People new to video cables often get confused between RGB and S-Video. So if you’re mystified between S-video and RGB, you’ve clicked on the right link. In this article, we’ll explore both the displaying technologies to clear your confusion for once and all.
What is S-Video?
S-video, which stands for Super-video or Separate-Video, is a signaling standard for transmitting video signals through a cable. This is used for SD or Standard Definition videos.
The cable is connected from a DVD player to a TV. A lot goes on behind the scenes which an average user doesn’t need to care about. But if you’re looking for the difference between S-video and RGB, then you should.
Let’s start with absolute basics.
The signal goes through several processing steps when it is transmitted from the broadcast station to the TV. In each of these steps, there is a loss of information and hence quality.
The first step is the conversion of RGB into YPbPr. We’ve explained RGB in more detail later, but now, just keep in mind that the color model is used to capture the color combination of live images.
YrPbPr signal is three signals combined into one. Manufacturers often refer to this as component video. Y is the first signal which is created by combining the original signals. There is a set formula that combines the signals in a specific proportion that produces the image’s brightness. In technical terms, this is known as luma.
Y signal once produced is subtracted from RGB’s blue, which produces Pb, and then subtracted from red that produces Pr. To recover the original RGB information, all of these are combined at the other end. You’ll see the green signal on your screen that confirms this output. To put it in another way, the black-and-white signals are separated by coloring signals to achieve SD image quality.
But this mode of transmission is as difficult to transmit as the original RBG signal. Therefore, YPbPr is further processed to form the C Signal, which stands for Chrominance.
In S-Video, the video information is first divided into two separate signals: Chrominance and others for the brightness or luminance. It is then combined at the television end to produce sharper images that are better than composite, the upper version of component videos.
You’ll find S-Video’s use in magnetic tapes, VCR players, and outdated gaming consoles from Nintendo and Sega Genesis.
What is RGB?
RGB is an analog video signal that is based on the Red, Blue, Green color model. These three colors are added together to generate other colors. In signal transmission, RGB has another component, which is Sync. Hence, it is known as RBGs or Red, Blue, Green, and Sync.
As mentioned earlier, most images are collected in RGB format. They are then processed multiple times by the time the signal reaches the TV screen. The signal is displayed in the same way the console or DVD player-generated it. If it’s an RGB-enabled monitor, then Red, Blue, and Green are separated into their own signals before being combined on your display.
For consoles or DVD players that support S-Video, the video signal is separated into two parts, namely, Chroma and Luma. Although this produces a decent quality signal, the RGB method is still better. Another advantage of the RGB video standard is that it requires no compression and doesn’t impose any limit on color depth or resolution. But as a downside, it requires much larger bandwidth for transmission.
There are many other video signals, but you’ll commonly find composite video signals and RF video signals. Both of these are inferior to both RGB and S-Signal. The superior of all is the HDMI signal, which promises and delivers high-quality images.
The Wrap Up
Here we come towards the end of this article. It won’t be wrong to say that S-video and RGB are very similar yet different. While S-video only shows a bit of color bleed, RGB provides you with the best picture in terms of clarity and vibrancy. S-video mutes the colors slightly and looks pretty bad in games like super ghouls and ghosts. However, this is not the case with RGB which looks the best regardless.
Another significant difference is the components both the video formats use. While S-video makes use of 2 signals – Chroma and Luma; RGB comprises of three signals – Red, Green, and Blue.
Since color, information needs 3 pieces of information, and S-video only consists of two signals. This means that one of the signals, Chroma, comprises of multiplexed information, which often deteriorates the quality due to real-world interference. This is the reason that TV with S-video doesn’t offer a great picture quality, suffers from interference, and spreads out.
However, in certain cases, the difference between the two might not be obvious, and both the video formats might look similar. This depends from device to device and your personal preferences as well.
So, these were the basic differences between S-video and RGB. Can you think of more? Let us know in the comments below.