Transformations.Audio 2.0.4.3

Transformations.Audio

Sample-rate conversion for .NET, with a repeatable, versioned fidelity benchmark behind every algorithm choice.

📖 Overview

Transformations.Audio resamples interleaved PCM audio (float[]) between arbitrary sample rates - the everyday "convert this 48 kHz recording to 44.1 kHz" or "upsample this 16 kHz voice clip to 48 kHz" problem. It ships several interchangeable algorithms behind one interface, from a cheap linear interpolator to alias-suppressing windowed-sinc variants, so you can pick the right speed/fidelity tradeoff for your use case.

Every algorithm in this package is backed by a deterministic fidelity suite that measures SNR, PSNR, and MSE across speech, music, transient, and alias-stress test signals - see DEVELOPMENT.md for the full evidence trail behind each one, including why some candidates were promoted and others retired.

📦 Install

<PackageReference Include="Transformations.Audio" Version="2.0.4.3" />

Depends only on NAudio (for WaveFormat interop). Targets .NET 8, 9, and 10.

🚀 Quick start

using Transformations.Audio.Resampler;

float[] input = GetSamples(); // interleaved PCM, e.g. from a WAV file
float[] output = Sinc.Resample(input, inRate: 48000, outRate: 44100, channels: 2);

Or resolve rates/channels from NAudio.Wave.WaveFormat directly:

float[] output = Sinc.Resample(input, inFormat, outFormat);

Extension-method form, including Span<float>/Memory<float> overloads:

using Transformations.Audio.Resampler;

float[] output = input.ResampleLinear(48000, 44100, channels: 2);

🎛️ Choosing an algorithm

Sinc.Resample takes an optional ResampleQuality (SuperFast through BestQuality) trading kernel width for speed. Plain Sinc has no anti-alias rolloff, so it can lose fidelity on aggressive downsampling of high-energy content - see DEVELOPMENT.md for alias-suppressing variants and the evidence behind when to reach for one.

🧪 Evidence, not vibes

Every algorithm swap in this package's history was decided by a repeatable fidelity suite, not by ear. If you want to see the actual numbers, reproduce them, or understand why a given default was chosen, DEVELOPMENT.md has the full build/test instructions and the evidence trail.