NAudio.SoundFile 3.0.0-preview.8

Prefix Reserved
.NET 9.0 This package targets .NET 9.0. The package is compatible with this framework or higher.
This is a prerelease version of NAudio.SoundFile. 
dotnet add package NAudio.SoundFile --version 3.0.0-preview.8
                    


                    

                
NuGet\Install-Package NAudio.SoundFile -Version 3.0.0-preview.8
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package. 
<PackageReference Include="NAudio.SoundFile" Version="3.0.0-preview.8" />
For projects that support PackageReference, copy this XML node into the project file to reference the package. 
<PackageVersion Include="NAudio.SoundFile" Version="3.0.0-preview.8" />
                    


                            Directory.Packages.props
                        

                    

                
<PackageReference Include="NAudio.SoundFile" />
                    


                            Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package. 
paket add NAudio.SoundFile --version 3.0.0-preview.8
                    


                    

                
#r "nuget: NAudio.SoundFile, 3.0.0-preview.8"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package. 
#:package NAudio.SoundFile@3.0.0-preview.8
#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package. 
#addin nuget:?package=NAudio.SoundFile&version=3.0.0-preview.8&prerelease
                    


                            Install as a Cake Addin
                        

                    

                
#tool nuget:?package=NAudio.SoundFile&version=3.0.0-preview.8&prerelease
                    


                            Install as a Cake Tool

NAudio.SoundFile

Cross-platform audio file reading and writing for NAudio, backed by libsndfile.

Type Role
SoundFileReader WaveStream + ISampleProvider — decode WAV/AIFF/FLAC/Ogg/Opus/MP3
SoundFileWriter Stream sink — encode WAV/AIFF/FLAC/Ogg-Vorbis/Opus/MP3
SoundFileCapabilities query which codecs the installed libsndfile supports
SoundFileException thrown on libsndfile errors (exposes ErrorCode)

This is the first cross-platform FLAC/Vorbis/Opus encoder in NAudio, and on Linux/macOS the first general-purpose decoder (there is no Media Foundation off Windows).

Platform

Truly cross-platform — net9.0, no [SupportedOSPlatform]. It P/Invokes a system libsndfile, resolved automatically per OS (libsndfile.so.1 / libsndfile.1.dylib / sndfile.dll / libsndfile-1.dll). You must provide it:

sudo apt install libsndfile1     # Debian/Ubuntu
brew install libsndfile          # macOS
vcpkg install libsndfile         # Windows (or the official binaries)

Not pulled in by the NAudio meta-package — reference it explicitly:

dotnet add package NAudio.SoundFile

Supported formats

Format Read Write Requires
WAV, AIFF, AU, CAF, W64, RAW ✅ ✅ always
FLAC ✅ ✅ libsndfile built with libFLAC (typical)
Ogg/Vorbis ✅ ✅ libvorbis (typical)
Ogg/Opus ✅ ✅ libsndfile ≥ 1.0.29 + libopus
MP3 ✅ ✅ libsndfile ≥ 1.1.0

Codec availability depends on how libsndfile was built — query it:

foreach (var f in SoundFileCapabilities.GetSupportedMajorFormats())
    Console.WriteLine(f);
bool canFlac = SoundFileCapabilities.IsFormatSupported(SoundFileMajorFormat.Flac);

AAC / M4A / ALAC / WMA are out of scope (the MPEG-4 family is FFmpeg territory).

Read any file

SoundFileReader decodes to 32-bit float, so it is both a WaveStream and an ISampleProvider:

using NAudio.SoundFile;
using NAudio.Wave;

using var reader = new SoundFileReader("song.flac");
Console.WriteLine($"{reader.WaveFormat} {reader.TotalTime}");
// feed it into any NAudio output, mixer or sample pipeline

Write FLAC / Ogg / Opus

using (var source = new SoundFileReader("in.wav"))
    SoundFileWriter.CreateSoundFile("out.flac", source,
        SoundFileMajorFormat.Flac,
        new SoundFileWriterOptions { CompressionLevel = 0.8 });

// Ogg Vorbis at VBR quality 0.6, with tags
using (var source = new SoundFileReader("in.wav"))
    SoundFileWriter.CreateSoundFile("out.ogg", source,
        SoundFileMajorFormat.OggVorbis,
        new SoundFileWriterOptions
        {
            VbrQuality = 0.6,
            Tags = new SoundFileTags { Title = "Demo", Artist = "NAudio" }
        });

