Re: SMPTE parsing algorithm?
Re: SMPTE parsing algorithm?
- Subject: Re: SMPTE parsing algorithm?
- From: Herbie Robinson <email@hidden>
- Date: Sun, 13 Jan 2008 23:36:04 -0500
At 9:50 PM -0500 1/13/08, Kevin Dixon wrote:
To clarify I'm parsing a recording of SMPTE LTC, in order to fix some time
skew problems on an old analog master tape that was too gunky to play at
real time throughout the dub to digital.
If the tape speed is unsteady due to sticky tape, I'm pretty sure you
won't be able to fix it using the time code track. There will be too
much jitter in the derived clock edges in the digitized time code.
They can be filtered to average them out, but that probably won't be
any good for driving a time stretching algorithm to compensate for
local variations (I'm guessing that's what you are thinking about
doing?). And even then, the quality will suffer.
A better idea would be to take the original tape to a tape
restoration place that can bake it to solidify the binder and redo
the transfer. There was a problem in the binder used for analog tape
in the late 80s and early 90s that caused the binder to migrate and
make the entire tape sticky (usually too sticky to play back at all).
The good news is that it can be temporarily cured by baking the tape
at VERY LOW temperatures (130 deg F) for a day or so. If you are
going to do this yourself, Google for more info, this is an
incomplete explanation. Or just find a tape restoration facility
that has experience with doing this. This will not only cure the
timing problems, but will also preserve the high frequency response
because the heads won't be getting gunked up.
--
-*****************************************
** http://www.curbside-recording.com/ **
******************************************
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden