Contents

kAudioUnitProperty_InputSamplesInOutput

A read/write AUInputSamplesInOutputCallbackStruct struct, valid on the audio unit global scope.

Declaration

var kAudioUnitProperty_InputSamplesInOutput: AudioUnitPropertyID { get }

Discussion

An audio unit calls this callback at the end of its render call. The audio unit supplies the following information:

  • outputTime - The timestamp passed in to the audio unit’s render call. This timestamp represents the time of the first output sample.

  • inputSample - The sample number of the first input sample that is present in the output audio.

  • numInputSamples - The number of input samples that were used and are present in the output audio.

This property allows a host application to determine which input samples correspond to a sample in the output buffer. It is useful only for audio units that do time-stretching, such as the macOS AUVaripseed and AUTimePitch units, where the relationship between input and output samples is non-trivial. For these units, the range of input samples that correspond to an output buffer typically differs from the range of input samples that were pulled for that render call. This difference arises because of internal buffering, processing latency, and other factors.

See Also

Properties