From owner-freebsd-hackers Fri Sep 22 15:41:34 1995 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.6.12/8.6.6) id PAA25486 for hackers-outgoing; Fri, 22 Sep 1995 15:41:34 -0700 Received: from Wit401402.student.utwente.nl (Wit401402.student.utwente.nl [130.89.236.162]) by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id PAA25480 for ; Fri, 22 Sep 1995 15:41:31 -0700 Received: (from alain@localhost) by Wit401402.student.utwente.nl (8.6.12/8.6.9) id AAA01125; Sat, 23 Sep 1995 00:41:18 +0200 Date: Sat, 23 Sep 1995 00:41:16 +0200 (MET DST) From: Alain Kalker Reply-To: A.C.P.M.Kalker@student.utwente.nl To: hackers@FreeBSD.ORG Subject: GUS users, can you please help me? (fwd) Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-hackers@FreeBSD.ORG Precedence: bulk Excuse me for posting about sound matters to the 'hackers' list, but I have tried 6(!) times now to post this to the 'multimedia' list without success (mail delivery problems). Furthermore, the problem I have may interest other hackers too. ---------- Forwarded message ---------- Date: Fri, 22 Sep 1995 17:41:58 +0200 (MET DST) From: Alain Kalker To: multimedia@star-gate.com Subject: GUS users, can you please help me? (fwd) While working on the sound driver, I have found the following problem: Using a GUS (MAX), when playing back an .mp2 file in _mono_ mode, using something like maplay -l .mp2 there are a few garbled fragments of sound (some of which were played previously) mixed in with the sound. After a few seconds sound plays normal again. This problem has also appeared when playing stereo .mp2 files using my improved version of the gus_copy_from_user() function (not released yet), but the problem playing files in mono existed even _before_ my first patch. Can anybody confirm this problem and, best of all, help me fix it? I must say I have not had this problem when I was using L...x. :-( My present idea as to what it could be is that somehow interrupts from the GUS are being lost or misplaced, i.e. not being serviced or serviced at some wrong moment during the _initial_ filling of the sound driver's buffers. Places where I have looked and hacked (unsuccessfully) are: - dmabuf.c: (DMAbuf_getwrbuffer) - wait for free space, (DMAbuf_outputintr) - gus_wave.c: (gus_sampling_output_block, gus_transfer_output_block, several routines called from interrupt handlers) Thanks in advance for helping me out. --- Alain