WOWZAudioSink

Introduction

WOWZAudioSink defines a protocol for callbacks that occur when audio samples are captured or audio levels change.

Methods

-audioFrameWasCaptured:size:time:sampleRate:

-audioLevelDidChange:

-audioPCMFrameWasCaptured:bufferList:time:sampleRate:

-canConvertStreamWithDescription:

audioFrameWasCaptured:size:time:sampleRate:

@optional

- (void) audioFrameWasCaptured:(nonnull void *)data size:(uint32_t)size 
        time:(CMTime)time sampleRate:(Float64)sampleRate; 

Parameters

Discussion

Called for each recorded audio sample. The format of the data is uninteresting to the protocol adopter; use audioFrameWasCaptured only for timing information. To access raw audio data, use the audioPCMFrameWasCaptured protocol method.

audioLevelDidChange:

@optional

- (void) audioLevelDidChange:(float)level; 

Parameters

Discussion

Called when the audio level value changes.

audioPCMFrameWasCaptured:bufferList:time:sampleRate:

@optional

- (void) audioPCMFrameWasCaptured:(nonnull const AudioStreamBasicDescription *)pcmASBD 
        bufferList:(nonnull const AudioBufferList *)bufferList time:(CMTime)time 
        sampleRate:(Float64)sampleRate; 

Parameters

Discussion

Called for each recorded audio sample. Instructs the SDK to convert audio from PCM to AAC before broadcasting. Do NOT implement this protocol unless you specifically need the unencoded audio data. When audioPCMFrameWasCaptured is used, the audioFrameWasCaptured protocol method isn't called. However, if the audio converter can't convert from PCM to AAC, then the capture hardware will fall back to capturing AAC directly and the audioFrameWasCaptured protocol will be called instead.

canConvertStreamWithDescription:

@optional

- (BOOL) canConvertStreamWithDescription:(nonnull const AudioStreamBasicDescription *)asbd; 

Parameters

Return Value

True if the format can be converted; false otherwise.

Discussion

Tests whether the audio sink adopting this protocol can convert from the specified format description. It would be very unusual for a client to implement this protocol, which is implemented by the WOWZAACEncoder class.