PAR errors
This is weird. If your driver does 3.75M/sec, it should handle even
the maximum block limit allowed. 3.75 yields a block limit of 256 as
you noticed. Also note that the maximum block limit is 255! There is
no reason to set it to anything higher than that as it is ignored.
Just leave it at 255. Also note that, unless you have a special
reason, you should always leave the Q Factor at its max which is 23.
The driver will automatically reduce it if a frame compresses to
something greater than the block limit (going back up with frames that
allow better compression). The Q Factor should only be changed when
doing real time recording with the TBC.