mAudioEngine.start() crash in ios - ios

Question

Terminating app due to uncaught exception
'com.apple.coreaudio.avfaudio', reason: 'required condition is false:
_engine->IsRunning()'
Getting crash in iphone 13 mini
public class SwiftSoundStreamPlugin: NSObject, FlutterPlugin {
private var channel: FlutterMethodChannel
private var registrar: FlutterPluginRegistrar
private var hasPermission: Bool = false
private var debugLogging: Bool = false
//========= Recorder's vars
private let mAudioEngine = AVAudioEngine()
private let mRecordBus = 0
private var mInputNode: AVAudioInputNode
private var mRecordSampleRate: Double = 16000 // 16Khz
private var mRecordBufferSize: AVAudioFrameCount = 8192
private var mRecordChannel = 0
private var mRecordSettings: [String:Int]!
private var mRecordFormat: AVAudioFormat!
//========= Player's vars
private let PLAYER_OUTPUT_SAMPLE_RATE: Double = 44100 // 32Khz
private let mPlayerBus = 0
private let mPlayerNode = AVAudioPlayerNode()
private var mPlayerSampleRate: Double = 44100 // 16Khz
private var mPlayerBufferSize: AVAudioFrameCount = 127000
private var mPlayerOutputFormat: AVAudioFormat!
private var mPlayerInputFormat: AVAudioFormat!
/** ======== Basic Plugin initialization ======== **/
public static func register(with registrar: FlutterPluginRegistrar) {
let channel = FlutterMethodChannel(name: "vn.casperpas.sound_stream:methods", binaryMessenger: registrar.messenger())
let instance = SwiftSoundStreamPlugin( channel, registrar: registrar)
registrar.addMethodCallDelegate(instance, channel: channel)
}
init( _ channel: FlutterMethodChannel, registrar: FlutterPluginRegistrar ) {
self.channel = channel
self.registrar = registrar
self.mInputNode = mAudioEngine.inputNode
super.init()
self.attachPlayer()
mAudioEngine.prepare()
}
public func handle(_ call: FlutterMethodCall, result: #escaping FlutterResult) {
switch call.method {
case "hasPermission":
hasPermission(result)
case "initializeRecorder":
initializeRecorder(call, result)
case "startRecording":
startRecording(result)
case "stopRecording":
stopRecording(result)
case "setBufferSize":
setBufferSize(call, result)
case "initializePlayer":
initializePlayer(call, result)
case "startPlayer":
startPlayer(result)
case "stopPlayer":
stopPlayer(result)
case "writeChunk":
writeChunk(call, result)
default:
print("Unrecognized method: \(call.method)")
sendResult(result, FlutterMethodNotImplemented)
}
}
private func sendResult(_ result: #escaping FlutterResult, _ arguments: Any?) {
DispatchQueue.main.async {
result( arguments )
}
}
private func invokeFlutter( _ method: String, _ arguments: Any? ) {
DispatchQueue.main.async {
self.channel.invokeMethod( method, arguments: arguments )
}
}
/** ======== Plugin methods ======== **/
private func checkAndRequestPermission(completion callback: #escaping ((Bool) -> Void)) {
if (hasPermission) {
callback(hasPermission)
return
}
var permission: AVAudioSession.RecordPermission
#if swift(>=4.2)
permission = AVAudioSession.sharedInstance().recordPermission
#else
permission = AVAudioSession.sharedInstance().recordPermission()
#endif
switch permission {
case .granted:
print("granted")
hasPermission = true
callback(hasPermission)
break
case .denied:
print("denied")
hasPermission = false
callback(hasPermission)
break
case .undetermined:
print("undetermined")
AVAudioSession.sharedInstance().requestRecordPermission() { [unowned self] allowed in
if allowed {
self.hasPermission = true
print("undetermined true")
callback(self.hasPermission)
} else {
self.hasPermission = false
print("undetermined false")
callback(self.hasPermission)
}
}
break
default:
callback(hasPermission)
break
}
}
private func hasPermission( _ result: #escaping FlutterResult) {
checkAndRequestPermission { value in
