From owner-freebsd-questions Tue Mar 26 9:57:33 2002 Delivered-To: freebsd-questions@freebsd.org Received: from mired.org (dsl-64-192-6-133.telocity.com [64.192.6.133]) by hub.freebsd.org (Postfix) with SMTP id 2EC2737B41B for ; Tue, 26 Mar 2002 09:57:21 -0800 (PST) Received: (qmail 26571 invoked by uid 100); 26 Mar 2002 17:57:19 -0000 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15520.46718.771063.761625@guru.mired.org> Date: Tue, 26 Mar 2002 11:57:18 -0600 To: "John M. Fannon" Cc: Gautham Ganapathy , Peter Leftwich , "FreeBSD.org - Questions" Subject: Re: Audio CD without cable In-Reply-To: References: <014201c1d4a6$bef8a370$1901a8c0@itg.ti.com> X-Mailer: VM 6.90 under 21.1 (patch 14) "Cuyahoga Valley" XEmacs Lucid X-face: "5Mnwy%?j>IIV\)A=):rjWL~NB2aH[}Yq8Z=u~vJ`"(,&SiLvbbz2W`;h9L,Yg`+vb1>RG% *h+%X^n0EZd>TM8_IB;a8F?(Fb"lw'IgCoyM.[Lg#r\ From: Mike Meyer X-Delivery-Agent: TMDA/0.49 (Python 2.2 on freebsd4) Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG In , John M. Fannon typed: > > the problem is that there is no actual cable. the only connection between > > the sound card and the cdrom is through the motherboard. soundcard to m/b > > through the PCI slot and m/b to cdrom through the ide connector. i am not > > sure exactly how it is done, unless windows is somehow reading the bits on > > the audio cd and sending it to the soundcard > That's exactly what it's doing. > > I have used this feature for years in extracting perfect digital samples > from cds. Think about it, why have so many wasted steps (other than freeing > up some cpu cycles). The cd-rom forst reads the data off the cd, it goes > thru That D/A converter (usually not great quality) then to be run in to the > sound card (through an unsheilded cable in the middle of a computer case > known for emitting all kinds of emf), then read back in the a/d to a digital > signal (already we have some digital aliasing) and then back out through the > soundcard to headphones/speakers/recording/etc.. That's not the normal path to *play* a cd. That's the path if you do what I suggested - esdrec | esdcat). However, the normal path for playing a CD is through the CDROM's d/a converter, through that - hopefully shielded - cable, then through the mixer as audio to the speaker output. I'm pretty sure that the mixer on sound cards mixes analog signals, not digital ones. That doesn't change what you're saying, though. Ripping the music through the controller gives you perfect samples, where doing it through the sound card won't. BTW, my suggestion as a solution to the original problem was wrong. He needs to use a ripper that can feed data to standard out, not fooling with the mixer and esdrec. http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message