Detect if there is a critical Avisynth initialization failure and print the associated error.
This, however, requires a feature present in the latest version of Avisynth alpha (2.6).
Previous versions are unaffected.
Requires avisynth_c.h from the Avisynth API headers.
Reports errors properly from Avisynth script input.
Automatically construct input scripts for almost any input file.
Tries ffmpegsource2, DSS2, directshowsource, and many other sourcing methods, based on the input file extension.
Automatically converts to YV12.