Strange Original DVD (some kind of blurring problem)

gaganspidey · 4th April 2008, 07:53

Hello friends,
I am new here and want some help from you people. I have this DVD and while watching it I noticed that 1 of the episode was not as clear as the other ones although I checked that both the files have 25fps (weird, isn't it ?) Then I found that there was something wrong with the frames,i.e, whenever there is any kind of motion in the video, it becomes kind of blurry and it can be easily seen by pausing the scene. So, I have here 2 screenshots of the same scene from 2 different episodes. Please see it so you will get a clear idea of what I mean.

© Hanna-Barbera

This must be some kind of defect when the professionals were authoring the DVD but why do they do so.Therefore I would like to know if there's any way of dealing with this problem (for eg: like ripping it to avi. format while reducing the framerate and then converting it again to .vob)
I want to free up space on my hard disk, so please let me have your helpful suggestions...

manono · 4th April 2008, 12:33

Hello and welcome to the forum,

The first pic looks like a bad conversion from an NTSC source to PAL. But without an unprocessed sample it's hard to know for sure. Pictures aren't good enough to learn what's going on.

gaganspidey · 4th April 2008, 18:04

Ok, here are the samples (13 MB both) :-
The sample for the blurry VOB is as follows:
http://www.megaupload.com/?d=B42YRUC7

And the sample for the other one which is good is as follows:
http://www.megaupload.com/?d=VINFK0QW

I am awaiting your advice...

manono · 5th April 2008, 02:38

Hi-

It's not a bad NTSC2PAL conversion at all. The bad one has the fields phase shifted. To explain; ordinarily the top and bottom fields of a progressive video go in the same frame, like so (where the capitalized letter is the top field and the small letter is the bottom field):

A B C D E
a b c d e

They will appear at playback as progressive, with no interlacing. However, when the fields are shifted they aren't lined up properly, the result is interlaced and may appear blurry, especially if played in a software player using a blend deinterlace. When just playing the DVD on an interlaced TV set, there's no problem as it only plays fields. Even on an HDTV, if you have a decent player it'll look OK, as a good DVD player can line the fields up properly. On the DVD they're like this:

A B C D E
b c d e f

If converting to progressive AVI, the answer or fix is to use a field matcher in your AviSynth script, such as TFM from TIVTC, or Telecide from Decomb.

gaganspidey · 5th April 2008, 07:16

I am really grateful to you for taking time from your schedule & answering me but to be frank I am new to AviSynth. Could you please give me a tutorial link so that I can learn about it.

manono · 5th April 2008, 07:22

How were you planning on doing the conversion to AVI if you know nothing about video encoding?

Anyway, read everything at the AviSynth site. Read the docs included with the DGMPGDec package, especially the QuickStart Guide:

http://avisynth.org/mediawiki/Main_Page
http://neuron2.net/dgmpgdec/dgmpgdec.html

gaganspidey · 5th April 2008, 07:46

I meant that I didn't knew the basics about AviSynth but I have worked a lot on VirtualDub and also I thought that after getting the .avi file, it would be easy to convert to DVD again by using [spam]. Thanks, anyways.

4th April 2008, 07:53	#1 \| Link
gaganspidey Registered User Join Date: Mar 2008 Posts: 21	Strange Original DVD (some kind of blurring problem) Hello friends, I am new here and want some help from you people. I have this DVD and while watching it I noticed that 1 of the episode was not as clear as the other ones although I checked that both the files have 25fps (weird, isn't it ?) Then I found that there was something wrong with the frames,i.e, whenever there is any kind of motion in the video, it becomes kind of blurry and it can be easily seen by pausing the scene. So, I have here 2 screenshots of the same scene from 2 different episodes. Please see it so you will get a clear idea of what I mean. © Hanna-Barbera This must be some kind of defect when the professionals were authoring the DVD but why do they do so.Therefore I would like to know if there's any way of dealing with this problem (for eg: like ripping it to avi. format while reducing the framerate and then converting it again to .vob) I want to free up space on my hard disk, so please let me have your helpful suggestions... Last edited by gaganspidey; 4th April 2008 at 07:57.

4th April 2008, 18:04	#3 \| Link
gaganspidey Registered User Join Date: Mar 2008 Posts: 21	Ok, here are the samples (13 MB both) :- The sample for the blurry VOB is as follows: http://www.megaupload.com/?d=B42YRUC7 And the sample for the other one which is good is as follows: http://www.megaupload.com/?d=VINFK0QW I am awaiting your advice... Last edited by gaganspidey; 4th April 2008 at 18:06.

5th April 2008, 02:38	#4 \| Link
manono Moderator Join Date: Oct 2001 Location: Hawaii Posts: 7,406	Hi- It's not a bad NTSC2PAL conversion at all. The bad one has the fields phase shifted. To explain; ordinarily the top and bottom fields of a progressive video go in the same frame, like so (where the capitalized letter is the top field and the small letter is the bottom field): A B C D E a b c d e They will appear at playback as progressive, with no interlacing. However, when the fields are shifted they aren't lined up properly, the result is interlaced and may appear blurry, especially if played in a software player using a blend deinterlace. When just playing the DVD on an interlaced TV set, there's no problem as it only plays fields. Even on an HDTV, if you have a decent player it'll look OK, as a good DVD player can line the fields up properly. On the DVD they're like this: A B C D E b c d e f If converting to progressive AVI, the answer or fix is to use a field matcher in your AviSynth script, such as TFM from TIVTC, or Telecide from Decomb. Last edited by manono; 5th April 2008 at 07:24.

5th April 2008, 07:46	#7 \| Link
gaganspidey Registered User Join Date: Mar 2008 Posts: 21	I meant that I didn't knew the basics about AviSynth but I have worked a lot on VirtualDub and also I thought that after getting the .avi file, it would be easy to convert to DVD again by using [spam]. Thanks, anyways. Last edited by Guest; 1st July 2010 at 15:06. Reason: 5

4th April 2008, 12:33	#2 \| Link
manono Moderator Join Date: Oct 2001 Location: Hawaii Posts: 7,406	Hello and welcome to the forum, The first pic looks like a bad conversion from an NTSC source to PAL. But without an unprocessed sample it's hard to know for sure. Pictures aren't good enough to learn what's going on.

5th April 2008, 07:16	#5 \| Link
gaganspidey Registered User Join Date: Mar 2008 Posts: 21	I am really grateful to you for taking time from your schedule & answering me but to be frank I am new to AviSynth. Could you please give me a tutorial link so that I can learn about it.

5th April 2008, 07:22	#6 \| Link
manono Moderator Join Date: Oct 2001 Location: Hawaii Posts: 7,406	How were you planning on doing the conversion to AVI if you know nothing about video encoding? Anyway, read everything at the AviSynth site. Read the docs included with the DGMPGDec package, especially the QuickStart Guide: http://avisynth.org/mediawiki/Main_Page http://neuron2.net/dgmpgdec/dgmpgdec.html