NAME

ASetSystemChannelGain − set system or monitor audio channel gain

SYNOPSIS

#include <audio/Alib.h>

void ASetSystemChannelGain(

Audio *audio,
ASystemGainType gain_type,
AChType channel,
AGainDB gain,
long *status_return

);

DESCRIPTION

ASetSystemChannelGain() sets the system gain to the value in gain. If gain_type is ASGTMonitor, the setting controls how much of the record input signal is fed to the internal speaker or auxiliary output.  This ability to monitor the input is particularly useful when the recording input is not from a microphone. 

audio Audio structure associated with this connection. 

gain_type Type of operation: ASGTPlay, ASGTRecord, or ASGTMonitor.  If this field is set to ASGTMonitor, the channel specification must be ACTMono. 

channel Type of channel: ACTMono, ACTLeft, or ACTRight.  If gain_type is ASGTMonitor, this field must be ACTMono. 

gain Specifies the volume: AUnityGain, AZeroGain, or a number of decibels. 

status_return receives the returned status of the operation unless it is set to NULL. 

ERRORS

If status_return is not set to NULL, one of the following is returned in status_return. 

0 AENoError

2 AEBadAudio

3 AEBadValue

EXAMPLES

The following example sets the gain on the monitor to −6. 

Audio *audio;               /* audio connection */
ASystemGainType *sgtype;    /* type of operation */
AChType *chtype;            /* type of channel */
AGainDB chgain;             /* gain specification*/
long status;                /* error status */
.
.
.
/* set monitor gain to -6 */
sgtype = ASGTMonitor
chtype = ACTMono
chgain = -6;
ASetSystemChannelGain(audio, sgtype, chtype, chgain, &status);

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 the hardware manual that accompanies your system. 

AUTHOR

ASetSystemChannelGain() 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), AOutputChannels(3X), AOutputDestinations(3X), ASetChannelGain(3X), ASetGain(3X), ASimplePlayer(3X), ASimpleRecorder(3X). 

Using the Audio Application Program Interface.

Hewlett-Packard Company  —  HP-UX Release 9.03: April 1994