[just_for_you]

Every JPEG 2000 encoder I've seen encapsulates the JP2K data in an MOV/MP4-like format (or if one likes using many syllables, technically the ISO Base Media File Format). Even when using Motion JPEG 2000 image sequences embedded as frames in an MP4 video file, each separate JP2K frame includes the MP4-like container as you would see if the stand-alone JP2K file was sitting on-disk.

Anyway, it is indeed cool that you can encode JPEG-LS, Lossless JPEG and friends in the exact same format as you see baseline JPEG images in - but just in different application segments! (eg, baseline=SOF0/SOF1 segment, Lossless JPEG=SOF3, JPEG-LS=SOF48, etc.).