@item -vframes @var{number} (@emph{output})
Set the number of video frames to record. This is an alias for @code{-frames:v}.
@item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream})
-Set frame rate (Hz value, fraction or abbreviation), (default = 25).
+Set frame rate (Hz value, fraction or abbreviation), (default = 25). For output
+streams implies @code{-vsync cfr}.
@item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream})
Set frame size. The format is @samp{wxh} (default - same as source).
The following abbreviations are recognized: