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Brite-View Air Sync HD testing round 1


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#1 William Demeritt

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Posted 14 May 2011 - 07:41 PM

I've actively posted in some of the other threads regarding using the Brite-View Air Sync HD as a low cost HD transmitter solution, so I'm here now to post my first round of results of testing with a few videos I shot at Clairmont last week.

For those unaware, Brite-View as well as Asus have been selling a consumer product which allows for streaming 1080p video inside your house, from one box to another. The guts that make this work are parts by an Israeli company called AMIMON, who also happen to supply the parts for the IDX Camwave (and I suspect parts for the Transvideo Titan HD).

Yes, these are consumer products which rely entirely on HDMI input and HDMI output. However, for $220, and with the advertised broadcast capability, I thought they'd be worth considering for our purposes (Steadicam, narrative, etc). If anything, my hopes are that this inspires some clever company to actually address the "low cost" HD transmitter market whose lowest price seems to be $5,400 (Camwave) -$6,000 (Boxx Atom).

FIRST CAVEAT: this system hates any video input that is not 29.97. I spent the first 30 minutes struggling with the transmitter because the F35 was giving me 23.976. Yes, that's a huge problem, and something I'm going to begin researching portable ways to address that problem. With a camera like the RED, that's not a problem, because the HDMI output on camera already does 29.97, so it plays very nicely.

So, here's my rig built with the transmitter:

Attached File  testbuild1.jpg   156.3KB   475 downloads

I built my own power cable with a 12/24v transformer that draws power off my AUX port and converts it to 5v. The transformer handles up to 6amps, which is good since the transmitter requires 3amps. My next task will be to build D-tap power cables.

The signal works this way:

Sony F35 -> HD-SDI -> Decimator 2 -> HDMI Loopthrough -> HDMI cable to -> AirSyncHD transmitter -> TRANSMISSION
...
TRANSMSSION -> AirSyncHD receiver -> HDMI Cable -> Monitor

NOTE: I also tested this, and it worked seamlessly:

TRANSMISSION -> AirSyncHD receiver -> HDMI Cable -> AJA HA5 -> HD-SDI -> Monitor.

The system works just fine with an AJA, so you don't always need an HDMI capable monitor. HDMI inputs are appearing more and more on set, but at least this protects against all scenarios.

ENVIRONMENT: we were testing at Clairmont yesterday, which for all I can tell was a fairly noisy RF polluted environment. They have wifi, LOTS of fluorescents, an elevator, plenty of cell phones and the such. With that in mind, we threw the system to the wolves and it did quite well.

Test 1: 60 feet moving camera with obstructions (several layers of drywall, a staircase, people, etc).

http://www.youtube.com/watch?v=RQjDxOVmAFM

Brian Freesh helped record me and my walking path, while a second camera recorded the monitor's live feed from my transmitter. I did the walk a few times, and during none of those trips did the image break up, pixellate or drop out. I removed my external antennas during one walk, and the image did distort.

Test 2: Latency at 12 feet, line of sight



Here, we rigged up the TVLogic monitor with both inputs in a split screen: one line is hard wired off the F35 HD-SDI, and the other is using the wireless transmitter. I used my iPhone 4's stopwatch to create a running clock for comparison. You can try to guess which is the transmitter and which is the hardwired.

Test 3: Latency at 60 feet, line of sight



Same test as the 12 feet, but it's at 60 feet. Same results: no discernible latency. My apologies for the glare.

Other tests performed included me getting into an elevator on the 2nd floor and riding down to the 1st floor. Image held up during the elevator ride, and 15 feet down the hallway before the image was lost. Image was not restored until I got back onto the same floor. (I'm hoping to address this problem with the next modification, where I'll add an antenna to the uplink, so the communication between devices is more robust).

My next phase will include tweaking the receiver unit to include an HDMI -> HD-SDI (most probably an AJA HA5), a single power until for both devices and possibly some more antennas. That being said, I'm still seeing the raw costs not exceeding $2,000 (so far, with the videos you see above, I have spent only $500 including cost of the kit).

