[plug] Workshop

[Craig Ringer]

On Mon, 2004-08-30 at 21:21, William Kenworthy wrote:
> 2. audio cd: Have audio CDs ever worked? Sound in general? (test with a
> hard disk audio file) In most cases, if sound works its a wire missing
> from the CD drive to the MB. 

> As to why audio CD's don't work - audio in
> this form goes via analog, not the data cable.

This varies by player. There are two different methods of reading audio
data from a CD. The older way is to use the ATAPI commands to tell the
drive to seek and play tracks via the analogue audio output, which is
normally connected to the sound card. The other technique, which really
only started seeing use when computers became fast enough, is to read
the audio data from the CD over ATAPI and send it in digital PCM form
down the ATAPI bus and feed it to the sound card in software over the
PCI bus. The latter method provides lots more control and flexibility
(read-ahead, buffering, equalisation, blah blah blah) but the former is
simpler.

Different players use different methods and some permit the user to
choose. As such, some players will work and others won't when the
analogue audio cable from the CD-ROM is not connected to the sound card.

So ... consider looking at your player settings or trying another
player.

I also suggest you use something like 'aumix' to make sure that the CD
audio channel or aux in channel on the sound card is not set to zero
volume (this will silence CD playing if it's playing via the analogue
cable; players that read the digital data will output via the normal
'pcm'/'wave' channel).

--
Craig Ringer