Where is the HEVC reference Software HM Change Log?

[xkfz007]

HM is the reference software of the latest video coding stancd HEVC. The newest version is 12.1. I get the codes and compare this with the HM11.0rc1 on several sequences. And the HM12.1 gets some improvement. And I am curious about the changes of HM12.1. However, I can't find files like change log. Does anybody know how to get differences between them. Why would not the HM provide some file to explain the improvement of different versions?

[JEEB]

You can read the commit log to see what was changed between versions. I personally use the git mirror of the repository, and it is available here (http://hevc.kw.bbc.co.uk/git/w/jctvc-hm.git/shortlog). You can see when various heads were merged into the main branch with the green markers.

[xkfz007]

Thanks, it is a great way