Computer demo bogus party iii video by bogus device

The demoscene is an international computer art subculture focused on producing demos: self-contained, sometimes extremely small, computer programs that produce audio-visual presentations. The purpose of a demo is to show off programming, visual art, and musical skills. Demogroups are teams of demosceners, who make computer based audio-visual works of art known as demos. Demos and other demoscene productions are shared at festivals known as demoparties, voted on by those who attend, and released online (first on BBS and later in Internet). Demo groups spend days or weeks coding their demos. Demos are made for the big screen!

Bogus Device was a combination of talented programmers from many Finnish demo teams ( Dante, Brainwash Inc, Jeskola, Gazebo, etc.).


The team was founded at Party III in Demark at the end of 1993. The team was founded at party place 10 hours before PC demo competition dead-line. The team was founded so that everybody that had interest and something to contribute could join. Some people had camera, some knew someone who had video digitizer, etc.. There was no clear roles. No list of all people involved has been saved.

Remember that this was very early days of video compression on home computers. If you never saw a digital video back in the 1990s, you’re not alone. The files were large and the downloads were slow. The MPEG-1 standard , established in 1992, is designed to produce reasonable quality images and sound at low bit rates. The MPEG-1 standard was standardized in 1993. But it was not widely used or available for normal computer users (no free open source video codecs then). Also an Intel 486 or Pentium would grind to a standstill trying to make sense of a simplistic Motion JPEG or MPEG-1 video, even at very low resolutions.

What I figured out that to be able to do something useful, I needed to figure out how I can determine the difference between different video frames, and store only the information what has changed. That would save a lot of data compared to whole picture. I could also maybe able to just skip storing the smallest changes (store only when pixel value clearly changes). Other tricks I used was just to have gray-scale video video that has limited number of different gray-scale values (in this case 16 values). I can also keep the amount of data low by keeping resolution low (114×82 and 160×100 pixels). I also found out that I don’t need full 24-60 Hz picture update rate, I could have something lower like 15 pictures or even less per second and people still see as video. JAF video format decoding

The file format is very easy to decode. I wrote a video decoding routine that decoded the picture to the screen and even did some “anti aliasing” to make picture smoother. When you smooth out the edges between pixels when you scale the video to full screen resolution, the video looks sharper than it really. The decoding anti-aliasing could also could generate more gray scales than was on original video.

I found that in practice my lossy compression can sometimes leave annoying pixels stay not changing for long time and some other artifacts. On some video material this was very annoying, and on some other material it looked as “artistic” video effect. I left some of the “artisticly flawed” material intentionally to production, but for some material I aimed for better. I developed a system so that in most frames I do the compression in pretty lossy way, but after every N very lossy frames there will be one frame that is stored with less compression. In this way those less compressed frames will clean up the messy pixels “that too much” compressed frames had left.

Generally I tried to chose quite high compression and fast decompression speed, so the quality was not best possible. In my final compression program I had a pretty aggressive noise filter to filter out some usual error caused by video tape and cheap digitizers. The system filtered out pixels which have no nearby pixels which change. Those pixels are usually caused by transient noise is video system. In this way the picture quality become better and compression ratio became better. I know that I might loose some of the smallest details of the picture, but the picture looked better with filtering. Even thought the video compression was simple (no DCT, no movement vectors, no different frame types) it worked better than I originally expected.

Bogus Party III video is hardly the first video compression demo in demoscene, but is was one of the early ones and first one released on big party for PC. The idea for making this product was inspired by Amiga Demo 242 by Fairlight & Virtual Dreams, that was released in summer 1993 and used video clips as part of the demo ( view video of demo).

Few years later Finnish demo team Coma made some more artistic PC demos that used video as integral part of their art. Most well known are their products ‘The control’ by Coma ( view video) and Paimen by Coma ( video video). COMA (shortform for Community Of Moral Advancement) is a Finnish pc demo group formed by previous members of Dante. I was a member of Dante in 1993. I suspect what Bogus Devices did once had some effect on what Coma did later at their own style.