crosvm/media/ffmpeg
Tatsuyuki Ishi d06145a1ce media: ffmpeg: Add binding to obtain the required buffer alignment.
FFmpeg requires buffer alignment in case of SIMD-accelerated codec
implementations. This patch prepares for exposing the
respective requirement in the virtio-video interface.

BUG=None
TEST=cargo build -p ffmpeg

Change-Id: Ia8f3b2987571ddb8cf84b1201019ded83547e8f0
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/3822430
Commit-Queue: Tatsuyuki Ishi <ishitatsuyuki@google.com>
Tested-by: Tatsuyuki Ishi <ishitatsuyuki@google.com>
Reviewed-by: Alexandre Courbot <acourbot@chromium.org>
2022-08-12 04:48:35 +00:00
..
src media: ffmpeg: Add binding to obtain the required buffer alignment. 2022-08-12 04:48:35 +00:00
bindgen.sh
build.rs
Cargo.toml
README.md
VERSIONS

FFmpeg wrapper

This is a minimal FFmpeg 4.4 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 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 Chrome OS 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 Chrome OS, 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.