From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Depner Subject: Re: alsa timer slippage Date: 14 Dec 2003 08:38:51 -0600 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: <1071412731.10990.11.camel@eviltwin> References: <200312141335.00239.cannam@all-day-breakfast.com> <1071410558.10990.3.camel@eviltwin> <200312141434.59757.cannam@all-day-breakfast.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200312141434.59757.cannam@all-day-breakfast.com> Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Chris Cannam Cc: alsa-devel List-Id: alsa-devel@alsa-project.org Multiple soundcards usually have to use word clock or some proprietary method of syncing the cards. Usually one card will be the master and the others slaves. I know you can put up to 4 ST Audio DSP24 cards in one system and set one up as master. I believe the same is true for the M-Audio Delta 1010. As for having a bad timer on a system, I've worked a lot with realtime systems and sometimes you just get a lemon. Jan On Sun, 2003-12-14 at 08:34, Chris Cannam wrote: > On Sunday 14 Dec 2003 2:02 pm, Jan Depner wrote: > > If I'm not mistaken the timing for your audio is coming from your > > sound card not your system clock. > > Is that so? Obvious though it is, that simply hadn't occurred to me. > > I mentally ruled out a hardware problem quite early on because I > wasn't seeing this problem when using a low-latency kernel on the > same hardware -- but maybe I just hadn't done enough testing with the > low-latency kernel. I'll give it another shot. > > The other points that brings to mind are, what if you have more than > one soundcard or no soundcard at all (only say USB devices)? and what > if the soundcard's just a chip on the motherboard, as mine is -- > wouldn't it get its own timing from the system clock? It's plausible > that this crappy i810 could have a crappy timer, though this example > would be unusually crappy. > > > Chris > ------------------------------------------------------- This SF.net email is sponsored by: SF.net Giveback Program. Does SourceForge.net help you be more productive? Does it help you create better code? SHARE THE LOVE, and help us help YOU! Click Here: http://sourceforge.net/donate/