# from recording.c vdr 1.7.18
#  uint64_t offset:40; // up to 1TB per file (not using off_t here - must definitely be exactly 64 bit!) 8byte
#  int reserved:7;     // reserved for future use 1 byte
#  int independent:1;  // marks frames that can be displayed by themselves (for trick modes) 1 byte
#  uint16_t number:16; // up to 64K files per recording 2 byte
#  tIndexTs(off_t Offset, bool Independent, uint16_t Number)
#  {