The latest craze in computer ports and connections is the HDMI port and cables. They are thinner and much easier to use than VGA or DVI. The most significant advantage is that they also carry an audio signal through the same cable as the video signal. Basically you get two in one. Now, I need to clarify that HDMI is not the latest format, but it is the latest craze.
So what is HDMI and why do we need this type of connection? Well, HDMI stands for High Definition Multimedia Interface. HDMI is the direct digital replacement of the analog signal. HDMI ports and cables became popular with the advent of HDTVs. These TVs require a lot of bandwidth to keep up with the information that they can process, which provides the killer picture that you see. Basically HDTVs require more data and need it a lot faster than standard televisions. The HDMI port and cable was the answer to that need.
So what can HDMI do besides transmitting more data at faster speeds? HDTVs can process a progressive signal instead of the older interlaced signal. Basically an interlaced signal means that each piece of a moving image is really only half a picture, but the picture changes so fast that your brain can’t tell the difference. A progressive signal means that each frame of the moving image is a whole picture. HDMI ready DVD players and TVs can process these progressive signals much faster and with minimal transmission loss. The same HDMI cables can also transmit 8 different kinds of uncompressed audio up to 7.1 surround sound. So when you ask why these cables cost so much, this should help you understand what goes into each HDMI cable.
Both HDMI and DVI use a processing system called TMDS, which stands for transition minimized differential signaling. It is just a way of moving information from one place to another. It encodes a signal to protect it from degrading as it moves down the cable. When the TV or monitor decodes the signal, it will know how to compensate for any signal loss.
Because HDMI and DVI use the same protocol, you can use a passive adapter to connect an HDMI cable to a DVI port. A passive adapter is just a cable or connector with different plug ends.
HDMI also has the ability to protect data from piracy. It uses high bandwidth digital copy protection, which you know as HDCP.
HDMI cables are rated as either category 1 or category 2. Category 1 cables will work on shorter lengths for 1080p content. When using a cable longer than five feet, a category 2 cable should be used. An HDMI 1.3a category 2 cable is defined as high speed. A high speed cable will allow for longer cable lengths with less signal loss for 1080p content. They should also be used for 4K monitors, 3D, Deep color and Blu-ray. Category 2 cables have a larger gauge and are built hardier.
I want to be sure to point out that more expensive does not always guarantee better quality. A lot of the time you are paying for the packaging, not just the cable. You can’t go wrong as long as the HDMI cable has these three features:
- Certified HDMI
- Quality materials
- Rated as category 2 or “high speed”
After that just look for the best price.
There are 5 different types of HDMI cables. Choose the one that works for your device. They are:
- Standard with Ethernet
- Standard automotive
- High Speed
- High speed with Ethernet
Personally, I wouldn’t pay extra for the Ethernet feature right now as there is really no need for a networking connection for what an HDMI cable is typically used for.