Re: [MacPerl] Querying audio CD for track pre-play times

[Ken Williams <ken@forum.swarthmore.edu>]

pudge@pobox.com (Chris Nandor) wrote:

>At 10.37 -0400 2000.04.19, David Ackerman wrote:
>>The information you are looking for on the compact disc is in the program
>>area of the Q subcode track.  The program area [mode 1] contains track
>>numbers, index numbers, track time, and absolute time.  The track running
>>time is set to 0 at the beginning of each track and increases till the end
>>of the track.  At the beginning of the pause, time decreases until 0 is
>>reached at the end of the pause. and so on till the disc lead out.
>>
>>Further a pause can be identified by the index number (X).  When set to
>>00, X designates a pause between tracks.  A non-zero X indicates index
>>points within the track.  A vaule of 01 designates the lead out.
>>
>>hope this helps some.
>
>Most likely.  See the DV22 technote for more info on how to do this kind of
>thing with Mac OS.
>
>    http://developer.apple.com/technotes/dv/dv_22.html

I just discovered the program "ASTARTE CD-Copy", which is very useful for
looking at the guts of CDs.  In particular, it can give me the pause times of
existing CDs.

The demo version, available at http://www.astarte.de/, seems to do everything
but save.

Chris, if you're interested in adding this functionality to AudioCD::Mac, it
looks like the pauses are implemented using track indexes, so perhaps adding
some index info to the module could be useful.  I'm still not sure how to tell
the difference between "regular" index points and ones that indicate pre-track
pauses, because I don't yet understand the specs listed above.

Another great source I discovered is http://www.fadden.com/cdrfaq/ .


  -------------------                            -------------------
  Ken Williams                             Last Bastion of Euclidity
  ken@forum.swarthmore.edu                            The Math Forum



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