From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Janssen Subject: Re: Control the exact moment of output Date: Wed, 30 Apr 2014 10:11:28 +0200 Message-ID: <5360B030.7010805@amsat.org> References: <5352BEA0.3050807@amsat.org> <535F59DD.2080207@ladisch.de> <535F61EC.9070003@amsat.org> <51940.86.107.254.57.1398840206.squirrel@boosthardware.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from pe1chl.nl.eu.org (pe1chl.nl.eu.org [89.18.172.156]) by alsa0.perex.cz (Postfix) with ESMTP id D85BE2651CB for ; Wed, 30 Apr 2014 10:11:32 +0200 (CEST) Received: from linux.pe1chl.ampr.org (linux.pe1chl.ampr.org [44.137.41.97]) by sys2.pe1chl.ampr.org (8.14.4/8.14.4/Debian-4) with ESMTP id s3U8BVJV031596 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 30 Apr 2014 10:11:32 +0200 Received: from [127.0.0.1] (localhost [127.0.0.1]) by linux.pe1chl.ampr.org (8.14.7/8.14.7) with ESMTP id s3U8BS2d030141 for ; Wed, 30 Apr 2014 10:11:28 +0200 In-Reply-To: <51940.86.107.254.57.1398840206.squirrel@boosthardware.com> 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: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Patrick Shirkey wrote: > > Have you looked into netjack? > > Several of the network timing issues have been worked through quite > extensively. We have used it to distribute data across several machines in > a cluster and find it to be very stable and workable with acceptable > latency over gigbit lan. > > You might find netjack gives you a good headstart on this project. > > Adding support for JACK is a minor task compared to rewriting (and > testing) netjack. You will also gain access to a host of other > professional functionality and ALSA, OSS, FIrewire support too. > > In addition your software will play nice with other professional software > and have direct access to data on the JACK graph as a bonus. > Thanks for the pointer! It indeed appears that this project is trying the same thing as we are doing. It will require some further study. Documentation appears to be scarce, I have not been able to locate a document yet that describles what it actually achieves and what caveats there are. I saw one thing on the Wiki: it transmits data all the time. We will probably need some form of on/off control to avoid wasting bandwidth, but maybe it can be done in a CODEC. I also saw it has fixed network latency setting, while I had already envisioned a system for automatically determining the added latency based on feedback from the remotes. But at least it provides a lot of insight into using Alsa in timing critical applications, something I had been looking for. (I know that writing documentation is a drag, but projects like Alsa and this one would be so much more useful and accessible when there would be more detailed documentation that goes beyond an installation HOWTO and a plain listing of available functions and parameters) Rob