Select provider of libav* libraries

[Andreas Cadhalpun]

Hi Fabian,

On 07.06.2015 14:39, Fabian Greffrath wrote:
> Am Samstag, den 06.06.2015, 21:29 +0200 schrieb Andreas Cadhalpun: 
>> Maybe we could even find a reasonable way to implement this in a dh7-style
>> debian/rules file without doubling the build-time.
> 
> yes, most probably. I do strongly believe that it is not necessary to
> clean the source and rebuild *everything* from scratch because of the
> additional codecs. I am sure it would be sufficient to back up the
> regular built library and merely call ./configure and make again with
> the extra rules to build the extra variant.

Yes, something like that should work.

> BTW, we are not talking about a single AMR encoder here:
> 
> $ LANG=C apt-cache show libavcodec-extra-56 
> [...]
>  This package is a replacement for the regular libavcodec56 library package;
>  it contains the following additional codecs:
>  .
>   * OpenCORE Adaptive Multi-Rate (AMR) Narrow-Band (Encoder/Decoder)
>   * OpenCORE Adaptive Multi-Rate (AMR) Wide-Band (Decoder)
>   * Android VisualOn AAC (Encoder)
>   * Android VisualOn Adaptive Multi-Rate (AMR) Wide-Band (Encoder)

FFmpeg has a native NB/WB AMR decoder as well as a native AAC encoder.
So the only missing functionality without the extra flavor is
encoding NB/WB AMR. (Since Narrow-Band and Wide-Band AMR are closely
related, I'm talking about 'an' encoder, even though they are implemented
as two different ones, provided by two different libraries.)

> So, please do not play down the importance of this additional package!

I'm not trying to play down the importance of the libavcodec-extra flavor,
but rather trying to find a reasonable assessment of it and this seems
to be quite low importance.

Another option of providing an AMR encoder in the Debian ffmpeg package
would be to write a native implementation for FFmpeg.

Best regards,
Andreas