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| 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 = 0 // 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:AVAudioChannelCount(2),
interleaved: true ) // 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
}
}
} |
Swift: Création d'un son fréquence et durée choisit
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