Class SmbPitchShiftingSampleProvider

Namespace

NAudio.Wave.SampleProviders

Assembly

NAudio.Core.dll

Author: Freefall Date: 05.08.16 Based on: the port of Stephan M. Bernsee´s pitch shifting class Port site: https://sites.google.com/site/mikescoderama/pitch-shifting Test application and github site: https://github.com/Freefall63/NAudio-Pitchshifter

NOTE: I strongly advice to add a Limiter for post-processing. For my needs the FastAttackCompressor1175 provides acceptable results: https://github.com/Jiyuu/SkypeFX/blob/master/JSNet/FastAttackCompressor1175.cs

UPDATE: Added a simple Limiter based on the pydirac implementation. https://github.com/echonest/remix/blob/master/external/pydirac225/source/Dirac_LE.cpp

public class SmbPitchShiftingSampleProvider : ISampleProvider

Inheritance

object

SmbPitchShiftingSampleProvider

Implements

ISampleProvider

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Extension Methods

WaveExtensionMethods.FollowedBy(ISampleProvider, TimeSpan, ISampleProvider)

WaveExtensionMethods.Skip(ISampleProvider, TimeSpan)

WaveExtensionMethods.Take(ISampleProvider, TimeSpan)

WaveExtensionMethods.ToMono(ISampleProvider, float, float)

WaveExtensionMethods.ToStereo(ISampleProvider, float, float)

WaveExtensionMethods.ToWaveProvider(ISampleProvider)

WaveExtensionMethods.ToWaveProvider16(ISampleProvider)

Constructors

SmbPitchShiftingSampleProvider(ISampleProvider)

Creates a new SMB Pitch Shifting Sample Provider with default settings

public SmbPitchShiftingSampleProvider(ISampleProvider sourceProvider)

Parameters

sourceProvider ISampleProvider

Source provider

SmbPitchShiftingSampleProvider(ISampleProvider, int, long, float)

Creates a new SMB Pitch Shifting Sample Provider with custom settings

public SmbPitchShiftingSampleProvider(ISampleProvider sourceProvider, int fftSize, long osamp, float initialPitch)

Parameters

sourceProvider ISampleProvider

Source provider

fftSize int

FFT Size (any power of two <= 4096: 4096, 2048, 1024, 512, ...)

osamp long

Oversampling (number of overlapping windows)

initialPitch float

Initial pitch (0.5f = octave down, 1.0f = normal, 2.0f = octave up)

Properties

Latency

The latency (group delay) introduced by the underlying STFT phase vocoder, expressed as a TimeSpan.

public TimeSpan Latency { get; }

Property Value

TimeSpan

LatencySamples

The latency (group delay) introduced by the underlying STFT phase vocoder, expressed as an interleaved sample count (latency per channel multiplied by the channel count). This is the value to use for SkipOverSamples when realigning pitch-shifted audio with unshifted audio.

public int LatencySamples { get; }

Property Value

int

LatencySamplesPerChannel

The latency (group delay) introduced by the underlying STFT phase vocoder, expressed as a number of samples per channel. The shifted output is delayed by this many samples relative to the input, and the equivalent number of samples is lost from the tail when the source ends. The value is fftSize - fftSize / osamp and depends only on the FFT size and oversampling factor passed to the constructor (not on the pitch factor).

public int LatencySamplesPerChannel { get; }

Property Value

int

Remarks

Use this to time-align pitch-shifted material with unshifted material, e.g. by skipping this many samples per channel from the start of the shifted output (see LatencySamples for the interleaved count to pass to an OffsetSampleProvider).

PitchFactor

Pitch Factor (0.5f = octave down, 1.0f = normal, 2.0f = octave up)

public float PitchFactor { get; set; }

Property Value

float

WaveFormat

WaveFormat

public WaveFormat WaveFormat { get; }

Property Value

WaveFormat

Methods

Read(Span<float>)

Read from this sample provider

public int Read(Span<float> buffer)

Parameters

buffer Span<float>

Returns

int