Avisynth+

[Groucho2004]

Originally Posted by davidhorman

Is this expected/deliberate behaviour?

function _flipit(clip c) { # note the underscore
  return c.flipvertical
}

function flipit(clip c) {
  return c.fliphorizontal
}

version._flipit # note the underscore

The result is flipped horizontally, not vertically as you might expect. It seems that when faced with a function call with a leading _, Avisynth first matches it without the underscore, and only falls back to the underscored function (_flipit) if there is no non-underscored function (flipit).

It flips vertically with classic Avisynth (2.60, 2.61).

Edit: It also flips vertically with AVS+ r1576.