I need to be able to parse these intermediate formats if I wish to convert the format to what my engine eventually uses.
Or, you can use Assimp to load the files for you. You will then get a general purpose data representation of the animation. The data will be organized into something like this:
It takes some effort to understand why a structure like this is needed. Possibly, depending on your requirements, you can simplify your layout. Some of the data can be intermediate.
Eventually, as was stated earlier in the discussion thread, you will want to use your own data format to load.