---
title: "Convert AIFF to WAV in C#"
url: https://recursiveai.org/onemedia/cookbook/convert-aiff-to-wav/
description: "Convert AIFF to WAV in C# without re-encoding: OneMedia’s remux rewrites the PCM samples as little-endian WAV (or RF64 past 4 GiB) and carries the title, with the same samples before and after. Also MOV, CAF and MKV PCM to WAV. No NAudio or FFmpeg."
version: "0.7.0-preview.1"
---

# Convert AIFF to WAV in C#

`Media.Remux("in.aiff", "out.wav")` writes the PCM audio of an AIFF file as a WAV file. AIFF stores samples big-endian and WAV little-endian, so each sample’s bytes are swapped; nothing else changes: no decoding, no new bit depth or sample rate. The same call takes the PCM, A-law or µ-law track of a CAF, MOV, MP4, MKV or W64 file. WAV writing is new in 0.6.0-preview.1, and past 4 GiB the file becomes RF64 by itself.

```shell
dotnet new console -o AiffToWav && cd AiffToWav
dotnet add package RecursiveAI.OneMedia --version 0.7.0-preview.1
ffmpeg -v error -f lavfi -i sine=f=440:d=3:r=48000 -ac 2 -c:a pcm_s24be -metadata title="Test tone" tone.aiff
```

`tone.aiff` is three seconds of a 440 Hz tone, 24-bit stereo at 48 kHz, with a title. Put this in `Program.cs` and run `dotnet run`:

```csharp
using RecursiveAI.OneMedia;
using RecursiveAI.OneMedia.Remuxing;

string input = args.Length > 0 ? args[0] : "tone.aiff";
string output = args.Length > 1 ? args[1] : "tone.wav";
RemuxReport report = Media.Remux(input, output);   // .wav: WAVE, RF64 past 4 GiB

foreach (RemuxTrackReport track in report.Tracks)
    if (track.OutputTrack >= 0)
        Console.WriteLine($"track {track.InputTrack} -> {track.OutputTrack}: {track.Packets} packets copied");
foreach (RemuxLoss loss in report.Losses)
    Console.WriteLine($"not carried: {loss.Kind} {loss.Subject}: {loss.Reason}");
foreach (string change in report.Changes)
    Console.WriteLine($"changed: {change}");
Console.WriteLine($"{report.Mux.BytesWritten:N0} bytes written");

using MediaFile wav = Media.Open(output);
Console.WriteLine($"{wav.Format}: {wav.Audio?.Codec}, {wav.Audio?.Audio?.SampleRate} Hz, {wav.Audio?.Audio?.Channels} channels, {wav.Duration}, title \"{wav.Tags.Title}\"");
```

```text
track 0 -> 0: 212 packets copied
changed: tags carried through the common view (1 edits, 0 pictures)
880,488 bytes written
wav: pcm, 48000 Hz, 2 channels, 00:00:03, title "Test tone"
```

The title travels through the common tag view into the WAV’s `LIST INFO` chunk. 24-bit stereo is written as `WAVE_FORMAT_EXTENSIBLE`, the record WAV uses for samples wider than 16 bits.

## Check it with ffmpeg

The samples decoded from both files are the same:

```shell
ffprobe -v error -show_entries stream=codec_name,sample_rate,channels,bits_per_sample:format=format_name,duration:format_tags=title -of compact tone.wav
for f in tone.aiff tone.wav; do echo "$f $(ffmpeg -v error -i $f -f s32le - | md5sum)"; done
```

```text
stream|codec_name=pcm_s24le|sample_rate=48000|channels=2|bits_per_sample=24
format|format_name=wav|duration=3.000000|tag:title=Test tone
tone.aiff e2631706b9a3b2520948316282c4988b  -
tone.wav e2631706b9a3b2520948316282c4988b  -
```

A browser can play the result where it couldn’t play the input: headless Chrome 149 refused `tone.aiff` and played `tone.wav`.

## Limits

- **PCM in, PCM out.** In the words of the [WAV writing page](https://recursiveai.org/onemedia/docs/muxing-wav/): “Nothing is decoded, converted between widths or rates, or encoded.” A track in another codec with no WAV format record is refused. To get WAV from MP3, AAC or Opus, decode it: [Extract the audio from a video](https://recursiveai.org/onemedia/cookbook/extract-audio-from-video/) does that with OneAudio.
- **One track, seekable output.** From the README: “**one track, and the output must be able to seek**”. The sizes in the header are written at the end, so a pipe can’t be the output.
- **Broadcast Wave.** `bext`, `cart`, iXML and `LIST INFO` chunks are written by `WavMuxer` with `WavMuxOptions`, and the chunks of a WAV or RF64 input travel unchanged; to edit the tags of an existing WAV, see [Edit MP4, MKV and MP3 tags](https://recursiveai.org/onemedia/cookbook/edit-video-tags/).
- **Big files.** Past 4 GiB the header is rewritten as RF64 in place, without moving a sample byte; set the layout in `WavMuxOptions` to refuse that or to write RF64 or BW64 from the start.