From owner-freebsd-multimedia Thu Jul 24 03:50:22 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id DAA22099 for multimedia-outgoing; Thu, 24 Jul 1997 03:50:22 -0700 (PDT) Received: from whqvax.picker.com (whqvax.picker.com [144.54.1.1]) by hub.freebsd.org (8.8.5/8.8.5) with SMTP id DAA22091 for ; Thu, 24 Jul 1997 03:50:18 -0700 (PDT) Received: from ct.picker.com by whqvax.picker.com with SMTP; Thu, 24 Jul 1997 6:45:51 -0400 (EDT) Received: from elmer.ct.picker.com ([144.54.57.34]) by ct.picker.com (4.1/SMI-4.1) id AA23119; Thu, 24 Jul 97 06:45:49 EDT Received: by elmer.ct.picker.com (SMI-8.6/SMI-SVR4) id GAA18950; Thu, 24 Jul 1997 06:43:35 -0400 Message-Id: <19970724064335.01827@ct.picker.com> Date: Thu, 24 Jul 1997 06:43:35 -0400 From: Randall Hopper To: Luigi Rizzo Cc: freebsd-multimedia@FreeBSD.ORG Subject: Re: dma handling in the sound driver References: <19970723232432.47587@ct.picker.com> <199707240508.HAA25745@labinfo.iet.unipi.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.76 In-Reply-To: <199707240508.HAA25745@labinfo.iet.unipi.it>; from Luigi Rizzo on Thu, Jul 24, 1997 at 07:08:53AM +0200 Sender: owner-freebsd-multimedia@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk Luigi Rizzo: |Randall Hopper: |> Ok. Well, the only commercial app I have this info for is the MpegTV's |> Linux mtv, since I buzzed it out when debugging the no-audio problem |> (before dumping it for the FreeBSD version). Here's the /dev/dsp ioctls it |> uses: | |Thanks for the detailed list. | |I am looking at the DSP_SETFRAGMENT thing, and while I have no problem |to implement it with the required features, it sounds quite odd that |the application requires many small buffers. If they are small it means |the app wants low latency, so why ask for many ? Small buffers gets it low latency on write()s. Many buffers minimizes the chance that the driver will have played everything by the time that it gets around to feeding it again. Randall