Bitscope Program
Nick Brown wrote:
The problem with a piece of generic software for this approach is that
in addition to the audio itself, it'll only be able to get the data
that the sound device API provides. For MME this appears to boil down
to device name, number of channels, sample rate, encoding
ASIO adds a few more things, like the ability to query what clock
sources are available, what range of buffer sizes are available,
whether hardware input monitoring can be controlled.
I'm not sure what API you're talking about. Since you mentioned MME and
ASIO, I suspect that this is a fancy name for the sound card driver.
Unless an API provides a means to get to the stuff embedded within the
AES signal, it seems to me that software won't be able to show you it,
other than by targetting a specific piece of hardware and talking to it
at a fairly low level
Oh, the bits I'm talking about are definitely embedded in the AES
stream. If you have access to IEC standards (they cost too much and I
haven't found any free bootlegs on the net) look at IEC-60958. It's all
there. I know that some sound card drivers can recognize the copy
protection channel status bits and occasionally the emphasis bit so
they're able to see the data.
It may be that it's necessary to talk directly to the sound card in
order to get all the data since the standard way to write a sound card
ignores a lot of that stuff (and everybody tries to do what everybody
else does). This may be why the RME utility that displays the channel
data bits and only works with their cards. I don't know what all it
shows. They never seem to have anything set up at trade shows to
demonstrate it to me (sorry Mr. RME guy who hangs out here - I didn't
intend to insult your show folks, they just didn't have or know that
they had what I wanted to see) and I don't own any RME I/O hardware so
I can't see for myself.
If the driver is where the channel data stops, then the answer is to
write a driver that will pass it on to anyone interested. There really
shouldn't be any harm in that should there? If all sound card drivers
passed all the data, then a generic program should be able to use it.
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