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AAC Chosen For DVD-ROM Section Of DVD Audio Discs
sootman writes "According to a news post at HighFidelityReview.com: 'The DVD Forum has chosen AAC for the DVD-ROM zone of DVD-Audio discs - the inclusion of a low-resolution (lossy) track suitable for solid-state and portable devices has long been championed by DVD-Audio figureheads such as Dolby's John Kellogg as a way of enhancing the value of the format to all listeners, not just those interested in its high-resolution potential. The selection of AAC came after a number of competing formats were proposed; they included MP3, ATRAC and Microsoft's WMA. Additional formats, such as [Ogg Vorbis] for example, were not put forward for consideration.'"
Lock in? AAC is an open standard and was NOT created by Apple. Of all the next generation audio formats (that aren't open source) it's the most open.
We should be happy.
Actually, you'll probably hear more whining from the four people who know what Ogg is.
Ogg is not an acronym, so don't uppercase it all.
Ogg is not an audio codec, so don't compare it to AAC.
You are probably thinking of the Vorbis audio codec.
But Apple doesn't own AAC and you don't license it from them. It's licensed from these guys:a ac/stan dard.html
http://www.vialicensing.com/products/mpeg4
On my mac my unprotected AAC's outnumber my purchased iTunes songs by 100:1.
How? By ripping my existing CD collection.. duh.
AAC ('Advanced Audio Coding') is the MPEG-4 audio standard, a.k.a. ISO 14496-3 -- it's hardly obscure or non-standard.
/ documents/w2670.html out for the ISO 14496-3 draft, if you're curious, or just search for ISO 14496-3 on Google. :)
Several of the digital and satellite radio systems use AAC, and a number of software music players support it; Apple's use of AAC to hold higher-quality-than-MP3 digital audio on the iTunes Music Store and for playback on the iPod is just the most-visible example of it.
You can check http://www.tnt.uni-hannover.de/project/mpeg/audio
--Rachel
There are only three recognized formats for audio on DVDs. On PAL DVDs, the compressed format is MPEG-1 Layer 2. On both PAL and NTSC DVDs, PCM (uncompressed digital audio) is used. On NTSC DVDs, the compressed format is Dolby Digital AC-3. The "AAC" you refer to is not the AAC that is sometimes referred to in the MPEG-2 specification; however, MPEG-2 for DVDs is a restricted subset of that specification. In fact, I get paid to show folks how to do this every day, since it's my work.
There's a great FAQ as to the formats for DVD audio.
However, the AAC standard referred to in the article is part of the MPEG-4 standard, and the MPEG-4 AAC does incorporate the formal MPEG-2 specification's AAC as one part of its capabilities.
That's true in a practical sense for North Americans, but MPEG audio is valid under the DVD specification.
If the video is NTSC, a DVD must contain either AC-3 or LPCM. It may also contain MPEG-1, MPEG-2, DTS, or SDDS audio.
See also the DVD FAQ.
-Dave
Microsoft's solution to this is called Secure Audio Path. It requires that the sound card drivers be signed by Microsoft if you want to play protected content. And they would presumably refuse to sign any driver which did as you suggested.