Syntrillium Backup Forums :: View topic - wave wrapper for allowing 24-bit in Win2k WDM

adriel · Posted - Mon Mar 04, 2002 6:29 am

This is a free device wrapper that may enable 24-bit recording in Win2k and CE. I'd be interested to know if this works out for anyone.

http://www.tonewise.com/www/

butchc · Posted - Mon Mar 04, 2002 6:19 pm

Thanks for telling us about this. I've just downloaded and installed this device wrapper, and so far it seems to work great!

DJClifft · Location: USA

I just tried it with an Echo Mia in Win XP and CE2000 and so far so good. The only thing is when you choose the device in CE2000 it may show up named as one of the other devices. Maybe it's a Win XP thing since it's actually for Win 2000. But it's always the first choice in the list. This will make more sense after you read the readme.txt file.

I had tried to determine 24-bit recording by zooming in on the file recorded in 32-bit to an individual sample and it showed a fractional value suggesting 24-bit recording. But the file played back as 16-bit as shown in the lower left of CE2000 and there was a slight hesitation when playback began caused by the Mia having to convert the file to 16-bit in order to play it. But now the hesitation is gone and it just says "playing" in CE2000.

What do you pros think? Is this thing really working?

Danny

post78 · Location: USA

Why not just record in 32-bit?

DJClifft · Location: USA

CE2000 does not allow 24-bit recording with WDM drivers. This will be fixed with Cool Edit Pro 2.0 but there are no current plans to upgrade CE2000. Recording in 32-bit float still only allows 16-bits to pass through. There has been a lot of discussion about this in the past few months. Do a search, you'll find a lot of good info. Maybe Synt will have a patch for CE2000. I sure hope so, but it looks like this will work for now.

DJClifft · Location: USA

The following is an email communication and response I had with the author of this driver. Thought it might help someone.

Hi Danny,

>I have an Echo Mia 24-bit audio card using CoolEdit 2000 and Win XP. CoolEdit 2000 does not have the capability to work with the WDM drivers in Win XP. So 16-bit recording is all you get. I tried your driver and I think it's working properly in Win XP. The only problem I incurred was choosing the driver in CoolEdit 2000 device settings. The name of the new driver is either just a symbol or a duplicate name of another audio driver. But it is always the first choice in the list and seems to work fine.

Glad you can make it work. Unforunately, I do not have time right now
to debug the display name thingy under Windows XP.

>My question is this. How do you know the audio is indeed recorded in 24-bit? Is there a way to tell for sure?

Here's the trick (I'm using Cool Edit Pro, but I do not think that 2K is
much different). Open the recorded file, and amplify it by +96dB (do
not play it after that Smile

. 96db corresponds to 16 bits, so all samples
exceeding 8 bit range clipped at either +1 or -1. Clipping destroys
upper 16 bits of each sample information, that is, if you find a sample
in the file after that amplification that is not clipped, that sample
had more than 16 bit precision before clipping.

Thus, just zoom in and scroll left and right in search for unclipped
samples... They are rare (statistically, one per 65536 samples), so you
may need to scroll a dozen of screens before you find one. I just found
a screen with 3 in a row, but they are rare! (see attached pic).

If you can find such samples, you have better than 16 bit precision. If
not, you are recording in 16 bit, even if the file is 24 bit - only the
higher 16 bits are significant.

HTH,

-kkm

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