From owner-freebsd-multimedia Wed Dec 9 03:00:00 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id DAA00391 for freebsd-multimedia-outgoing; Wed, 9 Dec 1998 03:00:00 -0800 (PST) (envelope-from owner-freebsd-multimedia@FreeBSD.ORG) Received: from hda.hda.com (hda-bicnet.bicnet.net [209.244.238.132] (may be forged)) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id CAA00384 for ; Wed, 9 Dec 1998 02:59:56 -0800 (PST) (envelope-from dufault@hda.hda.com) Received: (from dufault@localhost) by hda.hda.com (8.8.5/8.8.5) id FAA29204; Wed, 9 Dec 1998 05:58:13 -0500 (EST) From: Peter Dufault Message-Id: <199812091058.FAA29204@hda.hda.com> Subject: Re: Disk based audio editing tool? In-Reply-To: <18997.913182430@zippy.cdrom.com> from "Jordan K. Hubbard" at "Dec 8, 98 09:47:10 pm" To: jkh@zippy.cdrom.com (Jordan K. Hubbard) Date: Wed, 9 Dec 1998 05:58:12 -0500 (EST) Cc: benco@pendor.McKusick.COM, freebsd-multimedia@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL25 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-multimedia@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > > I wrote my own curses-based audio recording program, and I know how to > > crunch PCM data and calculate loudness in dB and stuff like that, > > but the identification and removal of the pops is beyond me. > > Hmm. If you've already figured out how to calculate loudness then the > elimination of pops just involves your existing work plus a little bit > of statistics keeping. :) Clicks and pops actually have very high > transient volume levels and stick out like a sore thumb on a 'scope. I expect those clicks and pops are at the angular velocity of the record - take a transform and put it through a notch filter at that frequency, kind of like the way they remove the gridding from piecewise scanned images. I expect they will really stick out in the frequency space. Peter -- Peter Dufault (dufault@hda.com) Realtime development, Machine control, HD Associates, Inc. Safety critical systems, Agency approval To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-multimedia" in the body of the message