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DVD-A Recording Format Still In Development

Consumers will soon have three DVD-Video recording formats to compare, but there’s not a single DVD-Audio recording format for audiophiles to audition.

Because the DVD-Audio format is still in its infancy, the DVD Forum doesn’t believe an urgent need exists to quickly finalize a DVD-Audio recording standard. Nonetheless, some of the capabilities of licensed DVD-Audio recorders were approved in early 1999, when the Forum’s Copyright Protection Technical Working Group responded favorably to a copy-protection agreement reached by the five major music companies and forum members IBM, Intel, Matsushita and Toshiba.

That agreement, which applies to consumer electronics and PC products, granted consumers the right to make digital copies of their DVD-Audio discs, but with limitations. For example, consumers can use a legacy CD-recorder, MiniDisc recorder, or DAT recorder to make any number of first-generation two-channel digital copies of a DVD-Audio disc through a DVD-Audio player’s unencrypted IEC958 (SP/DIF) digital outputs. Consumers, however, aren’t guaranteed full CD, MD or DAT quality. Instead, copyright holders will be able to add watermarked instructions on a prerecorded DVD-Audio disc to limit a DVD-Audio player’s digital output to any quality level they choose up to DAT’s 16-bit, 48kHz level. SCMS (Serial Copy Management System) technology, already required in legacy recorders by federal law, would preclude serial digital copying (making digital copies of digital copies). Sequential digital copying would continue to be permitted.

Likewise, on future licensed DVD-Audio recorders, consumers are guaranteed the ability to make only a two-channel digital copy up to DAT’s quality level on a blank DVD-Audio disc, via a DVD-Audio player’s encrypted IEEE-1394 digital output. The ability to make a same-as-source two- or multichannel copy on a recordable DVD-Audio disc will be controlled by the copying instructions included in a disc’s watermark.

For each music company, those instructions could differ from disc to disc, and even from track to track on the same disc. Instructions could prohibit any same-as-source copy, limit same-as-source copies to only one, or allow unlimited same-as-source sequential copies. Serial digital copying through the recorder’s 1394 input would always be disallowed — unless the content provider opts not to incorporate any copyright protection.

To enforce these rules, DVD-Audio recorders will remember how many times you’ve made a first-generation digital copy of a particular disc and particular tracks from that disc. The recorder will be able to identify a particular disc and its tracks, remember the recording instructions and the number of times it made authorized recordings, and prevent additional recording after the permitted number of recordings are made.

Enforcement could be potentially limited by the size of a recorder’s memory.

DVD-Audio discs could also contain transaction instructions. A DVD-Audio recorder with modem connection, for example, could link up with an e-commerce site, enabling a consumer to pay for the right to make a clone of a friend’s disc without going to the record store or having to download the music.

Not even the unencrypted analog outputs of a DVD-Audio player are immune from copy-protection controls. A prerecorded disc’s watermark will survive in the analog domain when passing through a DVD-Audio player’s full-bandwidth two- or multichannel analog outputs. Depending on the instructions, the watermark could restrict copying by licensed DVD-Audio recorders to a maximum of two-channel DAT quality, or not allow a copy at all. A DVD-Audio recorder won’t be able to make a serial digital copy of the copy.

Two-channel recordings could be made through the analog inputs of CD-recorders, MD recorders, and analog cassette decks. Future unlicensed multichannel digital audio recorders would be able to make full-bandwidth copies through their analog inputs, but the recording would be imprinted with a watermark to prevent licensed DVD-Audio recorders from making full-bandwidth copies of the copy.

(See March 8, 1999, page 25, for more complete details.)