Copyright ã1995 by NeXT Computer, Inc.  All Rights Reserved.

NXSoundOut

Inherits From:	NXSoundDevice : Object

Declared In:	soundkit/NXSoundOut.h

Class Description

NXSoundOut represents the sound-out device on a particular host.  Its functionality is completely provided by its superclass, NXSoundDevice; see the NXSoundDevice class specification for a detailed description of classes that represent sound driver devices.

The sound parameter keys that apply to NXSoundOut objects are listed below.

NXSoundOut Parameter Keys

NX_SoundDeviceBufferSize
NX_SoundDeviceBufferCount
NX_SoundDeviceDetectPeaks
NX_SoundDeviceRampUp
NX_SoundDeviceRampDown
NX_SoundDeviceInsertZeros
NX_SoundDeviceDeemphasize
NX_SoundDeviceMuteSpeaker
NX_SoundDeviceMuteHeadphone
NX_SoundDeviceMuteLineOut
NX_SoundDeviceOutputLoudness
NX_SoundDeviceOutputAttenuationStereo
NX_SoundDeviceOutputAttenuationLeft
NX_SoundDeviceOutputAttenuationRight
NX_SoundDeviceMonitorAttenuation

The first three are descibed in the NXSoundDevice class specification.

NX_SoundDeviceRampUp and ...RampDown are boolean parameters that determine whether extra buffers of ªrampedº data are placed at the beginning and end of the NXSoundOut's data stream.  These extra buffers help prevent clicks at the beginning and end of sound playback.

NX_SoundDeviceInsertZeros is a boolean parameter that's used when sound data needs to be ªup-sampledº during playback.  Some computers can store data in a number of sampling rates, but can play back in only a few.  If the stored rate is less (fewer samples per second) than the playback rate, new samples will need to be interpolated between existing samples during playback.  If the ...InsertZeros parameter is YES, then the values of these interpolated samples is zero.  Otherwise, the value is taken from the previous ªrealº sample.  

The NX_SoundDeviceDeemphasize parameter takes a boolean value that toggles the de-emphasis filter.  The Sound object and sound playback functions automatically turn this filter on when playing sound that have a format SND_FORMAT_EMPHASIZED.  The filter state can also be changed by the user, by pressing the upper volume key on the keyboard while holding down the Command key.    

The other parameters mute or attentuate the named output devices.  The ...OutputAttenuation... parameter values are applied (potentially) to all output devices.

Instance Variables

None declared in this class.

Instance Methods

None declared in this class.