The filter that aligns lines?

[roman]

In VHS captures present this sad artifact: lines quickly shifts one from one horisontally (and from frame to frame). I think it's due to nonuniform strob of linestart, that happens on old videocassettes, or, maybe, due to old bad sad VCR I have
I have tried DNR, smoother HQ, temporal smoother - they removes some portion of this artefact - but only into the areas, on edges and contrast contours remains as strong pixel flickering. This sh|t grabs a lot of bitrate at final compressing
I have thought about filter that could align lines horisontally. Don't know, maybe such filter already written? And for VDub?
On DGraft's page I haven't found some like it.

EDIT: I capture PAL at 768x576 by AIMSLab VHX.

[bb]

Do you get the same lines when capturing at a resolution of 720x576? For some people this solved the problem.

bb

[^^-+I4004+-^^]

true what you said:VHS doesn't give
perfect HSycn signals and
results is wiggle of lines from left
to right
different capture res. doesn't help....
[at least not for me]
this is less visible on tv as
tv has some mean circitry to lock
HSync and stabilise the image...
(also tv-tube is less precise and monitor shows all...)
ie. lines are indeed shifted because VHS machine
doesn't have TBC....
some machines yield better HSync "compliance"
some worse.....in some cases you'll have massive drops becasue
capture card receives very unstavle HSync signals...
my panasonic serves me well,and even poor tapes have
acceptable horizontal line stability.....
(cheap panasonic model..."nv-sd200")

filter for this?
no one will make filters that are hard to make;
this filter would have to look (spatially)
in every frame for lines that are shifted
and the lines seem to be shifted in a
temporal way (distribution of line shift observed
over a period of time) that reminds of white noise
(no pattern)
this would be hard to do and
would be slow,but idea is good.....

nice to see you capture at a PROPER(!) PAL
resolution

cheers

/ivo

[vhelp]

Hi roman,

If you mean these lines show up at the top of your captures' video
frame, and the video sort of "wiggles" as it plays, theres' not
much you can do about it. Even a TBC won't cure it. But, you can
do w/out them in your final encode (if MPEG-1 or MPEG-2) by cutting
out the first 24 pixels (top/bottom) of your video. And, no more
of those nasty lines, and your bitrate will sore back up (or is it
down)
These are over-scans, and your TV's frame area will not show them
anyways. So, cut them out and get better control of your bitrates.

But, if you mean your whole video frame by frame is all messed up,
then I don't know what else to say. Be nice if you could give us
a LINK to a pic. maybe U/L one on your website. Everyone has at
least 1 to 2 MB webspace.

-vhelp

[roman]

vhelp
Lines wiggles on whole frame. Sad
Here I'll try to get picture.

Thanks to ^^-+I4004+-^^
You have explained the problem excellently!
My English is very poor for it




See on this frame (if it will be downloaded )
Gophers are staying, only second gopher (at left) is standing up, and you can see his head interlaced. Also grass stems look interlaced. All other freezes. But see at figures contours - you can see wiggling of lines. It's not field-to-field shifting, as you may think, because it's not disappears after blending fields. And - see at the left border of image - lines begin nonuniformly.
(Things better seen in 2x-zoomed image.)


When I filter source in VDub, I use blend deinterlacing, cropping, then light cnr and heavy dnr, then smartsmootherHQ, temporal cleaner, at the end I do resize(Lanczos3) to 384x288. To significantly reduce contours flickering I should use heavy spatial and temporal smoothing, and it becomes compromise between flickering and "plastic image" + ghosts.

And lines aligning filter I said about thinks might work with line start points - detect theirs and shift all lines, at one frame and at other frames, to one defined X coordinate. Sorry, is it clear?
I don't see only one thing: how find the line start point?

[^^-+I4004+-^^]

few tips for my russian friend;
[side note]
i just reviewed few of my capturings,and i
noticed that most of my stuff
completely fills the screen (no black vertical line on the left
like
in your case)

here are few revealing screenshots:
http://i4004.bizhosting.com/cgi-bin/i/goodbye,lover_vfw[brooktree].jpg
http://i4004.bizhosting.com/cgi-bin/i/goodbye,lover_wdm[btwincap].jpg

(vhs capture..tried to get same frame of movie..and obviously did it....heh)

see that the vfw version fills more screen...
seems like btwincap has slight pixelAR error
(more than vfw does....squished image)


this is more hardware related problem;
bt8x8 has some built in tbc but it has it's limits..

my previous experinece proved that good deinterlacer
will remove good deal of problem...
blend deint. is not good (especially if you use VD bulit in filter)
use smart deinterlacer
or smooth deinterlacer...
http://home.bip.net/gunnart/video/
http://sauron.mordor.net/dgraft/

also,your source is not so good...it has noise..
(that doesn't help either...)
line won't be locked if the noise spike occured on
the hsync portion of the signal (and what's
stoppig the noise to intrued every portion of signal?right,nothing!)
it helps if the vcr has "drop out compensator" (although only older
models don't have it i think...)
this means "empty" lines are masked (previous "good" line is inserted
in that spot...)



with decent source you don't get this noise related troubles...
i get this troubles only when i have noisy satv channel
with lots of "sparklies" in video....
then lines cannot be locked properly...

>And lines aligning filter I said about thinks might work with line start points - detect theirs and shift all lines, at one frame and at other frames, to one defined X coordinate. Sorry, is it clear?
I don't see only one thing: how find the line start point?

nice idea for software TBC,but as i said i doubt you'll find developer
that would bite this one.......

cheers_
ivo