Tvheadend

Hi all

I notice around the various bits of TV Headend there are :

Stream :
Transport Errors
Uncorrected Blocks
Continuity errors

Susbcriptions :
Errors

DVR (Upcoming Current Recordings) :
Errors : Number of errors that occurred during recording
Data Errors : Number of errors that occurred during recording (Transport Errors)

What do they all exactly mean - and which ones suggest corrupt video and audio recordings?