使用AVAudioPCMBuffer的AVAudioPlayerNode -无音频播放

let engine = AVAudioEngine()
let playerNode = AVAudioPlayerNode()

let format = AVAudioFormat(standardFormatWithSampleRate: 44100, channels: 2)
let buffer = AVAudioPCMBuffer(pcmFormat: format, frameCapacity: 44100)
buffer.frameLength = 44100

for channel in 0..<Int(format.channelCount) {
    let channelData = buffer.floatChannelData![channel]
    for frame in 0..<Int(buffer.frameLength) {
        channelData[frame] = 0.0
    }
}

engine.attach(playerNode)
engine.connect(playerNode, to: engine.mainMixerNode, format: format)

try! engine.start()

playerNode.scheduleBuffer(buffer, at: nil, options: .loops, completionHandler: nil)

playerNode.play()