操作环境：
win11
.net framework 4.5
使用到NAudio、SoundTouch
步骤如下：
1 nuget安装NAudio，版本选择1.9.0
2 下载SoundTouch,找到SoundTouch.dll和SoundTouch_x64.dll,放到运行目录
https://codeload.github.com/naudio/varispeed-sample/zip/refs/heads/master
3 新建类SoundTouchInterop32、SoundTouchInterop64、SoundTouchProfile、SoundTouchSettings、SoundTouch、VarispeedSampleProvider如下：
cs
using System;
using System.Runtime.InteropServices;
using System.Text;
namespace Swisslog.CSSD.UI.SoundTouch
{
class SoundTouchInterop32
{
private const string SoundTouchDllName = "SoundTouch.dll";
/// <summary>
/// Create a new instance of SoundTouch processor.
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern IntPtr soundtouch_createInstance();
/// <summary>
/// Destroys a SoundTouch processor instance.
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern void soundtouch_destroyInstance(IntPtr h);
/// <summary>
/// Get SoundTouch library version string - alternative function for
/// environments that can't properly handle character string as return value
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern void soundtouch_getVersionString2(StringBuilder versionString, int bufferSize);
/// <summary>
/// Get SoundTouch library version Id
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern uint soundtouch_getVersionId();
/// <summary>
/// Sets new rate control value. Normal rate = 1.0, smaller values
/// represent slower rate, larger faster rates.
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern void soundtouch_setRate(IntPtr h, float newRate);
/// <summary>
/// Sets new tempo control value. Normal tempo = 1.0, smaller values
/// represent slower tempo, larger faster tempo.
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern void soundtouch_setTempo(IntPtr h, float newTempo);
/// <summary>
/// Sets new rate control value as a difference in percents compared
/// to the original rate (-50 .. +100 %);
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern void soundtouch_setRateChange(IntPtr h, float newRate);
/// <summary>
/// Sets new tempo control value as a difference in percents compared
/// to the original tempo (-50 .. +100 %);
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern void soundtouch_setTempoChange(IntPtr h, float newTempo);
/// <summary>
/// Sets new pitch control value. Original pitch = 1.0, smaller values
/// represent lower pitches, larger values higher pitch.
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern void soundtouch_setPitch(IntPtr h, float newPitch);
/// <summary>
/// Sets pitch change in octaves compared to the original pitch
/// (-1.00 .. +1.00);
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern void soundtouch_setPitchOctaves(IntPtr h, float newPitch);
/// <summary>
/// Sets pitch change in semi-tones compared to the original pitch
/// (-12 .. +12);
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern void soundtouch_setPitchSemiTones(IntPtr h, float newPitch);
/// <summary>
/// Sets the number of channels, 1 = mono, 2 = stereo
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern void soundtouch_setChannels(IntPtr h, uint numChannels);
/// <summary>
/// Sets sample rate.
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern void soundtouch_setSampleRate(IntPtr h, uint srate);
/// <summary>
/// Flushes the last samples from the processing pipeline to the output.
/// Clears also the internal processing buffers.
///
/// Note: This function is meant for extracting the last samples of a sound
/// stream. This function may introduce additional blank samples in the end
/// of the sound stream, and thus it's not recommended to call this function
/// in the middle of a sound stream.
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern void soundtouch_flush(IntPtr h);
/// <summary>
/// Adds 'numSamples' pcs of samples from the 'samples' memory position into
/// the input of the object. Notice that sample rate _has_to_ be set before
/// calling this function, otherwise throws a runtime_error exception.
/// </summary>
/// <param name="h">Handle</param>
/// <param name="samples">Pointer to sample buffer.</param>
/// <param name="numSamples">Number of samples in buffer. Notice that in case of stereo-sound a single sample contains data for both channels.</param>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern void soundtouch_putSamples(IntPtr h, [MarshalAs(UnmanagedType.LPArray)] float[] samples, int numSamples);
/// <summary>
/// Clears all the samples in the object's output and internal processing
/// buffers.
