From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Ladisch Subject: Re: Complex hw buffer with MMAP_COMPLEX? Date: Tue, 09 Oct 2012 15:49:32 +0200 Message-ID: <50742B6C.9080601@ladisch.de> References: <50742405.9070201@drcomp.erfurt.thur.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from out1-smtp.messagingengine.com (out1-smtp.messagingengine.com [66.111.4.25]) by alsa0.perex.cz (Postfix) with ESMTP id 94F742616CD for ; Tue, 9 Oct 2012 15:49:36 +0200 (CEST) In-Reply-To: <50742405.9070201@drcomp.erfurt.thur.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Adrian Knoth Cc: alsa-devel@alsa-project.org, Andre Schramm List-Id: alsa-devel@alsa-project.org Adrian Knoth 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? If yes, this might be useful. (And subdevices are usually used for streams that are mixed together.) > Or use MMAP_COMPLEX and then let every application deal with it > on its own? Alsa-lib can automatically convert this. Applications that insist on using hw devices have to deal with it (Jack does). Regards, Clemens