Read embedded metadata back:

using var reader = new SoundFileReader("song.flac");
Console.WriteLine($"{reader.Tags.Artist} – {reader.Tags.Title}");
Console.WriteLine(SoundFileCapabilities.LibraryVersion);

The output format is also inferred from the extension:

SoundFileWriter.CreateSoundFile("out.flac", source); // → FLAC

Streams

Both ends work over a System.IO.Stream (via libsndfile virtual I/O):

using var ms = new MemoryStream();
SoundFileWriter.WriteSoundFileToStream(ms, source, SoundFileMajorFormat.OggVorbis, null);
ms.Position = 0;
using var reader = new SoundFileReader(ms);   // stream not disposed by the reader

FLAC/Ogg/Opus/MP3 stream fine to a forward-only target; WAV/AIFF back-patch their header at close and require a seekable stream (the writer throws early if you pair a non-seekable stream with such a format).

Notes

  • The writer accepts 16-bit PCM or 32-bit IEEE float input — the two container types NAudio pipelines naturally produce. Convert other formats with SampleToWaveProvider16 or .ToSampleProvider() first.
  • AOT-compatible: source-generated [LibraryImport], SafeHandle lifetime, and [UnmanagedCallersOnly] virtual-I/O callbacks.
  • The wrapper is MIT; libsndfile itself is LGPL-2.1+ and supplied by the user as a system library (no binary is shipped) — the same model as NAudio.Alsa.

Tutorial

For a worked walkthrough (reading, encoding, format conversion, streams, tags, capability detection) see Cross-platform audio file reading and writing with NAudio.SoundFile.

Product Compatible and additional computed target framework versions.
.NET net9.0 is compatible.  net9.0-android was computed.  net9.0-browser was computed.  net9.0-ios was computed.  net9.0-maccatalyst was computed.  net9.0-macos was computed.  net9.0-tvos was computed.  net9.0-windows was computed.  net10.0 was computed.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last Updated
3.0.0-preview.8 37 5/22/2026
3.0.0-preview.7 35 5/21/2026
3.0.0-preview.6 37 5/21/2026

#### Breaking changes

* `IWaveProvider.Read` signature changed from `Read(byte[], int, int)` to `Read(Span<byte>)`. Existing callers with `byte[]` migrate via `source.Read(buffer.AsSpan(offset, count))`; implementations override `Read(Span<byte>)`
* `ISampleProvider.Read` signature changed from `Read(float[], int, int)` to `Read(Span<float>)` (same migration pattern)
* `MidiIn`, `MidiOut`, `MidiInCapabilities`, and `MidiOutCapabilities` moved from `NAudio.Midi` to `NAudio.WinMM` — all `winmm.dll` interop now lives in one assembly
* `MmResult`, `MmException`, and `Manufacturers` moved from `NAudio.Core` to `NAudio.WinMM`
* `DirectSoundOut` moved from `NAudio.Core` to `NAudio.Dmo` (DirectSound has always been Windows-only)
* **New `NAudio.Dmo` package.** DMO effects (echo, chorus, reverb, etc.), the DMO MP3 decoder (`DmoMp3FrameDecompressor`), the DMO resampler (`ResamplerDmoStream`), and `DirectSoundOut` carved out of `NAudio.Wasapi`. Namespaces preserved (`NAudio.Dmo`, `NAudio.Dmo.Effect`, `NAudio.Wave` for `DirectSoundOut`). Meta-package consumers see no change — `NAudio.Dmo` comes in transitively. Direct `NAudio.Wasapi` consumers who use the DMO/DirectSound types now need an explicit `<PackageReference Include="NAudio.Dmo" />`.
* `NAudio.Midi` is now cross-platform — its `net9.0` target no longer P/Invokes `winmm.dll`
* `MidiInMessageEventArgs.Timestamp` and `MidiInSysexMessageEventArgs.Timestamp` are now `TimeSpan` (previously `int` milliseconds) — preserves full WinRT 100 ns resolution on the WinRT backend
* `MidiIn.CreateSysexBuffers` removed — `MidiIn` now allocates sysex receive buffers automatically inside `Start()`
* `WasapiOut`, `WasapiCapture`, and `WasapiLoopbackCapture` are now `[Obsolete]` in favour of the new `WasapiPlayer` / `WasapiRecorder` APIs (the legacy types still ship and continue to work)
* `WasapiOut`'s embedded DMO resampler removed. Exclusive-mode callers whose source format is not natively supported now get a `NotSupportedException` from `Init` instead of silent on-the-fly resampling. Resample upstream (e.g. with `MediaFoundationResampler`), use shared mode (which still auto-converts via `AutoConvertPcm`), or switch to `WasapiPlayerBuilder`. Removes `NAudio.Wasapi`'s only intra-assembly dependency on DMO.
* `WaveOut` and `WaveIn` now default to event-driven callbacks; the legacy window-based variants are renamed `WaveOutWindow` / `WaveInWindow` and live in `NAudio.WinForms`
* `WaveInEventArgs` now fires one event per WASAPI packet (previously batched). A new `BufferSpan` property exposes the data without copying through the existing `Buffer` byte array
* Several `Mf*` Media Foundation wrapper types are now `internal` — only `MfActivate` and `MediaType` remain public
* `BufferedWaveProvider` buffer duration is now set in the constructor (default 5 seconds); `BufferLength` and `BufferDuration` are read-only
* `WaveBuffer` is deprecated — use `MemoryMarshal.Cast` instead
* `MMDevice.AudioClient` is `[Obsolete]` because it created a new instance per access; use `MMDevice.CreateAudioClient()`
* `PropertyStore[int]` now resolves `PropVariant` values safely; the indexer that returned the raw `PropVariant` is `[Obsolete]`
* Minimum target framework is now `net9.0` (previously supported legacy .NET Framework and .NET Standard 2.0)
* `CueWaveFileReader` removed - use `new WaveFileReader(...).Chunks.ReadCueList()` to get a `CueList`