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern void soundtouch_clear(IntPtr h);
/// <summary>
/// Changes a setting controlling the processing system behaviour. See the
/// 'SETTING_...' defines for available setting ID's.
/// </summary>
/// <param name="h">Handle</param>
/// <param name="settingId">Setting ID number, see SETTING_... defines.</param>
/// <param name="value">New setting value.</param>
/// <returns>'TRUE' if the setting was succesfully changed</returns>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern bool soundtouch_setSetting(IntPtr h, SoundTouchSettings settingId, int value);
/// <summary>
/// Reads a setting controlling the processing system behaviour. See the
/// 'SETTING_...' defines for available setting ID's.
/// </summary>
/// <param name="h">Handle</param>
/// <param name="settingId">Setting ID number, see SETTING_... defines.</param>
/// <returns>The setting value</returns>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern int soundtouch_getSetting(IntPtr h, SoundTouchSettings settingId);
/// <summary>
/// Returns number of samples currently unprocessed.
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern int soundtouch_numUnprocessedSamples(IntPtr h);
/// <summary>
/// Adjusts book-keeping so that given number of samples are removed from beginning of the
/// sample buffer without copying them anywhere.
///
/// Used to reduce the number of samples in the buffer when accessing the sample buffer directly
/// with 'ptrBegin' function.
/// </summary>
/// <param name="h">Handle</param>
/// <param name="outBuffer">Buffer where to copy output samples.</param>
/// <param name="maxSamples">How many samples to receive at max.</param>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern uint soundtouch_receiveSamples(IntPtr h, [MarshalAs(UnmanagedType.LPArray)] float[] outBuffer, uint maxSamples);
/// <summary>
/// Returns number of samples currently available.
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern uint soundtouch_numSamples(IntPtr h);
/// <summary>
/// Returns nonzero if there aren't any samples available for outputting.
/// </summary>
[DllImport(SoundTouchDllName, CallingConvention = CallingConvention.Cdecl)]
public static extern int soundtouch_isEmpty(IntPtr h);
}
}
cs
using System;
using System.Runtime.InteropServices;
using System.Text;
namespace Swisslog.CSSD.UI.SoundTouch
{
class SoundTouchInterop64
{
private const string SoundTouchDllName = "SoundTouch_x64.dll";
/// <summary>
/// Create a new instance of SoundTouch processor.
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern IntPtr soundtouch_createInstance();
/// <summary>
/// Destroys a SoundTouch processor instance.
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern void soundtouch_destroyInstance(IntPtr h);
/// <summary>
/// Get SoundTouch library version string - alternative function for
/// environments that can't properly handle character string as return value
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern void soundtouch_getVersionString2(StringBuilder versionString, int bufferSize);
/// <summary>
/// Get SoundTouch library version Id
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern uint soundtouch_getVersionId();
/// <summary>
/// Sets new rate control value. Normal rate = 1.0, smaller values
/// represent slower rate, larger faster rates.
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern void soundtouch_setRate(IntPtr h, float newRate);
/// <summary>
/// Sets new tempo control value. Normal tempo = 1.0, smaller values
/// represent slower tempo, larger faster tempo.
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern void soundtouch_setTempo(IntPtr h, float newTempo);
/// <summary>
/// Sets new rate control value as a difference in percents compared
/// to the original rate (-50 .. +100 %);
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern void soundtouch_setRateChange(IntPtr h, float newRate);
/// <summary>
/// Sets new tempo control value as a difference in percents compared
/// to the original tempo (-50 .. +100 %);
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern void soundtouch_setTempoChange(IntPtr h, float newTempo);
/// <summary>
/// Sets new pitch control value. Original pitch = 1.0, smaller values
/// represent lower pitches, larger values higher pitch.
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern void soundtouch_setPitch(IntPtr h, float newPitch);
/// <summary>
/// Sets pitch change in octaves compared to the original pitch
/// (-1.00 .. +1.00);
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern void soundtouch_setPitchOctaves(IntPtr h, float newPitch);
/// <summary>
/// Sets pitch change in semi-tones compared to the original pitch
/// (-12 .. +12);
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern void soundtouch_setPitchSemiTones(IntPtr h, float newPitch);
/// <summary>
/// Sets the number of channels, 1 = mono, 2 = stereo
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern void soundtouch_setChannels(IntPtr h, uint numChannels);
/// <summary>
/// Sets sample rate.
