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)