The Fraps video codec is used to store in real-time data that is captured from high frame-rate computer games played on Windows PCs.
There are at least 3 versions of the codec that are all used with the same FOURCC. v0 is a reordered YUV420, v1 is an upside-down BGR24 encoding. v2 - the most commonly found variant - is presumably a lossless encoding format. v0 and v1 can be decoded by FFmpeg while v2 is still undiscovered.