[alsa-devel] About 'SNDRV_PCM_CLASS_MULTI' for devices with multi-channels

[David Henningsson]

On 02/19/2014 03:57 PM, Takashi Sakamoto wrote:
> Hi all,
> 
> I have two questions about the usage of this macro.
> 
> Should I use this macro for new drivers which I'm working for?'
> http://mailman.alsa-project.org/pipermail/alsa-devel/2014-January/071820.html
> 
> 
> My drivers support some firewire devices, which is desinged for
> studio-use and have many channels. Its combination of channels are not
> designed for surround sound like 5.1ch.
> 
> Just judging from its name, 'SNDRV_PCM_CLASS_MULTI', I should use this.
> But there are no drivers which use this macro in current tree, against
> my expectation that some drivers (ICE1712-pro, RME9652, 6fire usb and so
> on) should use this macro.
> 
> Are there any reasons?

I've never heard of it before. I had a quick look in alsa-lib and
couldn't find any difference in handling between CLASS_GENERIC and
CLASS_MULTI.

It's probably something historic that nobody uses any more. Maybe people
who have been along longer knows what it is.

-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic