Color artifacts with composite to HDMI converter

[TomasoRock]

Dear Forum,

I am doing a computerless VHS to MP4 project with an AverMedia EzRecorder 130 capture device. As these capture devices nowadays have HDMI input only, I needed to convert the composite source to HDMI. I was looking for a converter that does not upscale the resolution of my PAL tapes of 720x576.

The first one I found was the AverMedia ET111, however it does the job poorly with oversaturated colors and on many footages there is a bit of vertical shaking.

So, I switched to a StarTech VID2HDCON converter which gives much better results. It has a Nuvoton W78E065A40PL microcontroller paired with an ADV7180 video decoder IC and something looking like a flash memory or RAM named CLU21.

However quite often I get the problem you can see on the attached screenshot named Bad. After a while it switches back to a more desired picture you can see on the other screenshot named Good. It produces this vertical/diagonal fish fin like artifacts and washed out colors on the picture randomly. I tested that it is not the capture device. The converter produces the issue when hooked directly to the TV as well. I got an RMA exchange, but the new converter is doing the same problem.

What do you think can cause such problem? For example, might it be that the comb filter of the ADV7180 video decoder does a poor job or the composite signal from my VHS player might be too weak?

Do you think there is a way to eliminate this issue maybe with some composite signal booster/amplifier? Or I should look for another type of converter? In the latter can you please advise any decent converter that retains the 720x576 resolution? Thank you!

[davexnet]

It looks like a herringbone pattern interference caused by cables/grounding issues

[TomasoRock]

It looks like a herringbone pattern interference caused by cables/grounding issues

Thanks, maybe this StarTech converter has some grounding/shielding issue. I used the same cables with the AverMedia ET111 it had no such herringbone issue, only other issues . I think this StarTech might be a bit higher in functions but still far away from a decent solution. It also has an S-Video input I wll try to fidle with that one, maybe that connector is better grounded.

Anyway I know that some may call these composite to HDMI converters a butchery to the video signal, for my needs this StarTech solution (without herringbone) would be an adequate solution for simple PC-less capturing of VHS to mp4.

Maybe the next step would be to try something like this, this is also capable of 720x576 resolution:
http://en.cypress.com.tw/store/catalog/app/product/CM-1392M/CVSV-to-HDMI-Scaler-with-2...CA-Audio-Input