Re: Modem sound input [was: When is sound recording going...]
Re: Modem sound input [was: When is sound recording going...]
- Subject: Re: Modem sound input [was: When is sound recording going...]
- From: Laurent Cerveau <email@hidden>
- Date: Sun, 11 Nov 2001 11:01:03 +0100
Alberto,
First in preliminary : not all machine have modem connected to the sound
codec. (You can go through the Apple doc for each machine and will see
it from a hardware perspective). Even on OS 9 modem sound was sometimes
a digital process and not a physical connection.
As far as accessing a serial port, you can always use the IOKit for
that . There is sample code on Apple web site for that.
Then you'll get a /plain /old /dev device that you can talk to.
Finally if his does not solve your problem you can always use Darwin
(Isn't it cool that our system is open sourced) !!
If you look at the audio drivers you'll see that there is a method
called "setModemSound" that is made available to other kernel extensions
through a publishresource call. So you need to write a very very small
kernel extension with a user client that
will activate that or not. Sample for how to use this call can be found
...in the modem/serial driver source code!
But, to come back to your first point, you'll also see that the number
of machine answering "as hardware expected" to that call is probably not
what you expect.
Laurent
On Saturday, November 10, 2001, at 05:49 PM, Alberto Ricci wrote:
About this audio-through-the-modem-connection thing, I'm currently
working on a project that has been relying on this capability (only
found on certain Macs, though, such as the iMac and PowerBook G4, but
not on iBooks for instance).
I am quite worried that it might stop being supported - as far as I
know, it currently works because there is a physical connection - a
wire - going from the modem chip to the sound chip on those Macs.
I know that you folks at Apple can't discuss future plans, but can you
suggest an alternative in case this wiring will disappear from future
PowerBooks or iMacs? Or in case I want to port my app to CoreAudio?
It's my last non-carbonized-yet project, because it heavily relies on
Open Transport Serial for serial communication.
Is there any hope there will always be the possibility to get decent
quality audio through the modem port?
And besides having this possibility on future machines, what about Mac
OS X? Is the input source simply not shown? Can I select it
programmatically?
Laurent Cerveau
Applications Division
Apple Computer Inc.
email@hidden