I wrote the code below to pass my custom object Engine in MTAudioProcessingTapCallbacks
Here is code:
func getTap() -> MTAudioProcessingTap? {
var tap: Unmanaged<MTAudioProcessingTap>?
func onInit(tap:MTAudioProcessingTap,clientInfo:UnsafeMutableRawPointer?,tagStroageOut:UnsafeMutablePointer<UnsafeMutableRawPointer?>) {
let engine = Engine()
tagStroageOut.pointee = Unmanaged<Engine>.passUnretained(engine).toOpaque()
}
var callback = MTAudioProcessingTapCallbacks(version: kMTAudioProcessingTapCallbacksVersion_0, clientInfo:nil, init: onInit, finalize: nil, prepare: nil, unprepare: nil) { tap, numberFrames, flags, bufferListInOut, numberFramesOut, flagsOut in
guard MTAudioProcessingTapGetSourceAudio(tap, numberFrames, bufferListInOut, flagsOut, nil, numberFramesOut) == noErr else {
preconditionFailure()
}
let storage = MTAudioProcessingTapGetStorage(tap)
let engine = Unmanaged<Engine>.fromOpaque(storage).takeUnretainedValue()
// This line crashed :
// ClientProcessingTapManager (14): EXC_BAD_ACCESS (code=1, address=0x544453e46ea0)
engine.dealWith(bufferPtr: bufferListInOut)
}
guard MTAudioProcessingTapCreate(kCFAllocatorDefault, &callback, kMTAudioProcessingTapCreationFlag_PostEffects, &tap) == noErr else{
fatalError()
}
return tap?.takeRetainedValue()
}
}
How can I do it?
let tapInit: MTAudioProcessingTapInitCallback = {
(tap, clientInfo, tapStorageOut) in
tapStorageOut.pointee = clientInfo
}
var callback = MTAudioProcessingTapCallbacks(version: kMTAudioProcessingTapCallbacksVersion_0, clientInfo:UnsafeMutableRawPointer(Unmanaged.passUnretained(self.engine).toOpaque()), init: tapInit, finalize: tapFinalize, prepare: tapPrepare, unprepare: tapUnprepare) { tap, numberFrames, flags, bufferListInOut, numberFramesOut, flagsOut in
guard MTAudioProcessingTapGetSourceAudio(tap, numberFrames, bufferListInOut, flagsOut, nil, numberFramesOut) == noErr else {
preconditionFailure()
}
let storage = MTAudioProcessingTapGetStorage(tap)
let engine = Unmanaged<Engine>.fromOpaque(storage).takeUnretainedValue()
engine.render(bufferPtr: bufferListInOut)
}