[mythtv] Decision on FFmpeg repository

[Peter Bennett]

On 05/17/2018 04:01 PM, David Engel wrote:
> My only current aim for ffmpeg is MediaCodec.  Ater that is done, I
> wouldn't mind going back to stable, ffmpeg releases.  The git handling
> with subtrees would probably be more complicated, but I have to
> believe it can be done.  In theory, it should boil down to a rebase.
Another option we could consider is using the ffmpeg 4.0 version and 
cherry-pick the commits from ffmpeg master that apply to mediacodec. We 
could do this with a subtree or a private ffmpeg repository and submodule.

I examined the FFmpeg repository carefully around the 4.0 release and it 
seems they use the same principles we do - the release branch is taken 
from the master branch shortly before release, and all commits in the 
release branch are cherry-picks from the master branch.

To be able to easily accomplish this I think the best is a private 
repository and a submodule to pull in the correct commit. The submodule 
could be switched to a new branch easily when FFmpeg gets a new version. 
To ensure that everybody gets the correct code when building, the "git 
submodule update" could be in the configure script as suggested by 
Jean-Yves. It will have to allow for building from a tarball, in that 
case it will have to assume everything is up to date.

I think that trying to switch release branches when using a subtree 
would be excessively complicated.

Peter