It was working fine on previous versions.
Error message: CaptureSample[13228:113286] [AVAB] AVAudioBuffer.mm:248 the number of buffers (810878176) does not match the format's number of channel streams (2)
From what I've found, this error is coming from the function createPCMBuffer on CaptureEngine
Link to sample project https://developer.apple.com/documentation/screencapturekit/capturing_screen_content_in_macos
Replacing the createPCMBuffer func for this one fixed the issue (source: https://stackoverflow.com/questions/75228267/avaudioplayernode-causing-distortion)
Are there any concerns in doing it this way?
func createPCMBuffer(from sampleBuffer: CMSampleBuffer) -> AVAudioPCMBuffer? {
let numSamples = AVAudioFrameCount(sampleBuffer.numSamples)
let format = AVAudioFormat(cmAudioFormatDescription: sampleBuffer.formatDescription!)
let pcmBuffer = AVAudioPCMBuffer(pcmFormat: format, frameCapacity: numSamples)!
pcmBuffer.frameLength = numSamples
CMSampleBufferCopyPCMDataIntoAudioBufferList(sampleBuffer, at: 0, frameCount: Int32(numSamples), into: pcmBuffer.mutableAudioBufferList)
return pcmBuffer
}
Thanks
I've also seen the createPCMBuffer implementation return nil in certain cases, breaking our microphone audiowave code and ScreenCaptureKit audio recording implementation.
Seems like copying the unsafe pointer and using it outside the block you pass to withAudioBufferList isn't a good idea. We've adjusted our implementation to this, and that fixes the problems:
func createPCMBuffer(for sampleBuffer: CMSampleBuffer) -> AVAudioPCMBuffer? {
try? sampleBuffer.withAudioBufferList { audioBufferList, _ -> AVAudioPCMBuffer? in
guard let absd = sampleBuffer.formatDescription?.audioStreamBasicDescription else { return nil }
guard let format = AVAudioFormat(standardFormatWithSampleRate: absd.mSampleRate, channels: absd.mChannelsPerFrame) else { return nil }
return AVAudioPCMBuffer(pcmFormat: format, bufferListNoCopy: audioBufferList.unsafePointer)
}
}