LibSampleRate.NET

A managed wrapper for the popular libsamplerate (aka Secret Rabbit Code) resampling library, written in C#.

Platform Support

The library currently supports Windows x86 and x64. Other platforms can be easily added, but are currently not included because the upstream repository only provides Windows builds.

Usage

The easiest way to use this library is by installing the package through NuGet.

The entire public API surface lives in and is documented in SampleRateConverter.cs. A minimal example:

using System;
using LibSampleRate;

var channels = 1;
var ratio = 2.0;
var inputBuffer = new float[1000];
var outputBuffer = new float[2000];

var src = new SampleRateConverter(ConverterType.SRC_SINC_BEST_QUALITY, channels);
src.SetRatio(ratio);

src.Process(
    inputBuffer,
    0,
    inputBuffer.Length,
    outputBuffer,
    0,
    outputBuffer.Length,
    endOfInput: true,
    out var inputSampleCount,
    out var outputSampleCount
);

Console.WriteLine($"{inputSampleCount} input samples resampled to {outputSampleCount} output samples.");

See the LibSampleRate.Demo project for a more complete streaming scenario that shows how to push blocks of audio through the converter.

Development

The solution contains two projects: the managed wrapper library, and a small console app demonstrating streaming resampling and serving as an integration test.

Run the helper script before building with Visual Studio or dotnet build so the native DLLs and their notices are available:

pwsh scripts/fetch-libsamplerate.ps1

License & Credits

Copyright (C) 2011-2025 Mario Guggenberger mg@protyposis.net. Released under the BSD 2-Clause license.

This project builds upon libsamplerate, Copyright (c) 2012-2016, Erik de Castro Lopo erikd@mega-nerd.com. Released under the BSD 2-Clause license.