Challenging problem with AJA converter and very specific combo of other equipment.

S

sissond

Member
I am troubleshooting this as a favor to another community access station in the area I occasionally work with. Before you dismiss the problem with the easy suggestion to just use a different camera, know the total budgets we work with at many of our local stations is only about $50,000-80,000. Most of that goes into payroll and we can only replace equipment every few years with grants. So, these Panasonic AG-HMC70 and HMC80 cameras are what they have to work with.

So the problem is that there is a heavy magenta colored cast in the video signal when using the HMC70 or HMC80, sent to in of Atomos Ninja Blade, out to AJA HDMI to HD-SDI converter, out to Tricaster 460 production switcher. It has the look of using component video without all the colors connected.

If I remove the Ninja Blade from the chain, the cast is gone. If I use a different model of camera, the cast is gone. If I send the HD-SDI signal to a external monitor or a Broadcast Pix production switcher, the cast is gone. I have tried LOTS of different settings on the cameras and the Tricaster with no success.

Now I'm no broadcast technician and I don't have any formal training in broadcast. I've just been doing this for a while now and I have a knack for technical stuff and troubleshooting. I'm the best hope these small local stations have and I'm stumped. Please help if you can.

To help the cameramen, I've been bringing my personal external on-camera monitors lately when I've been working with them directing the high school football games. I'd prefer to figure this out and stop putting my own gear at risk. And when I'm not there with my gear, they are stuck using the tiny 2" flip out LCD's on the side of the camera.

Here's a link to a hastily made video I made with my crappy cell phone late last night. I do apologize for the poor quality, but I worked a LONG day and I'm doing this troubleshooting as a favor. I just didn't have it in me to film it right.
https://youtu.be/e-YqyKkhu3s

FYI, I'll be posting this in Atomos, Panasonic, and Tricaster forums that I may find.

Thanks in advance for any help,
Doug
 
I'm 99% sure it is a Color space issue. But I don't know why.

HD-SDI is only YUV*, HDMI can be YUV or RGB.

So it seems like at some point, something is sending RGB down the HD-SDI cable & the Tricaster is expecting YUV, thus magenta. So either something is switching the YUV signal to RGB, or when going from the camera to the recorder one of those devices says "Let's do RGB today" and the other says "OK! Sounds like fun."

$300 solution is getting a Decimator MD-HX, the thing is amazing for the price for the 100 different things it does. One of the things it'll do is change (correct) the color space. The other thing it could do is take the HDMI signal from the camera, spit out HDMI to the Atomos & also spit out HD-SDI to the Tricaster.

http://decimator.com/Products/MiniConverters/MD-HX/MD-HX.html

Best of luck!


---


* YUV or YCbCr, there's a difference between the two, but I forget & for what we're doing close enough. Biggest thing it YUV is easier to say, and YUV / YCbCr is very different from RGB.
 
zijital said:
I'm 99% sure it is a Color space issue. But I don't know why.

HD-SDI is only YUV*, HDMI can be YUV or RGB.

So it seems like at some point, something is sending RGB down the HD-SDI cable & the Tricaster is expecting YUV, thus magenta. So either something is switching the YUV signal to RGB, or when going from the camera to the recorder one of those devices says "Let's do RGB today" and the other says "OK! Sounds like fun."

$300 solution is getting a Decimator MD-HX, the thing is amazing for the price for the 100 different things it does. One of the things it'll do is change (correct) the color space. The other thing it could do is take the HDMI signal from the camera, spit out HDMI to the Atomos & also spit out HD-SDI to the Tricaster.

http://decimator.com/Products/MiniConverters/MD-HX/MD-HX.html

Best of luck!


---


* YUV or YCbCr, there's a difference between the two, but I forget & for what we're doing close enough. Biggest thing it YUV is easier to say, and YUV / YCbCr is very different from RGB.
Click to expand...
Thanks for the PM! I have been very busy lately with election season ramping up and hadn't checked the forum lately. Yes, I agree that this must be the issue. A tech from Atomos suggested it being a color space issue as well, but did not mention that HDMI can be either YUV or RGB. I didn't know that.

So, if the HMC80 outputs YUV (not sure what it outputs), which the Ninja Blade might be okay with. And then the Atomos outputs RGB to the AJA box, could this cause this if the AJA only accepts YUV? Or is it more liekly a situation where sending the video through the Ninja Blade may be altering the signal in some way where the AJA box doesn't know what it's looking at?

Thanks for your help!

-Doug
 
Hi Doug,
AJA provides technical support free of charge. I would suggest contacting them for help. One thing to note: an AJA Ha5 converter supports HDMI input of YCbCr or RGB. You can read about this on page 6 of the user manual for the product. The user manual can be found here:
https://www.aja.com/assets/support/files/97/en/AJA_manual_HA5_v1.0r2.pdf

It is possible that RGB is being sent to the Ha5 converter and the output range of the Ha5 converter is not configured in a manner that is suitable for your downstream equipment. There is an internal jumper on the converter for the range which you can also read about on page 6 of the manual.

AJA Technical Support is available via phone or email, Monday through Friday between 9am and 5pm PST:
https://www.aja.com/en/support/contact
 
Jon Thorn said:
Hi Doug,
AJA provides technical support free of charge. I would suggest contacting them for help. One thing to note: an AJA Ha5 converter supports HDMI input of YCbCr or RGB. You can read about this on page 6 of the user manual for the product. The user manual can be found here:
https://www.aja.com/assets/support/files/97/en/AJA_manual_HA5_v1.0r2.pdf

It is possible that RGB is being sent to the Ha5 converter and the output range of the Ha5 converter is not configured in a manner that is suitable for your downstream equipment. There is an internal jumper on the converter for the range which you can also read about on page 6 of the manual.

AJA Technical Support is available via phone or email, Monday through Friday between 9am and 5pm PST:
https://www.aja.com/en/support/contact
Click to expand...

Thank you Jon! I went to bed shortly after posting last night and I was planning on contacting Panasonic and AJA today. I looked over that manual before (weeks ago) and didn't catch the info about the #2 jumper that adjusts the video range. I'll definitely give that a try this morning before I contact them.
 
The problem could be anywhere, and so could the solution.

I'm only guessing, but I think the Tricaster needs YUV coming down the HD-SDI cable. If you can tell the Tricaster it's getting RGB, maybe it can fix things up there.

I'd be surprised if the Atomos or AJA are changing the color from YUV to RGB (though maybe one of them is). I'd think they just send out what they get in.

My bigger guess is the HMC80 can send out either RGB or YUV. So when you connect the AJA to the HMC80, the HMC80isends YUV, but when you connect the Atomos to the HMC80 it sends RGB.

If that's the case, then one solution would be to have either the HMC80 only send out YUV or the Atomos to only accept YUV. But I'm thinkng that would have to be a firmware update as I'd be a little shocked if it was already built into the menu settings.

ugh, HDMI handshakes can be such a pain... Best of luck.


P.S. I've called AJA when I had trouble with a Ki Pro. Easy to get a hold of & they were quick to help me fix the problem. Great customer support.
 
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