Hi ,
Ya you need to take a look at the release notes file for the latest version. Currently its 1.3.5. In the release notes you will also see the fixes. There were two releases after 1.2.5 i.e. 1.3.0 and 1.3.5 .
Ideally, you should be on the newest version as we try to maintain backwards compatibility.
Yes there were some fixes and optimizations for audio and video in 1.3.0 and some more coming up in the next release.
From next release, we will try to put a version file right at the top folder of downloaded SDK so that it becomes even easier for you to take look. So, if you open the SDK Navigator app, it automatically detects if there is a new version and if so, asks you whether you want that.
Hope this helps
Thanks
Hironmay Basu