HTML webm vs mp4 (and/or webp vs jpeg)

[Legba]

Working on an HTML/Twine game and the question's in the title, really: I initially assumed mp4 would be a better choice for videos as it had wider compatibility, but with Safari capable of running webm now is there still a good reason to choose mp4 over webm? I know webm can reduce the size a bit, and I believe I read that mp4 is less taxing on a CPU so it may be better for tablet/smartphones, though I'm not working specifically for those.

Similarly, I know if you want transparency then webp is the way to go but other than that, is there a reason to pick webp over jpeg or vice versa?

Thanks in advance for any advice.

 

[DuniX]

is there a reason to pick webp over jpeg or vice versa?

From my tests webp that is lossy tends to mess with colors, only use lossless if you want it as a png substitute.
Jpeg on the other hand is known for their jpeg artifacts.
It depends on a case by case basis for what kind of results are acceptable depending on the color range that is affected which you can only do by testing.
Webp on a good qulity rate is great at maintaining details.
Webm is basically the same as webp I believe so similar tradeoffs. Not sure about mp4 as that can depend on codecs and stuff.

 

[Legba]

Thanks. I've been using the standard of H.264 with mp4, and no audio codec (so far, but probably would use the usual there too, AAC mpeg 2/4 is what my editing program defaults to).