JPEG 2000 not working

[Hanysix]

I want to compres around 30 images to JPEG 2000 using a command line script, because I want to change several things in a loop.

I've downloaded NConvert from the website https://www.xnview.com/en/nconvert/.

First thing according to Formats.txt file, it is possible to compress JPEG 2000 files with a plugin, but according to -help jpeg 2000 is not supported.

I've followed the instructions in Plugins.txt file, downloaded JP2 plugin, created a folder "Plugins" in the same folder as Nconvert is, the path looks like this:
.\XnView <- Extracting the downloaded .zip file created this folder
.\XnView\Plugins <- I made this folder where I put JPEG 2000 plugins

I tried a simple command to compress jpeg file into jp2:
.\nconvert.exe -out jp2 -o cmp.jp2 cmp.jpg

This resulted in an error: Bad output format: jp2.

I also tried placing the plugins directly in Nconvert folder with the same result as above.
Please note that I have not found any information about requiring XnView to use Nconvert for JPEG 2000 compression.

[xnview]

Is it the x64bits version of NConvert?

[Hanysix]

Yes, it is.

[xnview]

Yes, it is.

so you need the openjp2.dll from XnView MP 64bits

[Hanysix]

Thank you for your help, it works now.

I've installed 64bit XnView MP and copy-pasted the openjp2.dll from XnView MP Plugins folder to Nconvert Plugins folder.