Free online MK3D to TRP converter

Devices such as older HDTV receivers, DVRs, and media players may accept TRP transport-stream files but not Matroska-based MK3D files. Converting requires either remuxing compatible streams or transcoding them into the codecs and stream structure expected by the target device.

What the MK3D format is

MK3D is a Matroska container variant intended for stereoscopic 3D video. It can hold separate left- and right-eye video, stereoscopic metadata, multiple audio tracks, subtitles, chapters, and ordinary Matroska attachments. The video and audio codecs depend on the source; H.264, HEVC, AC-3, DTS, and AAC are common possibilities.

MK3D files are created by stereoscopic video authoring or muxing software, including MKVToolNix when a Matroska file is configured with 3D track metadata. You may encounter them after ripping or storing 3D Blu-ray content, exporting 3D footage, or downloading stereoscopic video. VLC and other Matroska-compatible players can usually open them, although playback depends on the codec and 3D arrangement.

What the TRP format is

TRP is commonly an MPEG-2 transport stream file used by HDTV receivers, set-top boxes, DVRs, and some older media players. It carries packetized video, audio, and service data in a stream format designed for broadcasting and recording rather than general-purpose file storage.

TRP can contain MPEG-2 or H.264 video and audio such as AC-3, MPEG audio, or AAC, depending on the device. Its transport-stream structure supports multiplexed streams and tolerates transmission errors better than many simple container formats. The .trp extension alone does not specify the codecs, bitrate, resolution, or 3D behavior that a particular device requires.

How to actually convert MK3D to TRP

Using FFmpeg on a computer

FFmpeg provides the most control over stream selection, codecs, and transport-stream settings. First inspect the source:

ffprobe -hide_banner input.mk3d

If the video and audio codecs are supported by the target device, try a stream copy so the content is not re-encoded:

ffmpeg -i input.mk3d -map 0:v:0 -map 0:a:0? -c copy -f mpegts output.trp

The -f mpegts option selects the transport-stream muxer; changing the filename extension without selecting a muxer is less reliable. This command copies the first video stream and, if present, the first audio stream. Subtitles, attachments, and Matroska chapters are omitted because typical TRP receivers do not support them.

If the device rejects the result, transcode to widely supported codecs:

ffmpeg -i input.mk3d -map 0:v:0 -map 0:a:0? -c:v libx264 -preset medium -crf 18 -pix_fmt yuv420p -c:a ac3 -b:a 384k -f mpegts output.trp

Replace -crf 18 with a higher value such as 22 to reduce size at the cost of quality. Use the device manual to select its required resolution, frame rate, audio format, maximum bitrate, and file-size limit.

Using the online converter

You can convert the file for free on 101convert.com without installing software: upload the MK3D file, choose TRP as the output format, start the conversion, and download the resulting file. Online conversion may transcode the video and may not retain stereoscopic metadata, so verify the output on the intended player.

Quality, compatibility, and limitations

A stream copy preserves the encoded video but does not guarantee compatibility: an MK3D file may contain HEVC, DTS, MVC, subtitles, or other streams that a TRP device cannot decode. Transcoding to H.264 with AC-3 is commonly accepted, but the device may still require a particular profile, level, frame rate, or transport-stream packet structure.

MK3D's 3D information is a major limitation. MPEG transport streams do not provide one universal equivalent for all Matroska stereoscopic metadata. Side-by-side or top-and-bottom 3D encoded directly into the video image usually survives transcoding, but separate-eye tracks, MVC video, frame-packing information, and Matroska 3D flags may be discarded. Check the result with ffprobe and test it on the target hardware before deleting the original.