AUDIO_TS extraction? .AOB files?

[chrs]

I'm doing a lot of screwing around with DVD-Audio disks, and most of the 'stuff' I need is in the AUDIO_TS directory. I can currently find nothing to extract the files from it, or any information on it whatsoever. I know that an .AOB file is an "Audio Object", but what's inside of it? Would anyone have any insight on how to extract/decrypt these files in order to copy them onto a dvd-r or mess around with them? I'd like to get a nice DVD-Audio project rolling :P

[BJ_M]

DVD-Audio Copy Protection

Both digital copy protection and watermarking are part of the DVD-Audio specification.


DVD-Audio offers both digital copy protection and watermarking.

Digital copy protection
Until December 1999, DVD-Audio digital copy protection was to be provided by CSS II, the successor to CSS, which is used on many DVD-Video discs. However, the existence of the DeCSS software hack for DVD-Video has meant that a better copy protection was needed for DVD-Audio to prevent a similar occurrence. Content Protection for Pre-recorded Media (CPPM) has been developed by 4C (comprising IBM, Intel, MEI and Toshiba) and uses 56-bit keys, instead of the 40-bit keys used for CSS, and the Cryptomeria Cipher (C2) for content encryption.
It allows for a hacked playback device to be revoked using a Media Key Block (MKB). The MKB contains a very large number of keys. Each licensed decoder model has assigned to it a set of unique device keys that allow it to obtain the Media Key (used to encrypt the audio content) from the MKB and decrypt the audio content. Any playback device can be revoked in future discs via the MKB. MKBs are unique for every DVD-Audio title and new MKBs must be used every three months to allow devices to be revoked.

CPPM was agreed in mid 2000 and is now available for use by licensees. The decoding process for CPPM protected audio data is illustrated in the diagram below.



Watermarking
The copy protection scheme for DVD-Audio also includes watermarking, needed to identify music tracks and trigger copy protection systems when recording the content when supplied as an analogue input. The watermark must remain intact when the content is converted to analogue but not be noticeable in listening tests.
Watermarks must provide

Transparency (no effect on audio quality)
Robustness (be detectable after content processing)
Security (against forgery)
Verance has created a watermark to meet specifications from the recording industry and is regarded as the "clear winner of multiple competitive industry evaluations". It is a component of DVD-Audio security architecture and adopted for SDMI Portable Device specification. It has been used in recorded and consumer products since December 1999.

The watermark contains 72-bits of data comprising 4 CCI (copy control information) bits and 8 Usage Identifier bits every 15 seconds plus 60 Content Identifier bits every 30 seconds.

Verance claims that their technology has been demonstrated to meet all industry requirements and is available for use for DVD-Audio. It is renewable for the future and audio-watermarking technologies can be expected to be appearing in additional applications.