Re: in & out Callbacks
Re: in & out Callbacks
- Subject: Re: in & out Callbacks
- From: William Stewart <email@hidden>
- Date: Tue, 15 Feb 2005 15:32:48 -0800
On 15/02/2005, at 3:05 AM, Herbie Robinson wrote:
- Are the two Callbacks 1a and 1b always guaranteed to be called
exactly alternating i-o-i-o-i-o-i-o... if running in one thread?
Absolutely not. While they will for the most part stay in the order
that they initially are called, the threads are working for two
different devices and as such have totally different time lines.
They
can easily drift to the point where the order of calling can be
inverted. Plus, if their duty cycles dictate that they are to wake
up
at times that are close together, the order of operations will be
essentially random each time.
This is why I talked about using AudioDeviceStartAtTime(). It
doesn't
cure the drift problem, but it does give you the ability to phase
the
threads in the order in which you want them, with the approximate
timing you want.
Will this "complexity" when handling USB devices be improved in
Tiger? I read somewhere that Tiger will provide ways to synchronize
several audio devices an allows to see them as on "unique" device.
Since this question about USB devices comes regularly, it seems that
it would be a big improvement if the coreaudio layer could take this
two devices question and solve it once for all developers, so that
using an USB device would be similar to using other full-duplex ones.
I hope any such thing would be optional. Professional applications
would not want to have the system inserting on the fly sample rate
conversion anywhere (without being told to).
Sure - that is an option under the control of the user.
Bill
--
-*****************************************
** http://www.curbside-recording.com/ **
******************************************
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden
--
mailto:email@hidden
tel: +1 408 974 4056
________________________________________________________________________
__
"Much human ingenuity has gone into finding the ultimate Before.
The current state of knowledge can be summarized thus:
In the beginning, there was nothing, which exploded" - Terry Pratchett
________________________________________________________________________
__
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden