将两个或多个mp3文件合并为一个，保持高性能

Question

我将两个mp3文件混合成一个问题。实际上，我已经找到了一些使用NAudio库的测试代码，但对我来说这太慢了。我是“音频编程”的新手，所以我需要你的帮助，建议如何使算法更快地解决这个问题。

代码在8 +秒内将两个文件混合成一个，这太慢了。实际上，我检查过并且ConvertWavToMp3（）持续8秒。文件1.mp3和2.mp3长度超过3分钟。

    static void Main(string[] args)
    {
        var watch = Stopwatch.StartNew();
        watch.Start();
        var path = @"C:\Users\gutek\Desktop\";
        // read mp3 files from disk
        Mp3FileReader mpbacground = new Mp3FileReader(path + "1.mp3");
        Mp3FileReader mpMessage = new Mp3FileReader(path + "2.mp3");

        //convert them into wave stream or decode the mp3 file
        WaveStream background = WaveFormatConversionStream.CreatePcmStream(mpbacground);
        WaveStream message = WaveFormatConversionStream.CreatePcmStream(mpMessage);

        var mixer = new WaveMixerStream32();
        mixer.AutoStop = true;

        var messageOffset = background.TotalTime;
        var messageOffsetted = new WaveOffsetStream(
        message, TimeSpan.FromSeconds(10), TimeSpan.Zero, message.TotalTime.Subtract(TimeSpan.FromSeconds(30)));

        var background32 = new WaveChannel32(background);
        background32.PadWithZeroes = false;
        // set the volume of background file
        background32.Volume = 0.4f;
        //add stream into the mixer
        mixer.AddInputStream(background32);

        var message32 = new WaveChannel32(messageOffsetted);
        message32.PadWithZeroes = false;
        // set the volume of 2nd mp3 song
        message32.Volume = 0.6f;
        mixer.AddInputStream(message32);
        var wave32 = new Wave32To16Stream(mixer);
        //encode the wave stream into mp3
        var mp3Stream = ConvertWavToMp3(wave32);
        // write mp3 on the disk
        File.WriteAllBytes(path + "output.mp3", mp3Stream.ToArray());
        watch.Stop();
        Console.WriteLine(watch.ElapsedMilliseconds);
        Console.ReadKey();
    }

    public static MemoryStream ConvertWavToMp3(Wave32To16Stream wavFile)
    {
        using (var retMs = new MemoryStream())
        using (var wtr = new LameMP3FileWriter(retMs, wavFile.WaveFormat, 128))
        {
            wavFile.CopyTo(wtr);
            return retMs;
        }
    }