self.sendResult(result, value)
}
}
private func startEngine() {
guard !mAudioEngine.isRunning else {
return
}
if mAudioEngine.outputNode.outputFormat(forBus: mPlayerBus).channelCount == 0 {
// if count is 0 then it throws a exception or crash
mAudioEngine.reset()
/*
or try changing object
mAudioEngine = AVAudioEngine()
*/
}
mAudioEngine.reset()
try? mAudioEngine.start()
}
private func stopEngine() {
mAudioEngine.stop()
mAudioEngine.reset()
}
private func sendEventMethod(_ name: String, _ data: Any) {
var eventData: [String: Any] = [:]
eventData["name"] = name
eventData["data"] = data
invokeFlutter("platformEvent", eventData)
}
private func initializeRecorder(_ call: FlutterMethodCall, _ result: #escaping FlutterResult) {
guard let argsArr = call.arguments as? Dictionary<String,AnyObject>
else {
sendResult(result, FlutterError( code: SoundStreamErrors.Unknown.rawValue,
message:"Incorrect parameters",
details: nil ))
return
}
mRecordSampleRate = argsArr["sampleRate"] as? Double ?? mRecordSampleRate
debugLogging = argsArr["showLogs"] as? Bool ?? debugLogging
mRecordFormat = AVAudioFormat(commonFormat: AVAudioCommonFormat.pcmFormatInt16, sampleRate: mRecordSampleRate, channels: 2, interleaved: true)
checkAndRequestPermission { isGranted in
if isGranted {
self.sendRecorderStatus(SoundStreamStatus.Initialized)
self.sendResult(result, true)
} else {
self.sendResult(result, FlutterError( code: SoundStreamErrors.Unknown.rawValue,
message:"Incorrect parameters",
details: nil ))
}
}
}
private func resetEngineForRecord() {
mAudioEngine.inputNode.removeTap(onBus: mRecordBus)
let input = mAudioEngine.inputNode
let inputFormat = input.outputFormat(forBus: mRecordBus)
let converter = AVAudioConverter(from: inputFormat, to: mRecordFormat!)!
let ratio: Float = Float(inputFormat.sampleRate)/Float(mRecordFormat.sampleRate)
input.installTap(onBus: mRecordBus, bufferSize: mRecordBufferSize, format: inputFormat) { (buffer, time) -> Void in
let inputCallback: AVAudioConverterInputBlock = { inNumPackets, outStatus in
outStatus.pointee = .haveData
return buffer
}
let convertedBuffer = AVAudioPCMBuffer(pcmFormat: self.mRecordFormat!, frameCapacity: UInt32(Float(buffer.frameCapacity) / ratio))!
var error: NSError?
let status = converter.convert(to: convertedBuffer, error: &error, withInputFrom: inputCallback)
assert(status != .error)
if (self.mRecordFormat?.commonFormat == AVAudioCommonFormat.pcmFormatInt16) {
let values = self.audioBufferToBytes(convertedBuffer)
self.sendMicData(values)
}
}
}
private func startRecording(_ result: #escaping FlutterResult) {
resetEngineForRecord()
startEngine()
sendRecorderStatus(SoundStreamStatus.Playing)
result(true)
}
private func stopRecording(_ result: #escaping FlutterResult) {
mAudioEngine.inputNode.removeTap(onBus: mRecordBus)
sendRecorderStatus(SoundStreamStatus.Stopped)
result(true)
}
private func sendMicData(_ data: [UInt8]) {
let channelData = FlutterStandardTypedData(bytes: NSData(bytes: data, length: data.count) as Data)
sendEventMethod("dataPeriod", channelData)
}
private func sendRecorderStatus(_ status: SoundStreamStatus) {
sendEventMethod("recorderStatus", status.rawValue)
}
private func setBufferSize(_ call: FlutterMethodCall, _ result: #escaping FlutterResult) {
guard let argsArr = call.arguments as? Dictionary<String,AnyObject>
else {
sendResult(result, FlutterError( code: SoundStreamErrors.Unknown.rawValue,
message:"Incorrect parameters",
details: nil ))
return
}
mPlayerBufferSize = argsArr["bufferSize"] as? AVAudioFrameCount ?? mPlayerBufferSize
// result(true)
}
private func initializePlayer(_ call: FlutterMethodCall, _ result: #escaping FlutterResult) {
guard let argsArr = call.arguments as? Dictionary<String,AnyObject>
else {
