Merge remote-tracking branch 'cus/stable'

* cus/stable:
  ffplay: fix build if avfilter is disabled
  ffplay: fix frame_delay calculation in new avfilter code
  ffplay: add support for changing pixel format
  ffplay: add missing filt_in assignment after video filter reconfigure
  ffplay: fix frame aspect ratio after qatar merge
  ffplay: fix use after free
  ffplay: use dummy video driver if display is disabled

Merged-by: Michael Niedermayer <michaelni@gmx.at>