From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Lloyd Subject: Re: DMIX and capture stream Date: Sun, 4 Jan 2004 18:02:11 -0600 (CST) Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: References: <200401040507.i0457Qbv005994@dhin.linuxaudiosystems.com> <20040104145223.25bddac3.mista.tapas@gmx.net> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <20040104145223.25bddac3.mista.tapas@gmx.net> Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Florian Schmidt Cc: Paul Davis , alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org On Sun, 4 Jan 2004, Florian Schmidt wrote: > On Sun, 04 Jan 2004 00:07:26 -0500 > Paul Davis wrote: > > > >I'm working on changing DMIX to allow clients to open the capture > > >stream. > > > > i don't get it. dmix is for playback, not capture. what would be the > > semantics of this? > > Hmm, i don't know the OP's answer to this, but i like to ask a very > related question: > > It is possible to create a playback pcm device with the help of the dmix > plugin. This way several apps can playback at once - nice. But now what > about using two apps that do full duplex at the same time? This is exacly my point. The fact that dmix and dsnoop are half-duplex is where I have a problem. There seems to be no way to allow more than one OSS-compatibility client to share audio in a satisfactory way. Which is to say, you can have two doing playback, or two doing capture, or maybe one each (haven't tried yet), but you can't do two full-duplex, or one full-duplex and one capture or playback. This is a bug in my opinion. It seems to me that this issue is not addressed by anyone, and that's why I started this code change, to allow capture to "pass through" so that one client can do full-duplex with multiple other clients still able to playback. This is not too much to ask IMHO. But at this point, I'm so disgusted I think I'll just buy a card with a hardware mixer like an SBLive, and forget about the whole thing. It looks like the plugin mechanism is completely ignorant of full-duplex applications anyway. I think that if a sound device doesn't have hardware mixing, it should be emulated in the kernel. I know a lot of people don't thing that's as "clean" as using a plugin, but it would make the life of the end-user a lot nicer. Have a nice day. - D ------------------------------------------------------- This SF.net email is sponsored by: IBM Linux Tutorials. Become an expert in LINUX or just sharpen your skills. Sign up for IBM's Free Linux Tutorials. Learn everything from the bash shell to sys admin. Click now! http://ads.osdn.com/?ad_id=1278&alloc_id=3371&op=click