My goal is to make this as set friendly as possible: the receiver could be a single box with minimal bells and whistles. The transmitter, while goofy looking now, is just a prototype. I want to rehouse it still into a box as lightweight, but with more internal space for cabling.
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#2 Michael Wilson

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Posted 14 May 2011 - 09:43 PM

That is awesome. Good work.
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#3 Caleb Ennis

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Posted 14 May 2011 - 10:03 PM

This is a kool idea! Love where this could go B)
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#4 Thomas K. Jensen

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Posted 15 May 2011 - 02:32 AM

Hey William.

How did you mount the extra antennas?
Is it a wireless access point of some sort?

I have bought the Titan HD - and I'm very impressed of the quality - both image and build.
But the it costs about 12-14 times as much as the Brite-View.
So for my second setup - I just ordered a Brite-View Sync HD.
It will also be really nice to have for getting the On Air signal back to my sled.

Can you post some detailed pics of your setup?

Thomas
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#5 William Demeritt

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Posted 15 May 2011 - 02:06 PM

Thomas,

The external antennas are rather crude on this prototype, but I think my final version will look similar:

Attached File  210447_10100359665833632_5110647_56680805_4367491_o-1.jpg   62.88KB   336 downloads

Not shown is my power cable, which is simply an AUX power LEMO for my PRO, runs to a 12/24v -> 5v transformer (big grey heatsink), runs out to a simple DC plug.

Basically, they're 4 wifi antennas specifically for 4.9-5.8Ghz range mounted to SMA connectors on pigtails. The pigtails are cut and soldered down to the PCB antennas inside the AirSync HD. I don't own a spectrum analyzer, or I could have verified their actual broadcast output, but when I removed the antennas and did my "walk", the signal didn't carry as long, so I know they're contributing.

Probably by mid-June, I'll have my final proof-of-concept finished and I'll begin showing my presentable version. Depending on the popularity, I may sell my conversion as a service for people who are interested, but that depends on other factors.
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#6 Charles Papert

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Posted 15 May 2011 - 02:36 PM

Good job Will!

One way to get around the input frame rate issue may be with the upcoming MD-DUCC unit from Decimator which is an up-down-cross converter; this will allow you to designate the output at 29.97 and feed it any of the 26 supported input formats (including SD!)

http://decimator.com...CC_brochure.pdf

Pricing is still being set but it is rumored to be not far off from current Decimator 2.

When I get a demo model in I can loan it to you for testing with currently "difficult" cameras for your setup.
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#7 William Demeritt

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Posted 15 May 2011 - 03:33 PM

Charles, that would be fantastic! I'd love to test it out with the system.
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#8 William Demeritt

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Posted 17 May 2011 - 01:38 PM

Fun new development I need to test, but the 1.1 Decimator 2 firmware upgrade (which also adds framelines over HDMI) also adds scaling over HDMI. I installed the control panel and set it to force 1280x720p29.97 over HDMI. I think that may solve my headaches with problem cameras, but we'll see.
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#9 David Williams

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Posted 18 May 2011 - 12:13 AM

Amimon released a new WHDI chipset late last year, and Hisense recently announced a product based on it. Might be worth investigating. The transmitter is now tiny, and powered from the HDMI port.

http://thetechjourna...cessories.xhtml

Supposed to be the same range, with the latest HDMI standard.
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#10 Jess Haas SOC

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Posted 18 May 2011 - 12:32 AM

When you soldered the pigtails to the antennas was there a place to solder the shield? if not the pigtail would be acting as part of the antenna screwing up the tuning.

Sounds like your mod voided the FCC approval for the device so I wouldnt plan on selling them unless you want the FCC breathing down your neck.

-Jess
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#11 Eric Fletcher S.O.C.

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Posted 18 May 2011 - 12:51 AM

Sounds like your mod voided the FCC approval for the device so I wouldnt plan on selling them unless you want the FCC breathing down your neck.



