1400506 - firefox does not load videos fully

Status: UNCONFIRMED

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

Description

[illumilor.e]

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:55.0) Gecko/20100101 Firefox/55.0
Build ID: 20170817115854

Steps to reproduce:

Since FF55 videos do not fully load/cache on sites such as youtube and they end up stuttering and buffering, even with mediasource disabled

Comment 1

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

Is the issue reproducible in safe mode? See https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode

Comment 2

[illumilor.e]

Yes it still happens

Comment 3

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

(In reply to illumilor.e from comment #0)
> Since FF55 videos do not fully load/cache on sites such as youtube and they
> end up stuttering and buffering, even with mediasource disabled

I don't get the same problem on my machine so I need to figure out exactly what is different on your system. I also need to make sure I've got your description crystal clear, so I'll pick it apart a little.

What do you mean by "do not fully load/cache"? Are you on a network that isn't capable of streaming YouTube?

You mention "even with mediasource disabled", which seems odd to me that you'd want to do that. However we did make a change by introducing media.cache_readahead_limit=60 which limits how much we buffer to 60 seconds on "fast" networks.

You say "stuttering and buffering" which describes running out of CPU resources and network resources respectively. Are you describing an issue with CPU usage?

Does the video play through if you pause it at the beginning? Does it play for 60 seconds then give trouble?

Is Firefox using a significant amount of CPU?

Are other sites affected?

Comment 4

[illumilor.e]

Okay I think the readahead option was what was causing it. Changing that to a larger number fixes it.

"However we did make a change by introducing media.cache_readahead_limit=60 which limits how much we buffer to 60 seconds on "fast" networks."

Why?

Comment 5

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

(In reply to illumilor.e from comment #4)
> Why?

Normally you expect MSE to stream the video at the appropriate resolution. For sites that don't support MSE we limit the download to 60 seconds on fast networks to avoid unnecessarily downloading large amounts of data.

Are you on a fast or slow network?

Comment 6

[illumilor.e]

It is a 50Mb/s connection.

Comment 7

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

(In reply to illumilor.e from comment #6)
> It is a 50Mb/s connection.

I'm still trying to make sense of your bug report. Can you explain exactly what you mean by stuttering and buffering? Can you video it with your phone?

Comment 8

[Maire Reavy [:mreavy]]

(In reply to Anthony Jones (:kentuckyfriedtakahe, :k17e) from comment #7)
> (In reply to illumilor.e from comment #6)
> > It is a 50Mb/s connection.
> 
> I'm still trying to make sense of your bug report. Can you explain exactly
> what you mean by stuttering and buffering? Can you video it with your phone?

To the reporter: Can you help us by providing this additional info?  Thanks.

Comment 9

[illumilor.e]

When watching youtube videos with media.cache_readahead_limit=60, the video will pause playing for about 5-10 seconds and the rotating circle will show up several times during most videos while paused. I do not have firefox on my phone, only desktop.

Comment 10

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

JW - we seem to have a weird side effect of media.cache_readahead_limit=60. Why do you think would cause this?

Comment 11

[JW Wang [:jwwang] [:jw_wang]]

(In reply to illumilor.e from comment #9)
> When watching youtube videos with media.cache_readahead_limit=60, the video
> will pause playing for about 5-10 seconds and the rotating circle will show
> up several times during most videos while paused. I do not have firefox on
> my phone, only desktop.

IIUC, youtube use MSE and media.cache_readahead_limit will not change the behavior of MSE.

Comment 12

[JW Wang [:jwwang] [:jw_wang]]

Benjamin has been working on MediaCache recently. He will look at this issue.

Comment 13

[Ralph Giles (:rillian)]

Benjamin is no longer able to work on this. Free for anyone to take and investigate.

Comment 14

[jerry654]

Cached files and cookies can sometimes cause issues with loading videos. Try clearing your browser cache and cookies. You can do this by going to the Firefox menu, selecting https://magicalkatrina.com/ "Options" or "Preferences," navigating to the "Privacy & Security" tab, and clicking on "Clear Data ."