我关注this question,但我尝试使用AVAudioPCMBuffer播放的音调无效。代码非常简单:
class Player: NSObject {
var engine = AVAudioEngine()
var player = AVAudioPlayerNode()
var mixer: AVAudioMixerNode!
var buffer: AVAudioPCMBuffer!
override init() {
mixer = engine.mainMixerNode
buffer = AVAudioPCMBuffer(pcmFormat: player.outputFormat(forBus: 0), frameCapacity: 100)
buffer.frameLength = 100
let sr = mixer.outputFormat(forBus: 0).sampleRate
let nChannels = mixer.outputFormat(forBus: 0).channelCount
var i = 0
while i < Int(buffer.frameLength) {
let val = sin(441 * Double(i) * Double.pi / sr)
buffer.floatChannelData?.pointee[i] = Float(val * 0.5)
i += Int(nChannels)
}
engine.attach(player)
engine.connect(player, to: mixer, format: player.outputFormat(forBus: 0))
engine.prepare()
}
func play() {
do {
try engine.start()
} catch {
print(error)
}
player.scheduleBuffer(buffer, at: nil, options: .loops) {
print("Played!")
}
player.play()
}
}
出于某种原因,iPhone没有任何声音。在我的ViewController中,我有这个:
class ViewController: UIViewController {
var player = Player()
override func viewDidAppear(_ animated: Bool) {
player.play()
}
}
如您所见,player
是一个类变量,因此不应从内存中释放。
当我在我的物理设备(iPhone 6s iOS 11)上运行应用程序时,它不起作用,但它可以在模拟器上运行。为什么这没有发出任何声音,怎么能我修理它?
提前致谢!