Easy screenrecording plugin

[mockersf]

Objective

• Followup on easy screenshot plugin #21235
• See mockersf/bevy@easy-screenshots...mockersf:bevy:easy-screenrecording for what's new
• Be able to record videos from Bevy in a consistent manner

Solution

• Make a new EasyScreenRecordPlugin in the dev tools

Testing

• Add to any example

        .add_plugins(bevy::dev_tools::EasyScreenRecordPlugin::default())

• Run the example with the feature bevy_internal/screenrecording enabled
• press the space bar
• wait for it...
• press the space bar again
• screen recording! 🎉
• almost... you now have a h264 file. VLC can read them, but they are not the most friendly format
• ffmpeg is our friend! for file in *.h264; do ffmpeg -i $file $file.mp4; done
• you now have a .mp4 file that can be shared anywhere!

---

Showcase

directly taken by Bevy

load_gltf-1758937494581.h264.mp4

[torsteingrindvik]

Would be even better imo if I could choose which resolution to record at.

One way could be to have the plugin take care to copy the source texture to another texture then rescale as part of the render graph.

Another could be to just use the CPU data and resize via e.g. the image crate or similar.

The user-responsibility way is probably to have them choose the correct primary window size, but if I have a low res screen and want to record e.g. 4k then it's better to have an off-screen render target.

[torsteingrindvik]

Also, why not https://crates.io/crates/video-rs?

[mockersf]

Would be even better imo if ...

I agree, but I think out of scope of this PR, that's part of the frame capture pipeline, this PR is mostly on what to do with the frames once captured. And hopefully to stay "easy and simple".

[mockersf]

Also, why not https://crates.io/crates/video-rs?

Mainly because I'm so used to use ffmeg on the command line that I didn't look for a crate for it but directly for an encoder