N音频WaveOut没有播放iSampleProvider提供的所有数据

Question

我正在使用nAudio开发一个点击生成器。作为测试，我创建了一个ISampleProvidor类来读取/播放音频文件。iSampleProvider读取PCM (32位ieee) wav文件，然后使用WaveOut播放器回放它。WaveOut只播放大约1/4通过IsampleProvidor Read()方法传递的音频。这会导致不稳定的回放。ISampleProvider read()方法在正确的时间间隔内请求正确的数据量，但是WaveOut只播放提供给接口的前25%的样本。是否知道如何解决这个问题，或者我是否使用了错误的类来构建单击跟踪( BufferedWaveProvider也可能工作，但它只缓冲了5秒的音频)？

 public void TestSampleProvider()
        {
            ISampleProvider mySamples = new MySamples();
            var _waveOut = new WaveOut(WaveCallbackInfo.FunctionCallback()) {DeviceNumber = 0};
            _waveOut.Init(mySamples);
            _waveOut.Play();
            Console.ReadLine();
        }

  public class MySamples : ISampleProvider
    {

        private float[] samplesFloats;
        private int position;
        private WaveFileReader clicksound;
        public int Read(float[] buffer, int offset, int count)
        {

            var copyCount = count;
            if (position + copyCount > samplesFloats.Count())
            {
                copyCount = samplesFloats.Count() - position;
            }

            Console.WriteLine("samplesFloats {0} position {1}  copyCount {2} offset {3} time {4}", samplesFloats.Count(), position, copyCount, offset, DateTime.Now.Millisecond);
            Buffer.BlockCopy(samplesFloats, position, buffer, offset, copyCount);

            position += copyCount;

          return copyCount;
        }

        public MySamples()
        {
            clicksound = new WaveFileReader(@"C:\temp\sample.wav");
            WaveFormat = clicksound.WaveFormat;
            samplesFloats = new float[clicksound.SampleCount];
            for (int i = 0; i < clicksound.SampleCount; i++)
            {
                samplesFloats[i] = clicksound.ReadNextSampleFrame()[0];//it;s a mono file
            }
        }
        public WaveFormat WaveFormat { get; private set; }
    }

Answer 1

我认为WaveOut使用ISampleProvider可能有问题，所以我使用IWaveProvider接口来做同样的事情。实际上，这里有一个基本的类，用于发送无终止点击到波形。如果让它运行很长时间，这可能会遇到内存问题，但是对于流行歌曲来说，应该是可以的。而且，这只适用于32位文件(注意字节缓冲区上的*4 )。

  public class MyClick : IWaveProvider
    {
        private int position;
        private WaveFileReader clicksound;
        private byte[] samplebuff;
        MemoryStream _byteStream = new System.IO.MemoryStream();
        public MyClick(float bpm=120)
        {
            clicksound = new WaveFileReader(@"click_sample.wav");
            var bpmsampleslen = (60 / bpm) * clicksound.WaveFormat.SampleRate;
            samplebuff = new byte[(int) bpmsampleslen*4];
            clicksound.Read(samplebuff, 0,(int) clicksound.Length);
            _byteStream.Write(samplebuff, 0, samplebuff.Length);
            _byteStream.Position = 0;
            WaveFormat = clicksound.WaveFormat;

        }
        public int Read(byte[] buffer, int offset, int count)
        {
         //we reached the end of the stream add another one to the end and keep playing
            if (count + _byteStream.Position > _byteStream.Length)
            {
                var holdpos = _byteStream.Position;
                _byteStream.Write(samplebuff, 0, samplebuff.Length);
                _byteStream.Position = holdpos;
            }
        return _byteStream.Read(buffer, offset, count);

        }

        public WaveFormat WaveFormat { get; private set; }
    }