Ubuntu Manpage: r.out.mpeg - Raster File Series to MPEG Conversion.

NAME

       r.out.mpeg  - Raster File Series to MPEG Conversion.

KEYWORDS

       raster, export

SYNOPSIS

       r.out.mpeg
       r.out.mpeg help
       r.out.mpeg        [-qc]       view1=string[,string,...]        [view2=string[,string,...]]
       [view3=string[,string,...]]          [view4=string[,string,...]]           [output=string]
       [qual=integer]   [--verbose]  [--quiet]

   Flags:
       -q
           Quiet - suppress progress report

       -c
           Convert on the fly, use less disk space (requires r.out.ppm with stdout option)

       --verbose
           Verbose module output

       --quiet
           Quiet module output

   Parameters:
       view1=string[,string,...]
           Raster file(s) for View1

       view2=string[,string,...]
           Raster file(s) for View2

       view3=string[,string,...]
           Raster file(s) for View3

       view4=string[,string,...]
           Raster file(s) for View4

       output=string
           Name for output file
           Default: gmovie.mpg

       qual=integer
           Quality factor (1 = highest quality, lowest compression)
           Options: 1-5
           Default: 3

DESCRIPTION

r.out.mpeg is a tool for combining a series of GRASS raster maps 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. MPEG-2 and MPEG-4 provide much better quality animations.

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 400 files per view (400 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. These size defaults are
overridden when using the -c flag (see below). 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 map
name, but wild cards must be quoted.

Example:


       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 animation.

       With  -c  flag  the  module converts "on the fly", uses less disk space by using r.out.ppm
       with stdout option to convert frames as needed instead of converting  all  frames  to  ppm
       before encoding.  Only use when encoding a single view.  Use of this option also overrides
       any size defaults, using the CURRENTLY DEFINED GRASS REGION for the output  size.   So  be
       careful to set region to a reasonable size prior to encoding.

       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.

BUGS

       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.

NOTES

       This program requires the program mpeg_encode (aka ppmtompeg):

       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 from Berkeley: http://bmrc.berkeley.edu/frame/research/mpeg/mpeg_encode.html
       or as part of the netpbm package (ppmtompeg): http://netpbm.sourceforge.net

       Playback may be done with many viewers;  mpeg_encode's  official  companion  is  mpeg_play
       available  from  Berkeley  at  ftp://mm-ftp.cs.berkeley.edu/pub/multimedia/mpeg/play/ or a
       precompiled  Debian   package   from   http://packages.debian.org/ucbmpeg-play   (includes
       maintained source code).

       Use of the -c flag requires the r.out.ppm GRASS module with the stdout option.

AUTHOR

       Bill Brown, U.S. Army Construction Engineering Research Laboratories

       Last changed: $Date: 2008-05-16 12:09:06 -0700 (Fri, 16 May 2008) $

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