HDMI Splitter shares video

HDMI Splitter shares video …

The HDMI Splitter does the opposite of what the HDMI “Switcher Box” that I covered in my last blog entry does – the Ying and Yang effect. Also known as a HDMI Distribution Amplifier, the HDMI Splitter allows a user to display the same HD image and listen to the same audio from one HDMI source on multiple targets such as LED/LCD TVs or projectors. This effect is sometimes referred to as “Mirroring”. One place where this is done a lot is in home Theater system. But, even more common is there usage in local electronic stores such as Best Buy. In these stores where they have many TVs on display you will notice that most of them are showing the same images. This is done with the use of the HDMI Splitter.

There is a strong correlation between the increase growth in the number of HDMI Splitters on the market and the popularity of High Definition sources, displays and availability of HDMI devices such as Blue Ray players and video gaming consoles. Over the years, there has also been tremendous improvements with regards to functionality for these devices. They track well with new functionality in the HDMI standard. For example, there are a lot of Splitters that has 3D and 1080P video resolution support. Like any other HDMI device there are limits to the allowable Splitter configurations due to system loss. However, it is not uncommon to have a bunch of HDMI Splitters cascaded together to display HD images on up to 64 devices simultaneously with minimal losses. In general, you can find Splitters available in 2, 4 or 8 port configurations. There is an active (require a separate power supply) and a passive version. The consensus is that the passive one is useless and should be avoided. Splitters have CE, FCC, and UL certifications. In some situations such as a consumer electronic show or even a home theater, long wire routes might be needed. In these cases, as with standard HDMI cabling, it is more cost effective to use Cat5e/Cat6 cables. Consequently, a CAT5e/CAT6 HDMI Splitter is used for these types of hook ups.

Conceptually, when you think splitter, the mind might visualize something like a headphone. While that would be representative, it would be a very simple form of this device. Contrary to your visual, like the HDMI Switch, the Splitter device is relatively complex. Beyond the need to make sure the HDMI signal is not degraded while it is being transmitted and shared, there is also a need to manage and account for all the back and forth communication that takes place between the signal device and the display. The information that is being communicated is called extended display identification data (also known as EDID) as documented in the HDMI specification. In a typical two device communication scenario, EDID is sent from the display to the source device to tell the source device what kind of data to send. By itself, that scenario is challenging enough, now add more than one display in the mix and the complexity is magnified. The original source has to communicate back and forth between the new Splitter source and all the displays that are connected to the splitter. Support for HDCP (High Definition Content Protection) which protects the multimedia content from being pirated and guarantees the content makes it to the display, adds an additional layer that needs to be managed by the splitter as well.

So, what are some of things one should consider before buying a HDMI Splitter?

1. The splitter will be limited by the display device with the lowest resolution. For example, if your source device transmits 1080p HD but one TV display 1080p and the second TV displays 720p, both TVs will only display in 720p even though the source device is capable of transmitting 1080p video.

2. It is recommended that you buy an active Splitter device. The passive ones are cheap and does not work as well. So, save yourself the headache and your money.

3. Try to keep the cable length between your source device and displays shorter than 50 feet. Anything more than that, will require some type of restoration/amplification device.

4. Make sure to only buy a splitter that is HDMI authorized testing center (ATC) certified. This will limit your options. But, should allow you to buy with more confidence.

5. Finally, try to buy from a vendor/manufacture that will allow you to return the device if you are not satisfied.

In the following section “Tech Talk”, I will get a little bit more technical about the HDMI Splitter and conceptually what is inside it.

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Inside the HDMI Splitter, basically, you have what is know as a DEMULTIPLEXER. This component is used in the Electronic Engineering world for expanding a single signal into multiple destinations (it might also be referred to as parallel drivers). I can go deep into the details of Boolean equations, logic diagram and truth tables to explain the digital behavior of a DEMULTIPLEXER but, I will save that for another time. Although, it is really not that complex since the expansion is not conditional. Anyway, instead, I will use a highway analogy to convey the point.

Imagine you have a one (1) lane highway that expands into three (3). This is a magical highway that allows the same car that enters via the single lane to exit and travel down the 3 new expanded lanes. By the nature of how the highway is constructed, the process outlined above is done automatically. So, fundamentally, the DEMULTIPLEXER behaves opposite to the MULTIPLEXER.

Also, some of these devices have repeater circuitry to help restore any signal loss that might have occurred as a result of Demultiplexing the digital signals.

