重用带有 NAudio 的混合通道

Question

我当然缺少 NAudio 的基础知识。我正在尝试 播放相同的声音两次 但不能。怎么回事？

var path = @"\Rim Shot 2.wav";
var path2 = @"\Rim Shot 4.wav";

var mStream1 = new MemoryStream(File.ReadAllBytes(path));
var mStream2 = new MemoryStream(File.ReadAllBytes(path2));

var stream1 = (new WaveFileReader(mStream1)).ToStandardWaveStream();
var stream2 = (new WaveFileReader(mStream2)).ToStandardWaveStream();

stream1.WaveFormat.Dump();
stream2.WaveFormat.Dump();

var channel1 = new SampleChannel(stream1);
var channel2 = new SampleChannel(stream2);

var format = stream1.WaveFormat;
format = WaveFormat.CreateIeeeFloatWaveFormat(format.SampleRate, format.Channels);
var mixer = new MixingSampleProvider(format);
mixer.ReadFully = true;

try
{
    output.Init(mixer);
    output.Play();

    mixer.AddMixerInput(channel1);
    Task.Delay(10).Wait();

    mixer.AddMixerInput(channel2);
    Task.Delay(10).Wait();

    mixer.AddMixerInput(channel1);
    Task.Delay(2000).Wait();
}
catch(Exception ex)
{
    ex.Dump();
}
finally
{
    if(mStream1 != null) mStream1.Dispose();
    if(mStream2 != null) mStream2.Dispose();

    if(stream1 != null) stream1.Dispose();
    if(stream2 != null) stream2.Dispose();
}

其中 ToStandardWaveStream() 是我的扩展方法：

public static WaveStream ToStandardWaveStream(this WaveStream stream)
{
    if(stream == null) throw new ArgumentNullException("The expected Wave Stream is not here.");

    var encoding = stream.WaveFormat.Encoding;
    var isNotPcmFormat = (encoding != WaveFormatEncoding.Pcm);
    var isNotIeeeFloatFormat = (encoding != WaveFormatEncoding.IeeeFloat);

    Func<WaveStream> convert = () =>
    {
        stream = WaveFormatConversionStream.CreatePcmStream(stream);
        stream = new BlockAlignReductionStream(stream);
        return stream;
    };

    return (isNotPcmFormat && isNotIeeeFloatFormat) ? convert() : stream;
}

Answer 1

您不能将同一个流作为输入添加到混音器两次。您需要从同一个 WAV 文件中创建第二个全新的流读取以添加。第二个流将在开头。为了提高效率，在鼓机中，我会缓存声音数据（就像你所做的那样），但你仍然需要创建新的 WaveFileReader（或 RawSourceStreams），所以它们从头开始

有关此操作的示例，请查看 WPF Drum machine demo 的 NAudio 源代码。

重用带有 NAudio 的混合通道

Reusing a mixed Channel with NAudio

c#

naudio