Re: kAudioDevicePropertyPlayThruDestination
Re: kAudioDevicePropertyPlayThruDestination
- Subject: Re: kAudioDevicePropertyPlayThruDestination
- From: Jeff Moore <email@hidden>
- Date: Wed, 24 Aug 2005 19:05:16 -0700
The play through model assumes that the data starts with the
corresponding input channel (i.e. play through channel 2 comes from
input channel 2). The data flows through the hardware to the
destination described by the play through destination control. Note
that what the destination really is, is purposefully not constrained
by the API to allow the most flexibility for the hardware. This
allows play through data to be sent to things that might not be an
output channel that you can send data to in an IOProc. For instance,
this is the case if the hardware has a stereo mix down bus or an
effect send that doesn't have any representation in the data that it
sends to the computer.
Here's a rough diagram of the conceptual signal flow for a pretend
input/play through channel.
Input Port 1 Input Port N
| |
| |
Source----------+
|
+----------------->Play Through On/Off------->Play Through
Volume------>Play Through Destination----->Hardware Port 1
|
|
|
+--------------->Hardware Port N
|
Volume
|
|
|
IOProc
On Aug 24, 2005, at 6:06 PM, Ethan Funk wrote:
Can any one point me to some documentation on Audio Device
Playthough? The best I can come up with is using
kAudioDevicePropertyPlayThruDestination from a list of possible
source ID retreived using kAudioDevicePropertyPlayThruDestinations.
What I don't understand is the source/destination nomenclature. Is
the play through destination property used to set a play though
source for a particular output channel on the device, or is the
property used to set an output (as destination would imply) which a
device input will play through?
Ethan... _______________________________________________
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
--
Jeff Moore
Core Audio
Apple
_______________________________________________
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