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern void soundtouch_setSampleRate(IntPtr h, uint srate);
/// <summary>
/// Flushes the last samples from the processing pipeline to the output.
/// Clears also the internal processing buffers.
///
/// Note: This function is meant for extracting the last samples of a sound
/// stream. This function may introduce additional blank samples in the end
/// of the sound stream, and thus it's not recommended to call this function
/// in the middle of a sound stream.
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern void soundtouch_flush(IntPtr h);
/// <summary>
/// Adds 'numSamples' pcs of samples from the 'samples' memory position into
/// the input of the object. Notice that sample rate _has_to_ be set before
/// calling this function, otherwise throws a runtime_error exception.
/// </summary>
/// <param name="h">Handle</param>
/// <param name="samples">Pointer to sample buffer.</param>
/// <param name="numSamples">Number of samples in buffer. Notice that in case of stereo-sound a single sample contains data for both channels.</param>
[DllImport(SoundTouchDllName)]
public static extern void soundtouch_putSamples(IntPtr h, [MarshalAs(UnmanagedType.LPArray)] float[] samples, int numSamples);
/// <summary>
/// Clears all the samples in the object's output and internal processing
/// buffers.
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern void soundtouch_clear(IntPtr h);
/// <summary>
/// Changes a setting controlling the processing system behaviour. See the
/// 'SETTING_...' defines for available setting ID's.
/// </summary>
/// <param name="h">Handle</param>
/// <param name="settingId">Setting ID number, see SETTING_... defines.</param>
/// <param name="value">New setting value.</param>
/// <returns>'TRUE' if the setting was succesfully changed</returns>
[DllImport(SoundTouchDllName)]
public static extern bool soundtouch_setSetting(IntPtr h, SoundTouchSettings settingId, int value);
/// <summary>
/// Reads a setting controlling the processing system behaviour. See the
/// 'SETTING_...' defines for available setting ID's.
/// </summary>
/// <param name="h">Handle</param>
/// <param name="settingId">Setting ID number, see SETTING_... defines.</param>
/// <returns>The setting value</returns>
[DllImport(SoundTouchDllName)]
public static extern int soundtouch_getSetting(IntPtr h, SoundTouchSettings settingId);
/// <summary>
/// Returns number of samples currently unprocessed.
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern int soundtouch_numUnprocessedSamples(IntPtr h);
/// <summary>
/// Adjusts book-keeping so that given number of samples are removed from beginning of the
/// sample buffer without copying them anywhere.
///
/// Used to reduce the number of samples in the buffer when accessing the sample buffer directly
/// with 'ptrBegin' function.
/// </summary>
/// <param name="h">Handle</param>
/// <param name="outBuffer">Buffer where to copy output samples.</param>
/// <param name="maxSamples">How many samples to receive at max.</param>
[DllImport(SoundTouchDllName)]
public static extern uint soundtouch_receiveSamples(IntPtr h, [MarshalAs(UnmanagedType.LPArray)] float[] outBuffer, uint maxSamples);
/// <summary>
/// Returns number of samples currently available.
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern uint soundtouch_numSamples(IntPtr h);
/// <summary>
/// Returns nonzero if there aren't any samples available for outputting.
/// </summary>
[DllImport(SoundTouchDllName)]
public static extern int soundtouch_isEmpty(IntPtr h);
}
}
cs
namespace Swisslog.CSSD.UI.SoundTouch
{
internal class SoundTouchProfile
{
public bool UseTempo { get; set; }
public bool UseAntiAliasing { get; set; }
public bool UseQuickSeek { get; set; }
public SoundTouchProfile(bool useTempo, bool useAntiAliasing)
{
UseTempo = useTempo;
UseAntiAliasing = useAntiAliasing;
}
}
}
cs
namespace Swisslog.CSSD.UI.SoundTouch
{
enum SoundTouchSettings
{
/// <summary>
/// Available setting IDs for the 'setSetting' and 'get_setting' functions.
