1336187 - HTML5 Video is out of sync with audio

Status: RESOLVED WORKSFORME

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

Description

[u464100]

User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:51.0) Gecko/20100101 Firefox/51.0
Build ID: 20170125094131

Steps to reproduce:

Played the following links from ted.com in HTML5 video player:

http://www.ted.com/talks/caleb_barlow_where_is_cybercrime_really_coming_from

Caution: The following link contains adult language from the beginning, but it actually demonstrates the issue very well.
http://www.ted.com/talks/ashley_judd_how_online_abuse_of_women_has_spiraled_out_of_control

Playing almost any ted.com video can reproduce the problem. Playing the same videos on IE or Edge HTML5 video players does not present the out of sync condition. 



Actual results:

The video and audio are out of synchronisation.


Expected results:

The video and audio are in synchronisation, as played on IE and Edge.

Comment 1

[Hani Yacoub, Desktop QA]

Could you please be more clear about the steps how to play a ted.com video in HTML5 video player?

Comment 2

[u464100]

(In reply to Hani Yacoub from comment #1)
> Could you please be more clear about the steps how to play a ted.com video
> in HTML5 video player?

Step #1: Do not have Adobe Flash extension installed, or if it is installed, disable the extension. This should allow ted.com to present their HTML5 video player, rather than Flash Player.
Step #2: Click on one of the links above: (http://www.ted.com/talks/ashley_judd_how_online_abuse_of_women_has_spiraled_out_of_control)
Step #3: Press the play button presented on the video player presented on the page.

Let me know if you require additional information.

Comment 3

[Hani Yacoub, Desktop QA]

Thanks for making it clearer now.
How significant is the out of synchronization between the video and audio? Because I really can't see it.

Comment 4

[u464100]

(In reply to Hani Yacoub from comment #3)
> Thanks for making it clearer now.
> How significant is the out of synchronization between the video and audio?
> Because I really can't see it.

It is significant, particularly on the Ashley Judd video. I had thought it might be a hardware issue, but, as stated above, these videos play fine on IE and Edge (that is, perfectly in sync).

Is there any additional information, like settings, that could help?

Comment 5

[u464100]

(In reply to Gary Sanders from comment #4)
> (In reply to Hani Yacoub from comment #3)
> > Thanks for making it clearer now.
> > How significant is the out of synchronization between the video and audio?
> > Because I really can't see it.
> 
> It is significant, particularly on the Ashley Judd video. I had thought it
> might be a hardware issue, but, as stated above, these videos play fine on
> IE and Edge (that is, perfectly in sync).
> 
> Is there any additional information, like settings, that could help?

OK, some more information (re Ashley Judd video):

[1] I have tried disabling hardware accelleration. The problem still occurs whether or not hardware accelleration is enabled or diabled.
[2] At about 0:11 there is a noticeable jump in the audio. From this point forward it is out of synch.
[3] Once it is out of sync at about 0:15, pause the video, reload /refresh the page age, press play, the video resums from where it was stopped, but is now in sync.
[4] My guess is that whatever caused the jump in the audio at about 0:11 is the cause of the out of sync situation.

Comment 6

[Hani Yacoub, Desktop QA]

> [2] At about 0:11 there is a noticeable jump in the audio. From this point
> forward it is out of synch.
This jump is also noticeable using Adobe flash and on other browsers. I really can't see the out of synchronization between the video and audio.

Do you have any add-ons installed on your profile? If yes please try to reproduce it in safe mode: https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode

If you still have the issue please create a new profile, you have the steps here: https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles?redirectlocale=en-US&redirectslug=Managing-profiles#w_starting-the-profile-manager

Comment 7

[Anthony Jones (:ajones, :kentuckyfriedtakahe, :k17e)]

I can't reproduce the issue in nightly. Are you still seeing it?

Comment 8

[u464100]

(In reply to Anthony Jones (:kentuckyfriedtakahe, :k17e) from comment #7)
> I can't reproduce the issue in nightly. Are you still seeing it?

Trying this with FF 53.0 it seems to operate much better. I am happy for this issue to be resolved.

Comment 9

[Blake Wu [:bwu][:blakewu]]

I have tried 53 and our nightly(55) and cannot see this problem either. So I am going to close this bug.