Unable to get smooth video playback on Linux

[Michael Hanke]

Hi,

I have a bit of trouble getting psychopy to play movie stimuli (with audio) without dropping frames. As long as there is no sound

everything is perfect. As soon as AVBin detects a sound stream frame drops appear.

I have posted more information on the nature of the situation and a builder demo for the problem here

http://bugs.debian.org/730810

The issue is reproducible on various hardware using the jwpIntro.mov file shipped with Psychopy. I followed all recommendations

for movie playback that I am aware of (uncompressed audio, ...). The only deviation from the golden path is avbin 7 instead of the

recommended version 5. There is no Linux binary to download and I failed to find information on the critical difference between 5 and

7 with respect to this specific problem.

I'd be grateful for advice. Thanks,

Michael

[Jonathan Peirce]

I think the problems you're having are caused by the fact that avbin is,
to use a technical term, a little bit rubbish! On Linux version 7 is
appropriate (that version was released alongside version 5 on win/OSX).
We should adjust the docs to indicate that correctly. After that a new
developer took the projec tover and it got even more rubbish!

Sol is actually working on a replacement already using opencv for the
video and VLC for sound decoding. That should allow us to forget avbin
completely, which will make us all happier people. And I think he was
finding good performance with it.

cheers,
Jon

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Jonathan Peirce
Nottingham Visual Neuroscience

http://www.peirce.org.uk

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[Michael Hanke]

Hi,

is there a chance to get my hands on this code to try it out?

Michael

[Michael Hanke]

I cannot easily find the VLC-based code that you referred to on github. I'd really like to stay in PsychoPy for this project, hence I'd appreciate a pointer.

Thanks,

Michael