Vocoding

Any one know how to vocode?
if u know pls send me a tutorial or tell me how
Much appreciated

Are you asking about vocoding as a musical or video soundtrack artistic effect, or about vocoding as a way of encrypting the soundtrack, or about vocoding to compress the bandwidth of a speech channel?

encrypting a sound track :smiley:

Back in the day, I was working for Comsat Labs, in the department that designed the vocoder equipment. There were courses available on vocoder technology; I didn’t take them, the prerequisite was a PhD in Mathematics or Computer Science, or a doctorate in Electrical Engineering.
But as for encryption, we never touched that. I was designing a modem for fax signals that bypassed the vocoders in the satellite channels.

oh cool

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That is rather interesting.
I’m assuming it was when SCPC was the norm and you needed to control the bandwidth of the fax signals to fit into one of the audio subcarriers.

" Where multiple access is concerned, SCPC is essentially FDMA." - Wikipedia, “SCPC”

We were involved in the the transition from FDMA to TDMA.

OK, I thought that the modem you were developing was still using SCPC (analog) and the
fax data was being frequency modulated onto a subcarrier normally used for audio.

I see the wikipedia page that you linked to states:

Was that you guys?

COMSAT Labs is a huge place; I think that was down the hall from us.

We were in the digital transition; audio calls - including frequency/phase encoded modem and fax - were being digitized on-the-fly, compressed (if possible) by vocoding and then sending only the envelope, etc digitally, (thus compressing 300Hz-3000Hz band-limited 8-bit audio to 4Kb/sec or experimentally 3Kb/sec), but if there was music or modem or fax, it broke down and reverted to all-the-bits, about 64Kb/sec. Or it mangled your music or fax or modem and you hung up and tried again. We were detecting the fax link-up signals and diverting the call to a fax decoder (the same unit in your fax machine) then sending the extracted raw digitized image over the link, then re-encoding it as a fax signal at the other end and completing the call on your landline.

Amazing.
These days however we think nothing about modern codecs like G.729, G.726, GSM, Opus, etc
and the amount of work, time and experimentation it took to get where we are now.

Is any of the work you did confidential?
If not, why not write a book and include illustrations, photos, diagrams, etc.
I think there are enough nerds like me out there that would be interested and read it.

EDIT:

Or even make a video about it.

Not there.

I’ve done some very highly classified work, but never with a clearance; the really black stuff doesn’t require a clearance, because issuing clearances leaves a paper-trail.
LOL :rofl:
Like the titanium-framed “lab test gear” that got shot down over China…

Writing a book…
That takes a lot of time.
I had a volunteer ghostwriter, then she vanished. :roll_eyes:
I am trying to document it on videos.

If it’s not even down on official papers, then it’s probably best to not write or make videos about it.
You certainly don’t want to be re-acquainted with your former ghost writer.

Not vanished like that.

Just seems to have realized that she had volunteered for more work than she had time for.

Ever since a certain foreign government put a $50K bounty on my head, I’ve gotten to the point where I don’t concern myself with such worries.
The Almighty has my back, and indeed seems to have delegated some of this responsibility to the local constabulary, as I have discovered that there is a “special response” specified for my address.

Glad to hear it.

Look after yourself and stay safe.

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