It is Nostr issue, yes. We are constrained by the sha256 requirements for uploaded content. This means that once you upload something, we cannot change a single bit of that file. Handbrake is a good software that will allow you to produce shareable media.
Discussion
This. 💯 is my issue as a creator with #nostr
I’ve never thought about this before.
But thank you for committing to this. 🫡
Personally I don't think nostr.build should be on the hook for media compression. But putting the creator on the hook isn't great either because they don't usually know anything about video formats.
A separate caching and compression service is probably the play. Some kind of paid service that clients look to for optimized media. Then the viewer is on the hook, voluntarily employing a middleman to compress, store, and serve content from other providers.