Convert M2TS to WMV — Free Online Tool
Convert M2TS Blu-ray and AVCHD files to WMV format using the Microsoft MPEG-4 (msmpeg4) video codec and WMA v2 audio, making high-definition disc footage compatible with Windows Media Player and legacy Windows-based workflows. This tool runs entirely in your browser — no upload required — and displays the exact FFmpeg command for processing files over 1GB on your desktop.
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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
M2TS is a MPEG-2 Transport Stream container used on Blu-ray discs and AVCHD camcorders, typically carrying H.264 or VC-1 video alongside AC-3, DTS, or TrueHD audio. Converting to WMV requires full re-encoding of both streams: the video is transcoded from the source codec into Microsoft's msmpeg4 codec (a variant of MPEG-4 Part 2), and the audio is transcoded into WMA v2 (wmav2). The output is wrapped in an ASF (Advanced Systems Format) container with the .wmv extension — this is why the -f asf flag is required, as ASF is the underlying container format that WMV files use. Because both video and audio must be fully decoded and re-encoded rather than simply remuxed, this conversion is computationally intensive, especially for long Blu-ray captures at high resolutions.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool, which handles the full decode-encode pipeline for this conversion — reading the MPEG-2 Transport Stream, decoding the video and audio, re-encoding them into Microsoft formats, and writing the ASF/WMV output. |
-i input.m2ts
|
Specifies the input M2TS file — a Blu-ray BDAV or AVCHD Transport Stream container that typically carries H.264 or VC-1 video and AC-3/DTS/TrueHD audio tracks. |
-c:v msmpeg4
|
Sets the video codec to Microsoft MPEG-4 version 3 (msmpeg4), the standard video codec for WMV files compatible with Windows Media Player and ASF-based streaming infrastructure. |
-c:a wmav2
|
Sets the audio codec to Windows Media Audio version 2 (wmav2), re-encoding the source AC-3, DTS, or other M2TS audio into the native WMV audio format expected by Windows Media Player and ASF-based players. |
-b:v 2000k
|
Sets the video bitrate to 2 Mbps for the msmpeg4 output. This is a reasonable baseline for standard-definition or compressed HD output, though Blu-ray source material at 1080p may benefit from a higher value like 4000k–8000k to better preserve detail. |
-b:a 128k
|
Sets the WMA v2 audio bitrate to 128 kbps, which provides acceptable stereo audio quality for most use cases. For multi-channel audio sources common in Blu-ray M2TS files, note that the output will be down-mixed to stereo at this stage. |
-f asf
|
Explicitly forces the output container to ASF (Advanced Systems Format), the actual container format underlying all WMV files. This flag is required because FFmpeg may not correctly infer the ASF container from the .wmv extension when using the msmpeg4 codec. |
output.wmv
|
Specifies the output filename with the .wmv extension, producing a Windows Media Video file using the ASF container, msmpeg4 video, and wmav2 audio — ready for playback in Windows Media Player or legacy Windows-based applications. |
Common Use Cases
- Preparing Blu-ray rip footage or AVCHD camcorder clips for editing or playback in legacy Windows software that only accepts WMV or ASF-based media
- Delivering video content to corporate environments standardized on Windows Media Player, where WMV is the expected format for internal training or presentation videos
- Compressing large M2TS Blu-ray captures (often 20–40GB) into smaller WMV files for archival or distribution where storage is limited and Windows compatibility is required
- Converting AVCHD footage from Sony or Panasonic camcorders into a format compatible with older Windows-based video kiosk or digital signage systems
- Re-packaging M2TS broadcast recordings for use with Microsoft Expression Encoder or legacy Windows Media Services streaming infrastructure
- Creating WMV preview copies of Blu-ray source material for review or approval workflows within Windows-centric post-production pipelines
Frequently Asked Questions
Yes, some quality loss is unavoidable. M2TS files typically contain H.264 or VC-1 video at high bitrates (often 25–40 Mbps for Blu-ray), while the default WMV conversion uses msmpeg4 at 2000k (2 Mbps). The msmpeg4 codec is also technically less efficient than H.264, meaning it needs a higher bitrate to achieve comparable visual quality. For high-resolution Blu-ray content, you may want to increase the video bitrate to 4000k or 6000k using the -b:v flag to better preserve detail.
The AC-3 or DTS audio tracks from your M2TS file are fully decoded and re-encoded into WMA v2 (wmav2) at the specified bitrate (128k by default). WMV's ASF container does not support AC-3 or DTS passthrough in standard implementations, so re-encoding to wmav2 is necessary for broad compatibility. If your M2TS has multiple audio tracks, only the first (default) audio track is included in the output by default.
No. While M2TS supports PGS (Presentation Graphic Stream) subtitles common on Blu-ray discs, the WMV/ASF container format does not support subtitle tracks in any practical sense for this conversion. Subtitle data from the M2TS source will be dropped during conversion. If you need subtitles preserved, consider converting to a format like MKV or MP4 instead, both of which support subtitle embedding.
Replace the -b:v 2000k value in the command with a higher bitrate. For example, use -b:v 4000k for improved quality on 720p content, or -b:v 6000k or -b:v 8000k for 1080p Blu-ray source material. The msmpeg4 codec is less efficient than modern codecs, so higher bitrates are generally needed to faithfully represent the detail present in high-definition M2TS source files. The full command would look like: ffmpeg -i input.m2ts -c:v msmpeg4 -c:a wmav2 -b:v 4000k -b:a 128k -f asf output.wmv
Yes. On Windows, you can use a for loop in Command Prompt: for %f in (*.m2ts) do ffmpeg -i "%f" -c:v msmpeg4 -c:a wmav2 -b:v 2000k -b:a 128k -f asf "%~nf.wmv". On Linux or macOS, use: for f in *.m2ts; do ffmpeg -i "$f" -c:v msmpeg4 -c:a wmav2 -b:v 2000k -b:a 128k -f asf "${f%.m2ts}.wmv"; done. This is especially useful for converting entire AVCHD folder structures or multiple Blu-ray chapters.
WMV is not technically its own container format — it is Microsoft's Advanced Systems Format (ASF) container with video content inside. FFmpeg does not always infer the correct container from the .wmv extension alone when using the msmpeg4 codec, so the -f asf flag explicitly forces the output into the ASF container format. Without it, the output file may be malformed or unplayable in Windows Media Player and other WMV-compatible applications.
Technical Notes
The msmpeg4 codec used in this conversion is Microsoft's proprietary variant of MPEG-4 Part 2, distinct from the open standard libxvid or libx264 implementations. It is specifically designed for compatibility with Windows Media Player and the ASF container, but it is a generation behind modern codecs in compression efficiency — expect WMV output files to be noticeably larger than equivalent H.264 or H.265 encodes at the same perceived quality level. M2TS files from Blu-ray discs often contain multiple audio tracks (e.g., TrueHD, DTS-HD MA, and a compatibility AC-3 track); FFmpeg will select the first detected audio track by default, so if you need a specific track, use -map 0:a:1 (or the appropriate index) to select it explicitly. Chapter markers and Blu-ray navigation metadata present in the M2TS file are not preserved in the WMV output, as the ASF container has no equivalent structure. The -f asf flag is mandatory for correct container wrapping — omitting it can result in an ASF container mismatch that causes playback errors. For files sourced from AVCHD camcorders (which use M2TS internally), the conversion workflow is identical to Blu-ray rips, though source bitrates are typically lower (around 17–24 Mbps), making 2000k–4000k output bitrates more appropriate for preserving quality.