[paranoia] cdparanoia inconsistent results

[J. Scott Edwards]

Well I've investigated it further and it appears that although it sounds
like there is silence between some of the tracks, there really isn't.
Therefore any skew in where it starts ripping those tracks changes where
it stops and so it only matches to there.  So I guess it's not worth
worrying about.

Thanks
  -Scott

<p>On Sun, 15 Dec 2002, I wrote:

>
> I have been using cdparanoia for years and I guess I have operating under
> a delusion (fantasy?) that the ripping results would be identical.  But
> now that I've started checking I'm finding it's not.
>
> Sorry this story is a little long...
>
> This all started several months ago when I started using Grip.  Prior to
> that I had always run cdparanoia from the command line by hand with good
> results.  After ripping and encoding several dozen CD's with Grip I
> discovered that many of the cd's I had ripped had a weird thing which
> sounded like a random sector inserted into the middle of the music.
>
> Since grip had deleted all of the wave files I couldn't go back and see if
> they were messed up.  So I tried re-ripping them but had Grip save the
> wave files.  The wave files had the weird random sector thing thing as
> well.  I played around and tried ripping from the command line and it
> seemed better (but now I can't remember if there were still problems or
> not).  I was running RedHat 7.2 at that time and I thought maybe it was a
> problem that cdparanoia wasn't getting good responce time so I installed
> the low-latency and pre-emptive kernel patches to see if that helped.  It
> didn't seem to make any difference.
>
> Sometime after that I switched from RedHat to Mandrake and the problem
> went away.  But after that I always had Grip keep the wave files and made
> a backup CD of them just in case.  Later I switched that machine to Gentoo
> Linux and although I have only ripped a few CD's on it, it seems to have
> worked as well.
>
> So last month I got an old machine that I wanted to use as a juke box, so
> I installed BeOS on it (this is another long story) and started ripping.
> Everything went well until the disk filled up.  Since it doesn't have a cd
> recorder, I was going to copy the files over my lan to another machine and
> back them up there.  After messing around for some time (yet another long
> story) I gave up on that idea and decided that I could re-rip them on the
> other machine, but them to a cd and then compare them to the files on the
> BeOS machine, verify they were the same and delete them.
>
> Well of course they didn't match.  The files were the same length, but
> they were not the same.  I looked at the hex dumps and it appeared that
> perhaps the lead in was just a different length.  So I wrote a program
> that stripped off the lead in and lead out and just left the actual data.
> I used it on the files and the first two tracks from the CD were then
> identical, so I thought all was well.
>
> But then the next three tracks were different.  They were longer on one
> machine than the other.  They appear to be identical up to where the one
> file ends, but the other one continues on with additional non-zero
> samples.
>
> I have ripped it now on a third (OpenBSD-Pioneer DVD-ROM drive) machine
> and files are again different than the files ripped on the Linux-Plextor
> Plexwriter drive machine.  I am going to compare them now to the BeOS
> ripped files.
>
> My guess is that cdparanoia isn't always starting in the same place, but
> always rips the same length (based on the toc?) and on the tracks where
> one is longer it started too early read too much lead-in and then cut off
> the last of the track?
>
> Thanks
>   -Scott
>
>
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