Vertical hunting (Bildpumpen)
 

Hi!
Does anybody know an Avisynth filter for reducing the Vertical hunting effect? My "Odyssey 2001" DVD (PAL) has plenty of this and I'm afraid it will worsen if I reencode it ..

"vertical hunting"... ... ... huh?

It occurs in still parts and it makes the picture seem "pulsating". I'm afraid I can't really define it..
But luckily PeachSmoother does away with that pretty nicely :D

Do you mean the difficulty NTSC DV sometimes has with straight edges or fine lines where it appears as if the encoder is having difficulty deciding the value a pixel should have so it wavers between frames?

excuse me new_bee and FredThompson:
:wink:
seems to me that you are "talking" about the same problem
that i post and don't got good solutions.
maybe in this thread,you can find solutions that help me to solve it.

please,read my 4th post in this thread,maybe is the same problem:
http://www.kvcd.net/forum/viewtopic....er=asc&start=0

thanks.
:)

What you are seeing is the introduction of a new GOP (actually the new I frame), that refreshes the picture. You probably only notice it on stills and very low motion scenes.

-kwag

All frames in DV are key frames. I,B and P-frames are concepts of MPEG compression. With DV, every frame is complete in and of it itself, it's just lossy.

What I was attempting to describe is a problem with 4:1:1 DV. The same source captured with 4:2:0 MPEG won't show the problem. NTSC DV is lousy. It would have been better as 4:2:0 like DVD and PAL DV.

What happens is you might have a static element and the pixels next to it are changing. Somehow, the encoder must pick 1 chroma value for 4 adjacent pixels. the encoder makes what it considers to be a best fit and sets the value. The problem is the analog source or CCD returns variable readings for every pixel every time. The effect is false motion in what should be static elements. Some of that disappears when it is played to a TV because the phosphor tends to blend adjacent frames.

FredThompson,
:)
the monitors have seamless phosphors like tvs.
the "persistence" of the light on the phosphors
is seamless too between tvs and monitors.

this problems of "false motion" can't be the differents
number of pixels or the differents number of lines
for tvs and monitors :?:

:?:

I think you mis-understood what I tryed to communicate.

Then again, maybe I misunderstand your misunderstanding :o

The phosphur on a TV has greater persistance than that of a monitor. This means the phosphur glows longer. Because of this, the display will tend to smooth the image temporaly. That is my understanding. Maybe it is incorrect. I meant DV played to a TV does not show as many problems as when it is played on a computer monitor because a TV screen is designed to blend different frames to hide interlace.

I did not mean phosphur is somehow divided into a grid pattern.

I still don't know if new_bee is using NTSC DV or PAL DV. The "problem" with NTSC DV is it uses 1 chroma value for four horizontal pixels. This chroma value is determined for each frame. If you have a static object which is in part of a 4-pixel block, the motion in the other pixels of that block will affect the choice of an "optimal" chroma value for all four pixels. This can result in a flickering effect of static objects as the edge chroma changes.

Also, with a camcorder or an analog capture, the source value of the analog portion which is sampled to a pixel changes slightly continuously. This also affects the choice of chroma and luma for any particular pixel.

oh sorry FredThompson,
i was not clear. :oops:

what i try to ask was:
if the tvs (standard-m) have
59,95hz vertical lines and 15.732hz horizontal lines
for each complete frame (picture frame).
the monitors have much more and show big details
(depend of the resolution,number of colors) and tvs can't show it all.

then,this could be the reason that we can't see this problems
cos the tv show less colors and have less lines for frame than monitor.
it means that the tv show less details,then don't show this like monitors.

i was clear? (sorry my poor english if you don't understand me)

:)

His source is "Odyssey 2001" DVD (PAL) :!:
Not DV :)

-kwag

oh, yeah, I've been messing with DV all day and somehow thought that was the subject here. :oops:

Yes, I suppose it IS possible that the "defects" are there in the source and we don't see them on a TV.

Peach is a temporal filter, correct? Doesn't it just average a pixel over time?

Sounds like a lousy conversion to DVD if this is related to new GOPs.

Hay, what a coinsidense..
I just bought the same "Odyssey 2001" DVD (NTSC) LOL..

-vhelp

I remember getting the same effect when I once did "The Fellowship" to 2 KVCDs 704x576 (old template!). It appeared in the still, dark shots of the Mines of Moria when I turned the CQ down. Maybe this is due to bitrate shortage :?:

However, Odyssey 2001 (source) has this effect in some well-lit scenes, maybe because of a bad encode (it's quite old I think)..

@vhelp
Very good movie, isn't it?!

FredThompson,
read this link please!
here, the things that i was trying to show are very clear.
see details and differences from tvs and monitors
:arrow: and the reasons of my questions.

read the itens: Television and Resolution: Lines, Lines & Lines
see the diiferences between ntsc,pal, monitors
and what is telecide,interlace,etc,etc.
of course,this page explain better than my poor english but
it was my work for 30 years, but can't write it all in english.
is a great link:

http://nickyguides.digital-digest.com/interlace.htm

:wink:

:arrow: a few lines from the link posted:
"To cut a long story short a TV screen
is about twice as fuzzy as a PC screen,
this means when we capture a TV picture onto a PC screen
we only need half the resolution for the same quality!
So capturing a TV movie at a PC resolution of 640 x 480 is overkill.
If you are recording from VHS the same quality should easily fit
into a resolution as low as 384 x 288 or smaller! "

:arrow: more:
"Resolutions are an important issue for amateur video
enthusiastswho want to capture their video at full TV quality.
Professional video editors are told to capture at 640 x 480 pixels
for highest quality. But a PAL TV resolution is 576 lines down.
Then we have the Mpeg group saying that 352 x 288 is the
full VHS video resolution! The problem seems to lie in the fact that
its hard to equate a TV resolution with a computer image.
The TV is built up of lines but the dot definition is rather "fuzzy" looking.
:!:

my hint:
:arrow: have some mistakes here in thie link
is not the pal system that have 576 lines down
is the standard "G"....means pal -G.
:arrow: the pal-M standard have everything like ntsc,
only changing the color system,
not the standard cos ntsc( USA) is standard :arrow: "M".
for more that you catch ,ever you got big mistakes,
like in this link that have great explanations.

thanks!