In article , Evelyn Carnate
wrote:
On 18/06/2012 16:23, Jim Lesurf wrote:

AIUI MicroSoft took his code and say they put it into their software
players. But they bought the HDCD Patents. I have my doubts they
actually know or care about the details beyond it being another
'feature' they can offer.

It's a while since I looked at it but I thought Windows Media Player
would decode HDCD if you have a 24-bit sound card. WMP11 on my laptop
shows 'HDCD' in the bottom left corner when playing an HDCD.

AIUI both WMP and foobar will 'decode' HDCD. However I'm far for certain
that they do this correctly. I've been looking at the foobar code and it is
rather odd. And it says it is based on the C J Key code, which is also IIUC
what ended up in WMP.

And I thought there were programs available that could intercept data
going to a soundcard and copy it to a file, though whether these work in
24-bit I don't know.

I don't have any problem with recording digital output from a computer.
However:

1) I have no windows machines.

2) I have no idea if foobar or WMP actually do the job correctly.

3) I want to actually detect and examine the embedded codes and their
effects to see how HDCD *actually* works. The Patents, etc, are very vague
about that. I'm far from sure it works exactly as described. And I'd need
that to decide on (2).

4) There is also the issue of being able to develop 'open' decoders and
players and maybe even improve on HDCD once the patents lapse. That won't
be long now, I think. However we need the actual details - not just vague
descriptions and complied code that *might* work - to do that.

TBH so far my impression is that most HDCDs on the market simply use the
'solf limiting' to get LOUDNESS. Albeit in a way that a minority can
'correct'. This aspect is actually easy to correct *if* you can identify
affected material. So the CJK and foobar (and WMP) may get that right, but
I'm less sure of the other aspects.

I suspect there is a divide here. 'Classical Music' HDCDs may *not* use the
soft limiting much. But pop/rock probably use that and none of the other
claimed 'features' of HDCD. And for pop/rock the soft limiting decoding
will have a fairly obviously audible effect making HDCDs sound 'better'
when decoded. So promoting a myth that HDCD is better than CD when in
reality a CD simply recorded carefully at a lower level might sound as
good.

Slainte,

Jim

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