It looks like BTV allocates 4MBytes, starts to fill it, (use the bitrate you are recording with to calculate how long this takes) and then allocates a new 4MByte
standoff=8000000 stays 8MByte from the end and with a recording bitrate of say 8MBit it takes a bit more then 4 seconds to fill this. The retries setting to 8 caused and actual waiting of 4 seconds which seemed just too low.
Looks like I do understand now.
