Filter framepack
  Generate a frame packed stereoscopic video.
    Inputs:
       #0: left (video)
       #1: right (video)
    Outputs:
       #0: packed (video)
framepack AVOptions:
  -format            <int>        ...V..... Frame pack output format (from 0 to INT_MAX) (default sbs)
     sbs                          ...V..... Views are packed next to each other
     tab                          ...V..... Views are packed on top of each other
     frameseq                     ...V..... Views are one after the other
     lines                        ...V..... Views are interleaved by lines
     columns                      ...V..... Views are interleaved by columns


