Free online JP2 to MKV converter

Some video editors, players, or devices accept MKV but cannot use a JP2 image as a video clip. Converting the image creates a still-image video that can be placed on a timeline or played as an MKV file.

What the JP2 format is

JP2 is the JPEG 2000 image format, used for still images with either lossy or lossless compression. You may encounter it in image archives or receive it from scanning, imaging, and JPEG 2000 conversion software, including tools based on OpenJPEG.

What the MKV format is

MKV, or Matroska, is a multimedia container that can hold video, audio, subtitles, and chapters. It can store video encoded with codecs such as H.264 or HEVC; support depends on the player and the codecs inside the file, not just the MKV extension.

Online on 101convert.com

1. Open the JP2-to-MKV converter on 101convert.com and upload the JP2 image. The page allows batch conversion and displays a per-file size limit.
2. Set show each picture for to choose how long the image is displayed.
3. Start the conversion, then download the resulting MKV file or files.

Offline with desktop software

FFmpeg is a free, open-source command-line tool available for Windows, macOS, and Linux. After installing it, run this command in the folder containing the image:

ffmpeg -loop 1 -framerate 25 -i input.jp2 -t 5 -c:v libx264 -pix_fmt yuv420p output.mkv

Replace input.jp2 with the source filename and output.mkv with the desired output name. The command makes a five-second, 25-frame-per-second H.264 video; change -t 5 to set another duration.

Quality and limitations

This is an image-to-video conversion, not a simple container change: the JP2 picture is repeated for the chosen duration and encoded as video. H.264 encoding can lose detail compared with a lossless JP2 source, and yuv420p does not preserve transparency. If the image has odd pixel dimensions, H.264 4:2:0 encoding may require padding or resizing to even dimensions.