How to search the error code of 'com.apple.coreaudio.avfaudio'? - avaudioengine

Question

Where could I get the information of com.apple.coreaudio.avfaudio error codes, such as:
Terminating app due to uncaught exception 'com.apple.coreaudio.avfaudio', reason: 'error -50'
I always get an error while writing PCM buffer to AVAudioFile. The buffer comes from AVAudioEngine's output node.
The error:
* Terminating app due to uncaught exception 'com.apple.coreaudio.avfaudio', reason: 'error -50'
* First throw call stack:
(0x18eb46fe0 0x18d5a8538 0x18eb46eb4 0x1a8d051cc 0x1a8d731dc 0x1000d45e0 0x1000d4820 0x1a8d14654 0x1a8d146c0 0x1a8d8c26c 0x1a8d8c1fc 0x100ae5a10 0x100af1a84 0x100b001f8 0x100ae7a60 0x100af3128 0x100ae9634 0x100af5630 0x100af6f48 0x18dc0968c 0x18dc0959c 0x18dc06cb4)
libc++abi.dylib: terminating with uncaught exception of type NSException
Could you help me?

Answer 1

https://www.osstatus.com/search/results?platform=all&framework=all&search=-50
I found the link just now.
You can see all the error code of apple coding

Answer 2

I didn't find the exact description of the error but it seems to be a generic "invalid parameters" exception.
In my case, and very likely in your case too, the issue was a mismatch between the buffer and the format of the AVAudioFile instance.
let settings: [String: Any] = [
AVFormatIDKey: kAudioFormatLinearPCM,
AVSampleRateKey: 44 * 1000,
AVNumberOfChannelsKey: 2
]
do {
try avFile = AVAudioFile(forWriting: URLFor(filename: "test.caf"), settings: settings)
avEngine.inputNode?.installTap(onBus: 0, bufferSize: 1024, format: avEngine.mainMixerNode.outputFormat(forBus: 0)) {
buffer, time in
do {
try self.avFile?.write(from: buffer)
}
catch {
// TODO
}
}
try avEngine.start()
} catch {
// TODO
}
In the example below I was getting the "-50" error when I created the AVAudioFile in any format other than PCM, 2channel 44khz.

Answer 3

I had a similar issue, where I was getting a com.apple.coreaudio.avfaudio -50 error with mismatched sample rates. I just had to set the AVAudioFile to match the mainMixerNode outputFormat.
let format = engine.mainMixerNode.outputFormat(forBus: 0)
self.musicTrackFinalOutputFile = try AVAudioFile(forWriting: temporaryFileURL, settings: [
AVFormatIDKey: NSNumber(value:kAudioFormatMPEG4AAC),
AVEncoderAudioQualityKey : AVAudioQuality.high.rawValue,
AVEncoderBitRateKey : 320000,
AVNumberOfChannelsKey: format.channelCount,
AVSampleRateKey : format.sampleRate
])