Framerate fixes

[KirbysDarkNebula]

Fixes #322, adds a signal during videobox initialization to adjust video framerate from scene framerate. Gets applied on asset import (drag and drop/ import menu) and on project load so we might want to bump up the project version, since along changing the video framerate to match the scene framerate it also adjusts the video length, which might be a breaking change (then again we were handling it incorrectly before so I don't think it should be allowed if possible, you let me know).

Problems // Limitations

• Changing scene framerate doesn't change the framerate of the videos immediately, you'd have to reopen the project after saving (reloading the media doesn't fix it).
• What I think is a bigger issue is the fact that videos only ever adjust to one framerate, that is, you can have multiple scenes in one project, but the videos will only adjust to the scene they're loaded into, which means the issue we had before persists or gets worse when we change to a scene with different framerate.
• This does not fix the issue for image sequences, but I can look into it.

The first and third problems seem easy enough to fix but the second one is kind of major and might need some general tweaking of the way the editor handles scenes and assets, so I'm not entirely sure how to approach it. Maybe it's not a big enough problem to look into it because we realistically don't know how much people would be working on scenes with different framerates in the same project but I still think it's important.

I'd appreciate any help to get this to a better state... (For some reason I'm unable to debug the project, that's why changes on my end take a while).

Here's some example videos I made (on friction) to better test the framerate changes, they sync on this branch but do not on the original.

30fpsanim.mp4

60fpsanim.mp4

600fpsanim.mp4

[rodlie]

Thanks for working on this, will take a look at the PR and the limitations/issues tomorrow.

[KirbysDarkNebula]

Hi, it has been almost a year since I worked on this and I was wondering if this was ever looked into. I saw there were a few release candidates through the year and I understand that the focus is elsewhere but I feel like something as "basic" as this should be looked into, because people will import media and expect it to play properly, and lacking this, in my opinion, makes workflows with assets of different origins very difficult. (some media being 30fps, other being 24.99fps, etc.)
I imagine the codebase has possibly changed a bit so if changes were needed I could look into that, and the issues I outlined on my original post persist, but those were intended to be looked into as we moved along with this initial change, so let me know how we should proceed on this, thanks.
(Also, as I as I was looking through my changes I remembered I was working on a feature that I wanted to propose, but seeing as this didn't move forward I never made a PR, so if this can get moving I would be interested in helping and working on that)

[rodlie]

Yeah, sorry about that.

I never did anything with this PR as there seems to be more issues lurking, and there might be other ways to solve this.

I imagine the codebase has possibly changed a bit

No changes has been made to videobox.

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I can try to look into this after RC3 (note that I forget easily, always too much stuff happening).

A list of everything that's broken related to video is needed before anything is done, as things might be connected (usually is).