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Introduction

This page focuses on creating MPEG-1 movies (video only) using NERSC and LBNL UNIX computers. The resultant movies can be played using any MPEG-1 player or on a web page. This page describes what you need to consider before you makeyou make your movie; some methods for creating a movie; and some advanced tips for the more adventuresome user. Note: The example movies shown in this page do not reflect the normal quality of output from the graphics & visualization packages used. We picked the worst way to create the images and movies to illustrate what you should not do.

Creating a movie is at least a two step process. First you need to create the individual frames that will comprise your movie. You then need to combine these images to create a movie that you and others can play back on a computer. Almost all computer-generated movie formats use a compression algorithm. Compression is necessary because of size constraints (size of image times the number of the images to make a movie (30 frames per second) equals hundreds to thousands of megabytes). The MPEG-1 standard is one movie format that supports a very good compression scheme. Others possible formats are Apple's QuickTime, and Microsoft's AVI. This page focuses on MPEG because most platforms support MPEG-1 players and there are lots of plug-ins available for web browsers.

When you decide to make your movie, be prepared to spend more time on creating the movie than you first thought or you would like to. Movie making is an art. There is no cookbook that will tell you exactly what you need to do to create your perfect movie. Factors that contribute to the problem is that the final movie size may be the most important factor to one user, another user is more interested in the highest-quality image, and yet another is interested in portability.

If you are interested in learning more about video and various standards like MPEG, check out the web and books and magazines on video, it's creation, and deployment. Click here to go to the official web site of the Movie Picture Experts Group (MPEG).

Making MPEG Movies

Things to consider before you make the images for your movie:

Creating Movies

SGI tools: available on escher.nersc.gov and LBNL SGI's.

Visualization Packages that provide MPEG generators.

Unix tools: available on escher.nersc.gov and LBNL sytems mounting the Software Farm.

Try out the different programs to see which one creates the movie quality and size you want. Here are two sample movies that show how the two encoders worked with small bouncing balls with their default settings for compression. In this case, mediaconvert did a better job than mpeg_encode but created a larger file (490K versus 90K). mpeg_encode did a better job when the balls were made a little larger and the colors were de-saturated. Movie 1, notice the balls are not distorted. Movie 2, the balls are distorted.

With both encoders you can play with changing the compression scheme by modifying the number of I, P, and B frames. The definition of these frame types are detailed at the Berkeley site mentioned in the previous paragraph or any article on MPEG. Basically, the more B and P frames you specify, the more compression.

Displaying Movies

SGI tools: available on escher.nersc.gov and LBNL SGI's.

Other tools: available on escher.nersc.gov and LBNL sytems mounting the Software Farm.

Advanced Tips

Useful tools for image manipulation

NERSC User Training on MPEG generation: link to a presentation. [an error occurred while processing this directive]