# HDMI over cat 5 aka, can I save $600



## TheaterEd (Dec 12, 2017)

My current venue came with a system to send a video monitor feed out to the auditorium lobby. It also has a send to our SL amp rack where our patchbay is located. I can then send the signal to the pit, where I want to set up a monitor. Here's the catch. They didn't include a receiver to turn the signal back from cat-5 to hdmi. 

They say that THIS is what I need, and then I can hook it up a tv and be good to go. But that is over $600.00, and that is what they used back in 2012 when we opened.

Now when I'm on Amazon I see THIS product, which I should be able to just plug the hdmi feed into instead and run it via my network.

Am I missing something, or should this work?

Additionally, I need to get a decent sized TV for this, I figure the money I save on the device will more than cover a workable tv, but I haven't bought one in a while so any suggestions on where to get the best bang for my buck on tvs, or what I should be looking for?

Note: I am at a high school, so I'm looking to do this cheaply, but I want to make sure I do it right.

If pictures of my set up would help, let me know.


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## MNicolai (Dec 12, 2017)

It's a proceed at your own risk kind of thing.

The Amazon widget is HDMI over ethernet. It's performing compression on the signal before shooting it across a network link. You'll get more latency out of it, and you won't be able to control your endpoint display/projector through the Crestron system. If you're using it for your pit conductor to have a good view of the stage, you'll be disappointed because it will be too delayed from the action. Use of this widget is contingent upon having an HDMI output from somewhere you can use for this. You can not use a DM 8G+ output from a switcher or transmitter to drive one of these receivers.

The Crestron widget is point to point, HDBaseT(ish). It does not have compression and only has a couple frames of latency(your display will still add some latency on top of this). It also has a scaler so if someone is presenting a 16:10 source through the system, it will show up correctly through the scaler on a 16:9 display. It'll also prevent upstream devices from getting hit with EDID issues and be forced into the 16:9 aspect ratio, depending on what exactly is upstream.

That said -- if you're using it for your conductor, you'll still have a little bit of latency through the display itself.

That it's 4K probably doesn't mean anything to you since I'm guessing whatever upstream switcher or transmitter is circa 2012 and non-4K. This receiver will still work but you won't be driving 4K into it anytime soon.

If they didn't give you an RX for this location, I'm guessing the cable was installed for future. In which case you may need the Crestron programming touched up on your control system in order to route video to this output unless they left you a phantom button on your touch panel for this purpose.


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## TheaterEd (Dec 12, 2017)

Mike,

I do have and HDMI output, also the current system is a stand alone system that isn't connected to any of my control panels. 

Just heard back from you're old employer that I would also need to pay a tech to come out and update the firmware on the transmitter. So that adds a service call to the $600 + box...

If the price was even close, I would just get the crestron and pay the man, but it's over half the cost of the whole project.

Currently I'm thinking to just get the tv, the cart, and the 'cheapo' option and then if it isn't working well enough I can return it and buy the crestron...

It sounds to me like Latency is my enemy here, so i guess my next questions are. Is there a 'middle of the road' product someone could recommend? What do I look for to get a TV with as little latency as possible?


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## FMEng (Dec 13, 2017)

HDBaseT is a standard, so another brand might work with the Crestron transmitter. I'd buy a Kramer TP-580R and see if it works. If not, buy the matching TP-580T and you are still money ahead.


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## MNicolai (Dec 13, 2017)

So you have a TX-201-C in your control booth that drives a CATx cable down to your amp rack, and from there you have a CATx cable that goes down to your pit, and you want to link the two together to get a signal from your booth down to the pit? Is my interpretation correct?

You could save a little bit on the firmware expense by shipping the TX to them, and then they upgrade and test in the shop and return ship to you. Doesn't save you buckets but maybe saves you a trip charge. If there are any issues with the upgrade, its faster to triage a problem on the phone with Crestron from the shop than in the field.

It's probably your best bet, given that hop-scotching from your booth to your racks, racks to the pit probably puts you over the ~165' limitation of most consumer-grade 1080p extenders. If you are going to try to order something cheaper first though that you can return, I would do it through B&H Photo's website. The customer reviews aren't all faked by bots and paid reviewers, and their return policy is better more "30-Day Satisfaction Guaranteed" on most purchases. Whereas if you go through Amazon you may end up having to go through hoops to justify the return, especially if isn't a product sold directly by Amazon.

Another option would be to look at the Blackbird products Monoprice sells and forgo the existing TX. Not sure what their open box return policy is but for $60 it's not much of a loss if you have to repurpose the units somewhere else. I haven't used the Blackbird products myself but I've heard okay things about them.

As for TV's, I would compare anything you're looking at with the results posted at DisplayLag. In general though for any TV you need to throw it into Game or PC mode to turn off the extra digital processing and get the fastest input latency possible.

In a case like this, you're looking at 3 stage of latency. Camera processing into HDMI > HDMI flipping to and from HDBaseT > Display Input Lag.

