DVI to HDMI - HDMI Basics Part 2

In the last post we discussed the benefits of HDMI and other basic information. Now we'd discuss some more details regarding the benefits of HDMI.

HDMI is mainly meant for transferring digital information like audio and video in an uncompressed format, and there would be no degradation of quality while that happens.

One important thing to note though is, that it is totally compatible in a backward way with dvi. So you would just require a dvi cable to connect and a dvi to hdmi adapter in between. This enables the device manufacturers to put in extra detail in the output given by the devices.

Previously in the earlier display devices, there used to be one way communication channel between the video source and the display device. But then with the advent of HDMI, there has been set up a two way communication channel between the two, and the the source of the video can now contact the display device, and then device can talk back to the source and try adjusting itself automatically based on the content being served by the source. This enables the device to identify whether a source is sending information at a 4:3 ratio or 16:9 ratio and then adjust itself to broadcast that resolution.

HDMI also keeps in mind the distances usually used for cables, and thus it can easily accommodated copper cables of length up to fifteen meters. And best part is, it doesn't even require amplifiers to amplify the signal. This is a lot better when compared to the dvi amplifier which need to be repeated every 5 meters.


Another great advantage of the HDMI cables is the fact that it is very easy to manufacture the HDMI cables. At higher resolutions you can easily make out the quality difference between a normal S-video and a HDMI brought in video. Even when you look at the corners of the text, it is very noticeable.

Very important advantage is the fact that, HDMI is a single cable, and thus reduces the hassle of connecting multiple cables at multiple spots. This also reduces the mess that is usually created behind the tv. This cable can be effectively used in dvi to hdmi connection.

DVI to HDMI - DVI Basics Part 2

DVI TO HDMI: Tech Spech of DVI

Among DVI to HDMI, DVI cable is capable of accommodating up to 2 transition minimized differential signaling ( TMDS ) links, the Extended Display Identification Data (EDID) services the VESA Display Data Channel (DDC), and also the blue, green and the red vertical and horizontal sync lines that belongs to an RGBHV video signal which is analog and is backward compatible with analog VESA video. In the DVI to Hdmi, when dvi is using TMDS, that can only mean that it is totally capable with both the DFP and the P&D standard is also compatible with HDMI.

DVI: Length and Bit Rate

Every link that is contained in the dvi is made up of 3 channels which carry data (RGB info) and is having a maximum of 165 Mhz Bandwidth, which in other words is equivalent to 165 million pixels per second. ; this equates to 165 million pixels per second, considering that its 8 bit per color, and 24 bit depth. The DC balancer minimizes the every incoming 8 bit color data word, and is transitioned into 10 bit word. And that means that every pixel is denoted by a sum of 30 bits. That means, among the dvi to hdmi, the dvi single cable is able to put up a throughput of 4.9 Gbps and when the case is of dual link dvi, then it is a maximum of 9.9 gbps.

The main thing about the DVI cable is the problem with the length. The DVI cable are usually very short, and the problem arises when you decide to do a dvi to hdmi transition or use it for your home theater system and want to connect the cable to a wall mounted projector or a far off tv.

If not DVI then what?

Usually people use twisted cable instead of coaxial, for video connection, but the same might degrade over the long distance and might introduce noise in the video and audio. Consider the dvi to hdmi thing for instance, your dvi cable is given a standard maximum length of 5 meters only. Now how long your cable is depends on what kind of bit rate you are expecting out of your dvi cable. The higher the bit rate, the shorter your cable has to be. There are manufacturers who claim up to 50 meter of dvi cable, but god knows at what bit rate!

Little more about DVI

As the dvi cable has a maximum bandwidth of 165 mhz, on a single link, it is capable of carrying 1080p HDTV signal at 60hz, within a single interface. Now the same is double in the dual link dvi. But you'd have to use a twisted dvi cable for the same purpose, and you would also be in need of additional pins to connect the additional dvi cable, as a second link. Before you jump over to dvi, better do a background check on the availability of the support for this cable in the present market and availability of support for the same upon the various devices.