#### New features

* **NAudio.SoundFile:** new cross-platform `SoundFileReader` / `SoundFileWriter` wrapping libsndfile — reads and writes WAV/AIFF/FLAC/Ogg-Vorbis/Opus/MP3 on Linux, macOS and Windows (the first cross-platform FLAC/Vorbis/Opus *encoder* in NAudio). `SoundFileReader` is a `WaveStream` and `ISampleProvider`; both reader and writer also work over a `System.IO.Stream`. Requires a system libsndfile; `SoundFileCapabilities` reports which codecs the build supports (#1289)
* **WASAPI:** new high-level `WasapiPlayer` and `WasapiRecorder` classes, built via `WasapiPlayerBuilder` / `WasapiRecorderBuilder`. Adds `IAudioClient3` low-latency support, MMCSS thread priority, `IAsyncDisposable`, zero-copy buffer access, and process-specific loopback via `WasapiRecorderBuilder.WithProcessLoopback()`
* **ASIO:** new `AsioDevice` class replacing `AsioOut` as the primary ASIO interface. Adds explicit `InitPlayback` / `InitRecording` / `InitDuplex` modes, non-contiguous channel selection, per-channel `Span<float>` callbacks, `Reinitialize()` for driver-reset recovery, and per-buffer timing fields (`SamplePosition`, `SystemTimeNanoseconds`, `Speed`, SMPTE `TimeCode`)
* **ASIO events:** `LatenciesChanged` and `ResyncOccurred` surfaced separately; buffer-size changes routed through `DriverResetRequest`
* **Media Foundation:** `MediaFoundationEncoder.EncodeToFlac` for lossless FLAC output. The FLAC/ALAC selector now falls back correctly on rate + channels
* **WinForms:** `WaveOutWindow` and `WaveInWindow` available as window-callback variants of the modernised event-driven `WaveOut` / `WaveIn`
* **DSP:** new `FftProcessor` with real-input specialisation and precomputed windowing
* **WAV chunks:** new `IWaveChunkInterpreter<T>` extension point, with built-in interpreters for cue lists, BWF `bext` (v1 and v2), and LIST/INFO metadata. RF64 promotion is now an explicit `WaveFileWriterOption`
* **`Span<T>` overloads:** added on `BiQuadFilter.Transform`, `ALawDecoder.Decode`, `MuLawDecoder.Decode`, and `IMp3FrameDecompressor.DecompressFrame` (default interface method preserves backward compatibility with `NLayer` and other third-party decoders)
* **MIDI:** new `WinRTMidiIn` / `WinRTMidiOut` classes in `NAudio.Wasapi` backed by `Windows.Devices.Midi`, with `MidiMessageConverter` for interop with the WinRT MIDI types. New `IMidiInput` / `IMidiOutput` interfaces (with a `Send(MidiEvent)` extension) let callers write backend-agnostic code; legacy `MidiIn` / `MidiOut` also implement them
* **MIDI:** `MidiFile` now reads RIFF-RMID (`.rmi`) files by unwrapping the RIFF container and parsing the embedded standard MIDI file (#1236)
* **ALSA (Linux):** new `NAudio.Alsa` package — `AlsaOut` (`IWavePlayer`) and `AlsaIn` (`IWaveIn`) backed by `libasound`, plus `AlsaDeviceEnumerator`. Linux-only (`[SupportedOSPlatform("linux")]`, AOT-compatible `[LibraryImport]`); reference it explicitly, it is not part of the `NAudio` meta-package (#1182)

