low latency is intalled? why video is running slow

[laurent.bellegarde]

quim a écrit :
> Hello folks!
> I recently changed my system from Ubuntu Studio 8.04 to Ubuntu Studio 
> 9.04, Jaunty Jackalope, It's running fine, but I noticed that the 
> video is running far slower than under the Hardy Heron (8.04) version.
> Is anybody here using Ubuntu Studio 9.04 for video editing?
>
> In the Ubuntu studio web page I read that 8.04 is still the 
> recommended release for production critical machines, but I thought it 
> was for security or reliability reasons, not for a lack of velocity...
> I wouldn't like to get back to the oldest release if it's possible, 
> but I don't know how to run video faster!
>
> Recently, I also read this in the Ubuntu Studio WebPage for the 9.04 
> install: "We are happy to announce the real time kernel will be 
> installed by default in Ubuntu Studio in this release, if the audio 
> task is selected...) Only If the audio task is selected? When I 
> Installed the US 9.04 I didn't installed the Audio software package, 
> only the Video ones. Does it means that low latency isn't installed in 
> my computer? Could be this fact the problem?
> Any suggestions?
> Thanks to all,
>
> Quim 
Hi,

low latency is installed only if you check ubuntustudio-sounds.

to know if you have low low latency running, in a terminal just do

uname -a

if generic is written, it's the normal kernel, if rt is written, low 
latency is on.

i'm using ubuntu studio for video editing, it works under jaunty RT, 
enough to edit videos, even HD ones, but video is a bit slower than in 
hardy. So for video production, i'm using hardy at this time.

I have to mention 2 things,

may laptop is 64bits, hardy is 64bits with full 3D graphic ATI 
acceleration with RT kernel. The jaunty i've installed, is only 32bit, 
and to run the RT kernel, i have to be under free 2D ATI driver, with 
ati propriotary driver, i've got a large crash of X. So with theses 
settings so differents, it's quite difficult to compare video performance.

One thing sure, the jaunty RT kernel is more efficient than the hardy's 
one, and pulseaudio is now working very well under jaunty.

Laurent,
lprod.org