Analogue Video (Composite and S-Video)

You will only want to use analogue video for one of a few reasons.

1. Your video is already in the analogue format on a video tape recorder/player.
2. You have an analogue camcorder and can't afford/don't want to buy digital.
3. Your PC has an analogue in/out card.
4. You like a challenge

How do I recognise them
Composite video uses a yellow Phono socket (or RCA jack) and cable, S-Video utilizes a four or seven-pin mini-DIN plug and S-Video cable.

Which is best
If you have the choice, it is best to use S-Video as you get a higher quality picture to composite video since it avoids some of the processing that composite video requires.

The longer answer
A video signal is a mixture of brightness or luminescence, the Y stream, and chrominance or colour, the C stream. The C signal carries values for red and blue, while green values are deduced. Hence, RGB, or red, green and blue, occupies just two data streams within the C signal.

Using composite video the Y and C signals are compressed into a single stream and passed through a single wire, then decoded at the other end. This process leads to a loss of picture quality. S-Video sends each of the Y and C signals through it's own wire which therefore reqires less processing and results in a better picture.

Both composite video and S-Video only transfer pictures. You will need audio cables to transferring sound as well.