Manpage of scramble.pl
Section: User Commands (1)
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scramble.pl - Scramble an mp3 file by reordering frames randomly
- scramble.pl inputfile.mp3
scramble.pl is a Perl script that randomizes the order of all the frames
in inputfile.mp3, saving the edits to the output file
scramble.mp3. scramble.pl is part of the main
mpgedit regression test test1.pl, or can be called as a
stand-alone program. scramble.pl is an mpgedit torture test,
but it can also be used for obscuring the contents of an mp3 file.
The original input file can later be recovered by calling the reciprocal
These are the steps scramble.pl follows to generate the
Save off the last frame of inputfile.mp3 to the file scramble_x.mp3
for later use. This must be done because the time duration of this frame
is likely to be less than a full frame time of 26ms, and will throw off the
unscramble operation when it appears somewhere in the middle of
Create a scrambled list of start/stop times for each frame in
inputfile.mp3 by calling the Perl script scramble_times.pl.
The list of scrambled start/stop times is saved to the file scramble.out
for later use by unscramble.pl.
Perform a series of 40-single frame edits controlled by the start/stop times
listed in the scramble.out file. These edits are all appended to the
output file scramble.mp3.
Append the saved final frame scramble_x.mp3 to the now scrambled output
saved in the file scramble.mp3.
The resultant scrambled output file is now completely unintelligible when
played back. The only use for this file is as input to the unscramble.pl
test script. Recovery of the scramble file scramble.mp3 is easily
accomplished by running ./unscramble.pl. The unscrambled output
is saved to the file descramble.mp3.
The final frame of inputfile.mp3 always appears as the final frame
of scramble.mp3. The scramble start/stop times are always saved to
scramble.out. The loss or modification of this file makes recovery
of descramble.mp3 impossible. Any ID3 tags present
in inputfile.mp3 are
edited away by the scramble/unscramble operation.
- SEE ALSO
This document was created by
using the manual pages.
Time: 21:47:16 GMT, January 25, 2009