[Ffmpeg-devel] New/extended filter API discussion

Michel Bardiaux mbardiaux
Wed Jan 3 12:22:48 CET 2007

Michael Niedermayer wrote:
>> (BTW, I think the library will need to provide two
>> separate APIs: one for audio and one for video... Or is it possible to
>> design a filter API that can support both audio and video?)
> yes 2 seperate APIs make most sense
I have been wondering about that, or more generally the asymmetry 
between audio and video in ffmpeg. Just some wild thoughts, maybe not 
even worth 2 Eurocents:

A number of attributes of audio have parallel in video:

Many audio codecs have a kind of 'superframe' (1152 in MPEG), akin to a 
video frame proper; superframe size <=> picture width.

Number of audio channels <=> picture height.

8/16/24 bits audio <=> picture colorspace (whether A-law and mu-law are 
'colorspace' or codecs is debatable)

In that view, a filter API that would support video pad/crop/rescale, 
would also support reorganization of audio channels (stereo to mono 
etc). There would also be an opportunity to reduce the amount of 
special-case code for audio in ffmpeg.

Season greetings,
Michel Bardiaux
R&D Director
T +32 [0] 2 790 29 41
F +32 [0] 2 790 29 02
E mailto:mbardiaux at mediaxim.be

Mediaxim NV/SA
Vorstlaan 191 Boulevard du Souverain
Brussel 1160 Bruxelles

More information about the ffmpeg-devel mailing list