In article , Eiron
wrote:
Glenn Richards wrote:

So short of doing an analogue "rip", is it possible to decode HDCD in
software and dither it down to 16-bit linear before encoding it as an
MP3, to avoid compression on playback?

Part of the licence agreement is, if I recall correctly, that the
decoded signal is not available digitally.

Erm... That may hinge on what they define as the 'decoded signal'.

My understanding of HDCD is that is repatterns the least significant bits
of the series of 16bit digital values in a proprietary way that the HDCD
decoder exploits in some way.

That would not prevent, say, an SPDIF output from giving you the (encoded)
series of 16bit values as they are present on the CD. Ditto for reading the
CD with something like a computer. Neither of these processes would
'decode' the HDCD data, just copy it with the bits in their 'encoded'
pattern.

I can't recall seeing a full and detailed technical description of the HDCD
system, so for all I know, though, the non-audio data on the disc may
contain some 'extra' info that tells the HDCD decoder 'this is an HDCD
disc' in such a way that a simple 'clone' of the audio data would not
duplicate. So far as I know, I have no HDCD discs, and none of my CD
players contain a decoder.

Slainte,

Jim

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