A problem for video experts

[Yonidan]

Hello,

first, pardon for my english, it's not my mother tongue.

here's the problem:
I bought a capture card few months ago. the card model is: Hauppauge WinTV PVR 150 MCE.
the problem is very strange: there is a black line in the lower part of the screen. the line is not straight.
it should be mentioned that the line appears only in records, not when I watch TV live through the TV Card.
I attached a pircture, and marked in red the line and its curving. just look into the red circle.
does anybody have any idea what the problem is?

[aedipuss]

try watching the video with a program set to de-interlace the video. the line will most likely not be there. vlc can be set to de-interlace or a dvd player like powerdvd does it automatically.

[edDV]

It comes from deinterlacing a half line for still capture. Last line is half wide.

Why is this a problem for you?

http://images.google.com/imgres?imgurl=http://www.kolumbus.fi/pami1/video/pal.gif&imgr...%3Den%26sa%3DN

PAL line 1 and 313 are half wide.

[2Bdecided]

It's actually lines 23 and 623 which are half width in PAL. I agree though - that's what the OP is seeing.


For NTSC its 19 and 263.

In practice, you rarely get video on line 23 (PAL) or 19 (NTSC) from professional broadcasts. PAL has WSS on line 23. NTSC has CC on line 21, so 19 and 20 are blank. The last few lines on NTSC are often blank too - digital NTSC only has 480 active lines.

Cheers,
David.

[lordsmurf]

This is in the overscan, won't be seen on tv.

[edDV]

It's actually lines 23 and 623 which are half width in PAL. I agree though - that's what the OP is seeing.

For NTSC its 19 and 263.

You are correct.

[Yonidan]

Hi again

well, I found an old version of PowerDVD, the black line became more thin and straight. the problem is, that it ruined the quality, the video bacame blurred. so I tried to de-interlace with "ffdshow". there are several of deinterlacing methods there. with some methods, the black line disappeared, but there were smears on moving objects in the video. I found there one method, called "TomsMoComp". with this method, the interlace lines disappeared but that black line stayed there. what can I do? if I'll convert the videos to divx or xvid, will I get a good quality video and all the lines will disappeare including the thick black one on the under part of the screen?
please help, thanks.

[jagabo]

if I'll convert the videos to divx or xvid, will I get a good quality video and all the lines will disappeare including the thick black one on the under part of the screen?

You can crop away any part of the frame you don't want. You have to deinterlace or inverse telecine (NTSC only) to get rid of the comb artifacts. For PAL you sometimes need to do a field phase correction (a progressive video broadcast top-field-first but captured as bottom-field-first). I would do all of this with AviSynth and VirtualDub. Here's a quick dirty example with just VirtualDub (deinterlace, crop, resize):

[Yonidan]

well, if I'll just encode the videos to Xvid, what will happen to the interlace lines?

[jagabo]

well, if I'll just encode the videos to Xvid, what will happen to the interlace lines?

You'll end up with an Xvid video with interlace comb artifacts. Xvid has the option of interlaced encoding but players generally do not automatically deinterlace on playback.

[Yonidan]

so I must get rid of the interlace lines on mpeg-2 before I convert the videos to Xvid?

[jagabo]

Yes.

[Yonidan]

I see
but how can I remove the interlace lines from the mpeg-2 for good? the mpeg-2 video is de-interlaced as long as the ffdshow is opened.
?

[Yonidan]

btw, you de-interlace the video I put here with virtual dub?

[jagabo]

Yes, I used VirtualDub with Donald Graft's "Smart Deinterlace" filter:

http://neuron2.net/smart/smart.html

For viewing the original MPEG file you can use any player that deinterlaces while playing. Most have the option, MPCHC, VLC, KMPlayer, etc.

[Yonidan]

so with VirtualDub and the Smart Deinterlace, I can de-interlace the video for good? which mean, the video will be de-interlaced also without external de-interlace filter?

[poisondeathray]

Yes, if you re-encode the video with a deinterlacing filter, the end result will be progressive (you will no longer need to activate the ffdshow deinterlace filter for playback)

[jagabo]

Note that interlaced video exists for a reason. Each frame encodes two half-pictures. When watched on an interlaced TV you see those half pictures one at a time. If you deinterlace you reduce the temporal resolution from 50 half-pictures per second to 25 full pictures per second. The video will be noticeably less smooth (motions). You will also lose some spacial resolution since there is no way to perfectly create a whole image from two different half images.

