avKode - Phonon backend for FFmpeg

[Allan Sandfeld Jensen]

On Friday 26 May 2006 21:23, Vlad C. wrote:
> Here are my questions:
>
> 1) Can FFmpeg reliably detect and play all the video
> and audio formats that Xine-lib can (Windows media,
> Quicktime, Real Player, DVD+menu, Audio CD, DivX, AAC,
> AVI, Ogg, Dirac, DVB, etc)? If not, FFmpeg won't by
> itself meet the needs of real-life users.
>
I don't really know yet. It meets the requirements of MPlayer.

> 2) Will avKode be simple a glue between FFmpeg and
> Phonon or will it also be a backend for other
> libraries like libMAD, libmpeg2, liba52, FAAD2, ogle,
> mpc, and xiph?
>
Glue. The rest is not really needed as it is already included in FFMPEG.

> 3) Why don't KDE apps (amaroK, Kaffeine, KMplayer,
> Codeine, etc) already use FFmpeg directly as a
> backend? My guess is that's because FFmpeg doesn't do
> everything users need.
>
Because it has an unstable and incomplete API. The FFMPEG developers are more 
interested in making cool new decoders and encoders than making a stable and 
usefull interface. One of the projects they proposed for SoC was a redesign 
of libavformat to make it more usefull, basically avKode is such a redesign 
just in a different programming language.

> 4) Does FFmpeg output sound via ALSA or will it need a
> sound server? If so, how hard will it be to port it to
> Windows, which is the plan for KDE4?
>
FFMPEG has poor audio-output. I will improve it using technology from aKode. 
Windows capabilities are irrelevant as Phonon should use a DirectX backend on 
Windows.

> Xine-lib does everything FFmpeg does (and more!)
> because Xine-lib combines FFmpeg and the other
> libraries mentioned above. Furthermore, Xine-lib takes
> care of outputting sound to ALSA. Lastly, Xine-lib has
> a dedicated core of developers who will make sure it
> gets updated. All KDE devs have to do is keep Phonon
> in sync with Xine-lib's API.
>
Is that all we have to do? ;) 

> My goal in sending this email is to encourage you to
> avoid duplicating work. Good luck any way you choose
> to do it!
>
I am glad you for you feedback. Please note though I consider the project a 
bit of an experiment. It might end up as not so good idea. This is why the 
SoC project also emphasizes sub-projects (KIO) which would also be needed by 
a Phonon-xine or any other backend. 

I do not plan to duplicate much work besides what I think I can do better, and 
I am mostly interested in improving the KDE side of things.


`Allan