DragonFly bugs List (threaded) for 2007-12
DragonFly BSD
DragonFly bugs List (threaded) for 2007-12
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Re: No Audio CD sound, but sound card works.

From: Chris Turner <c.turner@xxxxxxxxxxxxxxxxxxx>
Date: Mon, 17 Dec 2007 22:35:57 -0500

Petr Janda wrote:

This is a laptop. Audio CD sound doesn't work at all, all other sounds work.

Perhaps you've already checked this out, but ...

I'd like to point out there are 2 ways to play cd audio on PC's
(and probably the same goes other platforms too)

1. via an analog audio cable connected from the ad converters of a
   redbook compatible cd-rom drive to some analog mixer input on
   the sound card (think like a computer controlled hi-fi)

2. By reading audio tracks from the cd via the CD-ROM (i.e. yellow book)
   interface bus, buffering and converting appropriately, and
   sending this to the sound card's dsp inputs
   (typically through some kind of expansion bus, like ISA or PCI)

I'm not an expert on cdcontrol or what program you are using in KDE,
but based on a quick scan of /usr.sbin/cdcontrol/cdcontrol.c, it seems
like this program is designed to do #1, and perhaps the laptop hardware doesn't support it, as most media players are capable of and use by default #2 these days (for example IIRC windows media switched to #2 with XP, etc)

#1 wasn't possible with the advent of CD-ROM technology due to processing and bus bandwith limitations, but now this is kind of a moot point and implementing #2 is cheaper / easier / faster / more convenient / sounds better due-to-no-ad-conversion etc.

I'd be sure you're not getting these 2 confused before reporting it as a bug, although I suppose the manual could be clearer in this reguard..

good luck in your tests..

- Chris

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