AVFoundation or AVAudioPlayer
I use this code but does not work.
Compile is ok, not throw error, manner mode off, but it does not play tone
import Foundation
import AudioUnit
import AVFoundation
final class ToneOutputUnit: NSObject {
var auAudioUnit: AUAudioUnit! = nil // placeholder for RemoteIO Audio Unit
var avActive = false // AVAudioSession active flag
var audioRunning = false // RemoteIO Audio Unit running flag
var sampleRate : Double = 44100.0 // typical audio sample rate
var f0 = 880.0 // default frequency of tone: 'A' above Concert A
var v0 = 16383.0 // default volume of tone: half full scale
var toneCount : Int32 = 1 // number of samples of tone to play. 0 for silence
private var phY = 0.0 // save phase of sine wave to prevent clicking
private var interrupted = false // for restart from audio interruption notification
func setFrequency(freq : Double) { // audio frequencies below 500 Hz may be
f0 = freq // hard to hear from a tiny iPhone speaker.
}
func setToneVolume(vol : Double) { // 0.0 to 1.0
v0 = vol * 32766.0
}
func setToneTime(t : Double) {
toneCount = Int32(t * sampleRate);
}
func enableSpeaker() {
if audioRunning {
print("returned")
return
} // return if RemoteIO is already running
do { // not running, so start hardware
let audioComponentDescription = AudioComponentDescription(
componentType: kAudioUnitType_Output,
componentSubType: kAudioUnitSubType_RemoteIO,
componentManufacturer: kAudioUnitManufacturer_Apple,
componentFlags: 0,
componentFlagsMask: 0 )
if (auAudioUnit == nil) {
try auAudioUnit = AUAudioUnit(componentDescription: audioComponentDescription)
let bus0 = auAudioUnit.inputBusses[0]
let audioFormat = AVAudioFormat(
commonFormat: AVAudioCommonFormat.pcmFormatInt16, // short int samples
sampleRate: Double(sampleRate),
channels:1,
interleaved: false ) // interleaved stereo
try bus0.setFormat(audioFormat ?? AVAudioFormat()) // for speaker bus
auAudioUnit.outputProvider = { ( // AURenderPullInputBlock?
actionFlags,
timestamp,
frameCount,
inputBusNumber,
inputDataList ) -> AUAudioUnitStatus in
self.fillSpeakerBuffer(inputDataList: inputDataList, frameCount: frameCount)
return(0)
}
}
auAudioUnit.isOutputEnabled = true
toneCount = 0
try auAudioUnit.allocateRenderResources() // v2 AudioUnitInitialize()
try auAudioUnit.startHardware() // v2 AudioOutputUnitStart()
audioRunning = true
} catch /* let error as NSError */ {
print("error 2 \(error)")
}
}
// helper functions
private func fillSpeakerBuffer( // process RemoteIO Buffer for output
inputDataList : UnsafeMutablePointer<AudioBufferList>, frameCount : UInt32 ) {
let inputDataPtr = UnsafeMutableAudioBufferListPointer(inputDataList)
let nBuffers = inputDataPtr.count
if (nBuffers > 0) {
let mBuffers : AudioBuffer = inputDataPtr[0]
let count = Int(frameCount)
// Speaker Output == play tone at frequency f0
if ( self.v0 > 0)
&& (self.toneCount > 0 )
{
// audioStalled = false
var v = self.v0 ; if v > 32767 { v = 32767 }
let sz = Int(mBuffers.mDataByteSize)
var a = self.phY // capture from object for use inside block
let d = 2.0 * Double.pi * self.f0 / self.sampleRate // phase delta
let bufferPointer = UnsafeMutableRawPointer(mBuffers.mData)
if var bptr = bufferPointer {
for i in 0..<(count) {
let u = sin(a) // create a sinewave
a += d ; if (a > 2.0 * Double.pi) { a -= 2.0 * Double.pi }
let x = Int16(v * u + 0.5) // scale & round
if (i < (sz / 2)) {
bptr.assumingMemoryBound(to: Int16.self).pointee = x
bptr += 2 // increment by 2 bytes for next Int16 item
bptr.assumingMemoryBound(to: Int16.self).pointee = x
bptr += 2 // stereo, so fill both Left & Right channels
}
}
}
self.phY = a // save sinewave phase
self.toneCount -= Int32(frameCount) // decrement time remaining
} else {
// audioStalled = true
memset(mBuffers.mData, 0, Int(mBuffers.mDataByteSize)) // silence
}
}
}
func stop() {
if (audioRunning) {
auAudioUnit.stopHardware()
audioRunning = false
}
}
}
