NAME

AOutputChannels − get the output channels supported by the audio controller

SYNOPSIS

#include <Alib.h> AOutputChMask
AOutputChannels (

Audio ∗  audio );

DESCRIPTION

audio specifies the Audio structure associated with this connection. 

RETURN VALUE

Upon successful completion, AOutputChannels() returns a mask showing if the audio controller supports mono and/or stereo channels.  Each bit in the returned AOutputChMask correponds to one type of output channel. 

STRUCTURES

The following are defined in /opt/audio/include/Alib.h. 

typedef long                    AOutputChMask;
 #define AMonoOutputChMask       ( 1 << AOCTMono )
#define ALeftOutputChMask       ( 1 << AOCTLeft )
#define ARightOutputChMask      ( 1 << AOCTRight )

ERRORS

AOutputChannels() does not return an error status.  Note that the application program may crash if audio does not point to a valid Audio structure. 

EXAMPLE

The following example gets the types of output channels supported by the audio controller. 

AOutputChMask out_channels;  /∗ output channel mask ∗/

Audio ∗ audio;  /∗ audio connection ∗/
.
.
.

/∗ get output sources ∗/

out_channels = AOutputChannels(audio);

NOTES

AOutputChannels() is a convenience function that enables the client program to examine a component of the internal Audio structure that is created by AOpenAudio().  The contents of the structure should be treated as read-only. 

In order to ensure that the compiler finds the Audio Library (libAlib.sl) and the Alib.h header file, you must add the following switches:

-L /opt/audio/lib
-I/opt/audio/include

DEPENDENCIES

This function belongs to the Audio Library of functions that manage connections to an audio server.  The audio server must run on a system that has audio hardware. To find out whether or not your system has audio hardware, refer to Using the Audio Developer’s Kit or the online help for the Audio control panel.  For information about the audio capabilities of a particular system use the online example audioinfo.c. 

AUTHOR

AOutputChannels() was developed by HP. 

SEE ALSO

AGetChannelGain(3X) AGetGain(3X), AGetSystemChannelGain(3X), AGMGainRestricted(3X), AInputChannels(3X), AInputSources(3X), AMaxInputGain(3X), AMaxOutputGain(3X), AMinInputGain(3X), AMinOutputGain(3X), AOutputDestinations(3X), ASetChannelGain(3X), ASetGain(3X), ASetSystemChannelGain(3X), ASimplePlayer(3X), ASimpleRecorder(3X). 

Hewlett-Packard Company  —  Audio Library: February, 1995