|
INTRODUCTION
COPYRIGHT
MACHINE SETUP
REASONS TO USE
ANIMATION TYPES
OTHER TYPES
AUDIO TYPES
ANIMATED GIFs
AUDIO HOW-TO
AUDIO QUALITY
VIDEO HOW-TO 1
VIDEO COMPRESSION
VIDEO HOW-TO 2
CONCLUSION
|
Video Compression
There are many different schemes around for doing video compression.
I'm going to mention only the most general ones. Unless you've got some
really expensive equipment, just acknowledge that you're going to have to
compress your video to play on a computer. You can cut down the data by
restricting the frame size and reducing the number of frames per second,
but from there on out, you'll have to use a CODEC to make the file even
smaller. (CODEC stands for compression-decompression and refers to
different schemes for compressing and decompressing video.)
Some compression schemes are lossless (meaning they lose no
information), but in the world of video, most of the schemes are
lossy. (JPEGs are lossy and TIFs are not, in the still image world
of compression.) Certain CODECs are best for some animations and worst for
others, so it helps to take a minute to look at them:
(These aren't the greatest images, but they'll have to do for the
time being. They are screen grabs from the first frame shown twice
actual size. Click on the caption under each image to see the animation.
All animations are at 15 frames per second. Sorry for the large file
sizes. I'll try to put shorter versions online soon. )
None, 16-bit color, Most (6 MB)
|
None - Obviously, if you've got an amazing machine and don't
have to do compression, you'll end up with the best animation. If you
can, it's good to record with no compression because you then have the
best data when you write the movie out. You can always lose information
you have, but you can't "add" data back in after you've lost it in the
recording process.
|
Anim, 16-bit color, Most (5 MB)
Anim, 16-bit color, Medium (4 MB)
|
Apple Animation - This CODEC works well where there are
consistent fields of color like in computer-generated animations. It's
not as effective on captured video because video images tend to have a lot
more noise in the image.
|
Cinepak, 24-bit color, Most (1 MB)
Cinepak, 24-bit color, Medium (864 KB)
|
Cinepack - Is a CODEC commonly used for creating animation files
to be played on CD-ROMs. You can control the data rate at which the movie
plays back so you can be sure it will play on a 2x or 4x CD-ROM. This
CODEC takes a relatively longer time to compress an image than it does to
decompress, which makes it good for CDs and hard drives.
|
Graphics, Color (256), Most (1.7 MB)
|
Graphics - This CODEC forces the animation into 256 colors, so
it's fine if you aren't looking for beautiful image quality.
|
Photo, Color, Most (5 MB)
Photo, Color, Medium (992 KB)
|
Photo JPEG - Sometimes you might be making a movie of still images
where you care more about the stills than you do the movie. You might
choose Photo for this option, because it is based on the still-image JPEG
compression scheme. Since JPEGs are not very fast to decompress, it's not
a good candidate for movies you want to play back.
|
Video, Color, Most (2.3 MB)
Video, Color, Medium (1.2 MB)
|
Video - This CODEC does a good job of compressing
analog video (digitized video). It's a little slow, so not great for
playing on CD-ROMs.
|
Now, back to digitizing video...
|
