OFF : CDRDAO Problems

Chris Gibbs chris at HAWKLORD.UKLINUX.NET
Wed Mar 13 14:15:50 EST 2002


Hi ya folks,

A bit ago someone complained about getting clicks between tracks when
burning disks DAO.  I chipped in saying I had same problem and blamed
the software.

I think I just sussed what is going on and how to do DAO 'properly', you
can't be lazey!

I was wrong to say I had the same problem.  My problem was getting
silence between the tracks.  Delay in screen up date led me to think it
was about 2 sec before the end of the track.  It is at the end.

To get rid of clicks you need to pad the audio file to sector size.

BUT if you do that the audio gets padded, with 0 up to sector size.

If there is little padding you won't notice.

If there is much padding you WILL notice if there is sound at the track
break.

So you can go for ages and everything is ok especially if you are just
copying cdr's because track breaks will normally occur on sector
boundarys. But then you copy a commercial cd and the silences come
back.  Led me to think some sort of mithical copy protection was
responsible.  If you use cdrdao it automatically pads when writing dao.

The only way to get round the problem properly is to join the wav files
together into one big wav file (or raw or cdr), or else edit the wavs so
the data size is a multiple of sector size.  I think the number is 4096,
it also is the buffer size on many pc sound cards.

If you need help joining wav's together ask and I show how.

Tip for *NIX users: cdrdao uses the toc file to extract whatever
part/parts of a wav(s) (or raw or cdr or isofs) are needed to create a
track. So a continuouse wav file is easy to make a toc for. Also if you
use cdrdao to copy a cd the correct toc file will be created for you, so
you dont need to worry about it.

If my understanding of this is wrong please enlighten me!

Does anyone know what a p-q sub-channel is?  Where is there info?

Chris
--
Hurewitz's Memory Principle:
        The chance of forgetting something is directly proportional
to ..... to ........ uh ..............



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