#### Demo apps and Test Harnesses

* **NAudioConsoleTest:** new CLI test harness for driving various NAudio features without the need for GUI. Includes `run-batch` for JSON-driven test plans and `diagnose` for capturing a structured host audio snapshot (OS, ASIO drivers, WASAPI/WinMM/DirectSound devices, NAudio assembly versions).
* **WPF demos:** spectrum analyser rewritten with corrected dB formula (20·log₁₀), log-frequency mapping, real-input full-scale calibration, bars instead of polylines, peak-decay markers, and per-band smoothing. New `LiveWaveformControl` with configurable render styles, vertical scaling, and fill-between rendering
* **WAV recording demo:** added loopback support and a multi-API device combo with provenance embedding
* **MIDI In demo:** Refresh button for hot-plugged devices, device combos disabled while in use, test MIDI Out plays on channel 1 (was 2), Filter Auto-Sensing on by default, stopping test output now sends note-off so notes don't hang, and cleaner panel disposal
* **MfStressTest:** Reliability tests for the new Media Foundation interop implementation in NAudio 3.
* Replaced vendored NSpeex (deprecated) with Opus (Concentus) in the network chat demo; added round-trip unit tests

#### Performance

* Vectorised mix-add and volume kernels via `System.Numerics.Tensors` — significantly faster on AVX2 hardware for typical buffer sizes
* Eliminated per-`Read` allocations in `SmbPitchShiftingSampleProvider`
* `WaveStream.Read(Span<byte>)` overridden directly on every concrete reader (no intermediate byte-array copy)
* `WasapiCapture` capture path is now zero-copy via the native WASAPI buffer span
* `BiQuadFilter` state and coefficient fields hoisted to locals in batch loops for register retention
* `Mp3FileReader` now builds its table-of-contents lazily on first seek instead of eagerly during construction; the `Position` setter no longer blocks; rapid scrub seeks debounce and silence output
* Eliminated per-`Read` allocations in `ResamplerDmoStream` and `DmoMp3FrameDecompressor` (cached input buffer and output-buffer array) (#971)

