Ghosting on PAL VHS CApture

[tumaz]

ive tried de-interlacing my PAL VHS captures and it gets rid of the scan liens but i just cant get rid of the ghosting?

ive capped before and never noticed it but now its on everything i capture

Any advice?

heres a picture

[Richard_G]

Why deinterlace, the scan lines will only show on computer playback, if you are converting to DVD for playback on a TV, you won't see them.

The ghosting you are seeing are because the deinterlace has duplicated both fields and you are seeing them simultaneously and not sequentially.

[tumaz]

it is mainly for watching on a tv.

its that the case with watching it on a LCD/Plasma TV?

i was wanting to produce some xvid encodes too though is there a way to get rid of these ghostings?

[jagabo]

It looks like you're using VirtualDub. Try the Smart Deinterlace filter. A cruder solution is to use one of the "discard field" options of it's regular deinterlace filter.

On closer examination your sample appears to suffer from a partial field blending. That will make the ghosting very hard to eliminate.

[Richard_G]

All TVs are designed to play back interlaced video, even ones that are capable of playing progressive scanned footage will still play interlaced perfectly. So, if you intend converting to DVD for playback on TV, leave them interlaced.

As for deinterlacing for xvid, I can't help I'm afraid. Everything I do is for DVD and never use any other format.

[edDV]

You need to decide if xvid compression is more important (with "ghosting") or if lower compressed interlaced MPeg2 (no "ghosting") is most important. Try it both ways and decide.

There is progress on the interlaced MPeg4 codecs (e.g. VC-1, h.264) but not yet for extreme compression.

[tumaz]

could it be something i need to set virtualdub to do once its capturing?

ive noticed there is a partial blending of frames at certain intervals....is there a way to set my capture process to eliminate this?

[edDV]

could it be something i need to set virtualdub to do once its capturing?

ive noticed there is a partial blending of frames at certain intervals....is there a way to set my capture process to eliminate this?

Yes. Capture 576i/25 interlace and encode 576i/25 interlace MPeg2. That is what the broadcasters do.

[jagabo]

could it be something i need to set virtualdub to do once its capturing?

ive noticed there is a partial blending of frames at certain intervals....is there a way to set my capture process to eliminate this?

What video codec are you using when you capture with VirtaulDub?

[tumaz]

this is the current settings for virtualdub

Video

720x576
25FPS
Codec PICVIDEO MJPEG set at 15

Could this ghosting be something to do with the original VHS source? there all PAL VHS of odl 80s Cartoons which where all made in the USA

how can i remove these ghosting frames? im guessing there must be a way? ive never used Avisynth before.

I had a capture guide made by g00z along time ago and he's way of deinterlacing the source was quite good.

I no longer have the guide but i remember it was maybe Avisynth with a Chinesse/Japanesse program (GUI?) that had an english patch

it was maybe 3-4 years ago now this article though

[jagabo]

I've only seen one frame from your video (and even that was processed by JPEG compression) but it looks like it has the typical partial field blending that often comes with NTSC/PAL conversions.

Capturing with VirtualDub shouldn't be a problem. Be sure you set PicVideo MJPEG to encode as interlaced (in the advanced tab set "Encode as interlaced if more than 288 lines").

After you've captured with that enabled open the AVI file in VirtualDub. Add the Deinterlace filter and select the "Discard field 1" method. This is just to test for the partial field blend. The output window will be half the height of the input window (288 lines). Step through the video during a scene where there is significant motion. If the output window shows evidence of blended fields (ghosts) you have the partial field blend problem.

If you don't have that problem deinterlacing will be pretty straight forward. If you do it gets tricky.

[lordsmurf]

DO NOT DE-INTERLACE!
http://www.digitalfaq.com/dvdguides/capture/understandsource.htm#interlace

There's nothing worse than mindless de-interlacing.

[edDV]

Could this ghosting be something to do with the original VHS source? there all PAL VHS of odl 80s Cartoons which where all made in the USA.

No. You somehow chose to blend deinterlace,

how can i remove these ghosting frames? im guessing there must be a way? ive never used Avisynth before.

Start over. You can't reverse a blend deinterlace.

[tumaz]

i think its the source that has the problem

ive checked and all my cartoons that where made in this country are fine and any from the USA have the blended fields problem

heres a short AVI clip of what ive captured.

im guessing there isnt anything i can do about this?

PICVIDEO Codec was set to capture 2 fields if over 240 lines

www.tumaz.myby.co.uk/kissyfur.avi

[jagabo]

Tumaz, You have several issues you'll need to work out.