/// Enable/disable anti-alias filter in pitch transposer (0 = disable)
/// </summary>
UseAaFilter = 0,
/// <summary>
/// Pitch transposer anti-alias filter length (8 .. 128 taps, default = 32)
/// </summary>
AaFilterLength = 1,
/// <summary>
/// Enable/disable quick seeking algorithm in tempo changer routine
/// (enabling quick seeking lowers CPU utilization but causes a minor sound
/// quality compromising)
/// </summary>
UseQuickSeek = 2,
/// <summary>
/// Time-stretch algorithm single processing sequence length in milliseconds. This determines
/// to how long sequences the original sound is chopped in the time-stretch algorithm.
/// See "STTypes.h" or README for more information.
/// </summary>
SequenceMs = 3,
/// <summary>
/// Time-stretch algorithm seeking window length in milliseconds for algorithm that finds the
/// best possible overlapping location. This determines from how wide window the algorithm
/// may look for an optimal joining location when mixing the sound sequences back together.
/// See "STTypes.h" or README for more information.
/// </summary>
SeekWindowMs = 4,
/// <summary>
/// Time-stretch algorithm overlap length in milliseconds. When the chopped sound sequences
/// are mixed back together, to form a continuous sound stream, this parameter defines over
/// how long period the two consecutive sequences are let to overlap each other.
/// See "STTypes.h" or README for more information.
/// </summary>
OverlapMs = 5
};
}
cs
using System;
using System.Runtime.InteropServices;
using System.Text;
namespace Swisslog.CSSD.UI.SoundTouch
{
class SoundTouch : IDisposable
{
private IntPtr handle;
private string versionString;
private readonly bool is64Bit;
public SoundTouch()
{
is64Bit = false;
handle = is64Bit ? SoundTouchInterop64.soundtouch_createInstance() :
SoundTouchInterop32.soundtouch_createInstance();
}
public string VersionString
{
get
{
if (versionString == null)
{
var s = new StringBuilder(100);
if (is64Bit)
SoundTouchInterop64.soundtouch_getVersionString2(s, s.Capacity);
else
SoundTouchInterop32.soundtouch_getVersionString2(s, s.Capacity);
versionString = s.ToString();
}
return versionString;
}
}
public void SetPitchOctaves(float pitchOctaves)
{
if (is64Bit)
SoundTouchInterop64.soundtouch_setPitchOctaves(handle, pitchOctaves);
else
SoundTouchInterop32.soundtouch_setPitchOctaves(handle, pitchOctaves);
}
public void SetSampleRate(int sampleRate)
{
if (is64Bit)
SoundTouchInterop64.soundtouch_setSampleRate(handle, (uint) sampleRate);
else
SoundTouchInterop32.soundtouch_setSampleRate(handle, (uint)sampleRate);
}
public void SetChannels(int channels)
{
if (is64Bit)
SoundTouchInterop64.soundtouch_setChannels(handle, (uint) channels);
else
SoundTouchInterop32.soundtouch_setChannels(handle, (uint)channels);
}
private void DestroyInstance()
{
if (handle != IntPtr.Zero)
{
if (is64Bit)
SoundTouchInterop64.soundtouch_destroyInstance(handle);
else
SoundTouchInterop32.soundtouch_destroyInstance(handle);
handle = IntPtr.Zero;
}
}
public void Dispose()
{
DestroyInstance();
GC.SuppressFinalize(this);
}
~SoundTouch()
{
DestroyInstance();
}
public void PutSamples(float[] samples, int numSamples)
{
if (is64Bit)
SoundTouchInterop64.soundtouch_putSamples(handle, samples, numSamples);
