[X2Go-Dev] PulseAudio (ATTN: @Jan Wagner & @Stephan Diehl)

[Stefan Baur]

Am 30.05.2012 08:32, schrieb Mihai Moldovan:

>> A better test is: run the pavucontrol tool within the X2Go session and test if
>> the PA process on the MAC survives all the PA-specific mixer and volume meter
>> API calls.
>
> WORKSFORME... it seems to work fine on my Debian Unstable based remote server.
> I'll guess I'll have Stefan test on (older) Ubuntu boxes and stuff, if he's up to.

No can do. I can test against a Debian Squeeze server with X2Go's stable 
packages, though.

[...]

> I do have some other issues, though. Especially when starting a flash video in
> Iceweasel, sound is choppy, distorted, (<  buffer underruns?) the video will halt
> a few seconds in-play, sound will roll on for like 20 seconds, then stop, video
> catch up fast and once the video has reached the sound position, both video and
> sound playback will pick up again, but sound and picture will be desynchronized
> as the sound makes a 20 seconds jump into the "future".
>
> This is a very odd behavior, but I'm not sure what to make of it.

Our old friend Nagle?

> I have noticed problems when running pavucontrol and mplayer both at the same
> time, though.

What kind of problems?

> But I figure both the pavucontrol+mplayer and flash video problems are due to
> the remote ADSL connection. I see a peak incoming traffic of about 250KB/s,
> hardly enough for both sound and video. Another circumstance that may well
> confirm this theory is that lowering the image quality (i.e., set to JPEG
> compression with 64 colors) has a positive effect on the sound output.

Do we have some sort of rough estimate how much bandwidth we need for 
which color depth?

And would it be possible to lower the sound quality to conserve some 
bandwidth? I mean, it's rather unlikely somebody is going to expect 
Dolby 5.1 sound quality via GSM... ;-)

> I'd really be interested to see tests on LAN, but unfortunately my only other
> box has no PA installed and I don't want to pollute the system with it. However,
> I guess that Stefan could come in here handy.

I'll give it a try, but I'm not really a Mac user (I bought this Mac 
solely to support X2Go development for Mac), so Jan and Stephan should 
join in if you want reliable results.

> The code is not yet ready and I still have to tackle the esound emulation stuff,
> but I'd be happy to dump a test build here. Is anyone interested? Let me know.

Jan, Stephan, your call!

-Stefan