crosvm/media/ffmpeg/README.md
Daniel Verkamp ac0fc378a3 Fix remaining Chrome/Chromium OS instances
These should be written as ChromeOS and ChromiumOS (without the space)
to match the updated branding. The copyright headers were already
migrated to the new style (https://crrev.com/c/3894243), but there were
some more instances left over.

BUG=None
TEST=tools/cargo-doc

Change-Id: I8c76aea2eb33b2e370ab71ee9b5cc0a4cfd00585
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/4129934
Reviewed-by: Dennis Kempin <denniskempin@google.com>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>
2023-01-03 22:14:30 +00:00

1.3 KiB

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 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.