Convert MOD to AU — Free Online Tool
Extract and convert the audio track from MOD camcorder footage into Sun AU format using PCM signed 16-bit big-endian encoding. This tool strips the MPEG-2 video from your JVC or Panasonic camcorder file and outputs a lossless PCM audio stream in the classic Unix AU container — ideal for legacy audio workflows and Unix-based systems.
to
FFmpeg Command
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Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
MOD files from JVC and Panasonic camcorders use an MPEG-PS (Program Stream) container wrapping MPEG-2 video and typically AC-3 or MPEG audio. During this conversion, FFmpeg demuxes the MPEG-PS container, discards the MPEG-2 video stream entirely, and transcodes the audio into raw PCM signed 16-bit big-endian samples. These samples are then written into the Sun AU container, which uses a minimal header (encoding type, sample rate, channel count) followed by the raw audio data. Because the output is uncompressed PCM, there is no lossy re-encoding of the audio — the fidelity of the source audio is preserved as faithfully as PCM representation allows, though any compression artifacts from the original MPEG audio encoding remain.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary — the open-source multimedia processing engine that powers this conversion both in this browser tool (via FFmpeg.wasm) and on your local desktop. |
-i input.mod
|
Specifies the input MOD file from your JVC or Panasonic camcorder. FFmpeg automatically detects the MPEG-PS container and identifies the enclosed MPEG-2 video and compressed audio streams. |
-c:a pcm_s16be
|
Sets the audio codec to PCM signed 16-bit big-endian, the standard and most compatible encoding for the Sun AU format. This decodes the compressed MPEG or AC-3 audio from the MOD file into uncompressed PCM samples arranged in big-endian byte order as expected by the AU container. |
output.au
|
Specifies the output filename and triggers FFmpeg to write a Sun AU container. FFmpeg infers from the .au extension that it should use the AU muxer, which writes the standard 24-byte AU file header followed by the raw PCM audio data. The video stream from the MOD file is automatically dropped since AU is an audio-only format. |
Common Use Cases
- Extracting the audio from old JVC or Panasonic camcorder MOD recordings to ingest into legacy Unix or Sun workstation audio editing pipelines that expect AU files.
- Preparing camcorder-recorded audio for use with software synthesizers, samplers, or audio tools on Unix/Linux systems that natively support the AU format.
- Archiving the audio track of MOD home video footage as uncompressed PCM in AU format for long-term preservation without additional lossy compression.
- Stripping audio from MOD camcorder files to feed into early internet streaming servers or legacy web audio pipelines originally designed around AU file delivery.
- Converting MOD audio for use in Java applications or applets, which have historically had native support for the AU/PCM format via the Java Sound API.
- Isolating spoken-word recordings or event audio captured on a Panasonic or JVC camcorder into a simple, headerless-friendly format for scripted audio processing on Unix systems.
Frequently Asked Questions
The output AU file uses uncompressed PCM signed 16-bit big-endian audio, which is lossless in the sense that no additional compression is applied during the conversion. However, the audio inside a MOD file is typically already encoded as MPEG Layer II or AC-3 — a lossy compressed format — so any artifacts introduced at the time of original camcorder recording are already baked in. The conversion to PCM AU faithfully represents the decoded audio without adding further degradation.
The MPEG-2 video stream contained in the MOD file is completely discarded. FFmpeg reads the MPEG-PS container, selects only the audio stream for output, and writes nothing video-related into the AU file. The Sun AU format is a purely audio container and has no capability to store video data, so this is expected and intentional behavior.
AU files using pcm_s16be store raw, uncompressed audio samples — every second of stereo audio at 48 kHz requires approximately 192 kilobytes of storage. The audio inside a MOD file is stored in a compressed format (such as MPEG audio or AC-3), which is far more space-efficient. Decompressing to PCM inevitably results in a significantly larger file, often 5–15 times the size of the compressed source audio. This is a normal and expected characteristic of uncompressed PCM formats.
Yes. The AU format supports several PCM variants including pcm_mulaw, pcm_alaw, pcm_s8, and pcm_u8 in addition to the default pcm_s16be. To use mu-law encoding, for example, you would modify the FFmpeg command to use -c:a pcm_mulaw. Mu-law and A-law encodings are lossy companding codecs historically used in telephony and early internet audio, and will result in smaller files but reduced dynamic range compared to pcm_s16be.
On a Unix/Linux or macOS system, you can use a shell loop to process multiple files: for f in *.mod; do ffmpeg -i "$f" -c:a pcm_s16be "${f%.mod}.au"; done. On Windows, a similar batch loop works in PowerShell: Get-ChildItem *.mod | ForEach-Object { ffmpeg -i $_.FullName -c:a pcm_s16be ($_.BaseName + '.au') }. This is particularly useful for archiving an entire collection of camcorder tapes that were digitized to MOD.
The Sun AU format supports only a very limited metadata field — a brief ASCII annotation string embedded in the file header. MOD files themselves carry minimal metadata, typically just technical stream parameters rather than descriptive tags. In practice, FFmpeg does not transfer any rich metadata into the AU container during this conversion, so title, date, or camcorder model information from the MOD file will not be present in the AU output.
Technical Notes
MOD files use a modified MPEG Program Stream container with file extensions that can be deceptive — they may appear similar to Amiga MOD tracker files but are entirely unrelated. The audio stream inside a MOD file is typically MPEG Layer II audio at 48 kHz, though some JVC and Panasonic models record Dolby AC-3. FFmpeg's MPEG-PS demuxer handles MOD files natively without any special flags. The output codec pcm_s16be (PCM signed 16-bit big-endian) is the default and most compatible encoding for the AU format, which uses big-endian byte order as a legacy of Sun SPARC workstation architecture. The AU container has a fixed 24-byte minimum header and no support for chapters, subtitles, multiple audio tracks, or embedded artwork. Because AU files are not seekable in the same way as modern containers, very long camcorder recordings may produce large, unwieldy AU files that some modern players handle poorly. For files exceeding 1GB, running the FFmpeg command locally is strongly recommended, and the exact command is displayed on this page for that purpose.