Digitizing audio cassettes and extracting the contents of digital cartridges.

[Linux for blind general discussion]

Okay, I'v managed to find Perkins branded Digital Cartridges on
Amazon, but there doesn't seem to be any listings for the cables. Does
anyone know if the cartridges include the cables? Either way, I'm
tempted to pick up a 16GB cartridge as a stop gap for playing the
encrypted files if I can't figure out how to play them on my Blaze ET
or Linux PC, though considering how anemic 16GB is for storage this
day and age, I find myself wondering if my digital cartridge player
can play audiobooks stored on an SD card in a dongle-style reader
connected to the USB port on the side of the player. *Tries it with
the 256GB card from my Blaze ET.* Okay, its been beeping for a few
minutes and the pause, fast forward, and rewind buttons just play a
please wait message with no explanation. I can only assume its trying
to scan the SD card for compatible files.

Given a suggestion to use a standard tape deck to rip two of a
cassette's four tracks at a time and do post processing to account for
tapes having non-standard formats, I've been searching for a suitable
one on Amazon, and while there are several rather affordable models
designed specifically for converting cassettes to digital files, it
isn't always clear which models are stand-alone, which rely on a PC
and specific drivers, and which should work with any recording device
with a line-in/microphone jack, and many sound like they're hardcoded
to output mp3, which I deem completely unacceptable in this age of
terabyte harddrives and 256GB memory cards, and even cutting record
time by more than half isn't worth lossy compression when I already
have a recording device with line-in and wav support, and there's no
mention of sample rate or bit depth on any of the product pages I've
checked. If anyone has any suggestions for cutting through the cruft,
it would be greatly appreciated.

I've only ever used sox for concatenating flac files, but I understand
its one of the most versatile command line tools for manipulating
streamed audio. Can anyone provide instructions on how to do the
following tasks in sox or via another command line tool?

-Reversing an audio stream in a way equivalent to playing an audio
cassette backwards.
-Altering the sample rate for playback without altering the samples
themselves. Also, am I correct that, if your analog source is playing
at double speed, you'd want to record at twice the target sample rate
before slowing the recording down?
-Splitting multi-channel files into single channels files or merging
single-channel files into multi-channel files.
-Trimming silence to a given length at the biginning/end of a stream
or splitting a stream into multiple files in the middle of internal
silence exceeding a certain length.
-Anything else that might be useful for the task at hand.

Oh, and my digital cartridge player eventually finished whatever it
was doing, but still offered no explanation, not even a "no content
found" message. The contents of my SD card seems unaffected putting it
back in my Blaze ET.

Sincerely,

Jeffery Wright
President Emeritus, Nu Nu Chapter, Phi Theta Kappa.
Former Secretary, Student Government Association, College of the Albemarle.