I am trying to make a Param as in the example, using
let mut par = x264::Param::default_preset("medium", None).unwrap();
This leads to a thread panic with x264 printing out
x264 [error]: invalid preset '8졶U'.
The string is different every time the program runs.

I'm not very familiar with x264, but I needed it for a project I was working on, so I made a high-level wrapper of it over here (docs). If you think the crate is a decent enough safe abstraction, would you mind adopting it? Thanks for considering it!

I'm currently trying to use vl4 to get the video from a camera and x264 to encode it, but x264-sys's bindgen dependency is older the v4l, so it conflicts. Could you please update the version of bindgen dependency to 0.65?

It misgenerates code like this:

#[derive(Copy, Clone)]; 16usize ] , }#[test]
fn bindgen_test_layout___mbstate_t() {
    assert_eq!(
        ::std::mem::size_of::<__mbstate_t>(),
        128usize,
        concat!("Size of: ", stringify!(__mbstate_t))
    );

See this issue.

error: failed to run custom build command for 'x264-sys v0.1.0

panicked on an Err value Error(PkgConfig(MSVC))

new proper link should be:
https://code.videolan.org/videolan/x264

Leverage Frame and Packet instead of reinventing the wheel.

From version 153 8+10bits is supported.