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HMDI cable, Huh ?

Yep, another case of a mis-typed search term. Did you mean to type “HDMI Cable” instead of “HMDI Cable” ? It happens to the best of us! Numerous times I started my search with the intention of finding information about HDMI (High Definition Multimedia Interface) and ended up with accidentally typing “HMDI Cable” into the search engine. Assuming that you really wanted to find information about HDMI cables, you have come to the right site.

This entry was suppose to be about “Monster Cables” but, I mistakenly type “HMDI” so frequently that I thought it made sense to add a supplemental entry to help others that make the same mistake as I do.

My first entry on this blog tried to answer the question of “What is a HDMI Cable ?”. It goes into details about the benefits of HDMI and why it is better than the older analog solutions for connecting HD (High Definition) electronic devices together. The fact that it is all digital so the quality of the audio and video is crystal clear. The fact that HDMI is a “smart” cable so it facilitates communication and Ethernet sharing between the connected devices. The fact that a HDMI cable saves you money (even though it cost a little more than a single analog cable) and is easier to hookup since it combines more than 3 cables into one.

The second entry deals with the process of what to consider when buying HDMI cables and where to buy them. The process can be simple or complex based on a whole bunch of factors. However, in the latest 1.4 version of the standard, HDMI Licensing, LLC has new guidelines about labeling that should help to simply the buying process.

Anyway, although “HMDI Cable” led you to this site, I hope you are able to find the information you were searching for. By-the-way, you can also check out the “Additional HDMI Info” page that has links to some other valuable HDMI resources and the many more entries on this topic that will come in the future.

What is a HDMI Cable ?

All cables are not created equally – that is a literal statement ! In my opinion, their has been a paradigm shift in the cable world. This shift is for the better ! For the most part, analogous to the convergence of voice, video and data in the communication space, so too, there has been a convergence in the cables that carry them. The perfect example of this is the HDMI cable. These days, the HDMI port and cable is ubiquitous in both the Computer and Consumer Electronic world. It makes perfect sense, it can be used as a “smart” interface for almost any device that needs to transmit and receive HD signals. Simply, the HDMI cable and port is the best of all worlds:

Quality – All crystal clear digital vs. Analog. No conversion process to distort the signal.

Smart – HDMI connected devices has two way communication with each other. This enables new functionality such as automatic configuration or one-touch play.

HD Content Protection – This is done using a copy right protection protocol name High-bandwidth Digital Content Protection (HDCP) developed at INTEL. This will allow consumers to access premium content that can not be copied in transit.

Ease Of Use – Multiple cables are combined into one to prevent “rat nesting” for a simpler setup and hook-up. With billions of HDMI enabled devices shipped, there is little doubt that it will be the multimedia connection medium of choice. Therefore, using this interface will future proof your entertainment hardware investment.

So, what does HDMI mean anyway ? The acronym stands for: High Definition Multimedia Interface. The High Definition (HD for short) aspect of it is obvious (somewhat ! Since the popularity of this interface correlates with the popularity of HDTV and other HD devices). But, there is so much more to it. From a historical perspective, HDMI is somewhat of an evolution of DVI (Digital Visual Interface), which is a digital video connection that is used in the PC world. One of the main drawbacks of this interface is that it requires a separate audio cable. HDMI fixed that, it is an all in one solution – Video, Audio, High Definition, 3-D, Ethernet and then some. Sounds great, right ?

Well, there are a few things to consider and decisions that consumers need to make when considering the purchase of one of these cables. Like most standards, HDMI is constantly improving. It started with V1.0 and it is now at V1.4 (I won’t get into the details of what is included in each version for this posting – let me know if you would like a specific posting on that). But, naturally, as I stated above, the functionality and features improve with each new version. Here in lies the issue – not all HDMI cables are functionally equal. This stems from the fact that the standard does not require manufacturers to implement all the functions in any specific version. But, the problem goes beyond functionality when you consider non-genuine parts that does not meet official HDMI manufacturing standards. It has been found that a large majority of the HDMI cables on the market are not compliant – they do not meet the HDMI compliance test. This could be due to the fact that these “illegal” manufactures use poor components and manual processes (like soldering) to make these cables. Consequently, the consumer must be mindful of these facts when they are trying to make a buying decision.

Hopefully, I was able to answer your question of “What is a HDMI Cable ?” For the next blog entry I will speak to what a buyer needs to consider when buying  HDMI cables and where to buy them.