[Yonidan]

Note that interlaced video exists for a reason. Each frame encodes two half-pictures. When watched on an interlaced TV you see those half pictures one at a time. If you deinterlace you reduce the temporal resolution from 50 half-pictures per second to 25 full pictures per second. The video will be noticeably less smooth (motions). You will also lose some spacial resolution since there is no way to perfectly create a whole image from two different half images.

the de-interlacing you did to the picture I brought here looks good. the quality is good and without smearing.
I watched Xvid rips of ppl with a card like mine, without need to use a de-interlace filter. the quality was good, and I just want to create such videos. so in order to that, I need VirtualDub and the Smart Deinterlace?

[jagabo]

the de-interlacing you did to the picture I brought here looks good. the quality is good and without smearing.
I watched Xvid rips of ppl with a card like mine, without need to use a de-interlace filter. the quality was good, and I just want to create such videos. so in order to that, I need VirtualDub and the Smart Deinterlace?

There are many programs that can deinterlace and many ways of deinterlacing. Smart Deinterlace is one of the best for VirtualDub. The combination will do what you want.

[Yonidan]

thanks
may I get a link for VirtualDub please? I also need somebody to guide me.

[jagabo]

Link: VirtualDub

You'll probably need the MPEG 2 input filter:
http://forums.virtualdub.org/index.php?act=ST&f=7&t=12664

There are many VirtualDub guides in the Guide section here.
https://www.videohelp.com/guides?searchtext=&tools=2&madeby=&formatconversionselect=&ho...or+List+Guides

Start VirtualDub, then:

File -> Open Video File
Video -> Filters... Add... Smart Deinterlace
Video -> Compression... Select Xvid, set parameters
File -> Save as AVI

[Yonidan]

thanks alot..the VirtualDub does also the conversion from mpeg-2 to Xvid?
another question, with VirtualDub can I also crap the frame? as you did to the picture above? I want to ctop that black line.

thanking you in advance.

[jagabo]

thanks alot..the VirtualDub does also the conversion from mpeg-2 to Xvid?

Yes. Pick the compression codec with Video -> Compression...

another question, with VirtualDub can I also crap the frame? as you did to the picture above? I want to ctop that black line.

Yes, cropping can be applied to any filter. Video -> Filters... Add... Null Transform. Go to the main filter dialog, hilight Null Transform and press Cropping.

[Yonidan]

thanks jagabo, I tried it and I have some questions, but before I ask them, I want to ask about another problem that bothers me:

in my recorded videos, I noticed that where that black line, the video gets distorted, I mean getting pulled downwards. I maked it in red, take a look into the mark ( the end of the table). it's hard to see it.
it has no relation to VirtualDub, that's what I get from the software I use for capturing (GB-PVR).
how can I solve this problem? hope that my english is clear more or less..
thanks.

[jagabo]

That is a defect in the broadcast or video tape. You can't fix it. All you can do is crop or mask it. Broadcasters don't worry about crap at the edges of the frame because it's hidden by the TV's overscan.

[Yonidan]

ok thanks

another problem..I noticed that after the deinterlacing, there's a blurring and smearing on objects in quick movements. mabye I should change something in the settings of the deinterlacing? what are the recommended settings for deinterlacing? what settings did you use when you deinterlaced that picture I put here?
here's the splotch I'm talking about, on his hand:

[edDV]

ok thanks

another problem..I noticed that after the deinterlacing, there's a blurring and smearing on objects in quick movements. mabye I should change something in the settings of the deinterlacing? what are the recommended settings for deinterlacing? what settings did you use when you deinterlaced that picture I put here?
here's the splotch I'm talking about, on his hand.

That is the cost of blend deinterlace and the main reason to maintain interlace to the TV. Each deinterlace scheme has a quality loss. A fully adaptive, motion predictive deinterlace involves patents ($ royalty) and very long software processing times. TV hardware deinterlacers vary in quality from simple blend to high end but are real time. Full real time predictive deinterlace requires frames of memory in the hdtv.

[jagabo]

In Smart Deinterlace, instead of Blend, use Edge-directed Interpolate.

[Yonidan]

ok I tried the "Edge-directed Interpolate". the motions look better, but the quality became lower. so I have to choose between better quality to normal motion? thanks.