From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Revell Subject: Re: emu10k1 multichannel playback design (was Re: [PATCH] emu10k1: add interval timer support) Date: Sat, 25 Sep 2004 00:05:33 -0400 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: <1096085131.1407.18.camel@krustophenia.net> References: <200409242232.i8OMWXao032444@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200409242232.i8OMWXao032444@localhost.localdomain> Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Paul Davis Cc: Takashi Iwai , Jaroslav Kysela , alsa-devel List-Id: alsa-devel@alsa-project.org On Fri, 2004-09-24 at 18:32, Paul Davis wrote: > >It is more efficient to use a single 16 channel non-interleaved device > >if, as in the case of JACK, only one app will be using the device and it > >will use all channels. Individual mono streams become more efficient as > >the channel count gets lower. > > this is a reasonable point. > OK, thanks everyone for your help. I now have the basic device working. At least, it compiles and I can open it... I noticed the RME drivers use an interesting hack, of checking whether the playback and capture device are open by the same PID. My device will require something similar, as it also requires the same period size in both directions. Would you recommend using the same method, or is there a "better" way? Seems like this will work fine for jack, which is the targeted user anyway. With ASIO, I think this problem is solved by some kind of system wide hook. If I use different ASIO apps, each will have a button in the config that opens the system-wide ASIO control panel widget where I can set the buffer size; changing it will change it for all apps. Some handle this better than others; some will hiccup and some will have to have their audio engine restarted. Maybe ALSA should implement a system-wide method to set properties like this that apply to playback and capture devices. Or maybe this is better handled with a hardware specific app. Lee ------------------------------------------------------- This SF.Net email is sponsored by: YOU BE THE JUDGE. Be one of 170 Project Admins to receive an Apple iPod Mini FREE for your judgement on who ports your project to Linux PPC the best. Sponsored by IBM. Deadline: Sept. 24. Go here: http://sf.net/ppc_contest.php