Free online RMVB to M2TS converter

A Blu-ray authoring application, AVCHD player, or editing system may require an MPEG-2 transport stream instead of an RMVB file. Converting it creates an M2TS container, but it cannot restore quality already lost through RMVB compression.

What the RMVB format is

RMVB is RealMedia Variable Bitrate, a container developed by RealNetworks for video encoded with RealVideo and audio commonly encoded with RealAudio. Variable bitrate allocation reduces file size by assigning fewer bits to simple scenes and more to complex scenes.

RealNetworks encoding software such as RealProducer created RMVB files, which were common in older internet downloads, video archives, and collections intended for RealPlayer. Modern operating systems, editors, televisions, and hardware players often provide limited or no native RMVB support.

What the M2TS format is

M2TS is a Blu-ray and AVCHD variant of the MPEG-2 transport stream container. It stores timestamped video, audio, subtitles, and other streams in fixed-size transport packets, commonly using H.264/AVC video with AC-3 or AAC audio.

M2TS is suitable for Blu-ray authoring, AVCHD camcorder workflows, transport-stream playback, and devices that specifically require Blu-ray-compatible media. The extension identifies the container, not a single codec: an M2TS file can still be rejected if its video, audio, resolution, frame rate, or profile is unsupported.

How to convert RMVB to M2TS

Using FFmpeg

FFmpeg is the most controllable desktop option. Install a build with RealMedia and RealVideo decoding, open a terminal in the folder containing the source file, and inspect the streams first:

ffprobe "input.rmvb"

For a broadly compatible H.264 and AC-3 M2TS file, run:

ffmpeg -i "input.rmvb" -map 0:v:0 -map 0:a:0? -c:v libx264 -preset medium -crf 20 -pix_fmt yuv420p -c:a ac3 -b:a 384k -ar 48000 -f mpegts -mpegts_m2ts_mode 1 "output.m2ts"

-crf 20 controls H.264 quality; lower values produce larger files and less additional loss. The command selects the first video and optional first audio stream, converts the video because RealVideo is unsuitable for most M2TS targets, converts audio to AC-3 at 48 kHz, and enables M2TS packet mode. Remove the optional audio mapping only if the source is known to contain no audio.

On Windows, place the command in PowerShell or Command Prompt after installing FFmpeg. On macOS or Linux, run it in Terminal. Use an output filename in a different directory if you want to preserve the source.

Using the online converter

You can convert the file for free on 101convert.com without installing software: upload the RMVB file, select M2TS as the output format, start the conversion, and download the result. For a device with strict playback requirements, use a desktop conversion instead so you can specify H.264, AC-3, resolution, frame rate, and bitrate.

Quality, compatibility, and limitations

Re-encoding RMVB to H.264 is normally unavoidable because stream-copying the original RealVideo into an M2TS container does not make it Blu-ray-compatible. Avoid repeated conversions; set the output resolution and frame rate to match the source unless the destination requires a specific standard.

A file with an .m2ts extension is not necessarily a complete Blu-ray disc. Blu-ray authoring may also require playlists, clip information, menus, and a prescribed directory structure. Test the converted file with the intended player, because some devices accept only particular H.264 profiles, level limits, audio codecs, or transport-stream metadata.