Compression Technology    2002'ish

I'm calling this the "How to compress a 93Meg File to 300k" section. Currently the only answer is a codec called "divx". If you want information about this goto Divx. A codec is simply the instructions to the computer on how to decode a file format. If you don't know what I'm talking about and don't care,Simply goto the Divx web site and download and run the Executable. It will copy the instructions to the appropriate space on your computer.
 
Get the Freeware Player, it's about 3 Meg
      Online Divx

About the Animations
The Following Files have been compressed, cut, sliced, diced, and pretty much mangled in any and all ways to get the file size down for web use. Some notes are made next to each. If nothing else, this page is a great example of Compression Technologies.


divx_asteroid_50kps.avi
320w x 240h     52k
Asteroid Animation
 
This version actually looks better than the original. I think it's because of the extra blur and some noise. The Frame rate and size were both dropped by half.
 
Compression Notes
640x480 to 320x240
30fps to 15fps
24,100k to 52k (463:1)
Divx Compression set to 50kps quality
 

divx_circles_25kps_wsound_mp3.avi
424w x 240h     296k
Circles Stop Motion Animation with Sound
 
This animation has been turned into a "Stop Motion" animation. Basically 1 frame per second. The sound has been compressed with the mp3 format to 8 bit mono (think really cheap AM Radio). This was pretty much the only way to get a 300x compression as the original file was 93M (or for those non-metric people 93,000k vs 296k) An interesting effect, not entirely undesirable. The music REALLY helps. Kind of adds a sense of movement.(or I'm simply talking alot of BS)
 
Compression Notes
No change in Size
30fps to 1fps
90,700k to 296k (306:1)
Divx Compression set to 25kps quality
(44.100 kHz, 16 Bit, Stereo) to (mp3 11,025 Hz, 16 Bit, Mono)
 

divx_f1_nosound_50kps.avi
212w x 120h     151k
F-1 Fighter Animation
 
This animation was much harder to compress. My guess is that the grass texture was difficult for the program. The Size and Frame rate were cut by half. Due to web space the audio was also cut. The audio even at max compression would have doubled the file size. Even at a 50kps rate this animation skips during the first explosion sequence.
 
Compression Notes
424x240 to 212x120
30fps to 15fps
60,000k to 151k (397:1)
Divx Compression set to 50kps quality
(44.100 kHz, 16 Bit, Stereo) to (none)
 

divx_gear_wsound_mp3_50kps.avi
160w x 120h     k314
Gear Animation with Sound
 
This was another animation that was difficult to compress. The final file was about 1.4M and I need it under 500k to fit on the website. I finally saved the animation without sound, and then used the program "virtual dub"(www.divx.com) to cut about 1/2 the segments of the file out and then add the soundtrack compressed with mp3 audio. It sounded much better to add a continuous sound track then to cut and paste the audio portion along with the video. I'm actually quite pleased with the result. I was able to include all of the highlights from the animation and include the audio also. Looks like a "movie preview" in my opinion. Once again the frame size and frame rate were cut by half.
 
Compression Notes
320x240 to 160x120
30fps to 15fps
97,900k to 314k (312:1)
Divx Compression set to 50kps quality
(44.100 kHz, 16 Bit, Stereo) to (mp3 11,025 Hz, 16 Bit, Mono)
 

divx_mousetrap_50kps.avi
300w x 192h     k38
Mousetrap Animation
 
As small as the compressed file is, the ratio between this file and the original is not nearly dramatic as the other examples. Only about 66x's. (And yes I do know that this is comparing apples to oranges). On the other hand the final quality of the compressed version is very close to the original. Once again the frame size and frame rate were cut by half.
 
Compression Notes
600x384 to 300x192
30fps to 15fps
2,500k to 38k (66:1)
Divx Compression set to 50kps quality
 

divx_swinggear_50kps_15fps.avi
212w x 120h     k270
Swing Gear Animation
 
This file just wouldn't compress. Period. The Sound was dropped, the frame size and frame rate were cut in half, and the picture is very soft and fuzzy. While the soft focus effect was fine in the above pictures, a large part of the interest in this animation was the crisp gear fell which is ruined by the softness. And as always I feel the music adds tremendously(of course since I do my own music I feel this way!). Even with these changes the new animation was shortened from 71sec to 38sec. So the compression ration below takes this into effect(really I can divide, really). As you can see, the ration is only about 100x which is very bad in comparison to the other animations.(yes I know apples and oranges again, but this is what I've got).
 
Compression Notes
424x240 to 212x120
30fps to 15fps
52,000k to 270k (103:1)
Divx Compression set to 50kps quality
 

Technical Notes:
The Original Avi files were created from Three basic programs; MicroStation, 3dMax, and Premiere. The Original Sound in the Animations was done by two methods. One, with a microphone and me at the keyboard, and two, with a program called Acid Music. To recompress the Avi files Premiere was used with the divx codec. To add sound, the free program "Virtual dub"(available at www.divx.com)was used. This program was also used to cut some of the Avi files.