1435807 - Video playback on various sites runs about 4x normal speed in linux VM

Status: RESOLVED WORKSFORME

(Core :: Audio/Video: Playback, defect, P3)

Description

[arcooke]

User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:56.0) Gecko/20100101 Firefox/56.0
Build ID: 20180122144257

Steps to reproduce:

I run Firefox Nightly (60.0a1 2018-01-22) in a virutal machine though virtualbox on Xubuntu 16.04 (windows 10 host).  I get very strange behavior with video playback.  For some reason, videos on most websites play back way too fast.  

Here is a screen capture of a Youtube video:  https://gfycat.com/AdvancedDismalDartfrog

The problem happens with videos from multiple websites, not just youtube.  

I'm not sure what to make of this one.  I don't know if the problem is exclusive to my VM setup or if others might be experiencing it on bare metal.

lspci -vv output if it's of any use:  http://paste.ubuntu.com/26526051/

Comment 1

[Emil Pasca [:emilpasca]]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0

I've tested this issue in a virtual machine on Linux 4.12.8-2-ARCH (since this is the one that we have available for now) and also on a machine with Ubuntu 14.04 x64 with the latest Firefox release (58.0.1) and the latest Nightly (60.0a1-20180207220120) and haven't managed to reproduce the issue.

Could you please retest this using the latest Firefox release and latest Nightly build and report back the results? When doing this, please use a new clean Firefox profile, maybe even safe mode, to eliminate custom settings as a possible cause (https://goo.gl/AR5o9d).

Comment 2

[Ralph Giles (:rillian)]

Wow, that's pretty wild. Thanks for the report!

Thanks Emil for trying to reproduce.

arcooke, What happens with the sound when a video is playing too fast like that? We normally sync video to the audio clock; maybe there's a sample-rate mismatch between the vm and the host os?

Comment 3

[arcooke]

Thanks all.  Sorry for taking so long to get back to you.  This problem seems to have corrected itself in an update after me posting about it here.  I didn't make any changes on my end, it just seems to have stopped happening.  I'll update if it happens again, but in the meantime this can be closed.

I'm not sure about audio, I use the VM on my work PC and don't have sound.

Comment 4

[Ralph Giles (:rillian)]

Ok, thanks!

Comment 5

[arcooke]

Hello.. I'm the one who originally reported this. I'm not sure if this is a related issue, but I just ran into a similar thing yesterday. Except this time, the playback speed was increasing when I was moving my volume slider. And only when the volume slider was physically in motion.. very bizarre.

It fixed itself after restarting firefox, it may have been caused by an update that required a restart. Updates tend to bug out firefox.

This is no longer in a VM as originally reported, this is on my main desktop running Solus and Firefox 66.0.3 stable.

I captured a screen recording. https://www.youtube.com/watch?v=GrFDiDwQdog

I don't have the problem anymore, but I thought it still might be useful to share the information.