Strange DVD picture

geeees · 10th January 2010, 23:51

Hi Everyone,

I've realized that the picture of many widescreen DVDs (PAL) don't have a straight upper edge, but it has a step in it. It goes all the way through the movie and of course the ripped movies have the same problem as well. Here is a screenshot to make it easier to understand what I mean.
The problem occurs regardless player or computer (I don't have a TV, so no clue about this).
I was looking for answers on the web without success.
Does anyone know what is this and if it can be get rid of in the ripping process?
Thanks a lot for your help in advance!

Ghitulescu · 11th January 2010, 15:15

What kind of image is that that has 1023x767 pixels? Ripped or screen captured DVDs should always be 576 or 480 pixels height.

The half lines are part of the standard. Before explaining you more I need to know or to see a real image from that DVD, because not all WS DVDs have the 2 halflines (it should also be one below).

geeees · 13th January 2010, 12:57

Hi!

Thanks for the reply!

The thing is, I don't have the DVD on me anymore, I have to dig out one with the same half line feature. The screeshot was made by print screen (I guess that explains the abnormal hight of the pic). I've tried to use VLC and Gomplayer's snapshot, but it didn't work for some reason. I didn't know the size of the image is of importance.
If I remember correctly, the hight was 576 pixel.
Actually I've never noticed the half line on the bottom...

geeees · 13th January 2010, 13:09

OK, I've found another DVD with the same feature.
And guess what, there is a half line on the bottom as well

I managed to make a proper snapshot with VLC:

manono · 13th January 2010, 14:27

Quote:

Originally Posted by geeees

...and if it can be get rid of in the ripping process?

Crop it away and add back the black when reencoding. Since you resized the picture to some screwy dimension, I can't give a AviSynth specific script. My guess is that it was caused by the video being slightly off-axis

In the second picture, are you talking about the very thin lines that extend partway across the picture? Crop them away and either add back black or resize to do away with the black line entirely.

geeees · 13th January 2010, 23:32

Thanks manono!

I never really bothered to crop before ripping, but now I did and voilà, the half lines are gone.

But I'm still waiting for Ghitulescu's reply. He mentioned that those half lines are "part of the standard". I'm wondering what he meant with this.

Ghitulescu · 14th January 2010, 18:23

Well, as until HDMI/DVI didn't appear on the market, it played just a marginal role, whether a video was digital or analog stored. Once the interface (player -> display) was analog, then it had to follow the standards for analog signals, in your/our case PAL.
The PAL image starts with the second half of the first line, continues with the third one, then with 5th and so on, goes on the next field, and ends with the first half of line 576.

The reason was the state of the technique back in the fourties. You would also notice that the analog lines are also not perfectly horisontal, at least it was so for a long period of time.

Get a book, a standard, google or browse wiki if you need more. But it's not important for your daily work. It's something for perfectionists.

geeees · 14th January 2010, 18:42

Hi Ghitulescu,

thanks for the short explanation. Though I wouldn't describe myself as a perfectionist, it looks better without them 2 half lines. And it's really just a few seconds to set up before the encoding.

Thanks again!

Ghitulescu · 15th January 2010, 08:41

Quote:

Originally Posted by geeees

Hi Ghitulescu,

thanks for the short explanation. Though I wouldn't describe myself as a perfectionist, it looks better without them 2 half lines. And it's really just a few seconds to set up before the encoding.

I repeat myself: don't get rid of those 2 half-lines if you intend to play the image through an analog connection (FBAS, Y/C, RGB, YUV - the latter 2 in SDTV), because the player would recreate them again.

geeees · 15th January 2010, 11:38

The chance of playing these movies on an analog device is rather small, but thanks for the hint anyways!

Ghitulescu · 15th January 2010, 19:59

Quote:

Originally Posted by Ghitulescu

through an analog connection

Quote:

Originally Posted by geeees

The chance of playing these movies on an analog device is rather small, but thanks for the hint anyways!

Analog connection not device.

geeees · 17th January 2010, 20:30

Sorry, apparently I missed your point.
Here's what I was trying to say: I buy a DVD and want to back it up but don't have the capacity to save it in DVD format, so I want to encode and put it in an .avi or .mkv container. Before encoding I get rid of the half lines by cropping. I will only play this file on my laptop or PC. Am I all right then, or doing something useless/stupid by cropping?

loekverhees · 18th January 2010, 08:28

If you are only playing it on your PC/laptop, then cropping is fine.

