Convert MKV to WTV — Free Online Tool
Convert MKV files to WTV format for playback and archiving in Windows Media Center. This tool re-encodes your Matroska video using H.264 and AAC — the codecs natively supported by the WTV container — while preserving subtitle tracks and multiple audio streams.
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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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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
MKV is a highly flexible container that may hold video encoded in H.264, H.265, VP9, or other codecs alongside multiple audio tracks, subtitles, and chapter markers. WTV (Windows Television) is a more constrained format designed around Windows Vista Media Center's DVR pipeline, supporting only H.264 or MJPEG video and AAC or MP3 audio. Because of this, conversion from MKV to WTV always involves active re-encoding: the video stream is encoded to H.264 using the libx264 encoder, and audio is encoded to AAC. Crucially, WTV does not support chapter markers, so any chapter data embedded in the MKV will be dropped during conversion. Subtitle tracks and multiple audio streams can be carried over into the WTV container. The result is a file that Windows Media Center and compatible WTV-aware players can recognize as a recorded broadcast.
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 machine. |
-i input.mkv
|
Specifies the input Matroska file. FFmpeg reads and demuxes the MKV container, exposing its video, audio, subtitle, and chapter streams for processing. |
-c:v libx264
|
Encodes the video stream using the libx264 H.264 encoder, which is one of only two video codecs (alongside MJPEG) that the WTV container supports. This re-encodes the video regardless of the source codec in the MKV. |
-c:a aac
|
Encodes the audio stream to AAC, one of the two audio codecs supported by WTV. AAC provides good quality at the default 128k bitrate and is the most capable audio option available in the WTV format. |
-crf 23
|
Sets the Constant Rate Factor for the H.264 video encode to 23, which is the libx264 default and a balanced quality-to-file-size setting. Lower values produce higher quality and larger WTV files; higher values reduce quality and file size. |
-b:a 128k
|
Sets the AAC audio bitrate to 128 kilobits per second, sufficient for clear stereo audio in a recorded-TV context. Increase to 192k or 256k if your source MKV contains high-fidelity or multichannel audio that you want to preserve more faithfully. |
output.wtv
|
Defines the output filename with the .wtv extension, which signals FFmpeg to use the WTV muxer. The resulting file is structured as a Windows Television recording compatible with Windows Media Center. |
Common Use Cases
- Playing back a downloaded or ripped MKV movie in Windows Vista/7 Media Center, which only natively opens WTV and DVR-MS recorded files
- Archiving a personal video collection in WTV format to integrate with a Windows Media Center library alongside actual recorded TV content
- Converting an MKV-encoded home video or screen recording so it appears in the Windows Media Center 'Recorded TV' section for easy 10-foot UI browsing
- Transcoding an MKV file that contains H.265 or VP9 video — codecs WTV cannot handle — into a WTV-compatible H.264 stream for legacy Windows DVR software
- Preparing MKV content with embedded subtitle tracks for WTV playback where subtitle support is still needed but chapter navigation is not critical
Frequently Asked Questions
Yes, some quality loss is unavoidable because WTV is a lossy-only format and the conversion always involves re-encoding. If your MKV already contains H.264 video, it will be decoded and re-encoded to H.264 again, which introduces generational loss. To minimize this, use a lower CRF value (closer to 0 means higher quality) in the FFmpeg command. The default CRF of 23 is a reasonable balance between file size and quality for most content.
WTV does support subtitle tracks, so embedded subtitle streams from the MKV can be carried into the output file. However, subtitle codec compatibility depends on how subtitles are stored in your specific MKV — text-based formats like ASS or SRT may need to be handled explicitly with additional FFmpeg flags if they are not mapped by default. Chapter markers, on the other hand, are not supported by WTV and will be silently dropped.
WTV supports only H.264 and MJPEG for video. If your MKV contains H.265, VP9, PNG, or any other codec, direct stream copy into WTV is not possible and FFmpeg must re-encode. Even if your MKV already uses H.264, the WTV container's DVR-oriented structure means FFmpeg still performs a full encode by default in this command rather than a lossless remux, ensuring full compatibility with Media Center's playback pipeline.
WTV supports multiple audio tracks, and by default FFmpeg maps the first audio stream. To explicitly include additional audio tracks from your MKV, you would need to add stream mapping flags such as '-map 0:v -map 0:a' to the command before the output filename. Each additional audio track will be re-encoded to AAC at the specified bitrate.
The '-crf 23' flag controls video quality. CRF stands for Constant Rate Factor and ranges from 0 (lossless, largest file) to 51 (lowest quality, smallest file). For noticeably better quality than the default, try '-crf 18'. For a smaller file where quality is less critical, try '-crf 28'. You can substitute any supported value: 0, 10, 18, 23, 28, 35, or 51 in the WTV output profile.
Yes. On Windows, you can run a simple loop in Command Prompt: 'for %f in (*.mkv) do ffmpeg -i "%f" -c:v libx264 -c:a aac -crf 23 -b:a 128k "%~nf.wtv"'. On Linux or macOS with bash, use: 'for f in *.mkv; do ffmpeg -i "$f" -c:v libx264 -c:a aac -crf 23 -b:a 128k "${f%.mkv}.wtv"; done'. This processes each MKV in the current directory and outputs a matching WTV file. Note that the browser-based tool on this page processes one file at a time.
Technical Notes
WTV was introduced with Windows Vista Media Center as a successor to DVR-MS, designed to store digital broadcast recordings including over-the-air ATSC and CableCARD content. Its codec support is intentionally narrow — H.264 for video and AAC or MP3 for audio — reflecting the broadcast codecs common in that era rather than the broad codec flexibility of MKV. One important limitation of this conversion is the loss of MKV chapter data: WTV has no chapter structure, so any chapter markers embedded in the source file are discarded entirely. Metadata embedding in WTV is oriented toward broadcast TV metadata fields (series title, episode info, broadcast timestamps) rather than general-purpose tags, so rich MKV metadata may not translate meaningfully. Files produced by this conversion will be recognized by Windows Media Center as recorded TV entries. Note also that WTV playback support outside of Windows Media Center is limited — most third-party players require plugins or format conversion back to a more universal container like MP4 or MKV for general use.