How to required packages with variants

[David Evans]

Jean-Michel Pouré wrote:
> On Wed, 2009-01-28 at 11:43 -0800, David Evans wrote:
>   
>> My understanding is the without the x264 option, ffmpeg includes its
>> own 
>> codec (h264) and
>> with it an additional libx264 codec is included.  So I guess it
>> depends 
>> on whether the libx264
>> codec is being called by name and what the relative facilities of
>> each 
>> are -- you probably
>> know more about this than I do though.
>>
>>     
>
> FFmpeg includes codecs for reading and writing. Read and write support
> is not the same.
>
> => In the case of H264, FFMpeg can read natively but needs x264 to write
> to
> H264.
>
> => The same happens for mp3 : FFmpeg can read natively and not write.
> Therefore FFmpeg needs liblame. 
>
> I had a look at the sox package that MLT uses for effect and sound
> conversion. Well, I was surprised to see several variants:
>
> Variants: ffmpeg flac lame mad universal vorbis 
>
> Sox is the swizz army knife for converting files. What is the interest
> of Sox for users if people cannot read/write in vorbis or flac or even
> use FFmpeg with it. This could lead to problems in softwares like MLT or
> Kdenlive.
>
> Kind regards,
> JM
>
>   
Have opened a ticket for enhancement of ffmpeg based on JM's 
comments[1].  Please direct any further comments and/or suggestions there.

[1] http://trac.macports.org/ticket/18256