Full Changelog: https://github.com/uclouvain/openjpeg/compare/v2.1.1...v2.1.2
Note that meanwhile, in the master branch, an important improvement has been merged, namely T1 optimizations and multithreading support (contribution from Even Rouault … Thanks a lot !). A (much) faster OpenJPEG is on track … Stay tuned for v2.2.0.