else
SoundTouchInterop32.soundtouch_putSamples(handle, samples, numSamples);
}
public int ReceiveSamples(float[] outBuffer, int maxSamples)
{
if (is64Bit)
return (int)SoundTouchInterop64.soundtouch_receiveSamples(handle, outBuffer, (uint)maxSamples);
return (int)SoundTouchInterop32.soundtouch_receiveSamples(handle, outBuffer, (uint)maxSamples);
}
public bool IsEmpty
{
get
{
if (is64Bit)
return SoundTouchInterop64.soundtouch_isEmpty(handle) != 0;
return SoundTouchInterop32.soundtouch_isEmpty(handle) != 0;
}
}
public int NumberOfSamplesAvailable
{
get
{
if (is64Bit)
return (int)SoundTouchInterop64.soundtouch_numSamples(handle);
return (int)SoundTouchInterop32.soundtouch_numSamples(handle);
}
}
public int NumberOfUnprocessedSamples
{
get
{
if (is64Bit)
return SoundTouchInterop64.soundtouch_numUnprocessedSamples(handle);
return SoundTouchInterop32.soundtouch_numUnprocessedSamples(handle);
}
}
public void Flush()
{
if (is64Bit)
SoundTouchInterop64.soundtouch_flush(handle);
else
SoundTouchInterop32.soundtouch_flush(handle);
}
public void Clear()
{
if (is64Bit)
SoundTouchInterop64.soundtouch_clear(handle);
else
SoundTouchInterop32.soundtouch_clear(handle);
}
public void SetRate(float newRate)
{
if (is64Bit)
SoundTouchInterop64.soundtouch_setRate(handle, newRate);
else
SoundTouchInterop32.soundtouch_setRate(handle, newRate);
}
public void SetTempo(float newTempo)
{
if (is64Bit)
SoundTouchInterop64.soundtouch_setTempo(handle, newTempo);
else
SoundTouchInterop32.soundtouch_setTempo(handle, newTempo);
}
public int GetUseAntiAliasing()
{
if (is64Bit)
return SoundTouchInterop64.soundtouch_getSetting(handle, SoundTouchSettings.UseAaFilter);
return SoundTouchInterop32.soundtouch_getSetting(handle, SoundTouchSettings.UseAaFilter);
}
public void SetUseAntiAliasing(bool useAntiAliasing)
{
if (is64Bit)
SoundTouchInterop64.soundtouch_setSetting(handle, SoundTouchSettings.UseAaFilter, useAntiAliasing ? 1 : 0);
else
SoundTouchInterop32.soundtouch_setSetting(handle, SoundTouchSettings.UseAaFilter, useAntiAliasing ? 1 : 0);
}
public void SetUseQuickSeek(bool useQuickSeek)
{
if (is64Bit)
SoundTouchInterop64.soundtouch_setSetting(handle, SoundTouchSettings.UseQuickSeek, useQuickSeek ? 1 : 0);
else
SoundTouchInterop32.soundtouch_setSetting(handle, SoundTouchSettings.UseQuickSeek, useQuickSeek ? 1 : 0);
}
public int GetUseQuickSeek()
{
if (is64Bit)
return SoundTouchInterop64.soundtouch_getSetting(handle, SoundTouchSettings.UseQuickSeek);
return SoundTouchInterop32.soundtouch_getSetting(handle, SoundTouchSettings.UseQuickSeek);
}
}
}
cs
using System;
using NAudio.Wave;
namespace Swisslog.CSSD.UI.SoundTouch
{
class VarispeedSampleProvider : ISampleProvider, IDisposable
{
private readonly ISampleProvider sourceProvider;
private readonly SoundTouch soundTouch;
private readonly float[] sourceReadBuffer;
private readonly float[] soundTouchReadBuffer;
private readonly int channelCount;
private float playbackRate = 1.0f;
private SoundTouchProfile currentSoundTouchProfile;
private bool repositionRequested;
private float PlaySpeed=1.0f;
// =========新增字段：标记源是否已经读到末尾（提升为类成员）=========
private bool _sourceEof;
public VarispeedSampleProvider(ISampleProvider sourceProvider, int readDurationMilliseconds, SoundTouchProfile soundTouchProfile)
