Helping with Maintenance of Packages in Debian

[Andres Mejia]

On Fri, Apr 27, 2012 at 9:18 PM, Hans-Christoph Steiner <hans at at.or.at> wrote:
>
> On Apr 27, 2012, at 7:21 AM, Fabian Greffrath wrote:
>
>> Am 26.04.2012 18:18, schrieb Hans-Christoph Steiner:
>>> When I read statements like "Uploading ffmpeg would be a bad idea", it
>>> seems to me that the Debian-multimedia team has taken sides on the
>>> ffmpeg-libav fork dispute. That is not a position that a Debian team
>>> should take. Both ffmpeg and libav remain valuable free software that
>>> people want to use. And if someone is willing to do the work, Debian
>>> and Debian Multimedia should welcome both ffmpeg and libav.
>>
>> I disagree and second Andres' statement that uploading ffmpeg into Debian *now* in its current state is a bad idea. This is not because ffmpeg is bad per se - it isn't - it's just that we decided to go the libav route. This switch is not irrevocable, but so far no general problems have occured with libav and I think it fits better to Debian's release model. There is simply no pressing reason to switch back.
>
> We do not disagree at all on this point.  I'm not saying that we should just upload ffmpeg as is, obviously it would be stupid to upload ffmpeg if it broke things. But we should welcome anyone who wants to do the work to make it possible to install libav and ffmpeg at the same time, or any other reasonable solution.
>
> And since this is a very political issue, we do need to speak carefully and clearly.  That's why I object to the statement "Uploading ffmpeg would be a bad idea".  It is very broad, and wrong from some legitimate Debian-specific points of view.

To install libav and ffmpeg at the same time, you have to either make
them ABI compatible or have the libraries, headers, programs, and
anything else that conflicts renamed. I am for this only if you work
with (or anyone works with) the two upstreams. I am against this if
it's to remain Debian-specific changes. I rather not resort to forking
both projects, plus I don't want another situation similar to the
SSL/SSH keys issues from the past [1].

>> Furthermore, currently libav and ffmpeg share the same library name space without being binary compatible - they are just not drop-in replacements for each other. This is also the reason for most of the bug reports we receive from users, who mixed up Debian packages built against libav with ffmpeg libraries from d-m.o.
>
> From what I know, this really seems to me a question for libav itself.  IMHO, it is a version of the code with a new name, so that seems that the burden falls on libav to do it.  And for the record, I have zero interest in getting involved in the politics, and I don't even want to know what happened to cause the libav fork.  I am just offering a Debian user's perspective on two pieces of valuable software that have some technical conflicts.

Renaming of anything is up to the upstream projects, not Debian.

>> If we would re-introduce ffmpeg into Debian now, alongside libav, we'd have two choices. Either we get ffmpeg and libav binary-compatible and sustain this compatibility for all subsequent releases. Or we can live with the incompatibility, but then we sould have to rename the libraries of one of the projects and have to build each and every depending package twice, once against libav and once against ffmpeg - with appropriate package dependency declarations and migration plans.
>>
>> Do you think any of these alternatives is worth the effort? I don't!
>
> I'm specifically interested in the ffmpeg command line util, I don't really need all the libraries.  That wouldn't be hard to package.  As for libraries, how about putting the ffmpeg versions into /usr/include/ffmpeg and /usr/lib/ffmpeg?  Then if someone wants to build against them, they can add -I/usr/include/ffmpeg and -L/usr/lib/ffmpeg.  For most projects that use the libav* libraries, there probably wouldn't be any difference between using the ffmpeg or libav versions, so it would be silly to make all packages for both.

libav already builds and provides the ffmpeg package. This is done
despite it being removed in libav upstream. It's only provided in
Debian for backward compatibility and to ease migration to avconv. The
plan is to remove ffmpeg after the next release is out.

As for the suggestions in library and header placements for ffmpeg,
you're essentially asking for ffmpeg to be renamed. In this case, like
I said already, you need to work with upstream.

> And of course, I'm not telling anyone that they should do the work here.  I am saying we should welcome anyone who wants to do it.  Oops, I guess I already said that ;)
>
> .hc
>
> ----------------------------------------------------------------------------
>
> All mankind is of one author, and is one volume; when one man dies, one chapter is not torn out of the book, but translated into a better language; and every chapter must be so translated.... -John Donne
>
>

1. http://it.slashdot.org/story/08/05/13/1533212/debian-bug-leaves-private-sslssh-keys-guessable

-- 
~ Andres