Internship Video Wall Box Set Up

  Video Wall Box Set Up

For my broadcast engineering internship at Statefarm stadium, another intern and I had to assemble the box that would hold all the devices used for the video wall outside. We put everything we need in a box for accessibility and mobility: especially since the video wall itself can be set up anywhere. The box contains multiple devices that would be utilized to make the video wall work.

I will walkthrough each component that we put in the box. In the bottom, there was to be a mount that would be screwed on later which would contain the different plugs that we can use. In this instance, the bottom of the gray box on the bottom left of the picture was to be connected to the rf house plug that would be screwed on by someone else later as stated. We connect to the RF house, because the cables coming out of the gray box are RF cables. Afterwards, coming out from the top of the gray box is another RF cable. This RF cable connects directly to the tuner. The tuner is a device that grabs free television streams from the air waves and converts them to MPEG (MPEG is the standard for encoding and compressing video images) playbacks of shows and broadcast. How this works is, radio stations send out signals out into the air. However, distance and energy are inversely proportional. As you increase the distance, the signal strength becomes weaker; intuitively you know this. To counteract this, broadcast stations modulate the signal meaning they change the amplitude, phase, and frequency of the signal. According to the equation E = HV (which I learned in general chemistry where E is energy, H is a constant, and V is the frequency), a higher frequency means greater energy and therefore the signal can travel further distances. However, you cannot simply increase the frequency to high amounts because you eventually will pass the 20,000 Hz that humans can hear, so radio stations change the amplitude and phase which have similar effects of increasing the energy which I do not currently know how the amplitude and phase relate to energy. Either way, the signal becomes indistinguishable despite the best efforts to not exceed human hearing and understanding. This is where the tuner comes in. The tuner is responsible for error and buffer correction, demodulation, decompression, and picture reformatting with the key one being demodulation and decompression. As stated, for signals to travel far, broadcast stations need to modulate the signal (change frequency, amplitude, and phase), so the tuner grabs and demodulates the signal flowing through the air, so that we can actually see the signal coming in since modulation make it indistinguishable. You can think of the signal riding a plane, and the tuner gets rid of the plane and returns it to its original state before the flight. It then decompresses the signal to fit the small monitor that should be receiving the broadcast transmission (the monitor is behind the box facing the other way in the picture). In short, we chose a tuner to demodulate the signal.

After the tuner comes the decimator; the decimator is the red box you see in the picture. The tuner has an BNC plug in that we used to plug an SDI cable containing a BNC connector (SDI is a type of signal and BNC is a type of connector). The SDI then connected to a decimator. The decimator converted the SDI signal to HDMI. The HDMI then plugged into the microprocessor. Rewinding a bit, if you notice, the tuner has an HDMI plug in, so technically can plug the tuner directly to the processor without the need for a decimator and that extra step so one might think. The issue with this is that the purpose of the decimator is to scale up the resolution and scaling of the signal. As stated before, the monitor should display the signal coming in; notice how I did not say video wall. The signal still needs to be put onto a video wall. Without the decimator, the display will be indistinguishable since we did not scale up from the monitor to the video wall. The decimator does not only convert signal but also change resolution scaling which we choose from the list of options the decimator gives. In summary, the decimator allows us to scale the signal accordingly.

The last thing to mention is the microprocessor. As stated, the decimator connects to the microprocessor. The microprocessor, like any processor on a device, acts as the brain in processing, storing, and displaying the information it receives. Other than that, as of right now, my knowledge in the microprocessor does not extend beyond that.

One last thing to mention is that the power strip (while hard to see) is the in the middle which is where all the devices get power from.

In conclusion, the video wall box is designed to be portable and accessible. The end result was just that. We took it out where other interns assembled the video and more interns programmed the video wall which we got to learn how to do both.