manpage: explain "speed-adjusted" FPS for --interpolation-threshold

Fixes #3528.
This commit is contained in:
wm4 2016-09-15 10:11:44 +02:00
parent 30d147687f
commit f143665864
1 changed files with 5 additions and 2 deletions

View File

@ -3915,8 +3915,11 @@ The following video options are currently all specific to ``--vo=opengl`` and
``--interpolation-threshold=<0..1,-1>``
Threshold below which frame ratio interpolation gets disabled (default:
``0.0001``). This is calculated as ``abs(disphz/vfps - 1) < threshold``,
where ``vfps`` is the speed-adjusted display FPS, and ``disphz`` the
display refresh rate.
where ``vfps`` is the speed-adjusted video FPS, and ``disphz`` the
display refresh rate. (The speed-adjusted video FPS is roughly equal to
the normal video FPS, but with slowdown and speedup applied. This matters
if you use ``--video-sync=display-resample`` to make video run synchronously
to the display FPS, or if you change the ``speed`` property.)
The default is intended to almost always enable interpolation if the
playback rate is even slightly different from the display refresh rate. But