All you need to know about Video Outputs

If you are thinking of getting into home theater systems, there is no doubt you will encounter all the different connectivity jacks which you probably have never heard of. Here I will explain all the types of video outputs from a DVD player. You might have heard of these: composite video, component video, S-Video and the latest one will be HDMI. So which is actually the best? And what are their differences in the output of the picture quality?

First of all, the logic you need to know. Unless you are a beginner, skip this paragraph. If all you wanted to know is the conclusion, go to the last paragraph. In electronics terms, support and compatibility matters. So, if you have an excellent DVD player with the latest technology that can output very clear picture, but your TV does not support that output from your DVD player, you will still end up with poor picture quality. Isn't that obvious? You just wasted 5 seconds of your life. Now move on.

Let's get technical now. We can only see three colours in our eyes: Red, Green and Blue. I'm not lying. The rest of the colours is a mixture of these three. So in other words, all electronics equipment only need to have these three outputs to produce what our eyes can see. This is commonly called RGB format.

Back in 1953 when colour TV was borned, the standard used was a format called composite video and it has been around even today. These 'yellow video jack' has the poorest quality compared to other video jacks. However many of us are still using composite video jacks from our cable TV (eg. Astro), sadly because the receivers normally only has that particular output.

The composite video was developed by compressing all the information from the three components (RGB) into one single cable for broadcasting. Unfortunately, compressing and un-compressing these signals causes loses in distortions. ie. when you play a DVD disc, the DVD player convert (compresses) all the great component of your DVD signal into one single signal. The signal is then sent to the TV, the TV then un-compresses to restore to its original three component signal. Too much conversion, too much losses.

Next is the S-Video jacks. Just like the Composite Video, S-Video also has only one cable. An S-video cable actually carries two separate signals, one for luminance and one for chrominance or color. By keeping luminance and chrominance information separately it prevents most of the signal degradation that is inherent in the conversion to single-wire composite video. Have I lost you?

Then comes Component Video. It's easily identified by the three jacks that is available in most newer TV or DVD sets. DVD players with this output usually have three RCA jacks which are color-coded green, blue, and red. They are labeled either Y, B-Y, R-Y, or alternatively Y, Pb, Pr, or Y, Cb, Cr. So, three cables are required. These are better quality as it has less compression compared to Composite or S-Video.

The newest video jack is the High-Definition Multimedia Interface, abbreviated as HDMI. This is the latest industry standard un-compressed, all digital video/audio interface. Notice that I mentioned audio. Yes this jack differ from all others being that this single cable also incorporates audio signals in them.

If you have gone to this far and understood what I was blabbing about, Congratulations! If you have skipped the intermediate paragraphs, aren't you keen to know what actually happen behind all these electronics jargon? Now, scroll back up and read. Ok. Let's conclude. In terms of quality in the order from least to best picture quality: Composite (that yellow jack), S-Video, Component (that RGB wires), HDMI. Those are all you wanted to know isn't it?