viewing waveforms (Re: [sdiy] Voyager waveform animation)

[Gene Stopp]

I think it's on topic because it's a powerful waveform communicaton tool
sitting under our noses.

The MP3 encode/decode loss concept is an excellent one. My original thought
was to post the MP3 of the audio VCO being FM'd by the LF wave while
sweeping the LF waveshape from one extreme to the other. (My favorite way of
determining the curve of slow-moving voltages.) In this case a very lossy
encoding would work just fine.

But to record the fixed VCO pitch as the waveform is swept, to hear the
timbral change and then see the waveform in a DAW, that's different. As long
as I'm sitting there doing export/import, I might as well try AIFF or .wav
while I'm at it and compare them. And heck, maybe I can get my wife to shoot
an MPEG of an oscilloscope over my shoulder on her jukebox.

Wow this is getting to be a big project...

- Gene


-----Original Message-----
From: john mahoney [mailto:jmahoney at gate.net]
Sent: Friday, August 08, 2003 3:36 PM
To: synth-diy at dropmix.xs4all.nl
Cc: Ian Fritz
Subject: viewing waveforms (Re: [sdiy] Voyager waveform animation)


Ian Fritz wrote:
> You can see the dynamics just fine using CE or other wav software.  Just
> zoom way in and let it rip.

Thanks for the tip, a few people have now pointed that out. Since you've
brought it up again...

Looking at the waveform of an MP3 file isn't necessarily the same as looking
at the original waveform before it's been put through the data reduction
process (so-called MP3 "compression"). It depends on the data rate and the
codec used, too. Of course that's theory, speaking, because I have not tried
this. I know that audio data is removed, but I do not know how visible it is
on a scope.

(Now that I know about the CE and WinAmp scope views, I may try this out.
I'd like to see how much data gets thrown away at different bit rates, for
example. Compare different waveforms to see how each survives the MP3
encoding. That sort of thing, just out of curiosity.)

My apologies if this is all too off topic.
--
john