sendResult(result, FlutterError( code: SoundStreamErrors.Unknown.rawValue,
message:"Incorrect parameters",
details: nil ))
return
}
mPlayerSampleRate = argsArr["sampleRate"] as? Double ?? mPlayerSampleRate
debugLogging = argsArr["showLogs"] as? Bool ?? debugLogging
mPlayerInputFormat = AVAudioFormat(commonFormat: AVAudioCommonFormat.pcmFormatInt16, sampleRate: mPlayerSampleRate, channels: 1, interleaved: true)
sendPlayerStatus(SoundStreamStatus.Initialized)
}
private func attachPlayer() {
mPlayerOutputFormat = AVAudioFormat(commonFormat: AVAudioCommonFormat.pcmFormatFloat32, sampleRate: PLAYER_OUTPUT_SAMPLE_RATE, channels: 1, interleaved: true)
mAudioEngine.attach(mPlayerNode)
mAudioEngine.connect(mPlayerNode, to: mAudioEngine.outputNode, format: mPlayerOutputFormat)
// mAudioEngine.connect(mPlayerNode, to: mAudioEngine.mainMixerNode, format: mPlayerOutputFormat)
}
private func startPlayer(_ result: #escaping FlutterResult) {
startEngine()
if !mPlayerNode.isPlaying {
mPlayerNode.play()
}
sendPlayerStatus(SoundStreamStatus.Playing)
result(true)
}
private func stopPlayer(_ result: #escaping FlutterResult) {
if mPlayerNode.isPlaying {
mPlayerNode.stop()
}
sendPlayerStatus(SoundStreamStatus.Stopped)
result(true)
}
private func sendPlayerStatus(_ status: SoundStreamStatus) {
sendEventMethod("playerStatus", status.rawValue)
}
private func writeChunk(_ call: FlutterMethodCall, _ result: #escaping FlutterResult) {
guard let argsArr = call.arguments as? Dictionary<String,AnyObject>,
let data = argsArr["data"] as? FlutterStandardTypedData
else {
sendResult(result, FlutterError( code: SoundStreamErrors.FailedToWriteBuffer.rawValue,
message:"Failed to write Player buffer",
details: nil ))
return
}
let byteData = [UInt8](data.data)
pushPlayerChunk(byteData, result)
}
private func pushPlayerChunk(_ chunk: [UInt8], _ result: #escaping FlutterResult) {
let buffer = bytesToAudioBuffer(chunk)
mPlayerNode.scheduleBuffer(convertBufferFormat(
buffer,
from: mPlayerInputFormat,
to: mPlayerOutputFormat
));
result(true)
}
private func convertBufferFormat(_ buffer: AVAudioPCMBuffer, from: AVAudioFormat, to: AVAudioFormat) -> AVAudioPCMBuffer {
let formatConverter = AVAudioConverter(from: from, to: to)
let ratio: Float = Float(from.sampleRate)/Float(to.sampleRate)
let pcmBuffer = AVAudioPCMBuffer(pcmFormat: to, frameCapacity: UInt32(Float(buffer.frameCapacity) / ratio))!
var error: NSError? = nil
let inputBlock: AVAudioConverterInputBlock = {inNumPackets, outStatus in
outStatus.pointee = .haveData
return buffer
}
formatConverter?.convert(to: pcmBuffer, error: &error, withInputFrom: inputBlock)
return pcmBuffer
}
private func audioBufferToBytes(_ audioBuffer: AVAudioPCMBuffer) -> [UInt8] {
let srcLeft = audioBuffer.int16ChannelData![0]
let bytesPerFrame = audioBuffer.format.streamDescription.pointee.mBytesPerFrame
let numBytes = Int(bytesPerFrame * audioBuffer.frameLength)
// initialize bytes by 0
var audioByteArray = [UInt8](repeating: 0, count: numBytes)
srcLeft.withMemoryRebound(to: UInt8.self, capacity: numBytes) { srcByteData in
audioByteArray.withUnsafeMutableBufferPointer {
$0.baseAddress!.initialize(from: srcByteData, count: numBytes)
}
}
return audioByteArray
}
private func bytesToAudioBuffer(_ buf: [UInt8]) -> AVAudioPCMBuffer {
let frameLength = UInt32(buf.count) / mPlayerInputFormat.streamDescription.pointee.mBytesPerFrame
let audioBuffer = AVAudioPCMBuffer(pcmFormat: mPlayerInputFormat, frameCapacity: frameLength)!
audioBuffer.frameLength = frameLength
let dstLeft = audioBuffer.int16ChannelData![0]
buf.withUnsafeBufferPointer {
let src = UnsafeRawPointer($0.baseAddress!).bindMemory(to: Int16.self, capacity: Int(frameLength))
dstLeft.initialize(from: src, count: Int(frameLength))
}
return audioBuffer
}
}