1286875 - Firefox Nightly play/pause on Youtube creates syncronization issue between video and audio

Status: RESOLVED INVALID

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

Description

[Andrei Petcu]

User Agent: Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:50.0) Gecko/20100101 Firefox/49.0
Build ID: 20160713030216

Steps to reproduce:

1) Go to https://www.youtube.com/watch?v=GoQU9FcE2NI&feature=youtu.be&t=1726
2) Play the video and pause/resume it from time to time
3) Switch tabs back and forward from tab to tab


Actual results:

Video and audio are not synchronized anymore. 


Expected results:

It should have audio and video syncronized. This does not happen in Firefox Dev Edition.
I tested on this video also and it reproduces with Nightly 

http://download.gimp.org/pub/gimp/lgm/2014/day_4/063_Dear_designer__have_these_cool_tools/063_Dear_designer__have_these_cool_tools.ogv

Comment 1

[Andrei Petcu]

Not sure if this is related but I had a tab crashed while watching a video. unfortunately I don't know which one of these two crash reports happened when I was watching the video.

https://crash-stats.mozilla.com/report/index/ae92ccbe-9bdf-4cac-8247-0123e2160710
and
https://crash-stats.mozilla.com/report/index/418d8b84-d587-4cbf-b366-6104f2160713

Comment 2

[julesmyers2011]

I was able to reproduce issue for the video listed above on OSX Yosemite 10.10.2 via nightly build 50.0a1 (2016-7-18). I played a couple of more video tutorials from the same author and got the same video and audio inconsistencies. Sometimes the video and audio are inconsistent from the start of the video from this author. However, when I played totally different videos from different authors the issue did not occur as I went through the steps to reproduce. 

This may not be a firefox issue, but an issue with how (what settings) the author used to record his video or the software he uses might be the issue as well.

Comment 3

[Liviu Cirdei]

User Agent 	Mozilla/5.0 (X11; Linux x86_64; rv:50.0) Gecko/20100101 Firefox/50.0
Build ID 	20160718081125

I was able to reproduce the issue using the https://www.youtube.com/watch?v=GoQU9FcE2NI&feature=youtu.be&t=1726 video. However I observed the same behavior described in the previous comment. The video and audio are not consistent even if you don't switch tabs and play/pause the video. Moreover it does the same on other browsers like Chrome, so very possible this is a video recording issue. 

I also tried with the second video (http://download.gimp.org/pub/gimp/lgm/2014/day_4/063_Dear_designer__have_these_cool_tools/063_Dear_designer__have_these_cool_tools.ogv) but I could not reproduce the issue. 

Andrei, can you still reproduce the issue using the second video or any other videos? If yes, can you also  try with a new profile (https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles) and/or in Firefox Safe Mode (https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode)?

Comment 4

[Andrei Petcu]

I cannot reproduce the issue with the second video. I will mark it as resolved if you think this is ok.