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AVFoundation Framework Reference AVAudioMixInputParameters Class Reference

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AVAudioMixInputParameters

An AVAudioMixInputParameters object represents the parameters that should be applied to an audio track when it is added to a mix. More...

Inheritance


Import Statement


import AVFoundation @import AVFoundation;

Availability


Available in iOS 4.0 and later.
  • trackID trackID Property

    The ID of the audio track to which the parameters should be applied. (read-only)

    Declaration

    Swift

    var trackID: CMPersistentTrackID { get }

    Objective-C

    @property(nonatomic, readonly) CMPersistentTrackID trackID

    Import Statement

    import AVFoundation

    Availability

    Available in iOS 4.0 and later.

  • Obtains the volume ramp that includes the specified time.

    Declaration

    Swift

    func getVolumeRampForTime(_ time: CMTime, startVolume startVolume: UnsafeMutablePointer<Float>, endVolume endVolume: UnsafeMutablePointer<Float>, timeRange timeRange: UnsafeMutablePointer<CMTimeRange>) -> Bool

    Objective-C

    - (BOOL)getVolumeRampForTime:(CMTime)time startVolume:(float *)startVolume endVolume:(float *)endVolume timeRange:(CMTimeRange *)timeRange

    Parameters

    time

    If a ramp with a time range that contains the specified time has been set, information about the effective ramp for that time is supplied. Otherwise, information about the first ramp that starts after the specified time is supplied.

    startVolume

    A pointer to a float to receive the starting volume value for the volume ramp.

    This value may be NULL.

    endVolume

    A pointer to a float to receive the ending volume value for the volume ramp.

    This value may be NULL.

    timeRange

    A pointer to a CMTimeRange to receive the time range of the volume ramp.

    This value may be NULL.

    Return Value

    YEStrue if the values were retrieved successfully, otherwise NOfalse. Returns NOfalse if time is beyond the duration of the last volume ramp that has been set.

    Discussion

    The process of setting up volume ramps requires the configuration of an instance of AVMutableAudioMixInputParameters.

    Import Statement

    import AVFoundation

    Availability

    Available in iOS 4.0 and later.

  • The audio processing tap associated with the track. (read-only)

    Declaration

    Swift

    var audioTapProcessor: MTAudioProcessingTap! { get }

    Objective-C

    @property(nonatomic, readonly, retain) MTAudioProcessingTapRef audioTapProcessor

    Discussion

    You can use the audio tap to access the track’s audio data before it is played, read, or exported.

    This property is nil by default.

    The process of setting up a tap requires the configuration of an instance of AVMutableAudioMixInputParameters. If an instance of AVMutableAudioMixInputParameters is present in the inputParameters array of an AVAudioMix, the results of mutating the AVMutableAudioMixInputParameters while the audio mix is in use are undefined

    Import Statement

    import AVFoundation

    Availability

    Available in iOS 6.0 and later.