Video still not quite up to par

Jim Kronebusch jim at
Thu Jul 19 15:01:10 BST 2007

> I have run full screen video across LTSP5 on feisty using ssh forwarding
> with minimal skipping.  Just in case, I presume the problem is still
> present when you turn off LDM_DIRECTX?

Yes, with LDM_DIRECTX=True commented out, my video gets worse.  The bypassing of ssh for
video does add improvement, but it is still not as good as with LTSP 4.2 under K12LTSP6.

> It may have something to do with your video card setup.  I don't know much
> about this stuff but I think for example that the Xv extension is important
> for video playback.  It's possible X is not being configured optimally on
> that client.  Do you have thin clients with different hardware and if so,
> do you see it on all of them?
> If you install gxine, on first run it gives a wizard which shows you ways
> to improve video performances (such as Xv).

I was wondering the same thing yesterday.  I started messing with video settings in
lts.conf to see if there was any improvement.  At this point I am only testing with a
Term150 from  I am out of town now until Monday but maybe I
will try some other workstations to see if there is any difference.  I will also give
the gxine test a shot.

> Not really with feisty in my experience.  Although, if a lot of people
> started running full-screen video I can imagine things might start to go
> bad.  That's a fundamental issue with sending rendered video across the
> network though.  I presume you have a GigE switch at least for the server.

The server has 6 Gig NICs teamed with adaptive load balancing ran into a Gigabit switch
in my Cisco 4006 router.  Then another GBIC blade runs a separate gigabit connection to
each wire room feeding no more than 20 clients per Gig uplink.  I am certain the network
isn't the problem :-)  

> > I would like to try some modifications before testing both the
> > K12LTSP-5.0.0EL 64-bit and 32-bit with PAE.  Any suggestions would be
> > appreciated.

I will play around with the video settings next week.  There is just too much to be
gained in my opinion by using Edubuntu and LTSP 5 (the future of LTSP) to go back to the
old methods.  I don't really care if the students can play youtube videos full screen,
but I want to be certain apps like KStars run smoothly and that editing a text document
that spans more than one page isn't a problem (If I try and highlight text that requires
scrolling up or down in a document, the scrolling is very jerky).  I am just fine with
stating that other types of videos simply need to be shrunk down, after all most video
content on the internet gets very pixelated at larger resolutions anyhow.

Thanks Gavin.

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