[78-L] Fw: [BC] Windows 7 Audio Performance

[Mark D Mobile]

Forwarded from another list, FYI:

Mark Durenberger
On the Road

-----Original Message----- 
From: Greg Ogonowski
Sent: Tuesday, August 28, 2012 4:21 AM

Just because audio is in the digital domain, you cannot assume that
digital-domain audio processors such as sample rate converters and
equalizers provide excellent performance. The Windows 7 and Windows Server
2008 R2 Audio Kernel has a bug that can degrade its record sample rate
converter performance. I strongly urge any users of these operating systems
to update the Windows Audio Kernel with the Microsoft Hotfix that is
described and explained here:

http://www.indexcom.com/tech/WindowsAudioSRC/

In summary, the bug affects all audio record/capture/encoder applications
that use the Microsoft MME API. These applications include Audacity,
SoundForge, CoolEdit, older versions of Adobe Audition, and all streaming
encoders that do not include their own resampling. This problem appears when
the destination audio sample rate does not match the hardware sample rate.
This can be confusing because these parameters are set in the Windows 7
Sound Control Panel, under Device Properties/Advanced, and unless you know
to look there (which many production personnel will not), audio quality can
be compromised.

Testing sample rate converters requires paying attention to many details,
including what the audio hardware supports. Many do not know that the new
Microsoft WASAPI Audio API does not provide sample rate conversion, so
developers are required to include their own sample rate converters within
each application. Not all sample rate converter designs preserve the signal
to noise ratio of their input signals; some add nasty-sounding aliasing or
other junk. Choose your audio software wisely!

Here is an informative and revealing link to SRC Comparisons

http://src.infinitewave.ca/

After viewing this, you are likely to look at digital audio software much
more critically. I urge everyone to learn how to analyze and edit audio in
the spectral domain. Most audio editor packages offer this mode and some
amazing things can be done there.

I have worked with Microsoft to make this Hotfix available. This was a huge
effort. This is not a problem with Windows 8, but good luck with that for a
multitude of other reasons. We thank Microsoft for making this Hotfix
available.

Greg Ogonowski
orban