[vorbis] OggEnc - command line... (& getting Audiograbber to work)

Luke Usherwood Luke.Usherwood at clear.net.nz
Fri Jun 21 02:56:43 PDT 2002



 > You probably already know these programs, but I would really recommend 
 > that you use CDex ( http://cdexos.sourceforge.net/ ) or Exact Audio 
 > Copy-EAC (http://www.exactaudiocopy.de/ ).
 > I have not worked with the latest Audiograbber releases, but you will 
 > hear abig difference with poor cds (scratches, etc.). EAC and CDex 
 > will not giveyou glitches and pops that easy with their excellent technology.
 > 
 > metrom

<p>I haven't used CDEx or EAX in probably a year now.  Have they changed much?   

The reason I ask is that I have a number of particularly badly scratched CDs myself.  Last time I tried, none of the 3 above-mentioned programs were able to correct all of the clicks & pops that occurred.  Even with the multi-reads of the CD, and the click & pop removers provided.

So I began writing my own program that would remove clicks & pops post-mortem.  I.e., you would run my filtering program over the .WAV before compressing it to .OGG   I still haven't finished it, but it's looking really promising.  

If anyone's interested:  It works differently from standard pop & click removal algorithms (which work in the frequency domain, and might be designed for pops and clicks caused by microphones etc).  Mine stays in the time-domain and uses the fact that CD's error correction uses interlacing.  Therefore, when bursts of errors occur, 95% of the time the errors appear on every second sample.  If you can recognise when a burst error has occurred, you simply throw away the bad samples, and interpolate from the good samples. That fixes the clicks.  I also want to fix pops when the CD reader looses sync completely (hey, some of my CDs are really scratched!)

I'm also hoping that my program might be able to remove the artificial errors that occur when ripping "copy protected audio CDs" which I have read about on the internet.  I haven't seen one of these personally, but I'd love to hear what happens.  If anyone has run into one of these, maybe you could email me directly, and we could discuss sending me a short uncompressed sample for me to try my program on.

<p><p><p><p>--- >8 ----
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