Sound Input Manager under OSX
Sound Input Manager under OSX
- Subject: Sound Input Manager under OSX
- From: Mark Gilbert <email@hidden>
- Date: Mon, 7 Jul 2003 18:19:32 +0100
Folks.
I wonder if anyone could confirm a problem I am seeing.
- My app was originally written in 1995, and uses the SoundInput
Manager to record mono or stereo audio.
We are porting it to carbon for OSX/OS9 from a single binary, and we
are seeing some issues with the SoundInput manager behavior in OSX.
The Carbonised app in OS9 works fine, but in OSX, we see different
behavior for certain selectors using the SPBSetDeviceInfo and
SPBGetDeviceInfo.
In particular, we are NOT able to select '1 channel - mono' with the
'chan' selector. The 'chav' returns '2' as we expect, but whereas in
OS9, using 'chan' allows us to hence select either 1 or 2 channels to
record, we do not see that same behavior in OSX.
If we send 1 with the 'chan' selector, then read it back, it returns
2 again. It wont stick on 1.
Hence we are NOT able to select Mono recording with SPBRecord in OSX
It would appear to be an OS Bug. I presume that the SoundInput
manager is emulated via Core Audio under OSX, and I am guessing that
this emulation layer is not behaving as we expect.
It is not a practical option to port this app to Core Audio, since
its just a very simple recorder, and 90% of our users are still on
OS9. To support Core Audio we would need to make a dual branch
build, which seems totally un-necessary for such a simple task which
is supported in carbon. There are other issues such as metering, and
auto start stop on audio threshold which would further complicate an
attempt to support Core Audio and SoundInput manager in parallel.
Does anyone have any further information on this ?
Thanks
Mark Gilbert
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