Ah, an Australian newspaper (which shall remain nameless) reports:
The new [DVD Audio] standard, based on the MPEG-2 format used in DVD video, uses the extra storage to produce a high quality audio recording that more closely replicates the sound musicians hear in the recording studio.
Sorry, but that’s quite wrong. There actually is an MPEG Level 2 audio format used on some DVDs (eg. Evita and 20,000 Watt R.S.L.: The Midnight Oil Collection), but that has been around since the inception of DVD. All video DVDs are required under DVD Forum rules to contain at least one of the following audio formats: Dolby Digital, PCM (ie. like a CD) or, for countries outside the United States, MPEG2. (That’s why DTS DVDs always also have a Dolby Digital sound track). In the early days of DVD some Australian and European DVD producers thought that MPEG2 might end up being the format of choice, so they included this on some titles. Nobody uses MPEG2 for audio any more.
DVD Audio uses an entirely different technology. First, it’s PCM based, but instead of using the CD’s 16 bits of resolution and a 44,100 hertz sampling rate, it can use either 16 or 24 bits and anything from 48,000 to 192,000 hertz. Most tend to deliver 24 bits and 88,200 or 96,000 hertz in six channels.
Second, it does not use any form of ‘lossy’ compression such MPEG, Dolby Digital or DTS. These ‘lossy’ schemes work like MP3 (which, technically, is MPEG Level 1, Layer 3) and Sony’s ATRAC (used in the MiniDisc), using psycho-acoustic algorithms to eliminate bits of the signal that their designers believe people cannot hear. Of course audiophiles dispute this, with some justice.
The audiophile selling point of DVD Audio is that the audio format, in addition to using higher resolution bit depths and sampling rates, does not involve any ‘lossy’ compression. There is a compression system used, called Meridian Lossless Packing (MLP — sometimes called Packed PCM or PPCM), developed by UK audiophile equipment firm Meridian. This essentially manages to get the amount of PCM data down to somewhat less than half the size it would otherwise occupy (compared to 10:1 or more reductions for some of the lossy systems), but without using any pscho-acoustic trickery. The system is designed to allow a perfect reconstruction of the original signal. Rather than being MPEG, Meridian licensed MLP to Dolby Laboratories which took up the cudgels to have it specified as the standard DVD Audio format.