{
soundTouch = new SoundTouch();
// explore what the default values are before we change them:
//Debug.WriteLine(String.Format("SoundTouch Version {0}", soundTouch.VersionString));
//Debug.WriteLine("Use QuickSeek: {0}", soundTouch.GetUseQuickSeek());
//Debug.WriteLine("Use AntiAliasing: {0}", soundTouch.GetUseAntiAliasing());
SetSoundTouchProfile(soundTouchProfile);
this.sourceProvider = sourceProvider;
soundTouch.SetSampleRate(WaveFormat.SampleRate);
channelCount = WaveFormat.Channels;
soundTouch.SetChannels(channelCount);
sourceReadBuffer = new float[(WaveFormat.SampleRate * channelCount * (long)readDurationMilliseconds) / 1000];
soundTouchReadBuffer = new float[sourceReadBuffer.Length * 10]; // support down to 0.1 speed
_sourceEof = false; //初始化
}
public int Read(float[] buffer, int offset, int count)
{
if (repositionRequested)
{
soundTouch.Clear();
_sourceEof = false; // Seek跳转后重置eof标记！重要
repositionRequested = false;
}
int pos = 0;
while (pos < count)
{
// 只有源还没有eof，才继续去读源数据
if (!_sourceEof && soundTouch.NumberOfSamplesAvailable == 0)
{
var readFromSource = sourceProvider.Read(sourceReadBuffer, 0, sourceReadBuffer.Length);
if (readFromSource > 0)
{
soundTouch.PutSamples(sourceReadBuffer, readFromSource / channelCount);
}
else
{
// 源读到末尾，设置全局eof标记，执行Flush
_sourceEof = true;
soundTouch.Flush();
}
}
var desiredSampleFrames = (count - pos) / channelCount;
var received = soundTouch.ReceiveSamples(soundTouchReadBuffer, desiredSampleFrames) * channelCount;
for (int n = 0; n < received; n++)
{
buffer[offset + pos++] = soundTouchReadBuffer[n];
}
// 源已经eof，并且soundTouch也拿不出样本了 → 彻底结束，跳出循环
if (_sourceEof && received <= 0)
{
break;
}
}
return pos;
}
public WaveFormat WaveFormat => sourceProvider.WaveFormat;
public float PlaybackRate
{
get
{
return playbackRate;
}
set
{
if (playbackRate != value)
{
UpdatePlaybackRate(value);
playbackRate = value;
}
}
}
public void SetPlaySpeed(float playSpeed)
{
soundTouch.SetRate(playSpeed);
}
private void UpdatePlaybackRate(float value)
{
if (value != 0)
{
if (currentSoundTouchProfile.UseTempo)
{
soundTouch.SetTempo(value);
}
else
{
soundTouch.SetRate(value);
}
}
}
public void Dispose()
{
soundTouch.Dispose();
}
public void SetSoundTouchProfile(SoundTouchProfile soundTouchProfile)
{
if (currentSoundTouchProfile != null &&
playbackRate != 1.0f &&
soundTouchProfile.UseTempo != currentSoundTouchProfile.UseTempo)
{
if (soundTouchProfile.UseTempo)
{
soundTouch.SetRate(PlaySpeed);
soundTouch.SetPitchOctaves(0f);
soundTouch.SetTempo(1.0f);
}
else
{
soundTouch.SetTempo(1.0f);
soundTouch.SetRate(playbackRate);
}
}
this.currentSoundTouchProfile = soundTouchProfile;
soundTouch.SetUseAntiAliasing(soundTouchProfile.UseAntiAliasing);
soundTouch.SetUseQuickSeek(soundTouchProfile.UseQuickSeek);
}
public void Reposition()
{
repositionRequested = true;
}
}
}4 调用如下：
cs
using (var fileReader = new AudioFileReader(audioName))
using (var stretch = new VarispeedSampleProvider(fileReader, 50, new SoundTouchProfile(false, false)))
{
stretch.SetPlaySpeed(1.8f); //1.8倍速播放
using (waveOut = new WaveOut(WaveCallbackInfo.FunctionCallback()))
{
waveOut.Init(stretch);
waveOut.Play();
while (waveOut.PlaybackState == PlaybackState.Playing)
{
Thread.Sleep(10);
}
}
}