[FFmpeg-user] select a frame every second

[Roger Pack]

Anybody know if...it is possible to use the select filter to select a frame
"once per second" regardless of incoming frame rate?
If not then consider this a feature request--I suppose now that libavfilter
can pass dynamic variables down the chain maybe if it could pass down the
"FPS" as a variable then somehow eval could use it...
Thanks!
-roger-