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Dark Image from VidiU with composite source

Posted: Tue Sep 15, 2015 10:52 am
by ThomsonMA
I purchased the recommended Startech unit to convert our composite source to HDMI to use with the VidiU encoder.

If I test the Startech unit locally, for example by connecting a DVD player as input and connecting the HDMI output to a TV set, I get a reasonably good image.

But in my testing, when I connect the HDMI output to the HDMI input on the VidiU and try to run a broadcast, the resulting image is really dark, Sufficiently dark that it is not usable for our Stake Conference webcast. (I can't make the chapel at the receiving site dark enough that the image is viewable.

Has anyone else seen this issue with a dark image? I tried various settings on the Startech with no joy, and I could not find any settings on the VidiU that would allow me to improve the image quality.

Thanks for any feedback or help!

Re: Dark Image from VidiU with composite source

Posted: Tue Sep 15, 2015 11:10 am
by russellhltn
ThomsonMA wrote:But in my testing, when I connect the HDMI output to the HDMI input on the VidiU and try to run a broadcast, the resulting image is really dark,
Are you using the same DVD source in your test? I'd try that first before pointing fingers at the equipment.

If you're using the camera feed, then the signal is probably just getting weak before it hits the Startech. It may not look dark on the modulators because they can be set to compensate for the signal loss in the long cable. Also keep in mind that the camera video signal can't be split or shared with a passive splitter or "Y" cable. You have to use a distribution amp to send the camera signal to more than one device. If you have a distribution amp, see if you can adjust the gain to bring the picture up.

Re: Dark Image from VidiU with composite source

Posted: Tue Sep 15, 2015 11:42 am
by ThomsonMA
Thank you for the quick feedback. I was taking my input directly from a video distribution amplifier that also fed my local monitors and DVD burners, but the signal does go through a fork to the building video distribution before it hits the input to video distribution amplifier. I can see that there could be some loss there so I'll try putting my feed directly into the distribution amp and then take the output from there into the building systems. Hopefully that will help.

I will note, though that my plan B for the VidiU is OBS running on a PC with an Osprey video capture card, and I got a much brighter image using that method. It could just be that the Osprey has a better ability to deal with the weaker signal.

Re: Dark Image from VidiU with composite source

Posted: Tue Sep 15, 2015 8:05 pm
by rolandc
If you do not have an AVDH1 webcasting hub, then you will need two of the red emtech DA's one for the camera and one for the satellite system. neither output should be split before the DA.