First, why are you capturing at 640x480? You should be capturing PAL at 720x576. The resizeing on the vertical axis may be the cause of some of your problems. Also, since you will be putting this on DVD, it doesn't make sense to convert a 720x576 video source to 640x480 only to reconvert it back to 720x576 on DVD.

When you capture, be sure that PicVideo MJPEG is set to encode as interlaced, especially if you are using the 4:1:1 color subsampling option. Encoding interlaced video as progressive frames can also lead to problems like this.

Here is one frame of your AVI file split into two fields, stacked on top of each other:



As you can see, one field has ghosting (actually both have ghosting but one is very light). "Perfect" interlaced video would show no ghosting. Some of your frames have this problem, some don't. Partial field blending like this is very common in PAL/NTSC conversions. But you need to get proper captures to verify none of this was caused by your capturing process.

As others have mentioned, you don't want to deinterlace for DVD. But since you also want to make Xvid AVI files you really don't have much choice. Xvid supports interlaced encoding but playback of interlaced Xvid material is often a problem since most software and hardware don't expect it. There are AVISynth filters designed to alleviate field blending. The RePal() filter, for example, can remove a lot of the blending from PAL material that has been converted to NTSC. If your source doesn't have the partial field blending there are lots of filters that can deinterace with varying degrees of success. VirtualDUb's blend deinterlace is one of the worst (and is guaranteed give ghost artifacts). Something like LeakKernelDeint() is much better.

[tumaz]

heres a picture of the settings in the compression for PCIVIDEO

ill include several pictures and you can check to see if its something to do with my capture settings

[tumaz]

heres virtualubs setting swhilst im capturing

[tumaz]

that file before must of been a clip that i caputred at 640x480 too see if it was the resolution?

720x576
PICVIDEO MJPEG set at 14

do you need anymore info?

www.tumaz.myby.co.uk/kissyfur576.avi

[lordsmurf]

There's NOTHING wrong with capturing 640x480 1:1 aspect.

[jagabo]

There's NOTHING wrong with capturing 640x480 1:1 aspect.

There is if your capturing PAL and plan to make DVDs.

720x576
PICVIDEO MJPEG set at 14

do you need anymore info?

www.tumaz.myby.co.uk/kissyfur576.avi

That still shows partial field blending which will be hard to remove. As I mentioned earlier, AviSynth's RePal() filter can remove that type of blending from PAL video that has been converted to NTSC. I don't know if there's an equivalent for NTSC->PAL conversions. Also, RePal() is designed to restore original 25 fps progressive frames from blended 29.97 fps NTSC video. I suspect your video started out as interlaced NTSC video so the restoration will be even harder.

[tumaz]

Ah well guess ill just have to deal with the partial blending.

its nto too bad and on a TV its not really problem

[jagabo]

Try using VirtualDub's Deinterlace filter with the Discard Field 1 (or 2) option, followed by resizing to whatever size you want. You might find that slightly better than the Blend option.

[nbarzgar]

It's rather a late reply, but still: try using this AviSynth-Script:

AviSource("X:/path/to/movie-file.avi")
SeparateFields()
SelectOdd() #you can also use SelectEven() instead
HorizontalReduceBy2()
BicubicResize(x,y) #x and y representing original resolution of the clip

Try LanczosResize(x,y) instead of Bicubic... and compare results, it creates slightly sharper results while resizing lower-to-higher res material.
This method deals with the ghosting artefact very nicely, and should meet your requirements for watching the captured material on TV, esp. since you do NOT deinterlace this way.

As you possibly know by now(?) in order to use this, do the following:
1. Install AviSynth (download via tool-section)
2. Open any text-editor (Windows "Editor" or TextPad will do nicely) and copy-and-paste the script-lines into it. Anything with a "#" before it will be considered as a comment and not be processed during encode.
3. Save the file with ".avs"-extension and be careful to choose "all files" as filetype in Editor before saving. This is the file, you would load into VirtualDubMod or any other app.
4. Choose some encoder, that accepts AviSynth scripts. In case you like to use VirtualDub, load this script like any video-file into VirtualDubMod. TMPGEnc, HC, WinFF, SUPER, CCE or QEnc can do it, but HC, CCE and QEnc only output mpeg2.
5. Set up your encoder and enjoy.

On my system I test it by connecting to TV and then open the .avs-file with Media Player Classic. If the script does not contain very CPU-demanding filters (this one doesn't) I can preview the effect on my TV, and the difference is remarkable.
A slight drawback may be, that of course you loose a part of the orginal information of the capture, but the ghosting will disappear.

