Convert MXF to CAF — Free Online Tool
Convert MXF broadcast files to Apple's CAF audio format, extracting and transcoding the audio stream (typically PCM or AAC from professional MXF sources) into a flexible container built for macOS and iOS workflows. Ideal for moving broadcast-quality audio from post-production into Apple-native tools like Logic Pro or Core Audio pipelines.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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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
MXF is a professional broadcast container that typically carries video alongside one or more audio tracks encoded as PCM (pcm_s16le, pcm_s24le) or AAC. Since CAF is an audio-only container, FFmpeg discards the video stream entirely during this conversion — no video re-encoding occurs. The default output uses pcm_s16le (16-bit signed little-endian PCM), which means if your MXF source already contains pcm_s16le audio, the audio data is transcoded into the same encoding but repackaged into the CAF wrapper. If your MXF carries pcm_s24le or AAC audio, FFmpeg decodes and re-encodes it to pcm_s16le. The CAF container supports very large file sizes without the 4GB limit that affects WAV and AIFF, making it well-suited for long-form broadcast content like documentary or news rushes.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool — in this browser-based tool, it runs via FFmpeg.wasm compiled to WebAssembly, so no installation is needed and no files leave your device. |
-i input.mxf
|
Specifies the input MXF file. FFmpeg reads the container and identifies all streams inside — typically one or more PCM or AAC audio tracks alongside a video stream (H.264, MPEG-2, or MJPEG) and embedded broadcast metadata. |
-c:a pcm_s16le
|
Sets the output audio codec to 16-bit signed little-endian PCM, the standard uncompressed audio encoding used across Apple platforms and the default codec for CAF files. This produces a lossless, uncompressed audio output compatible with Logic Pro, GarageBand, and Core Audio on macOS and iOS. |
-b:a 128k
|
Specifies a target audio bitrate of 128k, though this flag has no effect on uncompressed PCM codecs like pcm_s16le — PCM bitrate is fixed by sample rate and bit depth. This flag would only apply if you switched the audio codec to a lossy format like AAC. |
output.caf
|
Defines the output filename and tells FFmpeg to write a CAF (Core Audio Format) container. Because CAF is an audio-only format, FFmpeg automatically drops the MXF video stream without requiring an explicit -vn flag. |
Common Use Cases
- Bringing MXF audio rushes from a broadcast camera (e.g., Sony XDCAM) into Logic Pro or GarageBand for music or dialogue editing on macOS
- Extracting the PCM audio track from an MXF news package for ingestion into an Apple-based radio station playout system
- Archiving the isolated audio from MXF broadcast masters as high-quality PCM CAF files for use in Core Audio-based applications on macOS
- Preparing MXF dialogue or voiceover audio recorded on set for delivery to an Apple-platform post-production sound editor
- Stripping and repackaging broadcast PCM audio from MXF deliverables into CAF for use in Xcode's audio asset pipeline for iOS app development
- Converting MXF interview recordings from a broadcast workflow into CAF files compatible with macOS Finder Quick Look and AVFoundation-based tools
Frequently Asked Questions
If your MXF source contains pcm_s16le audio (the most common professional broadcast PCM format), the conversion is essentially lossless in terms of bit depth — the audio data is decoded and re-encoded at the same 16-bit resolution into the CAF container. However, if your MXF source has higher-resolution audio (such as pcm_s24le at 24-bit), downconverting to pcm_s16le will reduce dynamic range. In that case, you can modify the command to use -c:a pcm_s24le to preserve the full 24-bit depth in the CAF output.
No — CAF does not support multiple audio tracks, whereas MXF files commonly carry several discrete audio tracks (e.g., stereo mix, isolated dialogue, ambient). FFmpeg will by default map only the first audio stream from the MXF into the CAF output. If you need a specific track from a multi-track MXF, you can add a flag like -map 0:a:1 to select the second audio stream before conversion.
The video stream is completely dropped. FFmpeg automatically omits video when writing to an audio-only container like CAF, so no video re-encoding takes place and no video data ends up in the output file. This also makes the conversion significantly faster than a full video transcode, since only the audio pipeline is active.
MXF is a metadata-rich format supporting timecode, clip names, and broadcast metadata such as UMID (Unique Material Identifier). CAF has a limited metadata model compared to MXF, so most professional broadcast metadata — including MXF timecode tracks and production metadata — will not carry over into the CAF file. If timecode preservation is critical, consider using the MXF audio in a DAW like Logic Pro that can read MXF directly, or retain the original MXF alongside the CAF.
To use a different audio codec, replace -c:a pcm_s16le with another CAF-compatible codec such as -c:a pcm_s24le for 24-bit lossless, -c:a aac for compressed output, or -c:a flac for lossless compressed audio. For lossy codecs like AAC, you can control bitrate by adding -b:a 256k (or any supported value like 128k, 192k, 320k). For example: ffmpeg -i input.mxf -c:a aac -b:a 256k output.caf produces a compressed AAC-in-CAF file suitable for smaller file sizes while retaining good audio quality.
Yes. On macOS or Linux, you can use a shell loop to process multiple files: for f in *.mxf; do ffmpeg -i "$f" -c:a pcm_s16le "${f%.mxf}.caf"; done. On Windows (Command Prompt), use: for %f in (*.mxf) do ffmpeg -i "%f" -c:a pcm_s16le "%~nf.caf". This is especially useful when working with large MXF rushes from a broadcast shoot where dozens of clips need audio extraction for an Apple-based editing environment.
Technical Notes
MXF files from broadcast cameras and post-production systems frequently carry audio as pcm_s16le or pcm_s24le, encoded at 48kHz sample rates standard for video production. When targeting CAF with pcm_s16le, the 48kHz sample rate is preserved by default, which is important for maintaining sync if the audio will be reassembled with video later. CAF's key advantage over AIFF and WAV — the formats it was designed to replace in Apple's ecosystem — is that it removes the 4GB file size ceiling, making it practical for long-duration broadcast recordings. The -b:a flag in the command is relevant only for lossy codecs like AAC; for PCM codecs (pcm_s16le, pcm_s24le), bitrate is determined entirely by sample rate and bit depth, so the -b:a 128k default in the resolved command has no practical effect on pcm_s16le output and can be omitted. CAF is natively supported by macOS and iOS via Core Audio and AVFoundation but has limited support outside the Apple ecosystem, so this conversion is best suited specifically for Apple-platform workflows rather than cross-platform delivery.