- Not to be confused with multi-layer or dual layer disc recording.
MultiLevel Recording (
ML) (also known as M-ary) was a technology originally developed by Optex Corporation and promoted by
Calimetrics to increase the storage capacity of
optical discs. It failed to establish itself on the market. Through a combination of proprietary media, recorder, reader and player modifications,
Calimetrics proposed that ML could increase the capacity of a
CD-ROM,
CD-R or
CD-RW to 2 GB, a single-layer
DVD,
DVD-R,
DVD+R,
DVD-RW,
DVD+RW or
DVD-RAM to 7.1 to 10 GB and a single-layer
Blu-ray Disc (BD) to as much as 60 GB. An optionally integrated
Digital Rights Management (DRM) system entitled MovieGuard was also suggested. An industry group called the ML Alliance was formed in 2000 to help commercialize ML technology. Members eventually included
Calimetrics,
TDK,
Sanyo Semiconductor,
Plextor, Matsushita Kotobuki Electronics,
Mitsubishi Chemical Corporation,
Verbatim,
Teac and
Yamaha.