Convert MTS to MXF — Free Online Tool
Convert AVCHD camcorder footage (.mts) to MXF, the broadcast-standard container used in professional post-production workflows. This tool re-encodes the H.264 video stream with configurable CRF quality and transcodes the AC-3/AAC audio to uncompressed PCM, making your camcorder clips ready for ingestion into Avid, Adobe Premiere, or broadcast playout systems.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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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
MTS files from Sony and Panasonic camcorders wrap H.264 video and AC-3 or AAC audio inside an MPEG-2 Transport Stream container — a format optimized for reliable streaming and recording, not professional editing. During this conversion, the H.264 video stream is re-encoded using libx264 with a CRF 23 quality setting, producing a new H.264 stream wrapped in the MXF OP1a container. The audio undergoes full transcoding from the compressed AC-3 or AAC track in the source MTS file to 16-bit PCM (pcm_s16le) — uncompressed linear audio — which is the standard audio format expected by broadcast systems and professional NLEs. The resulting MXF file carries proper timecode support and the metadata structure required by broadcast ingest pipelines, at the cost of a larger file size due to the uncompressed audio.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary. In this browser-based tool, FFmpeg runs via WebAssembly (FFmpeg.wasm) entirely within your browser — no file is sent to a server. When running locally on your desktop, this calls your installed FFmpeg binary directly. |
-i input.mts
|
Specifies the input AVCHD file in MPEG-2 Transport Stream format (.mts), as recorded by Sony or Panasonic camcorders. FFmpeg will detect the H.264 video and AC-3 or AAC audio streams inside the transport stream container. |
-c:v libx264
|
Re-encodes the video stream using the libx264 encoder, producing H.264 output wrapped in the MXF container. A full re-encode is necessary because the video cannot be stream-copied from an MPEG-2 Transport Stream into MXF without repackaging. |
-c:a pcm_s16le
|
Transcodes the compressed AC-3 or AAC audio from the MTS source into 16-bit signed little-endian PCM — fully uncompressed linear audio. This is the standard audio format for broadcast MXF files and is required for compatibility with professional playout servers and NLEs like Avid Media Composer. |
-crf 23
|
Sets the Constant Rate Factor for the libx264 video encode to 23, which is the default quality level offering a good balance between file size and visual fidelity for AVCHD camcorder footage. Lower values (e.g., 18) produce higher quality at larger file sizes; higher values (e.g., 28) reduce file size with more visible compression. |
-b:a 192k
|
This flag targets audio bitrate and is included for consistency, but has no functional effect on PCM audio — pcm_s16le bitrate is fixed by sample rate and bit depth (stereo 48kHz PCM is always approximately 1,536 kbps regardless of this value). It can be safely omitted when running this command locally. |
output.mxf
|
Specifies the output filename with the .mxf extension, which causes FFmpeg to use the MXF muxer and write the re-encoded H.264 video and PCM audio into an MXF OP1a container suitable for broadcast ingest and professional post-production workflows. |
Common Use Cases
- Preparing AVCHD footage shot on a Sony or Panasonic camcorder for ingest into a broadcast station's playout or archive system that requires MXF-wrapped files
- Delivering camera-original MTS clips to a post-production house or colorist whose Avid Media Composer or Da Vinci Resolve workflow expects MXF OP1a with PCM audio
- Converting event or documentary footage from a prosumer camcorder into an MXF format compatible with newsroom systems such as ENPS or iNEWS that require broadcast-compliant media
- Archiving AVCHD camcorder recordings in MXF for long-term institutional preservation, where the professional container and uncompressed audio tracks offer greater longevity than transport stream packaging
- Wrapping MTS clips in MXF to meet deliverable specifications for a broadcaster or streaming platform that mandates MXF containers with PCM audio tracks
- Re-packaging multi-audio-track AVCHD recordings into MXF to preserve separate language or isolated audio tracks in a format that supports structured multi-track audio in professional environments
Frequently Asked Questions
Yes, because the H.264 video stream is re-encoded rather than copied. The default CRF 23 setting produces visually good results for most camcorder footage, but any re-encode from a lossy source introduces some generation loss. If you need to minimize quality loss, lower the CRF value (e.g., CRF 18) to produce a higher-bitrate output closer to the original quality, at the cost of a larger file.
MXF in broadcast contexts overwhelmingly expects uncompressed PCM audio (either 16-bit or 24-bit) because it guarantees frame-accurate sync, simplifies mixing, and is required by most broadcast ingest standards. The AC-3 or AAC audio in your MTS file is fully transcoded to pcm_s16le (16-bit little-endian PCM) during conversion. This makes the resulting MXF immediately compatible with Avid, broadcast playout servers, and most professional NLEs without requiring additional audio rewrapping.
Almost certainly yes, primarily because of the audio transcoding. AC-3 audio in AVCHD footage is highly compressed (often 192–448 kbps), while the output pcm_s16le audio is uncompressed — for stereo 48kHz audio, that's roughly 1.5 MB per second. For a 10-minute clip, the audio alone in the MXF could be several hundred megabytes larger. The video size depends on the CRF setting chosen, but at CRF 23 it will be similar to or somewhat larger than the original H.264 source.
MXF natively supports timecode as part of its metadata structure, which is one of its core advantages over the MPEG-2 Transport Stream container used by MTS files. However, whether the source timecode from the camcorder is preserved depends on whether it is embedded in the MTS stream in a way FFmpeg can read and write through. In many cases you may need to set timecode manually using the -timecode flag in FFmpeg if broadcast-accurate timecode continuity is critical for your workflow.
Yes. On Linux or macOS, you can use a shell loop: for f in *.mts; do ffmpeg -i "$f" -c:v libx264 -c:a pcm_s16le -crf 23 -b:a 192k "${f%.mts}.mxf"; done. On Windows Command Prompt, use: for %f in (*.mts) do ffmpeg -i "%f" -c:v libx264 -c:a pcm_s16le -crf 23 -b:a 192k "%~nf.mxf". This is especially useful for converting an entire shoot day's worth of AVCHD clips for broadcast ingest.
For 16-bit PCM the -b:a flag does not apply in the same way as with lossy codecs — PCM bitrate is determined by sample rate and bit depth. To switch to 24-bit PCM for higher-end broadcast or archival use, replace -c:a pcm_s16le with -c:a pcm_s24le in the command: ffmpeg -i input.mts -c:v libx264 -c:a pcm_s24le -crf 23 output.mxf. This is common in audio-critical deliverables and is supported by MXF OP1a.
Technical Notes
AVCHD's MPEG-2 Transport Stream container was designed for robust recording on flash media and optical disc — it uses fixed-size 188-byte packets and includes error correction structures that are unnecessary and sometimes problematic in post-production environments. MXF OP1a, by contrast, is a self-describing essence container with rich metadata support including timecode tracks, descriptive metadata sets, and structured audio/video interleaving optimized for editing and playout. The video codec (H.264/libx264) remains the same between source and output, but re-encoding is required because the stream must be repackaged into MXF's essence container structure rather than simple stream copying. Note that MXF does not support subtitle tracks, so any subtitle or closed-caption data present in the MTS source will be dropped. Multi-audio tracks from AVCHD recordings are supported and will be preserved in the MXF output. The -b:a flag in this command has no effect on PCM audio since PCM bitrate is fixed by sample rate and bit depth; it is included for tool consistency but can safely be omitted when running locally. For files intended for Avid Media Composer, you may want to investigate Avid's DNxHD/DNxHR codecs as the video codec instead of libx264, as Avid natively manages those essence types.