Convert the video to specified constant frame rate by duplicating or dropping frames as necessary.
This filter accepts the following named parameters:
- fps
-
Desired output frame rate. The default is
25. - round
-
Rounding method.
Possible values are:
- zero
-
zero round towards 0
- inf
-
round away from 0
- down
-
round towards -infinity
- up
-
round towards +infinity
- near
-
round to nearest
The default is
near. - start_time
-
Assume the first PTS should be the given value, in seconds. This allows for padding/trimming at the start of stream. By default, no assumption is made about the first frame’s expected PTS, so no padding or trimming is done. For example, this could be set to 0 to pad the beginning with duplicates of the first frame if a video stream starts after the audio stream or to trim any frames with a negative PTS.
Alternatively, the options can be specified as a flat string: fps[:round].
See also the setpts filter.
Examples
-
A typical usage in order to set the fps to 25:
fps=fps=25
-
Sets the fps to 24, using abbreviation and rounding method to round to nearest:
fps=fps=film:round=near