Ben Klein wrote:
2009/6/2 Scott Ritchie scott@open-vote.org:
First, I talked with a Pulseaudio expert about what we can do to make things work better. He said that if we want good compatibility we will need our ALSA stack to use the Pulseaudio safe subset: http://0pointer.de/blog/projects/guide-to-sound-apis.html. I've filed a metabug tracking this here: http://bugs.winehq.org/show_bug.cgi?id=18740. Use of this unsafe subset can cause most problems with stuttering or even complete dropoff.
As far as I know, this is not possible for Wine (without massive latency issues caused by overbuffering in Wine itself) due to the fact that Wine has to make DirectSound apps happy. It's also not very consoling from this Pulseaudio expert that they don't seem to see a problem with the ALSA layer on their end - "it's the apps that need to be fixed". Wasn't the point of Pulse that you could use libasound/OSS apps without modification? :)
I'll admit I'm a bit over my head here, but I'd be surprised to find out if a typical DirectSound App on Windows was really as low-latency as we seem to be grabbing for. Windows doesn't generally grant applications direct control over the audio hardware either.
I'm not completely familiar with how sound works in Wine, but in the past I remember that one complaint about PulseAudio over ALSA was latency. Latency issues these days are mostly due to bad kernel configurations
PulseAudio will *always* have more latency than ALSA. This has nothing to do with kernel configurations, just that using a CONFIG_NO_HZ/CONFIG_HZ_1000 (or whatever it is) kernel from the -rt tree makes the latency issue less severe. New kernel won't fix Wine + Pulse problem.
Going from 200 to something like 50 ms latency will solve about 90% of the problem though. This is doable with kernel changes alone (some of the shipping kernels are indeed that bad).
Printing:
A printing expert from http://openprinting.org says we should output .pdf files to cups rather than postscript. .pdf are becoming the standard for printers, and apparently they allow some good things that postscript does not. I've filed a bug on this here: http://bugs.winehq.org/show_bug.cgi?id=18741
Something tells me this isn't going to happen soon in Wine :D
It would make a good summer of code project I bet. I agree there are probably more important things to do, though it's hard to recognize what's an important feature when talking about potential rather than current users. Potentially, Wine could be very valuable as a general office tool, where printing is much more important.
Security and Usability:
The security team thinks we should finally start respecting the execute bit - this means removing all MIME handlers for executable code from the desktop and replacing them with a single front end for programs lacking the execute bit. This front end would notify the user of the problem, scan the file for viruses, and then present some information about the path towards execution. It is still undecided whether the program should allow execution outright, however from a UI perspective this would clearly be more efficient.
This has been discussed before on -devel. I believe the consensus was "no, we don't want Wine to respect execute bit" (though I'd still like it to respect noexec mount option if possible).
The biggest problem with the GUI proposal for confirming execution of non-+x files as far as I can see is how do we handle a win32 app launching a non-+x app (as so many installers would be likely to do)?
That's simple; we let it. The execute bit is an indicator of trust in an app - once you've trusted it to run then it can do whatever it wants, so we might as well let it run other apps. Wine's pretty good about marking installed apps as +x anyway; this is really mostly an issue with freshly downloaded .exes (note that .exe's on CD drives are going to be assumed +x anyway).
Should that produce a new dialog (thus irritating the user to all kinds of heck) or should one confirmation per user-controlled app launch be enough (thus not providing any real benefit)?
I don't see how it's "not any real benefit" when the whole point is to prevent accidental launching. You see the prompt the first time, you dismiss it if you didn't mean to run something, and you let it go if you did. In the meantime it's scanned for viruses.
Thanks, Scott Ritchie