Some things I have noticed; Apparently you need the mbe library even if you use a AMBE dongle... I wasn't able to get around this dependency. On the other side of the coin, apparently you also need to build serialDV even if you don't use it.
We were able to get dsdccx to work with the NW digital dongle. But not without, as we get the "Error writing to output" repeatedly if not using the ambe3000 dongle.
And lastly I don't know if its just me but RTL devices on the Pi seem temperamental, as I get PLL not locked often. Wonder if its related to no real time clock or something.
Here is a basic guide.