If the user attempts to use AviSynth 2.5, an error message will now tell them they need to upgrade.
1492118 avisynth: drop support of AviSynth 2.5
compat/avisynth/avisynth_c_25.h | 68 ---------------------------------------
libavformat/avisynth.c | 23 ++++++++-----
2 files changed, 15 insertions(+), 76 deletions(-)