I have seen that you already had seen the RawSpeed issue, but I thought that it would be a good idea to at the request here to, so it doesn't get lost.

GoPro provides code to decode the Raw format here (MIT license):
https://github.com/gopro/cineform-sdk

More information and example images can be found here:
https://github.com/darktable-org/rawspeed/issues/40