Re: mpeg animations

[kobrien@xxxxxxxxxxxx (Troll)]

It was on Feb 21, at 12:32, when hermann@goofy.pmel.noaa.gov wrote:
> Subject: mpeg animations
>Hi Ferreters,
>     I was wondering who among you have turned ferret animations or still
frames
>into mpeg movies for web use. Currently I do this using a program hdf2mpeg,
but
>the results are uneven and kinda slow. Any other methods out there?
>
>-Al Hermann
>hermann@pmel.noaa.gov
>-- End of excerpt from hermann@goofy.pmel.noaa.gov


Greetings All,

Mpeg movies can be made either from hdf files or gif files.   Al Hermann and
Peter Braccio have already mentioned how the create mpeg movies using hdf
files, and both expressed reservations about this method.   I will describe a
way to create mpeg movies using gif files, which may prove easier (or it may
not, I suppose). You will need to install some (free) MPEG conversion software
on your system -- I have listed sources below.

The basic process is the same for both hdf and gif file formats, at least in Al
Hermann's case, ie:
	1) create frames from ferret for the movie
	2) run the frames through an mpeg encoder to create the movie

However, since Ferret allows frames to be saved as gif files, one can use the
resulting gif files to create mpeg movies.  For example, to create a movie
using gif files, I would have a ferret command like:
	.
	.	! set data stuff here, get plot ready, etc
	.
	repeat/l=1:25 (shade temp; frame/file=movie_frame.gif)
	.
	.

which will result in files named
	movie_frame.gif
	movie_frame.gif.~1~
	movie_frame.gif.~2~
	.
	.

Ferret knows to save the output in a gif file because of the ".gif" extension
given.   One nice side benefit of using gif files rather than hdf files is that
the gif files employ a compression method which makes them much more compact
than hdf files.

Once the gif files are created, they need to be run through the "mpeg_encode"
software, which in turn needs the "giftoppm" binary.   The naming scheme ferret
employs for the created gif files integrates quite well with what the
mpeg_encode software expects.  Below is an included message on where to pick up
the needed software.   The mpeg_encode package includes README files which will
elucidate the whole process of creating an mpeg stream from gif files.


good luck,

Kevin O'Brien


>The mpeg encoding software can be picked up at:
>
>Berkeley FTP archive (mm-ftp.CS.Berkeley.EDU)
>in directory
>		/pub/multimedia/mpeg/encode
>
>that directory contains binaries for
>	hpux
>	osf
>	sgi
>	sunos
>	ultrix
>
>as well as the source code:
>	mpeg_encode-1.5-patched-src.tar.gz
>
>If there exists a binary for the system, I recommend picking it up, but also
>picking up and extracting the source code.  This will allow access to
>documentation and examples.
>
>
>The package I have used to provide the giftoppm routine needed by mpeg_encode
>is pbmplus.  It can be picked up at:
>
>Host ftp.luth.se
>
>    Location: /pub/X11/R5contrib
>           FILE -r--r--r--     678238  Dec 11 1991  pbmplus10dec91.tar.Z
>