1494792 - MSE: waiting event is report event with audio still available

Status: RESOLVED INCOMPLETE

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

Description

[g.marcilhacy]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36

Steps to reproduce:

Hello,
We are a music streaming website and we are observing rebuffers (interrupted audio) even when multiple seconds are available to play. This is using the Media Source Extensions.


Actual results:

We are observing that the majority of rebuffer occur when the audio buffer is empty. This is expected since the customer is unable to download fast enough the next segment. However, our data also shows that rebuffers do happen even when more than 30 seconds are available to play.
Additionally, this is a pattern we see only in background tabs.

Lastly, we report rebuffers when the audio element emits a 'waiting' event after playback starts.


Expected results:

We expect to not see no rebuffers when audio element has audio available.

Comment 1

[Jean-Yves Avenard [:jya]]

Do you have a web page available for us to try and reproduce the problem?

Comment 2

[g.marcilhacy]

The issue is reproducible on music.amazon.com (.fr, .com.au, etc). This issue is very difficult to reproduce consistently. I've been using a Windows 10 VM with low settings to increase my chances to encounter this bug.

Comment 3

[Jean-Yves Avenard [:jya]]

If you install https://addons.mozilla.org/en-US/firefox/addon/devtools-media-panel/

When playing your stream and it stalls, press Ctrl-Shift-I (or Command-Option-I on mac) and go to the Media-WebRTC tab. There select the URL you want to study. If you click on the URL text will show providing information about the stream and various playback internal structure.

Please provide this text back here.

Having audio buffered ahead doesn't mean it will never stall. If there's a gap in your audio that is great than 750ms it will pause... This can happy with badly muxed content.

It's up to the player to monitor gap in the data (using the video.buffered attribute) and seek as needed.

Comment 4

[Firefox Bug Husbandry Bot]

2019-03-06

This bug is part of a group of bugs which have had an open needinfo for at least 12 weeks.

The request for information has not been answered, and we can't move forward on the bug so we are closing it.

If the defect is still present, please reopen this bug with an updated report.