Archiving data from old storage media can be a highly complex process. It can be as simple as putting a disk in an old drive and reading out the contents. These days, though, the state of the art is more complex, with advanced techniques helping to recover the most data possible. The VHS-Decode project is an effort to improve the archiving of old analog video tapes.
The project is a fork of the LD-Decode project, which was started to recover data from the BBC’s ancient Domesday Project laserdiscs. It’s designed to capture the raw RF signals straight out of a VHS tape head, which are the most direct representation of the signals on the tape. From there, these signals can be processed in various ways to best recover the original audio and video tracks. It’s much the same technique as is used by floppy disk recovery tools like the FluxEngine.
Despite the VHS name, the code currently works with several tape formats. VHS, S-VHS and U-Matic are supported in PAL and NTSC formats, while Betamax, Video8 and High8 tape capture remains a work in progress. Using the code requires a video tape player with test points or traces that make signals from the head accessible. Capturing those signals is achieved via a Domesday Duplicator hardware device, or alternatively a Conexant CX2388x analog-to-digital converter, often found in many old PCI TV tuner cards. Various techniques can then be used to turn the captured signals into watchable video files.
We love a good archival project, and VHS-Decode is clearly a useful tool when it comes to salvaging old video tapes. Video after the break.
[Thanks to JohnU for the tip!]