Convert MOD to CAVS — Free Online Tool
Convert MOD camcorder footage from JVC or Panasonic devices into CAVS format, re-encoding the MPEG-2 video stream to H.264 (libx264) and wrapping it in China's national broadcast-oriented container. This is useful for preparing camcorder recordings for distribution or archiving within CAVS-compatible workflows.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your MOD file here
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Settings
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 store MPEG-2 video inside a modified MPEG-PS container — the format written directly to SD cards or internal storage by JVC and Panasonic camcorders. Converting to CAVS requires a full re-encode of the video stream, since MPEG-2 is not valid inside a CAVS container. This tool uses libx264 to transcode the video to H.264, which CAVS supports as its video codec, and re-encodes the audio to AAC at 128k. The result is a .cavs file compliant with China's Audio Video Standard, with significantly smaller file size than the original MPEG-2 source due to H.264's superior compression efficiency.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool. In the browser, this runs via FFmpeg.wasm compiled to WebAssembly — the same command works identically on a desktop FFmpeg installation for files over 1GB or batch processing. |
-i input.mod
|
Specifies the input MOD file — the MPEG-PS-based camcorder recording from a JVC or Panasonic device. FFmpeg automatically detects the MPEG-2 video and AC-3 or MPEG audio streams inside. |
-c:v libx264
|
Transcodes the video stream using the libx264 encoder, converting the source MPEG-2 video to H.264. This re-encode is required because MPEG-2 is not a valid video codec inside the CAVS container. |
-c:a aac
|
Re-encodes the audio stream to AAC using FFmpeg's built-in AAC encoder, converting whatever audio format the MOD file contains (typically AC-3 or MPEG Layer II) to AAC, which is the standard audio codec for CAVS output. |
-crf 23
|
Sets the Constant Rate Factor for libx264 to 23, the default balance point between quality and file size. For MOD footage from standard-definition camcorders, this typically produces output that matches or exceeds the original MPEG-2 quality at a much lower bitrate. |
-b:a 128k
|
Targets an audio bitrate of 128 kilobits per second for the AAC output stream. This is sufficient for stereo camcorder audio and matches the typical quality of the source audio in MOD recordings. |
output.cavs
|
The output filename with the .cavs extension, which signals FFmpeg to write the result in the Chinese Audio Video Standard container format wrapping the H.264 video and AAC audio streams. |
Common Use Cases
- Preparing JVC or Panasonic camcorder footage for submission to Chinese broadcast or media platforms that require CAVS-compliant files.
- Archiving legacy MOD camcorder recordings in a more compressed format — H.264 inside CAVS offers far better file size reduction compared to the original MPEG-2 stream.
- Converting MOD footage recorded at events or ceremonies for distribution through Chinese state or regional media workflows that mandate CAVS as a delivery format.
- Transcoding MOD files from older camcorders for use in Chinese-market post-production pipelines where CAVS is the expected interchange format.
- Reducing storage requirements for large collections of MOD camcorder clips while maintaining broadcast-acceptable quality through CRF-controlled H.264 encoding.
Frequently Asked Questions
Yes, this is a lossy-to-lossy transcode — the original MPEG-2 video is decoded and re-encoded to H.264. However, H.264 at CRF 23 typically matches or exceeds the visual quality of the MPEG-2 source at a much lower bitrate. The original MOD footage was already lossy, so generational quality loss exists but is minimal at default settings.
The CAVS container format as supported by FFmpeg uses libx264 (H.264) for video encoding rather than the AVS1/AVS2 native codecs, which have limited open-source encoder support. This means the resulting .cavs file is container-compliant but uses H.264 as its video codec, which is widely decodable even outside dedicated CAVS players.
JVC Everio camcorders typically record Dolby AC-3 (stereo or 5.1) audio inside the MOD container. During this conversion, the AC-3 audio is decoded and re-encoded to AAC at 128k stereo. If the source has 5.1 surround audio, it will be downmixed to stereo — the CAVS output here does not support multiple audio tracks.
Change the -crf value in the command. CRF (Constant Rate Factor) for libx264 ranges from 0 (lossless) to 51 (worst quality), with 23 as the default. For higher quality output closer to the original MPEG-2, try -crf 18. For smaller file sizes where some quality loss is acceptable, try -crf 28. Lower numbers mean better quality and larger files.
Yes. On Linux or macOS, you can loop over all MOD files in a directory with: for f in *.mod; do ffmpeg -i "$f" -c:v libx264 -c:a aac -crf 23 -b:a 128k "${f%.mod}.cavs"; done. On Windows Command Prompt, use: for %f in (*.mod) do ffmpeg -i "%f" -c:v libx264 -c:a aac -crf 23 -b:a 128k "%~nf.cavs". The browser-based tool processes one file at a time.
MOD files can embed metadata such as recording timestamps in the MPEG-PS container headers. The CAVS container has limited metadata support, and FFmpeg does not guarantee transfer of all MOD-specific or camcorder-specific metadata fields during this transcode. Standard fields like duration will be present, but proprietary JVC or Panasonic metadata tags are likely lost.
Technical Notes
MOD is essentially MPEG-2 Program Stream with a renamed extension — the video bitrate in typical JVC/Panasonic camcorders ranges from around 4 Mbps to 8 Mbps for standard definition, sometimes higher for HD variants. Converting to CAVS with libx264 at CRF 23 will produce significantly smaller files (often 50–70% size reduction) while maintaining comparable perceptual quality. The CAVS format (.cavs) as handled by FFmpeg wraps H.264 video and AAC audio; it does not support subtitles, chapter markers, or multiple audio tracks. If your MOD source contains multiple audio streams (e.g., a reference audio track common in some JVC models), only the default stream will be encoded. The .cavs container is not widely supported by consumer media players outside of China-specific software, so this conversion is best suited for professional CAVS delivery workflows rather than general playback use.