[mythtv] Decision on FFmpeg repository

[James Linder]

> On 17 May 2018, at 8:00 pm, mythtv-dev-request at mythtv.org wrote:
> 
> I would like to get a decision on what to do about a couple of FFmpeg 
> questions:
> 
> 1. Use FFmpeg master or release branch? My recommendation is to use master.
> - the FFmpeg website recommends using master for those who are compiling 
> FFmpeg themselves. It states that the release branches are for those who 
> rely on downloaded prebuilt packages 
> (https://ffmpeg.org/download.html#repositories).
> - Only master has the recent mediacodec changes which I need for android.
> - If we sync to master, we can use a better approach for the repository 
> (question 2 below).
> 
> 2. What method should we use for storing and syncing with FFmpeg source?
> Options are:
> a. Reapply patches to the source from FFmpeg, resolve conflicts, and 
> copy the source over what we have in MythTV (current process). This can 
> be very time-consuming.
> 
> b. Use a subtree in the MythTV repository.
> - This will not work if we use a release branch (question 1).
> - When resyncing, we can do a git merge of the subtree from FFmpeg.
> - We can cherry-pick changes needed without resyncing everything.
> - We can sync to any required commit, we don't need to go all the way to 
> the latest commit.
> - git log shows FFmpeg commits intermingled with MythTV. You can use 
> "git log -- mythtv" which eliminates those.
> - This imports some 90,000 extra commits from FFmpeg.
> 
> You can see an example of the subtree in use at 
> https://github.com/bennettpeter/mythtv/tree/ffmpeg-subtree or clone that 
> repo and look at the ffmpeg-subtree branch.
> 
> c. Keep our own customized FFmpeg repository with patches applied.
> - This will not work if we use a release branch (question 1).
> - When resyncing, do a git pull or merge on the private FFmpeg 
> repository. Then copy the entire source over the MythTV FFmpeg source.
> - We can cherry-pick changes needed without resyncing everything.
> - We can sync to any required commit, we don't need to go all the way to 
> the latest commit.
> - git log in MythTV does not show all the FFmpeg commits.
> - git log in the private FFmpeg repository shows records of our patches 
> along with all the FFmpeg commits.
> - We can perform periodic pulls into the private FFmpeg repository 
> without affecting MythTV. This will make the eventual copying into 
> MythTV quicker and easier.
> - Any FFmpeg patches that we apply between copying into MythTV must be 
> applied in both MythTV and FFmpeg repositories, or apply them in the 
> private FFmpeg repository and then wait for the next copy into MythTV.
> 
> You can see an example of FFmpeg with patches applied at 
> https://github.com/bennettpeter/FFmpeg


Peter ta very much.
It seems that if I pull mythtv and build (rather than download a distro prebuilt) then option 2c is the simplist.
James