Sound recording / output is sometimes out of sync with display

[mgbellemare]

Sound is often output with a delay with respect to the displayed screen. Cause unknown.

[mhauskn]

Two notes and a possible fix:

1. I've been unable to reproduce the out-of-sync sound on Linux. I can only get it to happen on OSX.
2. I think we can fix it by reducing ALE's "fragsize" from 512 (default) to 64. In sharedLibraryInterfaceExample we can write:

ale.setInt("fragsize", 64);

With this fragsize I am unable to get the audio to delay after ~100 attempts. Fragsize is the size of the buffer into which audio is created. Low frag sizes result in more "in-sync" sound but require more computation. Some info is here:

http://atariage.com/forums/topic/134888-stella-audio-settings-what-does-each-thing-do/

[mgbellemare]

I've never noticed anything wrong with the sound in Stella. I'm wondering if somehow something got busted in our setting up the OSystem... I'll take a look into it tomorrow.

On Fri, Apr 24, 2015 at 9:11 PM, Matthew Hausknecht < [email protected]> wrote:

Two notes and a possible fix:

1. I've been unable to reproduce the out-of-sync sound on Linux. I can only get it to happen on OSX.
2. I think we can fix it by reducing ALE's "fragsize" from 512 (default) to 64. In sharedLibraryInterfaceExample we can write:

ale.setInt("fragsize", 64);

With this fragsize I am unable to get the audio to delay after ~100 attempts. Fragsize is the size of the buffer into which audio is created. Low frag sizes result in more "in-sync" sound but require more computation. Some info is here:

http://atariage.com/forums/topic/134888-stella-audio-settings-what-does-each-thing-do/

— Reply to this email directly or view it on GitHub https://github.com/mgbellemare/Arcade-Learning-Environment/issues/53#issuecomment-96050500 .