Join the Mozilla’s Test Days event from 9–15 Jan to test the new Firefox address bar on Firefox Beta 135 and get a chance to win Mozilla swag vouchers! 🎁

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

This thread was archived. Please ask a new question if you need help.

MSE & WebM VP9 not supported, causing YouTube to refresh

  • 4 replies
  • 1 has this problem
  • 1 view
  • Last reply by MarkRH

sabbath99
sabbath99
more options

When will Firefox support MSE & WebM VP9, because HTML5 was enforced on Firefox 37. The only thing that it's missing is MSE & WebM VP9 is not supported.

When will Firefox support MSE & WebM VP9, because HTML5 was enforced on Firefox 37. The only thing that it's missing is MSE & WebM VP9 is not supported.

All Replies (4)

MarkRH
MarkRH
more options

Go to about:config and make sure all these are set to True:

media.mediasource.enabled media.mediasource.mp4.enabled media.mediasource.webm.enabled

There is also: media.mediasource.youtubeonly

Which you can set however you prefer.

sabbath99
sabbath99 Question owner
more options

MarkRH said

Go to about:config and make sure all these are set to True: media.mediasource.enabled media.mediasource.mp4.enabled media.mediasource.webm.enabled There is also: media.mediasource.youtubeonly Which you can set however you prefer.

I have tried, and it's still giving me &hd=1 in the link.

sabbath99
sabbath99 Question owner
more options

MarkRH said

Go to about:config and make sure all these are set to True: media.mediasource.enabled media.mediasource.mp4.enabled media.mediasource.webm.enabled There is also: media.mediasource.youtubeonly Which you can set however you prefer.

I found the source of one of my problems. It's the YouTube HD extension.

MarkRH
MarkRH
more options

Right now https://www.youtube.com/html5 shows all six options with a blue checkmark for me. Is one of them still missing on your end or is it working now?