Motion vectors of P skip mode macroblocks

[serhannn]

Hi, I'm trying to extract the (derived) motion vectors of the P skip mode macroblocks using the H.264 reference software JM. Can anyone point me to the place in the decoder (ldecod) where they are actually computed?

I read the relevant parts in the standard and have a basic understanding of how these motion vectors are derived from the motion vector predictions of the neighboring macroblocks. However, I can't figure out where this calculation is done in the code of JM...