Provided by: mjpegtools_2.1.0+debian-6build1_amd64 bug

NAME

       yuvscaler - UPscales or DOWNscales a YUV4MPEG2 stream to a specified format

SYNOPSIS

       yuvscaler  [-I  input_keyword]  [-M  mode_keyword] [-O output_keyword] [-n p|s|n] [-v 0-2]
       [-h]

DESCRIPTION

       yuvscaler is a general (UP or DOWN) scaling utility that is provided to  allow  conversion
       between different video formats. It reads in a YUV4MPEG2 format stream from stdin (such as
       that produced by lav2yuv) and outputs such stream  to  stdout  (e.g.  to  be  consumed  by
       mpeg2enc).   The  most  common  use  of  yuvscaler  is to generate input suitable for MPEG
       encoding to VCD or SVCD formats using mpeg2enc(1).

       yuvscaler will automatically take into account PAL/SECAM  and  NTSC  format,  as  well  as
       widescreen   (16:9)   format  and  interlacing.  Use  of  yuvscaler  was  designed  to  be
       straightforward.

EXAMPLES

       VCD encoding:
       lav2yuv my-file.avi | yuvscaler -O VCD | mpeg2enc -f 1 -o vcd.%d.m1v

       SVCD encoding:
       lav2yuv my-file.qt | yuvscaler -O SVCD | mpeg2enc -f 4 -o svcd.%d.m2v

       Encoding anamorphic 16:9 as letterboxed VCD:
       lav2yuv my-ana16-9.eli | yuvscaler -M WIDE2VCD | mpeg2enc -f 1 -o letterbox_vcd.%d.m1v

       Encoding anamorphic 16:9 as letterboxed SVCD:
       lav2yuv  my-ana16-9.eli  |  yuvscaler  -M  WIDE2STD  -O  SVCD   |   mpeg2enc   -f   4   -o
       letterbox_svcd.%d.m2v

       Encoding anamorphic 16:9 as letterboxed DVD:
       lav2yuv   my-ana16-9.eli   |   yuvscaler   -M   WIDE2STD   -O  DVD  |  mpeg2enc  -f  8  -o
       letterbox_dvd.%d.m2v

OPTIONS

       -I input_keyword

              Specifies input processing  options.   Input  options  may  be  combined  by  using
              multiple -I flags. Possible input_keywords are:

              USE_WidthxHeight+WidthOffset+HeightOffset  to  select  a  useful  area of the input
              frame (all multiple of 2, Height and HeightOffset multiple of 4 if interlaced), the
              rest of the image being discarded

              ACTIVE_WidthxHeight+WidthOffset+HeightOffset  to select an active area of the input
              frame (all multiple of 2, Height and HeightOffset multiple of 4 if interlaced), the
              rest of the image being made black

       -M mode_keyword

              Sets  the  scaling  mode  options.   Scaling mode options can be combined by giving
              several -M flags.  Possible  are:

              BICUBIC - to use the (Mitchell-Netravalli) high-quality  bicubic  upsacling  and/or
              downscaling algorithm

              RESAMPLE - to use a classical resampling algorithm -only for downscaling- that goes
              much faster than bicubic. For coherence reason, yuvscaler will use RESAMPLE if only
              downscaling is necessary, BICUBIC if not.

              WIDE2STD - convert widescreen anamorphic (16:9) input video into letterboxed (4:3),
              generating necessary black lines.  Note that for MPEG applications if  your  player
              can  properly  decode anamorphic video you may wish to leave the video unscaled and
              simply specify the approprate format during MPEG encoding (see mpeg2enc(1)).

              RATIO_WidthIn_WidthOut_HeightIn_HeightOut   to   specified   scaling   ratios    of
              WidthIn/WidthOut  for  width and HeightIN/HeightOut for height to be applied to the
              useful area. The output frames that result from scaling can have a different format
              than  the  output  format  specified  using -O options(s).  In this case, yuvscaler
              automatically generate necessary black lines and  columns  and/or  skips  necessary
              lines and columns to center the scaled image in the output frame.

              WIDE2VCD  to  scale anamorphic widescreen (16:9) frames into letterboxed VCD format
              (equivalent to -M WIDE2STD -O VCD).

              FASTVCD to transcode full sized frames to VCD (equivalent to  -M  RATIO_2_1_2_1  -O
              VCD, see below).

              FAST_WIDE2VCD  to transcode full-sized anamorphic (16:9) frames to letter-boxed VCD
              (equivalent to -M WIDE2STD -M RATIO_2_1_2_1 -O VCD, see below).

              NO_HEADER to suppress stream header generation on output

              MMX to use MMX functions for BICUBIC scaling (experimental feature!!)

       -O output_keyword

              Sets the output frame format options.  Output format options  can  be  combined  by
              giving  several -O flags.  By default, output frames size will be the same as input
              frame sizes, as well as output frames interlacing if coherent with  output  keyword
              specification which prevails, top_first if not.

              MONOCHROME  to  generate  monochrome frames on output.  Chrominance information for
              the scaled pixels is set neutral (white).  MPEG encoding of black and  white  video
              will  be  both  inefficient and show annonying chrominance artifacts unless this is
              done.

              VCD to generate VCD compliant frames  on  output  (taking  care  of  PAL  and  NTSC
              standards). Non-interlaced output.

              SVCD  to  generate  SVCD  compliant  frames  on output (taking care of PAL and NTSC
              standards). Top-field-first interlaced frames.

              DVD to generate DVD compliant frames  on  output  (taking  care  of  PAL  and  NTSC
              standards). Top-field-first interlaced frames.

              SIZE_WidthxHeight to generate frames of size WidthxHeight on output (multiple of 4)

              If  VCD, SVCD or DVD keywords are not used, output interlacing is taken of the same
              type as input. By default, output frames size will be the same as input frame size.

       -n p|s|n
              (usually not necessary) if norm could not be determined from data  flux,  specifies
              the OUTPUT norm for VCD/SVCD (p=pal,s=secam,n=ntsc).

       -v 0|1|2
              Specifies the degree of verbosity: 0=quiet, 1=normal, 2=verbose/debug

       -h     Prints a summary of command line syntax.

       Note:  The  most  useful  downscaling ratios are handled using dedicated optimised scaling
       routines. They are:

              RATIO_WidthIn_WidthOut_2_1 => Full-sized frame to VCD downscaling

              RATIO_3_2_1_1 => Full-sized frame to SVCD downscaling

              RATIO_1_1_4_3 => WIDE2STD downscaling mode

              RATIO_WidthIn_WidthOut_1_1 => downscaling only concerns width, not height

              RATIO_1_1_HeightIn_HeightOut => downscaling only concerns height, not width

              RATIO_2_1_2_1 => FASTVCD, slightly width distorted (real ratio 45 to 22) but faster
              full-sized frame to VCD downscaling (-M RATIO_2_1_2_1 -O VCD)

              RATIO_WidthIn_WidthOut_8_3 => specific to WIDE2VCD downscaling (-M WIDE2STD -O VCD)

              RATIO_2_1_8_3  =>  specific  to  (slighly  distorted) FAST_WIDE2VCD downscaling (-M
              WIDE2STD -M RATIO_2_1_2_1 -O VCD)

              RATIO_1_1_1_1 => copy useful input part  of  possible  several  files  into  output
              frames

AUTHOR

       This man page was written by Xavier Biquard et al.
       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

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