Audio/ sound of video out of sync (slightly ahead) of visual element of video
I am presenting a compiled video in mkv. format using the media_player_mpy item. When I play the video stand-alone, it works fine. However, when I put it into OpenSesame, the sound of the video is about 2 seconds ahead of the video itself (so the visual lags behind the audio slightly), such that the final short audio segment is repeated quite a few times at the end while the video catches up.
I read about changing the backend settings to xpyriment (rather than legacy) but didn't find this to have any effect.
Does anyone know what the issue might be or how I could fix it?
Comments
Hi,
This sounds weird. I am just fishing in the dark here, but could you try to use different video formats? Like converting to avi, mp4, etc?
I think there are quite a few conversion tools online.
Good luck,
Eduard
Hi Eduard,
Thanks for your reply. I tried converting to both avi and mp4 but the problem still persists. 😓
Did you also try changing the sound playback settings of media_player_mpy? This also has three options (or backends) for playing sound. You can choose between pygame, pyaudio and sounddevice if I'm not mistaken. Maybe one of the other options does not elicit this problem.
Did you also try running the experiment on another computer to determine if this isn't a hardware problem?
Hi Daniel,
Thanks for your reply and sorry about my late reply.
I don't think it's a hardware problem because I tried it on my office computer as well and the lag is still there.
I emailed my supervisor the previous week to ask if he could try running the experiment, but changing the sound playback settings of media_player_mpy, but I'm still awaiting a reply. I can't run that part of the experiment on my own version of OpenSesame as I think I'm possibly missing a vital plug-in for video presentation (comes up with some sort of unicode error when it gets to that part).