SessionFilterFunc

This function will be called by the filter.

An implementation should return a value of FilterResult.

When this function returns REMOVE, media will be removed from sess.

A return value of KEEP will leave media untouched in sess.

A value of GST_RTSP_FILTER_REF will add media to the result List of filter.

Parameters:

sess	a Session object
media	a SessionMedia in sess
user_data	user data that has been given to filter

Returns:

a FilterResult.