Bill Brown brown at diego.cecer.army.mil
Wed Jul 6 16:48:37 EDT 1994

Hi Folks,

I just put a new version of a program on moon.  The first version has been
on moon for about a month, but was never announced, but if you got it 
already, you might want to get the newer version for better quality output.

The file on moon is r.out.mpeg.tar.Z

and here's the manual page for r.out.mpeg:

r.out.mpeg <contrib> GRASS Reference Manual  <contrib> r.out.mpeg

     _r._o_u_t._m_p_e_g - Raster File Series to MPEG Conversion Program

     r.out.mpeg help
     r.out.mpeg [-q] view1=_n_a_m_e[,_n_a_m_e,...]
        [view2=_n_a_m_e[,_n_a_m_e,...]] [view3=_n_a_m_e[,_n_a_m_e,...]]
        [view4=_n_a_m_e[,_n_a_m_e,...]] [output=_n_a_m_e] [qual=_v_a_l_u_e]

     _r._o_u_t._m_p_e_g is a tool for combining a series of GRASS raster
     files into a single MPEG-1 (Motion Pictures Expert Group)
     format file.  MPEG-1 is a "lossy" video compression format,
     so the quality of each resulting frame of the animation will
     be much diminished from the original raster image.  The
     resulting output file may then be viewed using your favorite
     mpeg-format viewing program.

     The user may define up to four "views", or sub-windows, to
     animate simultaneously.  e.g., View 1 could be rainfall,
     View 2 flooded areas, View 3 damage to bridges or levees,
     View 4 other economic damage, all animated as a time series.
     A black border 2 pixels wide is drawn around each view.
     There is an arbitrary limit of 100 files per view (100
     animation frames).  Temporary files are created in the
     conversion process, so lack of adequate tmp space could also
     limit the number of frames you are able to convert.

     The environment variable GMPEG_SIZE is checked for a value
     to use as the dimension, in pixels, of the longest dimension
     of the animation image.  If GMPEG_SIZE is not set, the
     animation size defaults to the rows & columns in the current
     GRASS region, scaling if necessary to a default minimum size
     of 200 and maximum of 500.  The resolution of the current
     GRASS region is maintained, independent of image size.
     Playback programs have to decode the compressed data "on-
     the-fly", therefore smaller dimensioned animations will
     provide higher frame rates and smoother animations.

     UNIX - style wild cards may be used with the command line
     version in place of a raster file name, but it _m_u_s_t _b_e

     r.out.mpeg view1="rain[1-9]","rain1[0-2]" view2="temp*"

     If the number of files differs for each view, the view with
     the fewest files will determine the number of frames in the

GRASS 4.1                U.S. Army CERL                         1

r.out.mpeg <contrib> GRASS Reference Manual  <contrib> r.out.mpeg


     -_q   Quiet - suppress progress report


          Raster file(s) for View1

          Raster file(s) for View2

          Raster file(s) for View3

          Raster file(s) for View4

          Name for MPEG output file (default gmovie.mpg)

     _q_u_a_l Quality factor (1-5) (default 3)

          A quality value of qual=1 will yield higher quality
          images, but with less compression (larger MPEG file
          size).  Compression ratios will vary depending on the
          number of frames in the animation, but an MPEG produced
          using qual=5 will usually be about 60% the size of the
          MPEG produced using qual=1;

     MPEG images must be 16-pixel aligned for successful
     compression, so if the rows & columns of the calculated
     image size (scaled, with borders added) are not evenly
     divisible by 16, a few rows/columns will be cut off the
     bottom & right sides of the image.
     The MPEG format is optimized to recognize image MOTION, so
     abrupt changes from one frame to another will cause a
     "noisy" encoding.

     This program requires the program _m_p_e_g__e_n_c_o_d_e :

                     MPEG-1 Video Software Encoder
                     (Version 1.3; March 14, 1994)

     Lawrence A. Rowe, Kevin Gong, Ketan Patel, and Dan Wallach
     Computer Science Division-EECS, Univ. of Calif. at Berkeley
     Available by anonymous ftp from: s2k-ftp.CS.Berkeley.EDU

2                        U.S. Army CERL                 GRASS 4.1

r.out.mpeg <contrib> GRASS Reference Manual  <contrib> r.out.mpeg

     Bill Brown, U.S. Army Construction Engineering Research
     Laboratories (brown at zorro.cecer.army.mil)

GRASS 4.1                U.S. Army CERL                         3

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