From: Adrian Knoth <adi@drcomp.erfurt.thur.de>
To: Clemens Ladisch <clemens@ladisch.de>
Cc: alsa-devel@alsa-project.org,
Andre Schramm <andre.schramm@iosono-sound.com>
Subject: Re: Complex hw buffer with MMAP_COMPLEX?
Date: Tue, 9 Oct 2012 16:09:11 +0200 [thread overview]
Message-ID: <20121009140911.GK2040@ltw.loris.tv> (raw)
In-Reply-To: <50742B6C.9080601@ladisch.de>
On Tue, Oct 09, 2012 at 03:49:32PM +0200, Clemens Ladisch wrote:
> > That is, we're dealing with 25 (or 26 for output) interleaved streams
> > with two or eight channels each.
> >
> > How could we represent such a layout in ALSA, that is, how are we
> > talking to userspace? Would one create subdevices and rejoin them via
> > plughw?
>
> Is it possible to start/stop the streams independently?
No, there's only a single start/stop call for the entire card.
> > Or use MMAP_COMPLEX and then let every application deal with it
> > on its own?
>
> Alsa-lib can automatically convert this.
The only remaining question is how to tell alsa-lib about the buffer
layout.
AFAIKS, there's not even a single driver that uses MMAP_COMPLEX atm.
Cheers
--
mail: adi@thur.de http://adi.thur.de PGP/GPG: key via keyserver
next prev parent reply other threads:[~2012-10-09 14:09 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-09 13:17 Complex hw buffer with MMAP_COMPLEX? Adrian Knoth
2012-10-09 13:49 ` Clemens Ladisch
2012-10-09 14:09 ` Adrian Knoth [this message]
2012-10-09 14:19 ` Takashi Iwai
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