Convert M2TS to WTV — Free Online Tool
Convert M2TS Blu-ray and AVCHD recordings to WTV format for playback and organization in Windows Media Center. This tool re-encodes the video stream using H.264 (libx264) and wraps it in Microsoft's broadcast-oriented WTV container, making high-definition disc footage compatible with Windows DVR workflows.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your M2TS 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
M2TS files use an MPEG-2 Transport Stream container designed for Blu-ray and AVCHD, typically carrying H.264 or MPEG-2 video alongside multi-channel audio codecs like Dolby TrueHD, DTS-HD MA, or AC-3 — none of which are natively supported by the WTV container. Because WTV limits video to libx264 or MJPEG and audio to AAC or MP3, a full re-encode is required rather than a simple remux. FFmpeg decodes the M2TS video stream and re-encodes it to H.264 using libx264 at CRF 23, then transcodes the audio to AAC at 128k bitrate. The resulting WTV file embeds broadcast-style metadata and is structured for compatibility with Windows Media Center's DVR library, though subtitle tracks from the M2TS can be carried over since both containers support them.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary, which is running here as FFmpeg.wasm compiled to WebAssembly and executing entirely inside your browser — no data leaves your machine. |
-i input.m2ts
|
Specifies the input M2TS file — a Blu-ray or AVCHD MPEG-2 Transport Stream container that may carry H.264 or MPEG-2 video alongside high-bitrate audio like Dolby TrueHD or DTS-HD MA. |
-c:v libx264
|
Re-encodes the video stream using the H.264 encoder (libx264), which is one of only two video codecs supported by the WTV container. This is a full transcode, not a stream copy, even if the source M2TS also contains H.264. |
-c:a aac
|
Transcodes the audio to AAC, replacing whatever audio codec the M2TS source uses (often Dolby TrueHD, DTS-HD MA, or AC-3) with the AAC format required by the WTV container — a lossy conversion that reduces audio fidelity. |
-crf 23
|
Sets the Constant Rate Factor for the libx264 encode at 23, a balanced default for HD content. Lower values (e.g., 18) increase quality and file size; higher values (e.g., 28) reduce both, which matters when compressing high-bitrate Blu-ray source material. |
-b:a 128k
|
Sets the AAC audio bitrate to 128 kilobits per second — sufficient for stereo dialogue and music but a significant step down from the lossless or high-bitrate audio tracks commonly found in M2TS Blu-ray files. |
output.wtv
|
Defines the output filename with the .wtv extension, instructing FFmpeg to write a Windows Television container file structured for compatibility with Windows Media Center's DVR library. |
Common Use Cases
- Importing Blu-ray disc rips or AVCHD camcorder footage into a Windows Vista or Windows 7 Media Center library for organized DVR-style playback
- Archiving recorded AVCHD wedding or event videos in WTV format so they can be catalogued and played back alongside Windows Media Center TV recordings
- Converting M2TS footage captured from a Blu-ray-capable camcorder into a format that legacy Windows Home Server or Windows Media Center extenders can stream
- Preparing high-definition M2TS source material for editing workflows that rely on Windows-native DVR tools which only accept WTV or DVR-MS input
- Consolidating a mixed library of Blu-ray rips and recorded broadcast TV into a unified WTV archive for consistent metadata handling in Windows Media Center
Frequently Asked Questions
No — WTV only supports AAC and MP3 audio, so lossless or object-based audio codecs like Dolby TrueHD and DTS-HD MA cannot be carried into the WTV container. FFmpeg will transcode the primary audio track to AAC at 128k by default, which is a lossy process. If your M2TS contains multiple audio tracks, only the default track is included unless you explicitly map additional tracks in the command.
Re-encoding is required in almost all cases. While both M2TS and WTV can carry H.264 video, WTV's codec support is limited to libx264 and MJPEG, and M2TS files from Blu-ray often use profiles or levels that WTV players cannot handle directly. Additionally, the container structure differs significantly enough that FFmpeg cannot simply remux without re-encoding. This means conversion takes longer and involves some generation loss compared to a copy.
Both M2TS and WTV support subtitles, so FFmpeg can map subtitle streams into the output WTV file. However, M2TS Blu-ray subtitles are often stored as PGS (Presentation Graphic Stream) bitmap subtitles, and WTV's subtitle support is oriented toward DVB or ATSC text-based streams. Compatibility depends on the subtitle type; you may need to test playback in Windows Media Center to confirm subtitle rendering works correctly.
The CRF value controls quality — lower numbers produce higher quality at larger file sizes. The default is -crf 23, which is a balanced midpoint for H.264. For a noticeably higher-quality output suitable for HD Blu-ray source material, try -crf 18; for a smaller file where some quality loss is acceptable, try -crf 28. Replace the 23 in the command with your chosen value: ffmpeg -i input.m2ts -c:v libx264 -c:a aac -crf 18 -b:a 128k output.wtv.
Yes — on Windows you can use a simple batch script to loop over all M2TS files in a folder. For example, in a Command Prompt: 'for %f in (*.m2ts) do ffmpeg -i "%f" -c:v libx264 -c:a aac -crf 23 -b:a 128k "%~nf.wtv"'. This processes each M2TS file individually and outputs a matching WTV file. Batch processing is especially practical for this conversion since WTV is a Windows-centric format and your desktop environment is already set up for it.
The output size depends heavily on the source. M2TS files from Blu-ray often use high-bitrate H.264 or MPEG-2 video at 20–40 Mbps, while re-encoding to libx264 at CRF 23 typically targets 4–10 Mbps for 1080p content. This means WTV output files are frequently significantly smaller than the source M2TS. However, because the audio is also transcoded from lossless formats like TrueHD to AAC 128k, there is a quality tradeoff on both streams.
Technical Notes
WTV is a proprietary Microsoft container introduced with Windows Vista Media Center, and its codec support is deliberately narrow — libx264 for video and AAC or MP3 for audio — reflecting its origins as a broadcast DVR format rather than a general-purpose multimedia container. When converting from M2TS, which is designed to carry the full fidelity of Blu-ray authoring including lossless audio, multi-angle streams, and PGS bitmap subtitles, the WTV output is necessarily a lossy reduction of the source. The libx264 encoder at CRF 23 produces visually acceptable quality for HD content but is not lossless; source material with high spatial complexity like film grain may benefit from a lower CRF value. WTV supports multiple audio tracks and subtitle streams in principle, but Windows Media Center's actual playback rendering is less flexible than VLC or other general players, so embedded subtitle and secondary audio track compatibility should be verified. The WTV container also embeds broadcast-style metadata fields (channel, recording time, program info) that FFmpeg will populate with generic or empty values during conversion from M2TS, since the source has no broadcast metadata. Chapters are not supported in either format for this conversion path.