An efficient and idiomatic cadeau to Rust

Idiomatic wrapper around the Cadeau library: performance primitives and media foundation.

It’s possible to choose between dynamically loading the library and regular static / dynamic linking at build-time for a total of three options. See xmf-sys to learn more about this.

Read decoded VPX pixels

VpxImage::i420_planes() borrows the Y, U and V planes of an 8-bit I420 image without copying. Use each plane's rows() iterator to read its visible pixels safely; the row slices keep the image borrowed, so the decoder cannot decode again while they are in use. The plane does not expose a single byte slice, because libvpx may leave the padding between rows uninitialized.

Code that takes a base pointer and a stride, such as a C or SIMD color converter, can use the unsafe as_ptr() with stride(), width() and height(). Its safety section lists what the caller must uphold: read only the width() pixel bytes of each row, and stop using the pointer before the image is dropped.

Example: generate a WebM file from a PNG image

use cadeau::xmf::image::Image;
use cadeau::xmf::recorder::Recorder;

fn main() -> Result<(), Box<dyn std::error::Error>> {
  #[cfg(feature = "dlopen")]
  unsafe { cadeau::xmf::init("libxmf.so")? };

  assert!(cadeau::xmf::is_init());

  let frame = Image::load_file("frame.png")?;

  let mut recorder = Recorder::builder(frame.width(), frame.height())
    .frame_rate(10)
    .init("output.webm")?;

  recorder.update_frame(frame.data(), 0, 0, frame.width(), frame.height(), frame.step())?;
  recorder.timeout();

  Ok(())
}