Lighten up Francis, last time I check modulus and canatrans transmitters are'nt FCC approved and no one is breathing down their necks
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#12 William Demeritt

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Posted 18 May 2011 - 12:53 AM

Amimon released a new WHDI chipset late last year, and Hisense recently announced a product based on it. Might be worth investigating. The transmitter is now tiny, and powered from the HDMI port.

http://thetechjourna...cessories.xhtml

Supposed to be the same range, with the latest HDMI standard.


AMIMON advertised the same device a few months ago at CES and last November, it actually powers over that USB mini plug on the side. I think the range of that will be less simply for the lower power, since the AirSync HD ops at 15w. USB is 5v but usually not above 2amps.


When you soldered the pigtails to the antennas was there a place to solder the shield? if not the pigtail would be acting as part of the antenna screwing up the tuning.

Sounds like your mod voided the FCC approval for the device so I wouldnt plan on selling them unless you want the FCC breathing down your neck.

-Jess


The FCC is definitely a concern but i need clarification on a few things. I found an article from 2004 indicating the FCC seemed to open up the 5ghz band to additional antennas since forbidding aftermarket wifi rubber ducks limit the capabilities for growth. The article needed more research to understand the context, but I wonder if it's safe in the same way routers are sold with u.fl connectors or mmcx connectors and people can buy 5ghz or 2.4ghz antenna to increase range.

However, yea, I'm already thinking my process would require FCC certification, even though I'm not adding to the power output but simply adding antennas.
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#13 Jess Haas SOC

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Posted 18 May 2011 - 09:00 PM

Sounds like your mod voided the FCC approval for the device so I wouldnt plan on selling them unless you want the FCC breathing down your neck.



Lighten up Francis, last time I check modulus and canatrans transmitters are'nt FCC approved and no one is breathing down their necks


Actually the FCC has been harassing people who sell and service them in the US. Just ask Terry West. Im not saying to abandon the project, just pointing out that there are legal concerns with starting a business over a non FCC approved device.

Routers with mmcx, etc connectors are approved for use with external antennas. A device without connectors is not. The FCC considers higher gain antennas to be adding to the power output. That being said your modded device is most likely still within the specs for the band, so you might not get too much flac, but modding a device in this way defiitely is not considered legal.

All that said im glad your experimenting with this and if theres anything i can do to help let me know.

-Jess
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#14 Michael Sanchez

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Posted 19 May 2011 - 10:40 AM

Will,

Great work you hav going on this project. I was AC on a feature here in CO in March where the DP was experimenting with both the Brite View and the Asus transmitters (shot on two RED MX's). We didn't have steadicam but the studio we were in was built for two big warehouses (crates to the ceiling, scaffolding, barrels etc - very crowded and they performed pretty decent. Your idea with the antennaes is great and would yield even better results.

We tested the transmission on several occasions walking throughout studio and from studio to outside and we would get roughly 120-130 ft before we'd lose signal. Not too bad for a $200 unit. We did run into issues when we ran two Asus units one on both A and B cams simultaneously where it occasionally drop signal for 5-10 seconds sometimes in middle of takes. When we would use one Brite view and one Asus combinations we saw less incidents with signal drops, they were still there but not nearly as frequent. A side note we would see big signal issues with our B camera when the AC ran signal from camera to his small hd dp6 monitor then through to the transmitter, it drop signal like crazy. Once he switched it for signal to run from camera to transmitter then to his monitor like I had on A cam it was less frequent.

We powered our transmitters with Tekkeon battery packs which would last about 4-5 hours each battery. And I really liked the Asus over the Brite view especially considering both transmitter and receiver were less than half the size of the Brite view and sat nicely on top RED cam with Velcro between battery/harddrive cradle and back of top handle compared to the Brite view which we had to Velcro to side of cradle body and was more cumbersome.

Looking forward to seeing more of what you come up with on this.
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#15 Andrew 'AJ' Johnson

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Posted 01 July 2011 - 07:33 PM

very interesting new little version of the WHDI HDMI units:
soon to be released i hope...
http://www.itechnews...one/#more-48550

.AJ
Andrew Johnson
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