Firefox takes 5 to 10 minutes to start playing and is jittery

[Luke 42308]

8 hours ago, SLMK said:

Please add force transcode as an option, ideally both server side per account, and client side options.

Playback and transcoding work well most of the time, but Ive run into quite a few edge cases over the years that this would have solved.

Worked for me as well, thanks.

Hi, the playback correction feature will also do it without having to mess with the quality setting.

[SLMK 19]

35 minutes ago, Luke said:

Hi, the playback correction feature will also do it without having to mess with the quality setting.

I actually didnt know that was even there, it works perfectly, thanks!.

(I would still love to see this as a per user option from the server end, because its a touched buried, but great to have).

[jawala 1]

"Good" to know this is a Firefox bug, not a bug in Emby's browser app!

Found this thread when I saw Emby (Firefox actually, apparently), trying to pre-fetch a whole ~16GiB movie ... cancelled it / gave up after ~6GiB (going by server logs) ...  

haproxy[185627]: [206] 192.168.1.10:48730 [31/Mar/2026:15:33:27.753]... 0/0/0/4/63732 6556730260 - -
    CD-- 19/19/1/1/0 0/0 {emby.example.org} "GET /emby/videos/185771/original.mkv?DeviceId=... HTTP/1.1"

That's 6,556,730,260 bytes.   

Here's the related Firefox bug report, for those curious: 
https://bugzilla.mozilla.org/show_bug.cgi?id=2000420

Sucks that most non-tech-savvy users might end up thinking it's Emby at fault!  

[LoveYou2 1]

On 1/19/2026 at 11:08 PM, Jefemy said:

The recently released Firefox MKV support doesn't allow for partial retrieval of the video content it seems. You can disable it by going to about:config and changing media.mkv.enabled to false.

That solved all my problems. Thank you—you saved me a lot of searching.

[LoveYou2 1]

Before make changes to "about:config"

After make change