[FFmpeg-devel] change installation directory for ffpresets

[Reinhard Tartler]

On Sat, May 15, 2010 at 22:01:52 (CEST), Stefano Sabatini wrote:

> Presets are parsed and processed by ffmpeg the binary, shipping them
> with libavcodec looks a very bad idea (TM).
>
> Since presets files are processed by ffmpeg they need to depend on the
> ffmpeg version. For example we could decide to change the presets
> syntax, this would merely depend on the revnumber, and nothing on the
> library numbers.

In practice, the preset syntax doesn't change. What does change is the
options and values it sets. Therefore in practice, the dependency of the
presets on the libavcodec package at least "feels" much stronger than on
FFmpeg.

The thing is this, in ubuntu/debian, I maintain in fact two versions of
FFmpeg.  One that builds and installs the 'ffmpeg' utility package but
no libx264 wrapper, and the other one with libx264 enabled but without
the ffmpeg utility (called the '-extra-' variant. In practice, it can
indeed happen that the -extra- variant is lagging a few days/weeks
behind the regular variant. Therefore, it is convenient to ship the
preset files in the libavcodec binary package.

This can be of course considered as a self-made problem, but I'd prefer
a solution at an upstream level over a sub-optimal distro-only one.

>> The trouble is now that this will create a file conflict when
>> libavcodec53 is introduced. In order to prevent this, I can either a)
>> move them back to the ffmpeg package and use a much stricter dependency
>> on the libavcodec binary package or b), have the presets installed in
>> /usr/share/libavcodec${major}. This makes it possible to have different
>> ffpresets installed for libavcodec versions with different major
>> versions.
>> 
>> As I feel b) is much more elegant, and datadir is currently used for
>> nothing else, I'm proposing the following patch:
>
> a) seems the only sane solution to me, just my two ?cents.

Another solution would be to create an ffpresets package, but that feels
like pure overkill to me.

OTOH, I can of course understand that having the option to change the
syntax of the preset files is desirable and therefore, I think your
argument is reasonable as well. Hm. I guess I'll have to wait a few days
and hope that more people can comment on that.

-- 
Gruesse/greetings,
Reinhard Tartler, KeyID 945348A4