yuvfps - Converts to a different frame rate
] [-s Num:Den
] [-I Interlacing
] [-v 0
is a general (UP or DOWN) resampling utility that is provided to
allow the generation of video streams with the frame rates required for each
standard video format. yuvfps
reads a YUV4MPEG stream from the standard
input and outputs a YUV4MPEG stream to the standard output in which frames
from the original ones are skipped (downsampling) or duplicated (upsampling).
This allows for other mjpegtools that require a specific frame rate to process
uses by default Bresenham's algorithm to do the resampling so that
the new video stream is similar to the original one. Note, however, that
downscaling is a non-reversible operation because frames are dropped.
Moreover, the resulting video stream may not have the exact same duration as
the original one if the new frame rate is not a whole multiple of the original
As an alternative to simply dropping or duplicating frames each output
frame/field can be produced as a weighted average of the two temporally
closest input frames/fields. In this mode, yuvfps
can also change the
interlacing mode of the stream.
also can "fix" the framerate specified in the YUV4MPEG
header. This allows for the generation of effects (fast-forwarding, slow
motion) and also when the source stream has some framerate that is very close,
but not exactly, the rate required for some standard video (for example, 24.9
- -r Num:Den
- Specifies the resulting stream frame rate.
- -s Num:Den
- Ignores the frame rate in the input stream and assumes this frame rate for
the input stream.
- -i Interlacing
- Specifies the interlacing mode of the resulting stream. The interlacing
mode can be changed only when using the weighted average resampling mode
(the -w option).
- p - progressive (non-interlaced)
t - top-field first
b - bottom-field first
- -I Interlacing
- Ignores the interlacing mode information in the input stream and assumes
this interlacing mode for the input stream. The possible values are the
same as for the -i option.
- Changes the stream header frame rate and interlacing mode in the output
stream but copies frames from the original stream without changes. The -r
and -i options specify the frame rate and interlacing mode for the output
- By default yuvfps tries to find a normalized framerate. Some programs
create framerates like: 29969909:1000000 which is actually th typical NTSC
framerate of 30000:1001. yuvfps prints out the normalizes values and the
original when it starts. If you think the normalized value is not correct
and want yuvfps to use the original given number you have to add that
option. So yuvfps does not try to normalize the values.
- Produce each output frame/field as a weighted average of the two
temporally closest input frames/fields instead of simply dropping or
duplicating frames. The blending of two adjacent frames/fields reduces
visible stepping compared to the default drop/duplicate algorithm but as a
drawback it makes fast moving objects appear blurred and is much
- -v [0,1,2]
- Set verbosity level.
0 = warnings and error messages only.
1 = add informative messages, like the framerate conversation information.
2 = add chatty debugging message, too.
This man page was written by Alfonso García-Patiño Barbolani.
Johannes Lehtinen added information about the weighted average resampling mode
and the related options.
If you have questions, remarks, problems or you just want to contact the
developers, the main mailing list for the MJPEG-tools is:
- For more info, see our website at