000000000000000000000000000000011110101
0000000000000000000000000000000000000000000000000000000011110000
"
"
0000000000000000000000000000000000000000000000000000000001010000
0000000000000000000000000000000000000000000000000000000000000000
"
Given no one's likely to turn up soon with my hardware, and I've
provided lots of detail as to the problem, perhaps someone experienced
in XVideo can consider if this can be made confirmed without having to
reproduce it themselves.
+
+ [lspci]
+ 00:00.0 Host bridge [0600]: VIA Technologies, Inc. VT8366/A/7 [Apollo
KT266/A/333] [1106:3099]
+ 00:09.0 VGA compatible controller [0300]: Matrox Graphics, Inc. MGA 2164W
[Millennium II] [102b:051b]
+ 00:0a.0 VGA compatible controller [0300]: Matrox Graphics, Inc. MGA 2064W
[Millennium] [102b:0519] (rev 01)
--
mga XVideo driver swaps columns
https://bugs.launchpad.net/bugs/289893
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
