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Re: SMPTE parsing algorithm?

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.


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 >Re: SMPTE parsing algorithm? (From: "Kevin Dixon" <email@hidden>)



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