Convert MTS to WMV — Free Online Tool
Convert MTS camcorder footage (AVCHD with H.264 video and AC-3/AAC audio) to WMV format using Microsoft's MPEG-4 video codec and WMA audio — making your Sony or Panasonic camcorder recordings compatible with Windows Media Player and legacy Windows-based workflows. The conversion fully re-encodes both the video and audio streams since MTS and WMV share no common codecs.
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FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your MTS 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
MTS files use the MPEG-2 Transport Stream container carrying H.264 (AVC) video and either AC-3 or AAC audio — the standard AVCHD format recorded by Sony and Panasonic camcorders. WMV uses Microsoft's Advanced Systems Format (ASF) container, which requires Microsoft MPEG-4 video (msmpeg4) and Windows Media Audio (wmav2). Because there is no codec overlap between these two formats, this conversion performs a full transcode: the H.264 video stream is decoded and re-encoded as MPEG-4 v3 (msmpeg4), and the audio is decoded and re-encoded as WMA v2 (wmav2). The output is wrapped in the ASF container using the -f asf flag, which produces the .wmv file. This re-encoding process is computationally intensive compared to a remux, and introduces a second generation of lossy compression.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool. In this browser-based tool, FFmpeg runs locally via WebAssembly (FFmpeg.wasm) — no data leaves your device. The same command can be run on your desktop with a standard FFmpeg installation for files over 1GB. |
-i input.mts
|
Specifies the input file — your AVCHD camcorder recording in MTS format, which carries H.264 video and AC-3 or AAC audio inside an MPEG-2 Transport Stream container. |
-c:v msmpeg4
|
Re-encodes the video stream using Microsoft MPEG-4 Version 3 (msmpeg4), the native video codec for WMV files. This completely decodes the original H.264 stream from the MTS file and re-encodes it as MPEG-4 v3. |
-c:a wmav2
|
Re-encodes the audio stream to Windows Media Audio version 2 (wmav2), the standard audio codec for WMV/ASF files. This replaces the AC-3 or AAC audio from the MTS source, as neither is natively supported by the ASF container in most Windows Media workflows. |
-b:v 2000k
|
Sets the target video bitrate to 2000 kilobits per second for the msmpeg4 output. Unlike the H.264 CRF system used in MTS encoding, msmpeg4 uses bitrate-based quality control — 2000k is a reasonable default for standard definition but may need to be raised to 4000k–6000k for HD AVCHD footage. |
-b:a 128k
|
Sets the audio bitrate to 128 kilobits per second for the wmav2 stream. This is a standard quality level for stereo audio and is well-suited to voice and general camcorder audio; raise to 192k if the source MTS file contains high-quality stereo or surround sound music. |
-f asf
|
Explicitly forces FFmpeg to use the ASF (Advanced Systems Format) muxer, which is the container format underlying all WMV files. This flag is required because FFmpeg needs explicit instruction to use the ASF muxer when outputting to a .wmv file with the msmpeg4 and wmav2 codecs. |
output.wmv
|
Defines the output filename with the .wmv extension, producing a Windows Media Video file ready for playback in Windows Media Player or any application that supports the ASF/WMV format. |
Common Use Cases
- Submitting camcorder footage to a Windows-based corporate video editing or archiving system that only accepts WMV files
- Sharing holiday or event recordings captured on a Sony or Panasonic AVCHD camcorder with family members who use Windows Media Player on older Windows PCs
- Uploading camcorder footage to a legacy intranet or content management system that was built around Microsoft's Windows Media streaming infrastructure
- Preparing camcorder clips for use in older versions of Windows Movie Maker or PowerPoint, which have strong native support for WMV but may struggle with raw MTS files
- Converting AVCHD footage for playback on a Windows-based digital signage player or kiosk that only supports ASF/WMV streams
- Archiving MTS recordings in WMV format to comply with an organization's legacy media standards before a storage migration
Frequently Asked Questions
No — this conversion involves a full re-encode from H.264 (the codec inside your MTS file) to Microsoft MPEG-4 v3 (msmpeg4), which is a significantly older and less efficient codec. At the default bitrate of 2000k, most HD camcorder footage will look noticeably softer than the original. AVCHD footage is typically recorded at 17–28 Mbps, so outputting at 2000k (2 Mbps) represents a substantial bitrate reduction. For best results with HD footage, increase the video bitrate to 4000k or 6000k in the command.
No — the ASF/WMV container does not support AC-3 audio. This tool automatically re-encodes the audio to Windows Media Audio v2 (wmav2), regardless of whether your MTS file contains AC-3 or AAC audio. The wmav2 codec is broadly compatible with Windows Media Player and other Windows applications, though it is not supported on most non-Windows platforms.
The conversion will pass the interlaced frames through to the WMV output by default, so the output should retain the interlaced structure. However, msmpeg4 has limited interlacing support compared to H.264, which can introduce minor artifacts on fast motion in interlaced content. If you notice combing artifacts in the output, consider adding a deinterlace filter to the FFmpeg command, such as -vf yadif, before the output filename.
Yes — the -b:v flag controls video bitrate. Replace 2000k with a higher value such as 4000k or 6000k for noticeably better quality, particularly with 1080p or 1080i AVCHD source footage. For example: ffmpeg -i input.mts -c:v msmpeg4 -c:a wmav2 -b:v 4000k -b:a 128k -f asf output.wmv. Keep in mind that unlike H.264's CRF-based quality control, msmpeg4 uses constant bitrate targeting, so setting a higher bitrate directly increases both quality and file size.
No on both counts. WMV (ASF container) does not support chapter markers or subtitle tracks, so any metadata of that kind present in the source MTS file will be dropped during conversion. If you need subtitles, you would need to burn them into the video using FFmpeg's subtitles filter before encoding, as there is no way to carry them as a separate stream inside a WMV file.
Yes — on Windows you can use a simple loop in Command Prompt: for %f in (*.mts) do ffmpeg -i "%f" -c:v msmpeg4 -c:a wmav2 -b:v 2000k -b:a 128k -f asf "%~nf.wmv". On macOS or Linux, use: for f in *.mts; do ffmpeg -i "$f" -c:v msmpeg4 -c:a wmav2 -b:v 2000k -b:a 128k -f asf "${f%.mts}.wmv"; done. This is especially useful for converting a full SD card of AVCHD recordings in one pass.
Technical Notes
The msmpeg4 codec used for WMV output is Microsoft's MPEG-4 Version 3 implementation, sometimes called MS-MPEG4v3 or DivX-ancestor codec. It predates the modern ISO MPEG-4 Part 2 and H.264 standards and is considerably less efficient — meaning you need a significantly higher bitrate to achieve comparable visual quality to the original H.264 content in your MTS file. The ASF container requires the special -f asf flag in FFmpeg because the .wmv extension alone does not reliably trigger the correct muxer. Audio is re-encoded to wmav2, a proprietary Microsoft codec that sounds acceptable at 128k but is not as efficient as AAC or Opus at low bitrates. Metadata such as recording date and GPS coordinates stored in the AVCHD/MTS wrapper may not be preserved in the ASF container, as FFmpeg's ASF muxer supports only a limited set of metadata tags. Multiple audio tracks are technically supported by ASF, but most WMV players including Windows Media Player only expose the first audio track. If your MTS file contains 5.1 surround AC-3 audio, the wmav2 output will be stereo by default unless you explicitly specify channel layout flags.