Filter loop
  Loop video frames.
    Inputs:
       #0: default (video)
    Outputs:
       #0: default (video)
loop AVOptions:
  loop              <int>        ..FV..... number of loops (from -1 to INT_MAX) (default 0)
  size              <int64>      ..FV..... max number of frames to loop (from 0 to 32767) (default 0)
  start             <int64>      ..FV..... set the loop start frame (from 0 to I64_MAX) (default 0)