#### Reliability and bug fixes

* `AcmInterop`: serialised all `msacm32` P/Invokes process-wide via a reentrant lock — fixes process-killing access violations under concurrent ACM access
* `AcmStream`: fixed double-close in finalizer by zeroing the handle field before close
* `MediaFoundationReader`: informational source-reader flags (`STREAMTICK`, `NEWSTREAM`, `NativeMediaTypeChanged`, `AllEffectsRemoved`) are now non-fatal instead of aborting reads
* `MediaFoundationReader.Reposition`: fixed using a stale field instead of the parameter (seeks would default to stream start)
* `MediaFoundationEncoder`: unselected `MediaType` instances are now disposed to prevent finalizer-thread COM ref leaks
* `Mp3FileReader`: fixed false sample-rate-change errors near end of file
* MP3 frame parsing: more robust against false frame detections from album art and trailing metadata
* `MidiFile`: preserved running-status across meta events (fixes "Read too far" errors when meta events interrupt running-status sequences)
* `WaveStream.CurrentTime` setter: now lands on a block boundary, preventing garbage audio on seek in custom readers
* `BlockAlignReductionStream.Position` setter: now validates the incoming value instead of the stale current position, so a block-aligned seek after an arbitrary-length read no longer wrongly throws "Position must be block aligned" (#368)
* `IconExtractor.Extract`: now guards against null icon handles from `ExtractIconEx`
* `DirectSoundOut.InitializeDirectSound`: wrapped notification setup in try/finally to prevent COM ref leak on `SetNotificationPositions` failure
* ASIO: implemented missing `Asio64Bit` conversions (Int24LSB and Float32LSB output sample types)
* ASIO: fixed byte-order bug in `AsioDriver.GetSamplePosition` for `Asio64Bit` reassembly
* `WdlResampler`: backported three upstream Cockos WDL bug fixes (latency calculation, `ResampleOut` clamping, Blackman-Harris window correction)
* `MediaBufferLease`: hardened against out-of-order disposal
* Added finalizers to DMO `MediaBuffer` and the `Mf*` wrappers that hold (RCW, IntPtr) pairs to prevent COM ref leaks
* `WaveFileChunkReader`: fixed `ArgumentException` parsing WAV files whose odd-length chunks are followed by non-UTF-8 bytes — the word-alignment pad-byte check no longer decodes via `BinaryReader.PeekChar()`, and is now guarded against end-of-stream (#959)
* Clarified `BiQuadFilter` `q` parameter docs (#1264)
* Removed dead `naudio.codeplex.com` links from README, MixDiff Help menu, and source comments (CodePlex was shut down by Microsoft in 2017) (#985)
* `AudioClient.Dispose`: made idempotent and safe against concurrent/re-entrant disposal — fixes an intermittent `NullReferenceException` from the COM interop layer when a WASAPI capture or playback wrapper is disposed more than once (#1183)
* `WaveFileReader` / `AiffFileReader`: malformed headers that declared `BlockAlign=0` now throw `InvalidDataException` from the constructor instead of `DivideByZeroException` from the `Position` setter (#1254)
* `AiffFileReader.Read`: truncated `SSND` chunks no longer trigger `IndexOutOfRangeException` in the byte-swap loop — the read count is rounded down to a whole block (#1254)

#### Modernisation (Native AOT, source-generated COM)

* `NAudio.Core`, `NAudio.Midi`, and `NAudio.Wasapi` are now `IsAotCompatible=true`. AOT compatibility is enforced at build-time by `NAudioAotSmokeTest`, which fails CI on any new trim or AOT analyzer warning
* Most COM interop migrated from `[ComImport]` to `[GeneratedComInterface]` / `ComWrappers`. Affected interfaces include the WASAPI / Core Audio activation chain (`IActivateAudioInterfaceCompletionHandler`, `IMMNotificationClient`, `IAudioSessionNotification`, `IAudioSessionEvents`, `IAudioEndpointVolumeCallback`, `IAgileObject`, `IPropertyStore`), the Media Foundation cascade, the DMO interfaces, DirectSound, and the `ComStream` CCW (now source-generated `IStream`)
* DirectSound P/Invokes migrated to `[LibraryImport]` with `[UnmanagedCallersOnly]` thunks; `BufferDescription` and `BufferCaps` converted from class to struct
* `AcmDriver` ported from legacy `NativeMethods` to `NativeLibrary`
* Most `MediaFoundationInterop` blittable P/Invokes migrated to `[LibraryImport]`

#### Packaging and dependencies

* Each NAudio package now ships its own README in the NuGet payload
* Test project migrated from VSTest to `Microsoft.Testing.Platform`
* `NAudioTests` split into `NAudio.Core.Tests` (cross-platform, `net10.0`) and `NAudio.Windows.Tests` (Windows-only, `net10.0-windows`) — eliminates the dual-TFM double-run on Windows CI and lets non-Windows devs run just the cross-platform suite
* `NAudio.Alsa.Tests` and `NAudio.SoundFile.Tests` now ignore MTP exit codes 8/9 so `dotnet test` succeeds on machines where the suite legitimately runs zero tests (ALSA off-Linux) or self-skips (libsndfile absent)
* Migrated to the modern `.slnx` solution format
* Renamed `license.txt` to `LICENSE` for GitHub license detection; refreshed copyright year to 2008–2026
* Added per-package `<Description>` metadata to every shipping NAudio NuGet package so each clearly identifies itself as part of the NAudio family