1532250 - [meta] Issues playing video on youtube.com/tv in GeckoView on Amazon Fire TV devices

Status: RESOLVED INCOMPLETE

(Core :: Audio/Video: Playback, defect, P2)

Description

[Bas Schouten (:bas.schouten)]

It appears that in GeckoView on Amazon Devices playing a video on https://www.youtube.com/tv is a significantly worse experience than on the WebView based browser. Basically once a link to a video is followed it takes a lot longer to play, if it plays at all, some observations here:

• The browser does not seem to be particularly busy
• Sometimes playback doesn't start at all
• I seem to be able to force playback to start by clicking pause and then play again

This all leads me to believe there may be one of these things or a combination going on:

• We buffer more video before starting playback than WebView on these devices
• There may be some event handling issues related to autoplay

Comment 1

[Vicky Chin [:vchin]]

While we don't autoplay it takes a long time to get to a point where we can even press play, and is longer than the time it takes to autoplay on Webview.

Comment 2

[Jean-Yves Avenard [:jya]]

YouTube is using MSE, they decide how much to buffer and when playback is to start.
If you play with the user agent, does it make a difference?

We do fire canplay event once we have a certain amount of time of data buffered, however Iirc, YouTube doesn't use that signal.

Comment 3

[Nils Ohlmeier [:drno]]

I think before talking about buffering we should first test if this behavior is not caused by block auto play kicking in on the device.

Comment 4

[Chris Pearce [:cpearce (Not reading bugmail)]]

(In reply to Bas Schouten (:bas.schouten) from comment #0)

• Sometimes playback doesn't start at all

I think this is caused by YouTube querying MediaCapabilities a lot, and we try to create a decoder for each request and then we reach the device limit for concurrent decoders.

I believe John Lin is working on that.

Comment 5

[Nils Ohlmeier [:drno]]

Most likely another side effect of bug 1533252 at it looks right now.

Comment 6

[Jean-Yves Avenard [:jya]]

(In reply to Chris Pearce [:cpearce (GMT+13)] from comment #4)

I think this is caused by YouTube querying MediaCapabilities a lot, and we try to create a decoder for each request and then we reach the device limit for concurrent decoders.

I don't think so.

The video element is only ever constructed after the MediaCapablities requests have been exhausted. While it may reduce some use resolutions, it will never fully fail.

And by the time the video element is created and content loaded, we have plenty of decoders available.

In any case, I'll have a fix for bug 1533252 today

Comment 7

[Nils Ohlmeier [:drno]]

Bas, did this get any better after landing bug 1533252? In other words is still reproducible?

Comment 8

[Chris Peterson [:cpeterson]]

Is this a block autoplay issue? cpearce sometimes sees a YouTube loading screen but clicking the center button then loads the video as expected.

This bug might be a dupe of bug 1535086.

Comment 9

[u597032]

https://support.mozilla.org/en-US/kb/end-support-firefox-amazon-devices