yano signal processing
StretchFix
programs:stretchfix
plug-ins:psYchobass | multiband panner | a+/-b analysis tool
pedals:phase 100 | bazz fuss
papers:compressor effect study
projects:mixer | reference | opamp calculator
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StretchFix: home | manual | download | developer | license
 

Mac OS X Universal Binary
Download: StretchFix 0.9.2 [dmg, 3.72MB]

before... de-stretched and mixed

Problem Definition
The effects of age on a tape can make it playback through the tape heads at varying speeds. If dubbing an old master tape to digital, a gunky tape can make this task difficult. The end result may be an un-listen-able, slo-motion, and totally worthless dub of the original tape master.

If you've run out of time at the studio, but you were lucky enough to have a SMPTE Linear Time Code track, then StretchFix is what you're looking for.

StretchFix uses a two step process to restore your audio files to "normal speed".
First, you load the SMPTE Linear Time Code track, as dubbed from your gunky tape. StretchFix then parses the time code to determine how much each LTC frame varies from real-time.
Secondly, given this data, it processes any tracks you select using a varispeed, to restore them to real-time.

Wondering where to begin? Read the Walkthrough How-To.