From owner-freebsd-multimedia Tue Aug 26 08:11:30 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id IAA15577 for multimedia-outgoing; Tue, 26 Aug 1997 08:11:30 -0700 (PDT) Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by hub.freebsd.org (8.8.7/8.8.7) with SMTP id IAA15572 for ; Tue, 26 Aug 1997 08:11:14 -0700 (PDT) Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id PAA00328; Tue, 26 Aug 1997 15:34:00 +0200 From: Luigi Rizzo Message-Id: <199708261334.PAA00328@labinfo.iet.unipi.it> Subject: Re: guspnp17 and vat/rat To: hasty@rah.star-gate.com (Amancio Hasty) Date: Tue, 26 Aug 1997 15:34:00 +0200 (MET DST) Cc: CSP1DWD@MVS.OAC.UCLA.EDU, multimedia@FreeBSD.ORG, luigi@labinfo.iet.unipi.it (Luigi Rizzo) In-Reply-To: <199708260224.TAA07033@rah.star-gate.com> from "Amancio Hasty" at Aug 25, 97 07:24:35 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-freebsd-multimedia@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk >From what I know, rat tries to adapt to differences in play/record speeds, whereas vat does not and relies to silence intervals to resync. As a consequence, rat should never cause overruns, whereas vat might. On top of this, Amancio's driver uses non blocking io and seems not to check the return value from write()s to the device. So, on overruns, partial blocks might be written, and this could cause the observed behaviours (both in vat and mpeg123, which I have not looked at). With my new driver I have had a chance to look at many interface modules for the audio devices. Almost all of them use non-blocking io and do not really check for error conditions short writes. My sound driver distribution has updated interface modules for many applications (including vat), which are tested with my code but might work well with guspnp as well. Cheers Luigi -----------------------------+-------------------------------------- Luigi Rizzo | Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it | Universita' di Pisa tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/ _____________________________|______________________________________