The PostEffects, PreEffects, Siphon values are used both when creating a audio queue tap (using AudioQueue.CreateProcessingTap) and are provided to the tap callback (of type AudioToolbox.AudioQueueProcessingTapDelegate).
The StartOfStream and EndOfStream are returned by AudioToolbox.AudioQueueProcessingTap's GetSourceAudio method.
| Member Name | Description |
|---|---|
| EndOfStream | Indicates the end of the audio stream, it happens when the queue is being stopped asynchronosuly and is returned by a call to GetSourceAudio. You must propagate this value to the caller. |
| PostEffects | The tap is executed after any effects have run. |
| PreEffects | The tap is executed before any effects have run. |
| Siphon | The tap is a siphon tap, it can only examine the AudioBuffers provided to the callback, but should not modify its contents. |
| StartOfStream | Indicates the start of audio and is returned by GetSourceAudio. As a flag passed to a tap processor, this indicates a discontinuity in the audio. Either because it is starting, or because there is a playback gap. For the tap processor this means that the data being requested should correspond to the first frame in the audio source. This should reset any internal state in the tap processor that might have been saved from previous invocations to the tap handler. |