opencv-rust VS oxipng

I never tried it, but the OpenCV bindings might work.

I thought it was going to be unsafe because of how Mat is implemented (more information here). ... I tested it and it should be fine memory-wise. My thought was that the code below was going to be allowed to compile.

There are rust language bindings for opencv. https://github.com/twistedfall/opencv-rust

That would seem to indicate you do not actually have OpenCV installed, then. I'd recommend perhaps following the steps for getting the Windows prerequisites set up that the OpenCV Rust bindings provide in their readme.

I added opencv-rust as a dependency to a project. It makes my builds and even cargo check s really slow. It seems to invoke the build.rs script every time even when just type checking. Is this intentional? Is there any way to avoid this?

Assuming your frames are PNG files, you could use a lossless optimizer like optipng to try if their size can be reduced. I prefer oxipng, which is faster and multithreaded, and seems to have more active development.

Not sure what extensions of images you use, but if they’re PNG you could use oxipng: https://github.com/shssoichiro/oxipng

For PNGs specifically oxipng is awesome. It even has Zopfli compression, which is compatible regular compression, but is ~30% smaller (but requires lots of CPU time to compute).

They do. ripgrep and fd extensively use parallelism, which is specifically enabled by Rust's safety guarantees. oxipng is also in the same boat.

PNG: oxipng SVG: svgcleaner

Or go Commando: https://github.com/shssoichiro/oxipng