Tvheadend

I'm using pidvbip on a Raspberry PI 2 with tvheadend 4.0.8 also running on the same PI. I'm using a dual tuner HDHomerun device. I get constant DTS discontinuity errors, intermixed with other messages like this:

GOP: 421564 bytes (500500ms) - 6.738Mbps (avg: 6.789Mbps, min: 6.292Mbps, max:
DTS discontinuity - DTS=4942033, prev_DTS=4925355 (diff = 16678)

It seemslike the Mbps should be a lot higher then 6 (ATSC North american OTA streams). Thanks for any advice