[Openvortex-dev] Re: [Alsa-devel] Re: Volume per voices [Feature Request]

[Takashi Iwai]

At Fri, 05 Aug 2005 18:23:20 +0800,
Raymond wrote:
> 
> Takashi Iwai wrote:
> > At Mon, 01 Aug 2005 00:37:26 +0800,
> > Raymond wrote:
> > 
> >>Jaroslav Kysela wrote:
> >>
> >>>On Thu, 28 Jul 2005, Raymond wrote:
> >>>
> >>>
> >>>
> >>>>In theory, and sound cards with hardware mixing can support this kind of
> >>>>volume control.
> >>>>
> >>>
> >>>Nope. Please, define the controls at the driver initialization phase and 
> >>>make them inactive when the stream is not open. See emu10k1 or trident 
> >>>driver for hints. You must also map the voice volume with substream 
> >>>number.
> >>>
> >>
> >>Beside volume control, Is it feasible to bind other controls (e.g.
> >>Interaural Time Difference, Interaural Level Difference and SAMPLE RATE 
> >>CONVERTOR - Doppler Effect ) to the substream ?
> > 
> > 
> > I think yes.  Whatever directly bound to a PCM substream should be
> > handled as IFACE_PCM with a certain subdevice number.
> > 
> > 
> 
> It's OK for au88x0 to use a sample rate different from that of PCM 
> stream play the PCM stream to produce a different pitch.
> 
> Does the alsa-lib really allow using a kcontrol to change the sample 
> rate while playing the PCM to produce the Doppler Effect ?

Currently not officially supported.  The rate is assumed to be
constant.
But changing rate dynamically seems working, though.


Takashi