Raspberry Pi Forums

1. The TV in question is an NTSC one. I've since had a look in the user manual and didn't find an option to disable the comb filter.

2. Comb filtering is much easier with NTSC because of the simpler relationship between the line and subcarrier frequencies.

3. I still have one of those 13 inch Sony Trinitron TVs which avoided the PAL patent. The method employed was to use a 1H delay line (similar to that in a conventional PAL-D decoder) to substitute the chroma for every alternate (in time) line with that from the previous line. This converted the PAL chroma signal to one similar to NTSC but with the burst phase shifted by 45 degrees. An NTSC type decoder, tweaked for the different subcarrier frequency and the 45 degrees, recovered the two colour difference signals. Just like with a NTSC decoder, the set has a front panel hue control to fine tune the recovered subcarrier phase.

bensimmo wrote: ↑

Mon Aug 14, 2017 3:33 pm

Have you looked in the service menu (if you haven't already) ?

...service menu? Sorry, you need to be more specific, I don't know what that is. The only menu I know on my TV is the one I can access pressing the menu button, which I already talked about.

Also pop you config.txt or tvservice setting you use up.

I've hardly changed anything from the default, just the resolution mainly. I don't know what posting the whole config would help, this isn't an issue I've caused by messing with a setting, it's like this from a clean install.

I was just reading through a link given above and came across this, same thing possibly ?
https://github.com/raspberrypi/firmware ... -287445721

I can't be sure, there's nothing in those photos that look exactly like the issue I posted above, but maybe it's related.
Maybe I'm missing it but I don't see any specific fixes to try in that thread for this. Will this be something I'll just have to wait for an update to fix it?

It mentioned rainbow banding/fringing and then lots of figuring stuff out and a link to other github to spin it off.

I don't know the ins and outs just a link to read up on in case it helps.


Samsung have a service menu, with more options and tweaks, you'll need to search for that specific TVs method of accessing it. Often some button combination.
I used it on my old Samsung CRTs to LCD to ones in hotels to retune them too.
A quick search shows it has one, but not looked for the method to get into it.
Note you can cause serious problem in the service menu. I may of course be no help for the issue.

The config/tvservice whatsits was a just in case.