TVOAudioDeviceCapturer Protocol Reference
| Conforms to | NSObject |
|---|---|
| Declared in | TVOAudioDevice.h |
Overview
TVOAudioDeviceCapturer defines the capturing half of TVOAudioDevice. An audio capturer produces samples by
repeatedly calling TVOAudioDeviceWriteCaptureData() when it needs to deliver new data. A capturer need not record
audio from the device microphone, it could perform other operations such as reading audio samples from disk instead.
– captureFormat
required method
Provides the format to be used for capturing audio.
- (nullable TVOAudioFormat *)captureFormatReturn Value
A TVOAudioFormat instance which describes the audio which will be captured. Returning nil indicates
that audio capture is not supported.
Discussion
This method is called once before capture starts. If you wish to change the format after you’ve started
capturing audio then you should call TVOAudioDeviceFormatChanged() and prepare for this method to be queried again.
Declared In
TVOAudioDevice.h
– initializeCapturer
required method
Initializes the capturer.
- (BOOL)initializeCapturerReturn Value
YES if initialization succeeded, or NO if it did not.
Discussion
This method is called before startCapturing:. You should use this opportunity to pre-allocate any
fixed size buffers or other resources that you need for audio processing.
Declared In
TVOAudioDevice.h
– startCapturing:
required method
Starts the capturer.
- (BOOL)startCapturing:(nonnull TVOAudioDeviceContext)contextParameters
context |
A context pointer to be used with the audio capture function callbacks TVOAudioDeviceFormatChanged(), TVOAudioDeviceWriteCaptureData() and TVOAudioDeviceExecuteWorkerBlock(). |
|---|
Return Value
YES if capturing started, or NO if it did not.
Discussion
This method is called after initializeCapturer. Before your implementation returns it should have
started your audio capturing pipeline. This may involve spinning up audio threads via CoreAudio or starting your own
high priority capture thread.
Declared In
TVOAudioDevice.h
– stopCapturing
required method
Stops the capturer.
- (BOOL)stopCapturingReturn Value
YES if capturing stopped, or NO if it did not.
Discussion
This method is called some time after startCapturing when audio capturing is no longer needed by the
media engine. Before your implementation returns it should have stopped your audio capturing pipeline.
Declared In
TVOAudioDevice.h