Serious chroma problem, please help!

[fellaw]

Here are two clips:

a rather old movie, captured uncompressed and no need to deinterlace.
Compressed with DivX3 low motion@6000kbps
1 (http://people.freenet.de/TC.Xan/clips/chroma.avi)
newer clip, from a wedding show. Also captured uncompressed, then deinterlaced using avisynth and vdub. compressed with divx5@100% qb.
2 (http://people.freenet.de/TC.Xan/clips/chroma2.avi)

Look at the first clips' sky. There are ugly diagonal stripes slowly moving from top left to bottom right.
Next have a look at the bright blue area in the second clip. Similar stripes. Where do they come from? Input was the composite, 640x480, YUV2.
I think those are really ugly chroma errors, aren't they?

How to avoid those stripes?

Plz help!

[theReal]

Probably it's the composite cable.

When I compare DV recordings viewed through composite and through s-video cable on the same tv set, the composite also introduces horrible chroma errors.

btw. the second clip looks pretty good to me. What capture card are you using and what is your tv-connection (cable, satellite)?
With my WinTV pci (bt878 chip) and terrestrial cable, I hardly get such good results (there's usually more noise)

[fellaw]

Do you mean it's because I'm using the composite or do you really mean only the cable(which was rather cheap)?

I've got a Terratec TV+ with a BT878 chipset, hooked onto an ordinary sat via composite. Drivers are the up to date WDM from Terratec. I captured that one uncompressed, as it only had to be a sample and I wanted to keep the chroma errors almost intact, as they're hardly noticable. For deinterlacing I used avisynth with seperatefields and a vdub filter named Deinterlace Smooth(don't know who programmed it).
DivX 5.0.2 pro was set to 100%, preprocessing(normal), GMC, Quarter Pixel and Bidirectional frames enabled.

[theReal]

It could be better with a better cable - but I meant that composite is bad anyways. It's only one channel for all the video information, you'll always lose quality with a composite cable.

[fellaw]

I can't use anything better than composite. S-video does not work I started a thread about that a few days ago. And the RF is even worse than composite.

[^^-+I4004+-^^]

1->these are NOT chroma errors!
2->these are NOT caused by using the composite connectiton
[i only use composite and never any problems]
3->this is interference to video signal->check your surroundings,
if needed turn off one by one all devices so you're only left with
SATV & PC.......(probably some device is causing this inerference..)
[noise is penetrating your composite signal and distorting it a bit..]

[fellaw]

Thx man!

I'm glad to hear that. I powered off all devices despites my sat and pc.
They're still there. Could they be caused by a heating element? I've got a central heating, and the heating element is about 4 feet away from my sat.

[theReal]

There's another possibility: the device that causes distortions might be the PC itself. You have many high frequency electronic parts in there...

With my WinTV, I get distortions as soon as the 5V line is below 4.9V (which it doesn't do anymore with a better PSU). However, I can still see slight distortions in the TV picture when the cpu is under heavy load (that means I better don't run Seti@home while capturing).

Just my 2 cents, I don't think you can expect much better quality with a brooktree chip - at least your captures look quite okay to me.

[fellaw]

I had only capture card + gfx card inside. I have 7 coolers: 4 case, 1 cpu, 1 northbridge, 1 gfx card. I had them installed all the time. My PSU is from Antech. This is high end, isn't it? Which of those components are considered to be high frequency devices?

[theReal]

Which of those components are considered to be high frequency devices?I'd say that everything above 100MHz can be considered "high frequency" - so the question is more like "which components are NOT high frequency devices?" ;)

An Antec PSU is perfect, you don't have to worry about that, I think. But still there's a lot of electronics involved in a pc that could cause interference with an A/D converter and cards with brooktree chipsets seem to be very sensitive to everything (at least my WinTV is...)

[^^-+I4004+-^^]

theReal>I'd say that everything above 100MHz can be considered "high frequency" - so the question is more like "which components are NOT high frequency devices?"

_composit signal is 5,5MHz tops.......how 'bout that?

theReal>An Antec PSU is perfect, you don't have to worry about that, I think. But still there's a lot of electronics involved in a pc that could cause interference with an A/D converter and cards with brooktree chipsets seem to be very sensitive to everything (at least my WinTV is...)

_how 'bout piece of "Enermax" there?
also i've never seen any of these interferences....(never used
on-card tuner..)....always with intel chipsets and cpu's
ther are no problems with that...
(there are problems with chroma noise,but that's inherent to VHS,not
problem of card itself....that noise exists even when watched
on tv.etc.....chroam noise is easily solved with some flavour of CNR filter.....)

@fellaw->as i've said turn off everything (and anything) in the vacinity of
satv.......i've read somewhere that some heating devices can cause this
it was in context of some old tv's but interference looked like yours
this is so called HF interference.....(i'm not sure if it's that,but for sure something is bothering your composite signal.......)
after that turn of one by one ventilators in your PC (hehehe 7 coolers?that must be amd....right?)

btw. you can both go--->

http://free-st.hinet.hr/ikostic3/video_/video.htm

for some short divx samples.....it'll show you at least
that bt can be interferenceless...heh

[theReal]

_composit signal is 5,5MHz tops.......how 'bout that? OK, but that has nothing to do with what I meant: FSB is 133MHz, CPU is at least 600MHz, GPU is about 250MHz

_how 'bout piece of "Enermax" there?The newer Enermax are good, but some older models had serious 5V stability problems (it was only a problem for a few Athlon mainboards)
However, Antec are probably some of the best PSU's around, so why should I tell fellaw to get a new PSU?

[^^-+I4004+-^^]

Originally posted by theReal
OK, but that has nothing to do with what I meant: FSB is 133MHz, CPU is at least 600MHz, GPU is about 250MHz




_you've said that you had interference when certain voltage lowered
what that has to do with electro-smog from the PC components...?
i won't get into details over which design is better etc. but as i've
said i've never had any interference problems because capture card(s)
are located IN the box with the rest of the stuff....
(loaded CPU makes interference?that says something about manufacturer
of that device....)

if this was the case,then anyone could of have such problems on any
PC platform.......
noise from PC components DOESN'T affect capturing quality in proper PC
system....i can say that much...

PSU?i dont think so->i had the shitty PSU that didn't do any problems to my capture devices.....
on the end that PSU destroyed whole system.(that shitty,yes!)

i've mentioned enermax because it serves me well....
antec is probably another decent brand.......