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HostCallback_GetTransportState

When called by the system, provides audio transport state and timeline information to an audio unit from a host application.

Declaration

typealias HostCallback_GetTransportState = (UnsafeMutableRawPointer?, UnsafeMutablePointer<DarwinBoolean>?, UnsafeMutablePointer<DarwinBoolean>?, UnsafeMutablePointer<Float64>?, UnsafeMutablePointer<DarwinBoolean>?, UnsafeMutablePointer<Float64>?, UnsafeMutablePointer<Float64>?) -> OSStatus

Parameters

  • inHostUserData:

    Custom data that you provided when registering your callback with the audio unit.

  • outIsPlaying:

    On output, TRUE if audio is playing, or FALSE otherwise.

  • outTransportStateChanged:

    On output, TRUE if the transport state changed since the last time the callback was invoked, or FALSE otherwise.

  • outCurrentSampleInTimeLine:

    On output, the sample number, indexed from zero from the beginning of the timeline.

  • outIsCycling:

    On output, TRUE if cycling, or FALSE otherwise.

  • outCycleStartBeat:

  • outCycleEndBeat:

Discussion

If you named your callback function MyHostCallback_GetTransportState, you would declare it like this:

See Also

Getting Information from the Host