10th January 2010, 23:51	#1 \| Link
geeees Registered User Join Date: Jan 2010 Posts: 7	Strange DVD picture Hi Everyone, I've realized that the picture of many widescreen DVDs (PAL) don't have a straight upper edge, but it has a step in it. It goes all the way through the movie and of course the ripped movies have the same problem as well. Here is a screenshot to make it easier to understand what I mean. The problem occurs regardless player or computer (I don't have a TV, so no clue about this). I was looking for answers on the web without success. Does anyone know what is this and if it can be get rid of in the ripping process? Thanks a lot for your help in advance! Attached Images

13th January 2010, 13:09	#4 \| Link
geeees Registered User Join Date: Jan 2010 Posts: 7	OK, I've found another DVD with the same feature. And guess what, there is a half line on the bottom as well I managed to make a proper snapshot with VLC: Attached Images

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11th January 2010, 15:15	#2 \| Link
Ghitulescu Registered User Join Date: Mar 2009 Location: Germany Posts: 5,769	What kind of image is that that has 1023x767 pixels? Ripped or screen captured DVDs should always be 576 or 480 pixels height. The half lines are part of the standard. Before explaining you more I need to know or to see a real image from that DVD, because not all WS DVDs have the 2 halflines (it should also be one below).

13th January 2010, 12:57	#3 \| Link
geeees Registered User Join Date: Jan 2010 Posts: 7	Hi! Thanks for the reply! The thing is, I don't have the DVD on me anymore, I have to dig out one with the same half line feature. The screeshot was made by print screen (I guess that explains the abnormal hight of the pic). I've tried to use VLC and Gomplayer's snapshot, but it didn't work for some reason. I didn't know the size of the image is of importance. If I remember correctly, the hight was 576 pixel. Actually I've never noticed the half line on the bottom...

13th January 2010, 23:32	#6 \| Link
geeees Registered User Join Date: Jan 2010 Posts: 7	Thanks manono! I never really bothered to crop before ripping, but now I did and voilà, the half lines are gone. But I'm still waiting for Ghitulescu's reply. He mentioned that those half lines are "part of the standard". I'm wondering what he meant with this.

14th January 2010, 18:23	#7 \| Link
Ghitulescu Registered User Join Date: Mar 2009 Location: Germany Posts: 5,769	Well, as until HDMI/DVI didn't appear on the market, it played just a marginal role, whether a video was digital or analog stored. Once the interface (player -> display) was analog, then it had to follow the standards for analog signals, in your/our case PAL. The PAL image starts with the second half of the first line, continues with the third one, then with 5th and so on, goes on the next field, and ends with the first half of line 576. The reason was the state of the technique back in the fourties. You would also notice that the analog lines are also not perfectly horisontal, at least it was so for a long period of time. Get a book, a standard, google or browse wiki if you need more. But it's not important for your daily work. It's something for perfectionists.

14th January 2010, 18:42	#8 \| Link
geeees Registered User Join Date: Jan 2010 Posts: 7	Hi Ghitulescu, thanks for the short explanation. Though I wouldn't describe myself as a perfectionist, it looks better without them 2 half lines. And it's really just a few seconds to set up before the encoding. Thanks again!

15th January 2010, 11:38	#10 \| Link
geeees Registered User Join Date: Jan 2010 Posts: 7	The chance of playing these movies on an analog device is rather small, but thanks for the hint anyways!

17th January 2010, 20:30	#12 \| Link
geeees Registered User Join Date: Jan 2010 Posts: 7	Sorry, apparently I missed your point. Here's what I was trying to say: I buy a DVD and want to back it up but don't have the capacity to save it in DVD format, so I want to encode and put it in an .avi or .mkv container. Before encoding I get rid of the half lines by cropping. I will only play this file on my laptop or PC. Am I all right then, or doing something useless/stupid by cropping?

18th January 2010, 08:28	#13 \| Link
loekverhees Registered User Join Date: Sep 2005 Location: Holland Posts: 86	If you are only playing it on your PC/laptop, then cropping is fine.