Re: [gentoo-user] I want to play movies without hangs

[Alex Schuster]

I wrote:

> Mark Knecht writes:

> >    OK, fire up two terminals. In one run top, hit 1 & z so you see all
> > your CPUs and then watch CPU usage. In the second terminal su to root
> > and run iotop -o. Now, watch for a few minutes and get a feel for
> > what's going on when video is not running. Then start your video and
> > watch IO usage and CPU usage. Where's the problem?
> >
> >    Once you get an idea where the bottleneck is we can address what a
> > solution might be. In general, if the CPUs aren't maxed out and it's
> > an I/O problem then usually a bit more buffering is a simple solution.
> > Other more draconian solution might be a real-time kernel with a
> > player (if there is one) that is set up for real-time playback.
> >
> >    Looking forward to hearing your test results.
>
> Thanks for your support, Mark!
>
> I did this already, but sometimes I do not notice anything. I guess it's
> short I/O operations in that case. CPU load is not the problem, and it
> happens for both high-quality videos and small ones.
> Currently iotop shows stuff like kjournald, kworker, kdeinit4,
> akonadiserver, firefox. And lots of virtuoso-t and nepomuk when I enable
> indexing again, which I just suspended.
> And mplayer of course, it shows up in about every 2nd redisplay, which
> happens every second.
>
> Well... but when I do the same in the other window manager, it seems I
> see fewer processes then. Are they mostly suspended when I am on another
> display?

I watched for longer now, and this does not seem to be true.

> And I should fire up the same stuff (Firefox, Chromium, maybe KDEPIM
> stuff) in the other WM and see if this makes things worse. But I'll do
> this tomorrow. Thanks for the inspiration, though, at least I have
> something more to try now.

I am running Enlightenment 0.16 in parallel now, with Firefox, Chromium,
Kontact, Claws, Liferea, Amarok (which is doing a lot of I/OP stuff at
the moment according to iotop), and Dolphin showing a large directory of
multimedia files wit thumbnails. But I don't see akonadi related processes
in iotop, that is unusual.
I did the dd command to create more I/O. No gaps in video display at all.

When I play the video from within KDE (running Konsoles, Konqueror,
Dolphin and a lot of plasma stuff), I have gaps, and when I do the dd
command, there are in the range of seconds. Even for some seconds after
I canceled the dd.

I also tried a fresh, unconfigured KDE session by another user. I've
already done that, and there were also gaps in video playback, although
it seems they were fewer. But this time, I was not able to reproduce
them. Huh?

I guess I could remove anything running on my KDE desktop one by one,
including plasmoids, and see if playback gets better. But not now, I
finally have to actually do some work.

	Wonko