使用 Swift for MacOS 播放音频文件

Question

我正在尝试使用AVAudioFile，AVAudioEngine和AVAudioPlayerNode简单地播放文件(在主捆绑包或磁盘上(。

这是我正在做的事情：

import Foundation
import AppKit
import AudioToolbox
import AVFoundation
struct readFile {
static var arrayFloatValues:[Float] = []
static var points:[CGFloat] = []
}
class AudioAnalisys : NSObject {
class func open_audiofile() {
let audioEngine: AVAudioEngine = AVAudioEngine()
let audioPlayer: AVAudioPlayerNode = AVAudioPlayerNode()
//get where the file is
let url = Bundle.main.url(forResource: "TeamPlaylist", withExtension: "mp3")
//put it in an AVAudioFile
let audioFile = try! AVAudioFile(forReading: url!)
//Get the audio file format
//let format = AVAudioFormat(commonFormat: .pcmFormatFloat32, sampleRate: file.fileFormat.sampleRate, channels: file.fileFormat.channelCount, interleaved: false)
let audioFormat = audioFile.processingFormat
let audioFrameCount = UInt32(audioFile.length)
//how many channels?
print(audioFile.fileFormat.channelCount)
print(audioFrameCount)
//Setup the buffer for audio data
let audioFileBuffer = AVAudioPCMBuffer(pcmFormat: audioFormat, frameCapacity: UInt32(audioFile.length))
//put audio data in the buffer
try! audioFile.read(into: audioFileBuffer!)
//readFile.arrayFloatValues = Array(UnsafeBufferPointer(start: audioFileBuffer!.floatChannelData?[0], count:Int(audioFileBuffer!.frameLength)))
//Init engine and player
let mainMixer = audioEngine.mainMixerNode
audioEngine.attach(audioPlayer)
audioEngine.connect(audioPlayer, to:mainMixer, format: audioFileBuffer!.format)
audioPlayer.scheduleBuffer(audioFileBuffer!, completionHandler: nil)
audioEngine.prepare()
do {
try audioEngine.start()
print("engine started")
} catch let error {
print(error.localizedDescription)
}
audioPlayer.play()
}
}

我可以看到通道计数，帧计数。 我什么都听不到。我做错了什么？ 这是我在控制台中得到的内容：

阿拉伯数字 17414784 可选(0x00006080000006c0( 2018-10-09 21：21：02.161593+0200 频谱[1668：327525] [AudioHAL_Client] 音频硬件.cpp：666：音频对象获取属性数据：音频对象获取属性数据：没有给定 ID 为 0 的对象 发动机启动 2018-10-09 21：21：02.594136+0200频谱[1668：327593] 消息跟踪器：回退到默认白名单

Answer 1

这是答案： 无法在 AVAudioPlayer 中播放文档中的文件

这导致：

import Foundation
import AppKit
import AudioToolbox
import AVFoundation
struct readFile {
static var arrayFloatValues:[Float] = []
static var points:[CGFloat] = []
}
let audioEngine: AVAudioEngine = AVAudioEngine()
let audioPlayer: AVAudioPlayerNode = AVAudioPlayerNode()
class AudioAnalisys : NSObject {
class func open_audiofile() {
//get where the file is
let url = Bundle.main.url(forResource: "TeamPlaylist", withExtension: "mp3")
//put it in an AVAudioFile
let audioFile = try! AVAudioFile(forReading: url!)
//Get the audio file format
//let format = AVAudioFormat(commonFormat: .pcmFormatFloat32, sampleRate: file.fileFormat.sampleRate, channels: file.fileFormat.channelCount, interleaved: false)
let audioFormat = audioFile.processingFormat
let audioFrameCount = UInt32(audioFile.length)
//how many channels?
print(audioFile.fileFormat.channelCount)
print(audioFrameCount)
//Setup the buffer for audio data
let audioFileBuffer = AVAudioPCMBuffer(pcmFormat: audioFormat, frameCapacity: UInt32(audioFile.length))
//put audio data in the buffer
try! audioFile.read(into: audioFileBuffer!)
//readFile.arrayFloatValues = Array(UnsafeBufferPointer(start: audioFileBuffer!.floatChannelData?[0], count:Int(audioFileBuffer!.frameLength)))
//Init engine and player
let mainMixer = audioEngine.mainMixerNode
audioEngine.attach(audioPlayer)
audioEngine.connect(audioPlayer, to:mainMixer, format: audioFileBuffer!.format)
audioPlayer.scheduleBuffer(audioFileBuffer!, completionHandler: nil)
audioEngine.prepare()
do {
try audioEngine.start()
print("engine started")
} catch let error {
print(error.localizedDescription)
}
audioPlayer.play()
}
}