NAME

       yuvfps - Converts to a different frame rate

SYNOPSIS

       yuvfps [-r Num:Den] [-s Num:Den] [-i Interlacing] [-I Interlacing] [-c] [-n] [-w] [-v 0-2] [-h]

DESCRIPTION

       yuvfps  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 the stream.

       yuvfps 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 rate.

       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.

       yuvfps  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 vs 25).

OPTIONS

       -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.

       -c

              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 stream header.

       -n

              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.

       -w

              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 slower.

       -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.

AUTHOR

       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:
         mjpeg-users@lists.sourceforge.net

       For more info, see our website at
              http://mjpeg.sourceforge.net/

SEE ALSO

       yuvscaler(1), mjpegtools(1), lavpipe(1), lav2yuv(1) mpeg2enc(1)

MJPEG Tools Team                                   8 Jan 2006                                          yuvfps(1)