Free online WTV to M2TS converter

Windows Media Center recordings use WTV, but Blu-ray authoring tools, AVCHD devices, and some media players expect M2TS. Converting the recording changes its container and may also require video or audio re-encoding for compatibility.

What the WTV format is

WTV, or Windows Recorded TV Show, is a Microsoft container created primarily by Windows Media Center in Windows 7 and earlier versions of Windows. It stores broadcast or cable television recordings together with video, audio, subtitles, metadata, and sometimes copy-protection information.

WTV files commonly contain MPEG-2 video with AC-3 audio for standard-definition broadcasts, or H.264 video with AC-3 or AAC audio for newer broadcasts. Recordings are usually found in the Windows Media Center recorded-TV folder and may have filenames based on the program title.

A WTV file can contain multiple audio or subtitle streams. Copy-protected broadcasts may be encrypted or restricted by DRM; software cannot produce a usable unrestricted M2TS file from such a recording.

What the M2TS format is

M2TS is a Blu-ray Disc Audio-Video and AVCHD transport-stream container. It is based on MPEG-2 Transport Stream but uses 192-byte packets, adding a 4-byte arrival-time stamp to each 188-byte transport packet.

M2TS is used by Blu-ray discs, camcorders, AVCHD equipment, Blu-ray authoring applications, and hardware players that expect BDAV or AVCHD media. It can carry MPEG-2, H.264/AVC, and other broadcast-compatible video streams, with AC-3, AAC, or other supported audio formats depending on the target device.

M2TS is a container, not a compression method. Changing a WTV extension to .m2ts does not convert the file and can make it unreadable; the streams must be remultiplexed into an M2TS-compatible transport stream.

How to convert WTV to M2TS

Using FFmpeg without re-encoding

FFmpeg can read WTV files and copy compatible streams without changing their quality. Inspect the source first with:

ffprobe -i 'recording.wtv'

If the video and audio codecs are suitable for the intended player, remux the first video and audio streams with:

ffmpeg -i 'recording.wtv' -map 0:v:0 -map 0:a:0 -c copy -f mpegts -mpegts_m2ts_mode 1 'recording.m2ts'

-c copy avoids generation loss and is usually much faster than encoding. The -mpegts_m2ts_mode 1 option enables M2TS packetization instead of producing an ordinary 188-byte MPEG-TS file.

To select a different channel or audio track, inspect the stream indexes in ffprobe and change the -map values. For example, -map 0:v:0 -map 0:a:1 selects the first video stream and second audio stream.

When re-encoding is required

Some Blu-ray or AVCHD devices reject the codecs, frame rate, resolution, or audio format contained in the WTV file. Create a more widely supported H.264/AC-3 M2TS file with:

ffmpeg -i 'recording.wtv' -map 0:v:0 -map 0:a:0 -c:v libx264 -preset medium -crf 18 -c:a ac3 -b:a 384k -f mpegts -mpegts_m2ts_mode 1 'recording.m2ts'

Lower CRF values increase H.264 quality and file size; 18 is a high-quality starting point. Re-encoding takes substantially longer and cannot restore detail already lost in the broadcast recording.

Using the online converter

You can convert the file on 101convert.com for free without installing software. Upload the WTV file, choose M2TS as the output format, start the conversion, and download the resulting file. Large recordings can take time to upload, and DRM-protected WTV files may be rejected or produce no usable output.

Quality, compatibility, and limitations

• Use stream copying whenever the target device accepts the original WTV codecs; it preserves the broadcast quality.
• Conversion does not automatically reduce file size. A copied M2TS file is approximately the size of the source, while H.264 re-encoding can make it smaller or larger depending on the selected bitrate and quality setting.
• Check the output with ffprobe or MediaInfo. Confirm that it reports an M2TS-compatible transport stream and the expected video, audio, resolution, frame rate, and duration.
• WTV metadata, Windows Media Center recording information, commercial markers, and some closed-caption data may not survive conversion.
• A file can be technically valid M2TS but still fail on a particular player if its resolution, frame rate, level, audio codec, or bitrate exceeds that device's supported Blu-ray or AVCHD profile.