The introduction of the DVD-Audio format angered many early adopters of the DVD format, because DVD-Audio discs were not playable on DVD players sold prior to the new format's introduction. While DVD-Audio discs are capable of higher fidelity sound than CDs, there is debate as to whether or not the fidelity above 48 kHz is distinguishable to typical human ears. However, 24 bit recordings at 44.1 kHz and 48 kHz are widely accepted to be of substantial improvement to the 16 bit recordings currently available on Compact Discs. DVD-Audio currently forms a niche market, probably due to its dependency upon new and relatively expensive equipment and a lack of education regarding higher fidelity and multichannel music. DVD-Audio is currently in a format war with SACD.
The introduction of the DVD-Audio format angered many early adopters of the DVD format, because DVD-Audio discs were not playable on DVD players sold prior to the new format's introduction. While DVD-Audio discs are capable of higher fidelity sound than CDs, there is debate as to whether or not the fidelity above 48 kHz is distinguishable to typical human ears. However, 24 bit recordings at 44.1 kHz and 48 kHz are widely accepted to be of substantial improvement to the 16 bit recordings currently available on Compact Discs. DVD-Audio currently forms a niche market, probably due to its dependency upon new and relatively expensive equipment and a lack of education regarding higher fidelity and multichannel music. DVD-Audio is currently in a format war with SACD. DVD-Audio might find more success in the form of DualDisc and CD/DVD packages than as a standalone format, although newer formats such as HD-DVD and Blu-ray may render the format obsolete.
Copy prevention
DVD-Audio discs employ a copy protection mechanism called Content Protection for Prerecorded Media (CPPM). CPPM, managed by the 4C Entity, prevents users from extracting audio to computers and portable media players.
Because DVD-Video's content-scrambling system (CSS) was quickly broken, DVD-Audio's developers sought a better method of blocking unauthorized duplications. They developed CPPM, which uses a media key block (MKB) to authenticate DVD-Audio players. In order to decrypt the audio, players must obtain a media key from the MKB, which also is encrypted. The player must use its own unique key to decrypt the MKB. If a DVD-Audio player's decryption key is compromised, that key can be rendered useless for decrypting future DVD-Audio discs. DVD-Audio discs also can utilize digital watermarking technology developed by the Verance Corporation.
The 4C Entity also developed a similar specification, Content Protection for Recordable Media (CPRM), which is used on Secure Digital cards.
DVD-Audio's copy protection was overcome in 2005 by tools which allow data to be decrypted or converted to 6 channel .WAV files without going through lossy digital-to-analogue conversion. Previously that conversion had required expensive equipment to retain all 6 channels of audio rather than having it downmixed to stereo. In the digital method, the decryption is done by a commercial software player which has been patched to allow access to the unprotected audio. The fully digital method is still in very early stages, for example having problems with watermarked disks. As the DVD-A format has not gained wide commercial interest or acceptance further decryption tools are unlikely to be developed for some time.
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