[MPlayer-dev-eng] Ambisonic playback

[Reimar at mplayerhq.hu]

Hi,
On Thu, Nov 10, 2005 at 01:32:42PM +1100, etienne deleflie wrote:
> The Ambisonic community is putting together a specification for an 
> Ambisonic player. We are aiming at a free, open source and 
> cross-platfrom implementation. Hopefully we can integrate with an 
> existing and established player like Mplayer.
> 
> Ambisonic playback is slightly more complicated than straight file 
> playback because Ambisonic files typically have 4 channels, which need 
> to be "decoded" to whatever speaker array the user has. So the typical 
> use case is the user opens the file, configures Ambisonic playback for 
> his/her specific speaker setup (like 6 speakers horizontally, or 8 
> speakers in a cube, or 5.1 or whatever).

Hmm... As I understand this, this has not much to do with
decoding/playing a file, it actually is just "postprocessing" the audio.
In that case, any media player IMHO is the wrong place to put this, it
should go into something like e.g. JACK (http://jackit.sourceforge.net/)
or otherwise an audio filter like e.g. libaf/af_hrtf.c
(http://www1.mplayerhq.hu/cgi-bin/cvsweb.cgi/main/libaf/af_hrtf.c?rev=1.8&content-type=text/x-cvsweb-markup).
Though MPlayer might need some fixing to properly play multichannel
audio in all case, none of the developers (AFAIK) have the proper
hardware to play more than 2 channels, so it tends to be more flakey
than the rest...

> There is hence a significant GUI effort to undertake ... and there is 

Hmm... maybe I understand something wrong, but is setting this up not a
one-time thing? Any kind of GUI can't become an essential part of
MPlayer, and external configuration program should be no problem though
(and have other advantages, like being able to easily port the system
e.g. to another player/plugin architecture.

> Could Mplayer integrate such a functionlity in its architecture and 
> would the Mplayer community be interested in helping out, and hosting 
> this effort?

Helping out: probably not beyond giving some tipps, due to both lack of
time and hardware
Hosting: well, not before we have our new server up, anything else the
others will have to answer


Greetings,
Reimar Döfinger