If you're working at 60FPS on the camera, and display 60FPS on the TV, sometimes you get a little extra performance bump because with something like the Crestron TX/RX, those conversions are measured in frames instead of ms. So if you have 1 frame of latency at 60FPS (16.6ms/frame) across the HDBaseT link, you cut the conversion time in half instead of driving the system at 30FPS (33.2ms/frame).

If you didn't already have the copper in place I'd say you'd be better off with HD-SDI across coax. Cameras can spit the signals out analog faster than digital, you don't have extra conversions in their along the transmission path, and then you're really only fighting the input lag on the TV.

It's probably not make or break out to proceed as-is. A little practice and everyone learns to anticipate or lead the video so long as you keep the overall latency somewhat tame. I put together a few quad split videos awhile back showing how the different latencies affect speech and musicians that can give you a sense of magnitude on how much latency is too much.

Top left video is in-sync. All others are following the audio by the marked latency. Frame rate is 29.97 for both sets. Frame numbers marked in the upper right corner of each quad.


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## Chris15 (Dec 13, 2017)

MNicolai said:


> The Crestron widget is point to point, HDBaseT(ish). It does not have compression and only has a couple frames of latency(your display will still add some latency on top of this). It also has a scaler so if someone is presenting a 16:10 source through the system, it will show up correctly through the scaler on a 16:9 display. It'll also prevent upstream devices from getting hit with EDID issues and be forced into the 16:9 aspect ratio, depending on what exactly is upstream.



The link is to a DM-RMC-4K-100-C. The 100 C is not a scaler, you'd need a DM-RMC-SCALER-C or DM-RMC-4K-SCALER-C to get that functionality...


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## MNicolai (Dec 13, 2017)

Correct. I was responding on the fly and mistakingly thought that the scaler unit was linked.

Not sure it matters for a pit camera feed either way. IIRC, the scaler adds another touch of latency and it would be best to not use scaling in this application.


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## TheaterEd (Dec 13, 2017)

MNicolai said:


> So you have a TX-201-C in your control booth that drives a CATx cable down to your amp rack, and from there you have a CATx cable that goes down to your pit, and you want to link the two together to get a signal from your booth down to the pit? Is my interpretation correct?



I believe that is correct. Here are some pictures.





Am I correct in thinking that if the distance to too far for a direct run, that I could run it into the switch and then patch it to the correct spot?


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## TheaterEd (Dec 13, 2017)

FMEng said:


> HDBaseT is a standard, so another brand might work with the Crestron transmitter. I'd buy a Kramer TP-580R and see if it works. If not, buy the matching TP-580T and you are still money ahead.


Imagine for a moment that I have no idea what HDBaseT is..... Lol. I'm learning, but slowly. I think I'm starting to get what's going on here the more I look into it, and the more questions I ask.

You are saying that I might just be able to get one of THESE and it MIGHT work with my current transmitter, but if not I can always just get a transmitter as well and still be under $400 with no need to pay for a tech to come out.

I didn't see it in the write up, but if I run the signal into my switch, could I then send it to two different of these Kramer units? If I am able to save this much, then I might as well just get two set ups and have a mobile backstage monitor. (or am I just getting greedy now )


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## MNicolai (Dec 13, 2017)

TheaterEd said:


> Am I correct in thinking that if the distance to too far for a direct run, that I could run it into the switch and then patch it to the correct spot?



Not in this case. HDBaseT is not an TCP/IP ethernet-based protocol and will not jump through a switch. Strictly point to point and takes advantage of being able to use CATx cable for something other than network data. Any TX/RX pair is designed for a specific transmission distance.

There are some newer very low latency networked solutions out there, but they're still pretty pricey. To the tune of $1400/endpoint. Certainly some networked options available below that price tag but they suck up more time in the compression/encoding/decoding process and are way too high of latency to be useful for this application.


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## TheaterEd (Dec 13, 2017)

MNicolai said:


> HDBaseT is not an TCP/IP ethernet-based protocol and will not jump through a switch.



Got it, so the device like this that I originally linked is capable of going through a switch because it translates the signal to TCP/IP, however that adds latency whereas the HDBaseT is a different type of signal and needs an uninterrupted run between transmitter and receiver.


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## MNicolai (Dec 13, 2017)

Right on the money!


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## TheaterEd (Dec 13, 2017)

Got it. So. Here is my current plan of attack.

Step 1: Research and buy low latency tv, buy $80 dongle, and see if that is good enough for the conductor. If that works, then I buy an additional receiver and monitor for backstage with the extra money #twoforthepriceofone.

Step 2: If that is too much latency, I buy the kramer receiver. If that works, then I buy an hdmi splitter so I can still use the cheapo for a backstage monitor which I will purchase at that time (note, I plan to plug the splitter into the line feeding the lobby monitor as latency there will be less important (this is the one thing that sounds fine but I feel like is more complicated than I think it is).

Step 3: If the Kramer doesn't play nice with the crestron transmitter, then I'll buy a kramer transmitter as well and look at remaining budget at that time to see if backstage monitor is an option.

Step 4: Accept all the praise and adoration from my coworkers for figuring all of this out as they will surely understand how complicated this all is.....


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