Blossom would work however its not quite there yet, You would have to encode and optimize the videos yourself and they would only have one resolution setting

There is the option of using HLS (which is what twitch uses for providing multiple resolutions of a video) with blossom or any other hosting service, but you would still have to convert your videos to HLS which is even harder than mp4 😞 

I think @Kieran was working on HLS in zap.stream and @jb55 was also experimenting with encoding videos to HLS  nostr:nevent1qvzqqqqqqypzqvhpsfmr23gwhv795lgjc8uw0v44z3pe4sg2vlh08k0an3wx3cj9qy88wumn8ghj7mn0wvhxcmmv9uq3kamnwvaz7tm5dpjkvmmjv4ehgtnwdaehgu339e3k7mf0qqsxhezqs2vd9e5jcgg9u5jwa94da49xv4pz7vdek8ca2atgx426ajsmfx8yj

I also created a hacky experiment for uploading HLS videos to blossom https://github.com/hzrd149/blossom-hls-upload (sorry there are no instructions) 

 Ooookay, very nice! I definitely need to check and keep an eye out on the workings of blossom then. Thanks a lot 🙏 

 It's probably pointless to reply to this so late, but "encoding and optimizing the videos yourself" is the foreseeable future for decentralized video hosting. Everyone has a powerful phone or computer that's usually idle for at least several of every 24 hours, so it doesn't make sense to expect video hosting infrastructure to dedicate idle resources to doing that for everyone.