Is libav feature-complete?

[Reinhard Tartler]

On Wed, Jun 20, 2012 at 10:54 AM, Fabian Greffrath <fabian at greffrath.com> wrote:
> Hi team,
>
> just unteil yesterday, when Irebuilt libav several times to check the
> cond_enable() macros, I believed the libav packages we ship were
> feature-complete - at least in its -extra flavour. However, there are still
> a handfull of "no" messages emerged by the configure script. Just out of
> curiousity, what do they mean:
>
>> Sun medialib support      no
>
>
> What is this? Sounds like it is only relevant on Sun/Solaris systems?

AFAIUI yes.

>> libdxva2 enabled          no
>
>
> What is this? According to google, it stands for DirectX Video Acceleration.
> Is this relevant on non-Windows systems?

I don't think that it is relevant for non-Windows systems.

>
>> AVISynth enabled          no
>
>
> What is this?

http://avisynth.org/mediawiki/Main_Page

I think there is a Linux port of avisynth, but we haven't packaged it
(yet) and AFAIUI it is also not as usuable as the windows original.
However, that is AFAIUI and YMMV.

>> libfaac enabled           no
>
>
> This is one of the features that would turn the license into "nonfree and
> unredistributable". Also, libfaac has been REJECTED by our ftp-masters.

Well, partly correct. I guess we could get libfaac in non-free. I do
remember an old, unfinished patch to make libavcodec dlopen() it at
run-time, which we could finish.

>> libnut enabled            no
>
>
> It seems that this was designated to become ffmpeg's own universal container
> format. Development seems to have stalled, I cannot find any stable relase
> of this library. I think the role of the universal container has been taken
> by MKV. Is this relevant at all?
>

I haven't seen any .nut file in the wild, so I'd rather wait for some
user requesting it. Also, I'm not sure how usable it is in its current
form.

>> libxavs enabled           no
>
>
> This seems to be an obscure video codec developed in China in order to avoid
> patent fees towards the West. Even d-m.o does not have this packaged. Is
> this relevant? Would we do our Chinese friends a service by packaging and
> enabling this?

Probably, but as you say, we would first need libxavs in debian main.
I'd leave packaging this as exercise for our less experienced team
members.

>> openssl enabled           no
>
>
> This is the other feature that would turn the license into "nonfree and
> unredistributable". Typical issue linking of GPL source against OpenSSL
> code.

AFAIUI, libav can be linked against gnutls or openssl, and for debian
only the former makes sense.

> So, how about enabling sun-medialib, dxva2, avisynth, libnut and libavs?
> What is missing to enable them and is it possible at all?

>From the list, I only see libxavcs.

Thanks for your feature review!

-- 
regards,
    Reinhard