[jagabo]

AviSource("X:/path/to/movie-file.avi")
SeparateFields()
SelectOdd() #you can also use SelectEven() instead
HorizontalReduceBy2()
BicubicResize(x,y) #x and y representing original resolution of the clip

A slight drawback may be, that of course you loose a part of the orginal information of the capture, but the ghosting will disappear.

The ghosting won't disappear. It's in the fields. See the picture from my earlier post:

https://forum.videohelp.com/topic326075.html#1682189

That was made with SeparateFields().

[lordsmurf]

There's NOTHING wrong with capturing 640x480 1:1 aspect.

There is if your capturing PAL and plan to make DVDs.

You change to 4:3 and valid DVD specs when encoding the final MPEG.

[nbarzgar]

@jagabo/tumaz

Sorry, if I did make a hasty presumption. The crucial thing would be to do the

SelectOdd() #SelectEven()
HorizontalReduceBy2()
LanczosResize(x,y) # or BicubicResize

additonally. It would not suffice only using 'SeparateFields()'.

But if you/tumaz tried the above already and it did not help, well - good luck then.
If not solved already...
Am at my wits end, sorry to say. Haven't had this problem too often.

EDIT: I am in PAL-land as well, and I get these annoying artefacts mostly, when capturing interlaced analogue material that was NTSC originally and apparently is badly converted to PAL-format at the broadcast-station here. So having captured some VHS and lately TV-Shows that originate in the US and which have been through frame-rate-change (and than been broadcast) the wrong way, I get ghosting and the above given script did the trick for me every time.
The capture-app I use does make no difference, VirtualDub, VirtualVCR or ATIs MMC and I have tried PicVideo MJPEG as well as XViD, 3ivx (great, since very fast) and ffsdhow, set to mpeg4 (mp4v as FOURCC).
What makes a difference, though, is resolution and with PicVideo the resulting frames look much better, since I can use higher resolution on my system, so loss of detail is comparatively small. EDIT.

[jagabo]

It would not suffice only using 'SeparateFields()'

Obviously. It would leave you with twice the frame rate and half the frame size. I was simply using that as an example to show that the fields have ghosting artifacts. So dropping a field will still leave you with ghosts.

the above given script did the trick for me every time.

It's not going to do the trick with the OP's video. Here's a sample frame from his video using your script:

[dphirschler]

I am not sure if this will help, but I had a problem dealing with fields in what should have been progressive PAL video. I managed to fix it by changing my capture settings to PAL_H. See the thread below:

https://forum.videohelp.com/topic265063.html?highlight=pal%20video%20field%20order%20changing

Basically, my source was progressive 25 FPS PAL. If it came in interlaced, it should be easy to restore to progressive (without deinterlacing).


Darryl

[nbarzgar]

@jagabo

Thanks for showing me. I have two questions left though:

1. How does this kind of ghosting happen in the first place?
2. What exactly IS partial field blending, and what is the difference - if any - to material I have been dealing with, that was taken care of by 'my' script.

It's not mine actually, I found it over at www.doom9.org: http://www.doom9.org/index.html?/capture/postprocessing_avisynth.html (This particular script is to be found under the heading 'Deinterlacing' although this script does no real deinterlacing as far as I can see.)
Very helpful guide for using AviSynth called "Potprocessing with AviSynth".

[jagabo]

1. How does this kind of ghosting happen in the first place?

There must some kind of NTSC/PAL converter that's in common use by broadcasters that does this. It generally doesn't look too bad when viewed on interlaced displays. Unfortunately there is no way to perfectly convert interlaced PAL to interlaced NTSC or vice versa.

2. What exactly IS partial field blending,

It's a weighted average of adjacent fields. Consider a diagram of the duration of NTSC fields vs PAL fields. I'll use a | followed by several -'s to indicate the duration on the field:

NTSC: |----|----|----|----|----|----|
_PAL: |-----|-----|-----|-----|-----|

As you can see each PAL field is diaplayed for a longer period of time than each NTSC field (1/50 second vs ~1/60 second). With partial field blending each PAL field becomes a weighted average of two (possibly more) NTSC fields. The wieght is based on how much the fields overlap.

In the diagram the first PAL field is made by averaging together 5 parts the first NTSC field plus 1 part of the second NTSC field. The second PAL field consists of 4 parts the second NTSC field plus 2 parts of the third NTSC field. The next PAL field is 3 parts of one NTSC fields plus 3 parts of the next NTSC field. Etc.

and what is the difference - if any - to material I have been dealing with, that was taken care of by 'my' script.

Your script basically throws away one field and resizes what is left. It is useful for sources without field blending.