gecko-dev/media/libdav1d/README_MOZILLA

This directory contains build files for dav1d. The actual library
source is in $TOPSRCDIR/third_party/dav1d/

Any patches or additional configuration to be applied to the
upstream source should be kept here in the media/libdav1d
directory.

To update the library source and build config files, execute

  ./mach vendor media/libdav1d/moz.yaml

To update to a specific upstream git tag or commit, use

  ./mach vendor media/libdav1d/moz.yaml -r <commit>

The upstream git repository is https://code.videolan.org/videolan/dav1d

To update to a fork, use

  ./mach vendor media/libdav1d/moz.yaml --repo <repository url> [-r <commit>]


The rough steps are:
- Execute ./mach vendor media/libdav1d/moz.yaml -r {tag-name}  # ex: ./mach vendor media/libdav1d/moz.yaml -r 0.6.0
- Update ./moz.build and ./asm/moz.build to add new files and remove deleted ones using
  third_party/dav1d/src/meson.build as a guide (confirm with the diff) (note the
  empty .asm file in x86_64)
- Clone the tag from the dav1d repo and build a stand-alone libdav1d following the steps here:
  https://code.videolan.org/videolan/dav1d#compile
- Copy vcs_version.h from the local build/include/vcs_version.h
  to media/libdav1d/vcs_version.h
- Copy version.h from local build/include/dav1d/version.h to
  media/libdav1d/version.h
- Add new options, if any, in moz.build or config.h

Tips:
- If you see build failures in build-linux64-base-toolchains (or
  similar jobs) dav1d may now require a higher minimum nasm version
  than our base toolchains currently support.  A bug updating the
  minimum nasm version will probably be necessary.