[MPlayer-dev-eng] Audio plugins

[Alban Bedel]

Hi Arpi,

on Mon, 18 Feb 2002 12:42:18 +0100 you wrote:

> Hi,
> 
> > 3. Multi channel EQ.
> hmm :)
> 
> > I also wrote a proposal of how to auto configure the plugins a few
> > weeks ago but no one responded to it, so here it is again:
> i don't remember, maybe i missed it :(
> 
> > I have been thinking of the audio out and how to configure the sound
> > card and selecting audio plugins depending on format of the audio
> > stream and the capabilities of the audio device.
> > 
> > I would like to extend the interface to the ao drivers with a new
> > function called get_capabilities() or something like that. This
> 
> why isn't control() enough?
> i really don't like API changes when avoidable...
> 
> > function would return a struct containing the limitations of the sound
> > card. This information could then be used to select the correct audio
> > decoder and audio plugins in order to maximize the sound quality and
> > make stuff work automaticly. The scheme would be combined with manual
> > override. It would also require some changes in the audio plugins or
> > the audio decoders and in mplayer (to get automatic hw ac3 and mpeg
> > decoding) if we want everything to auto configure.
> > 
> > Is this a good idea? Please give me your thoughts.
> good idea. anyway we shouldn't make it too auto. i mean, don't enable hw
> decoding unless user specified it in config file (like hw_audio=auto|yes|no)
> as it's very problematic at the momemt. the ac3 passthrough is a big hack,
> sending ac3 packets hidden in lpcm packets handled like le16 pcm played at
> volume 100%... i don't think it's easily detectable if the card can do taht,
> and anyway even if the card has sp/dif mayeb the user has analog system...
> 
> anyway the volume setting plugin is a good idea, someone should implement
> it. then we could move mixer code to libao drivers, and if they report 'no
> mixer support' we can automagically enable software volume control.
And make it avaible when the user want it. My sound card don't have pcm
volume control just the global one. It would be great in such case.
	Albeu