Convert MPG to CAF — Free Online Tool
Convert MPG video files to CAF (Core Audio Format), extracting the MP2 or MPEG audio track and re-encoding it as uncompressed PCM audio in Apple's extensible container. Ideal for bringing legacy broadcast or DVD audio into macOS and iOS audio workflows without file size or codec limitations.
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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
MPG files carry video (MPEG-1 or MPEG-2) alongside lossy audio encoded in MP2 or occasionally AAC. Since CAF is a pure audio container, the video stream is discarded entirely during this conversion — only the audio is processed. The audio is decoded from its compressed MP2 format and then re-encoded as 16-bit little-endian PCM (pcm_s16le), producing uncompressed audio. This means the output CAF file is lossless in the sense that no further compression is applied after decoding, though any quality lost in the original MPG's lossy MP2 encoding cannot be recovered. The CAF container, developed by Apple, supports arbitrarily large files and integrates natively with Core Audio on macOS and iOS.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg program, the open-source multimedia processing engine that handles demuxing the MPG container, decoding the MP2 audio stream, and re-encoding it into the CAF output format. |
-i input.mpg
|
Specifies the input MPG file. FFmpeg reads this MPEG-1/2 container, identifying its video (mpeg2video) and audio (mp2) streams so it can process them — in this case, extracting only the audio for conversion. |
-c:a pcm_s16le
|
Sets the audio codec for the output to signed 16-bit little-endian PCM, decoding the compressed MP2 audio from the MPG and storing it as raw uncompressed audio samples — the standard uncompressed format expected by Core Audio and compatible with all CAF-supporting Apple applications. |
-b:a 128k
|
Specifies a target audio bitrate of 128kbps; for the PCM codec selected here this value has no practical effect since PCM output bitrate is determined by sample rate and bit depth rather than a compression target, but the flag is passed for tooling consistency. |
output.caf
|
Defines the output file with the .caf extension, signaling FFmpeg to wrap the PCM audio in Apple's Core Audio Format container — an Apple-native format designed to handle large uncompressed audio files without the 4GB size ceiling of WAV or AIFF. |
Common Use Cases
- Extracting the audio commentary or dialogue track from an MPEG-2 broadcast recording for use in a Final Cut Pro or Logic Pro X project on macOS
- Converting DVD-ripped MPG files into high-fidelity CAF audio for archiving legacy spoken-word recordings or lecture content in an Apple-native format
- Pulling audio from VCD-format MPG files to edit or restore old home recordings using GarageBand or other Core Audio-compatible apps
- Preparing audio extracted from broadcast MPG segments for use in an iOS app's sound asset pipeline, where CAF is the preferred uncompressed format
- Decoupling the MP2 audio from an MPEG-2 video file received from a broadcast partner to run audio quality checks or loudness normalization workflows on macOS
- Archiving audio from MPG news or sports footage clips as uncompressed CAF before further processing, to avoid repeated lossy re-encoding cycles
Frequently Asked Questions
No — the output quality is limited by the original MP2 audio in the MPG file. The conversion decodes the lossy MP2 stream and stores it as uncompressed PCM in the CAF container, which means no additional compression artifacts are introduced. However, the quality ceiling is set by the original MP2 encoding; any detail lost there is permanently gone. Think of it as losslessly preserving whatever quality was already present.
The MPG file stores audio in compressed MP2 format, which is lossy and compact. The CAF output uses uncompressed 16-bit PCM audio (pcm_s16le), which stores every audio sample in raw form with no compression. A typical MP2 audio stream at 192kbps might be 10–20x smaller than the equivalent uncompressed PCM. Additionally, the video stream from the MPG is discarded, so you are not carrying video weight — but the audio itself expands significantly from decompression.
MPG files based on MPEG-1/2 carry very limited metadata to begin with — typically no ID3-style tags or chapter markers. The CAF format supports rich metadata including text annotations, though FFmpeg's MPG-to-CAF conversion does not automatically map or populate these fields. You would need to add metadata separately using a tool like afinfo, afconvert, or a dedicated audio editor after conversion.
CAF is primarily an Apple ecosystem format (macOS, iOS, tvOS) and is not natively supported on Windows or Android. Most Windows media players and DAWs do not recognize CAF without additional plugins. If you need cross-platform compatibility, consider targeting a format like WAV or FLAC instead. CAF is best used when your entire workflow stays within Apple platforms or Core Audio APIs.
Replace '-c:a pcm_s16le' with a compressed codec supported by CAF, such as '-c:a aac' for lossy compression or '-c:a flac' for lossless compression with a smaller footprint than PCM. For AAC you can also set '-b:a 192k' to control bitrate. For example: 'ffmpeg -i input.mpg -c:a aac -b:a 192k output.caf' will produce a significantly smaller CAF file using AAC encoding, which Core Audio handles natively.
Yes, on macOS or Linux you can wrap the command in a shell loop: 'for f in *.mpg; do ffmpeg -i "$f" -c:a pcm_s16le "${f%.mpg}.caf"; done'. On Windows Command Prompt, use 'for %f in (*.mpg) do ffmpeg -i "%f" -c:a pcm_s16le "%~nf.caf"'. This processes every MPG file in the current directory and outputs a corresponding CAF file, making it efficient for batch archiving broadcast or DVD audio collections.
Technical Notes
The MPG container supports MPEG-1 and MPEG-2 video alongside MP2 audio (the standard for broadcast and VCD/DVD) or occasionally AAC or MP3. When converting to CAF, FFmpeg automatically drops all video streams since CAF has no video codec support — no explicit '-vn' flag is required because the output container dictates audio-only output. The default codec chosen here is pcm_s16le (signed 16-bit little-endian PCM), which matches CD-quality audio representation and is universally supported within Core Audio. Note that the '-b:a 128k' flag in the command is technically a no-op for PCM codecs since PCM is an uncompressed format with a bitrate determined purely by sample rate and bit depth — it is included by the tool for consistency but has no effect on the output. If the source MPG contains a stereo MP2 stream at 48kHz, the resulting PCM output will reflect those same parameters. CAF supports large files natively (unlike WAV's 4GB limit), making it suitable for archiving long-form broadcast recordings. The format does not support subtitles, chapters, or multiple audio tracks in this conversion pipeline.