From owner-freebsd-hackers@FreeBSD.ORG Wed Mar 10 15:16:22 2004 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4920716A4D0 for ; Wed, 10 Mar 2004 15:16:22 -0800 (PST) Received: from cain.gsoft.com.au (cain.gsoft.com.au [203.31.81.10]) by mx1.FreeBSD.org (Postfix) with ESMTP id 66AB343D2D for ; Wed, 10 Mar 2004 15:16:21 -0800 (PST) (envelope-from doconnor@gsoft.com.au) Received: from inchoate.gsoft.com.au (localhost [127.0.0.1]) (authenticated bits=0) by cain.gsoft.com.au (8.12.9/8.12.8) with ESMTP id i2ANGCQ9054180; Thu, 11 Mar 2004 09:46:13 +1030 (CST) (envelope-from doconnor@gsoft.com.au) From: "Daniel O'Connor" To: freebsd-hackers@freebsd.org Date: Thu, 11 Mar 2004 09:46:10 +1030 User-Agent: KMail/1.6 References: <1078875485.404e555d87e85@www.bu.edu> In-Reply-To: <1078875485.404e555d87e85@www.bu.edu> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200403110946.10284.doconnor@gsoft.com.au> X-Spam-Score: -1.5 () CARRIAGE_RETURNS,IN_REP_TO,QUOTED_EMAIL_TEXT,REFERENCES,SPAM_PHRASE_00_01,USER_AGENT X-Scanned-By: MIMEDefang 2.16 (www . roaringpenguin . com / mimedefang) cc: jhoder@bu.edu Subject: Re: Equalizer X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 Mar 2004 23:16:22 -0000 On Wed, 10 Mar 2004 10:08, jhoder@bu.edu wrote: > i'm interested is learning more about freebsd's digital audio > functionality, and in particular, i'm interested in developing a graphic > audio equalizer which could be run from the command line, but allowing > greater control than the stock "mixer" bass and treble functions. > > would someone explain to me where, for example, the bass and treble > controls get their frequency range values? which source files (besides > "soundcard.h") need modification to accomplish something like this? > forgive my ignorance. i'm new to writing and compiling code but not to the > audio world. with some initial guidance, i'm sure i could make a > contribution. The bass and treble controls are connected to the sound card (really the AC97 codec your soundcard uses) so the actual shape is controlled by that.. You could probably shove a graphic equalizer into the kernel but it would be fairly complex to debug, and you can only use integer math :) You're probably better off modifying one of the audio multiplexer daemons - I know artsd at least can do plugins already. -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 9A8C 569F 685A D928 5140 AE4B 319B 41F4 5D17 FDD5