| # FFmpeg wrapper |
| |
| This is a minimal FFmpeg 5.0 wrapper for use with the virtio-video device, allowing to run a virtual |
| video device backed by software decoding or encoding. This is useful for development and testing in |
| situations where no supported video acceleration is available on the host. |
| |
| Although several FFmpeg binding crates exist, most of them are not able to link against the system |
| FFmpeg, and [the only one that does](https://crates.io/crates/ffmpeg-sys) is released under a |
| software license that makes our lawyers nervous. Also they all run bindgen at build time, which is |
| not possible to do under the ChromeOS build system and would require to patch the crate with fully |
| generated bindings. |
| |
| So taking this in consideration, as well as the extra work that it is to depend on external Rust |
| crates in ChromeOS, it is preferable to add our own simple bindings here that cover just the parts |
| of FFmpeg that we need. |
| |
| This crate has minimal dependencies ; on the FFmpeg side, it just uses `libavcodec`, `libavutil` and |
| `libswscale`. |
| |
| The bindings can be updated using the `bindgen.sh` script. A few elements that bindgen cannot |
| generate because they are behind C macros are re-defined in `avutil.rs` and `error.rs`, as well as |
| tests to ensure their correctness. |
| |
| And that's about it. |
