在Swift中将音频转换为二进制数据

import AVFoundation

guard let audioURL = Bundle.main.url(forResource: "audio", withExtension: "mp3") else {
    return
}
let asset = AVAsset(url: audioURL)

do {
    let reader = try AVAssetReader(asset: asset)
    let outputSettings: [String: Any] = [
        AVFormatIDKey: kAudioFormatLinearPCM,
        AVLinearPCMIsBigEndianKey: false,
        AVLinearPCMIsFloatKey: false,
        AVLinearPCMBitDepthKey: 16
    ]
    let track = asset.tracks(withMediaType: .audio).first!
    let output = AVAssetReaderTrackOutput(track: track, outputSettings: outputSettings)
    reader.add(output)
    reader.startReading()
    
    var audioData = Data()
    while let sampleBuffer = output.copyNextSampleBuffer() {
        guard let blockBuffer = CMSampleBufferGetDataBuffer(sampleBuffer) else {
            continue
        }
        var length = 0
        var dataPointer: UnsafeMutablePointer<Int8>?
        CMBlockBufferGetDataPointer(blockBuffer, atOffset: 0, lengthAtOffsetOut: nil, totalLengthOut: &length, dataPointerOut: &dataPointer)
        if let dataPointer = dataPointer {
            let buffer = UnsafeBufferPointer(start: dataPointer, count: length)
            audioData.append(buffer)
        }
        CMSampleBufferInvalidate(sampleBuffer)
    }
    
    // 使用音频数据进行后续处理
    // ...
    
} catch {
    print("Failed to read audio data: \(error)")
}