VP9 on youtube is causing it to drop frames especially on livestreams, disabling it results in avc1 being used and solved my problems for now.

wow, great addon

Thanks !
Solve a big problem with Waterfox classic + Youtube 360° and Nivida driver:
Youtube video seems to crash Waterfox content proces [Github].
Solution:
Install "enhanced-h264ify":
https://addons.mozilla.org/en-US/firefox/addon/enhanced-h264ify/
Open about:config:
1 - Set media.windows-media-foundation.allow-d3d11-dxva:false
2 - reset media.hardware-video-decoding.failed to false

I found HUGE (5000->500 kbp/s) download speed drop after using this. Useless. Deleted.

FANTABULOUS.

I don´t understand the previous reviews. It still works PERFECTLY on FF 83.0, even when used with Enhancer for Youtube+Thumbnail ratings bar+Blocktube+Toggle youtube playlist, giving me the smoothest Youtube experience ever.

And it makes a MASSIVE difference on my old tablet, which using the extremely underpowerered Intel Atom and a miserable GPU. I just blocked everything but h264 in the addon menu (which reads as AVC1 in the Youtube right click menu) and it allows me to play 1080p videos smoothly, when it used to stutter badly at 720p using the default youtube codecs.

I truly hope you can keep this updated when it´s truly needed, Mr. Developer.

Thanks!

No longer works. YouTube probably changed something yet again, and broke it. This is the problem with unmaintained add-ons, they quickly become obsolete. Sadly there are no functioning alternatives, so I'm forced by YouTube to use the AV1 codec, even though my hardware is too slow to use it without stuttering. Even setting media.av1.enabled to false has no effect any more. Mozilla seems to think that every PC user can afford 2020 hardware. At this rate, I'm just going to have to stop using YouTube, unless Google/Alphabet/Whatever wants to send me a new PC.

Does't work

seriously this should be available from youtube natively.
what does Google think, that everyone jups on 3xxx series gpu's soon as they are available, as they are the only ones with hardware support for av1 codec currently.
so why not offer option for vp9 if my machine can easily do 8k 60fps on vp9, but struggles on 4k av1.

Works great.

This causes YouTube to load low-res version of videos though :/