Video Connectors Tutorial
Composite Video (RCA)
Contents
Composite video is one of the most popular video connection types, and it uses an RCA connector. (Older video projectors can use a BNC connector for this connection.) Composite video is used on the popular “video in” and “video out” connectors, found on VCRs, TVs, DVD/Blu-Ray players, video game consoles from the 1990’s on, and video projectors. On PCs, video capture cards and some older video cards can provide this output.
This is the best option to connect your VCR to your TV set, assuming that they don’t have an S-Video connector. (Usually, newer TV sets have this connector, but VCRs usually don’t have an S-Video output.) For other devices, such as DVD/Blu-Ray players, contemporary video game consoles, video projectors, and PCs, you should not use this connection, because other connection types offer better image quality, and these devices support at least S-Video.
In Figure 7, you can see the composite video input on a TV set, and in Figure 8, the composite video output on a VCR. Usually, the female RCA connector used by composite video is yellow in order to be differentiated from other commonly found RCA connectors, especially audio, where red indicates the right audio channel and white or black indicates the left audio channel. Notice that the TV set from Figure 7 also has an S-video input, which is our next subject.
Since a VCR allows you to record videos, it has two composite connectors, an input and an output. You should co
nnect the VCR output to the input located on the TV set to make the proper connection. The VCR input should be used in case you want to record something from another video source, such as another VCR (for copying tapes) or even a PC with composite video output.
Figure 7: Composite video on a TV set
Figure 8: Composite video on a VCR
In Figure 9, you can see the outputs of a typical DVD player. Even though it has a composite video output, it shouldn’t be use to connect the player to your TV or videoprojector, since usually it has S-Video and/or video component outputs, which provide a better video quality. We only see two uses of the composite video output of a DVD player: if your TV set is very old or if you want to record on VHS tape the contents of a DVD.
Figure 9: Outputs found on a typical DVD player
Some older video cards have an RCA connector, thus providing composite video. This output can be used to connect your PC to a TV (so you can use your TV as a video monitor) or to a VCR, to record images and videos on a VHS tape. The image quality of an analog TV set, however, is far below any video monitor. There are two reasons. First, the screens of analog TV sets work at 640×480 resolution, lower than the most common screen resolutions nowadays. Second, analog TV sets work with interlaced scanning, while video monitors work with non-interlaced scanning (a.k.a. progressive scanning), which provides a far better video quality.
You can also connect your video card to your TV using S-Video, if both devices have this connector. Furthermore, S-Video output from video cards can be transformed into composite video by the use of an adapter, as we will explain on the next page.
However, with digital TV sets (flat-screen TVs) the situation is different, because digital TVs provide higher resolution than analog TVs and are able to use progressive scanning. If you have this kind of TV set, you must use a better connection type to attach your computer to it in order to get the best image quality possible.
Figure 10: A video card with composite video output
You will also find composite video on video capture cards, allowing you to connect your VCR to your computer in order to transform VHS tapes into computer videos.
In Figure 11, you can see the famous RCA male connector used by the composite video connection. The cable on the picture has two more connectors for carrying analog audio (one cable using a white plug for the left channel and one cable using a red plug for the right channel). The composite video cable uses the yellow plug.
Figure 11: Composite video cable
Since RCA connectors are used for several different purposes (take a look at Figure 9), they are usually colored. In order to help you, here is a small list of the most frequently used colors for RCA connectors and cables:
- Yellow: Composite video
- Red: Right channel (audio)
- White or black: Left channel (audio)
- Purple: Subwoofer (audio)
- Orange: Digital audio (a.k.a. SPDIF)
- Green: Component video
- Blue: Component video
- Red: Component video
