Video Connection Guide

[Jamisonia]

I wrote this guide for people to understand the different video game connections, and why we mod consoles for better connections.

I. What Humans See

Humans are trichromats meaning we can only perceive three colors. These three colors are RGB: red, green, and blue. All other colors we see are made up of these three colors. Therefore our photography, TV, video, movies, and computers are based on this RGB model. Televisions output light in either red, green, or blue. Newer technology TVs have red, green, and blue pixels, and older CRT technology TVs have red, green, and blue phosphors. This means no matter how we input video into our televisions, we will be betting out red, green, and blue color along with a black and white picture.

RGB Colorspace
RGB is a colospace used to store video on a medium. RGB is usually stored as R+Y, G+Y, B+Y, and a sync signal. The +Y stands for plus Luma. Luma is the brightness, or the black and white picture in a signal. It is where all the details are. The Luma signal on its own would be black and white. Sync is the signal that stabilizes the picture. Without sync the picture would jump all around. Sync tells the TV where to keep the image. Sync can be sent in two lines: horizontal sync, and vertical sync. Computer monitors accept sync in this manner over VGA cables. It can also be sent as composite sync, which is horizontal and vertical sync combined, or a composite. This is usually how sync is sent in the video world.

What Uses the RGB Colorspace?
First and foremost computers work almost exclusively with RGB. Only very early computers did not. So almost anything derived from computers, such as video games are stored in RGB. That means on the game disc or cartridge, the game itself is stored into separate R+Y, B+Y, G+Y, and sync signals. Any other way you get video out of your game system means these video signals have been changed.

All things being equal, you would get the best signal quality by not changing these signals at all. However; this is not possible. Not everything system supports RGB video input. The American television system: NTSC does not support RGB video input. No consumer level American NTSC TV ever had a VGA input, nor any other sort of RGB input. Due to this Americans are forced to compromise the video signal in some way. Many Americans are unaware of this and compromise it to more of a degree than is necessary. PAL, the European system, did support RGB input over a connector called SCART. The new worldwide HDTV standard also supports RGB video input.

II. Video Connection Standards

There are many methods of getting video into our TVs. Some are better than others, some are more readily available than others. As mentioned before the best way is to get the pure video signal into our TV, doing these least amount of changing possible. This is not always an easy task to accomplish. This is what leads many people to modify their systems.

RF (aka Radio Frequency)
RF is the oldest and probably most familiar way. This is where the audio and video travel on one line into our TVs. Usually the RF modulator lets us select if we want the video displayed on channel 3 or 4. All video game consoles support this method of connection ending with the N64, PS1, Saturn era. All VCRs support this connection. Early Laserdisc players support this connection. This is the worst way to connect your system. Except with the earliest video game systems, there are always better options available without modifying your system. Use them!

Composite Video (aka Video, Yellow Plug Video)

Composite video is a combination, or composite of the RGB Colorspace into one video signal. It is likely the most recognized type of video connection, but unfortunately it is the worst. It was the cheapest to manufacture cables for so free composite cables were always included with DVD players. It is also found on most TVs made in the 90s. It is very common, and therefore very popular. Composite video usually uses a yellow color coded RCA jack. The RCA is not the type of connection, it is only a type of connector.

Composite video is known for having many video problems, such as dot crawl, and other video artifacts. It tends to be overly blurry.

S-video (aka Super Video, S-VHS Video, Super VHS Video, Y/C Video)

S-video is a standard developed by JVC for the introduction of their Super VHS players. S-video is a color under standard. This means the Color or Chroma and Brightness or Luma is stored separately. VHS tapes have their video stored in this way, the color is stored under the luma. S-video cables have 4 pins. Luma signal is sent along one pin, chroma signal is sent along a second pin, and the third and fourth pins are used as ground. S-video is also known as Y/C meaning Luma/Chroma. Remember Y always means Luma. At this point the sync signal is lumped in with Y.

S-video is a noticeable step up from composite. The results are no dot crawl, better colors, and a much sharper image. Many consoles support this type of video, or it can be easily added to them via modification. Unfortunately this connection is being removed form HDTVs. It was never very popular in the 90s, and is almost unheard of now.

III. The YPbPr, and YCbCr Colorspace

Before the next connection standard can be discussed, I must first explain the YPbPr Colorspace. With the invention of DVD an alternative to RGB was developed. RGB is very bandwidth heavy, meaning it requires a tremendous amount of data. The move to digital video signals was accompanied by the need to reduce bandwidth. It was discovered one could store video in YPbPr instead of RGB and achieve very close results in picture quality. Y=Luma, Pb=Blue minus Y, Pr=Red minus Y. This is also sometimes represented as Y, B-Y, R-Y. Notice there is no green. Green is the color we perceive the most. Engineers figured out that they could send Luma and sync, Blue, and Red, and let the TV fill in for green. This saved a tremendous amount of bandwidth as green was no longer required to be sent. YCbCr is the same idea, only the signals are digital instead of analog.

DVD used this new YCbCr colorspace to store its video information. Unlike a video game, the picture is stored on the DVD separated into YCbCr. YPbPr is then derived from converting this signal into analog, since TVs at the time were all analog.

Component Video (aka YPbPr, RGB Connectors, RGB)

The first thing to note is although I put aka RGB, and RGB connector, this is a misnomer. People often incorrectly refer to YPbPr as RGB, because the connectors are color coded green, blue, and red. RGB is not the same thing as YPbPr.

Component video I readily available on DVD players, and is available on current and last generation video game systems. It is often the holy grail of video signals, as it is often the best an American gamer can hope to achieve. Component video connectors were only found on higher end CRT TVs, but are found on almost all HDTVs.

HDMI (aka High Definition Multimedia Interface)

HDMI is the connection use for High Definition components. It is found on all newer HDTVs. You may find DVI ports on older HD equipment. DVI is mostly compatible with HDMI. HDMI is also found on many Xbox 360s, and all PS3s. It will be on the new Wii U. HDMI is a connector used to send HD video and HD audio along the same cable. It simplifies connections, and has bandwidth exceeding previous standards. Its important to note that HDMI cables have severe distant limitations when compared to older connection standards. Older standards can go 300 feet without many problems. Most HDMI cables are limited to about 15 feet in length.

[CRTGAMER]

Nice article, good round of connections. I really hated how the SVideo standard did not adopt the Commodore 1701 monitor Twin RCA Chroma Luma hookup. The SVideo cable pins are so fragile. New HDTVs pretty much let the SVideo connection drop, sadly maybe because of the temperamental cable connection?

You forgot to mention DVI, common in the early days of HD CRTs.

[BoringSupreez]

You forgot to mention DVI, common in the early days of HD CRTs.

That, and you also said that both RF and composite are the worst possible video connection.