Lossless VOB to MPEG interlace issues.

Prodoc · 6th July 2006, 15:04

Hi,

I've been playing with DGMPGDec, VobEdit and PgcDemux in combination with ImagoMPEG-Muxer to be able to convert VOB files to MPEG files without loosing quality. The reason I used the mentioned programs is because I need a plain and simple program to convert the stuff because I sometimes need to do this in a hurry. Having to start 'scripting' first will be too much of a hassle imo.

Today I ran into a VOB file which has interlaced video. After the conversion I get to see artifacts in VLC and Windows Media Player, WMP Classic plays it fine. In VLC I have to set a deinterlace option manually which isn't a clean solution.

What are my options to solve the interlace problems? The way I see it is that I'll have to deinterlace the video to make sure it will play fine in most players (VJ purposes), don't I? The programs mentioned above don't have a deinterlace option as far as I can tell. Is there a clean and simple program that can deinterlace the VOB right away when converting? Will I loose any/much video quality in the process?
Preferably a all-in-one program would be handy, I'm already using 2 programs to do the trick, I hope it's not required to use a third program/step to deinterlace the video?

neuron2 · 6th July 2006, 15:10

Are you sure it is interlaced and not telecined (or phase-shifted PAL)? If so, then use any of the available good Avisynth deinterlace filters. If not, then do IVTC or field matching.

Keeping high quality while avoiding "hassle" are likely incompatible goals.

Prodoc · 6th July 2006, 15:44

Quote:

Originally Posted by neuron2

Are you sure it is interlaced and not telecined (or phase-shifted PAL)?

I only know that the issue was fixed when enabling deinterlace in VLC under 'Video - Deinterlace - Blend'. Is this test sufficient enough? If not, how do I make sure what I'm dealing with?

unskinnyboy · 6th July 2006, 16:36

It is probably interlaced. The "artifacts" you saw after the conversion is interlacing. You didn't see the "artifacts" in MPC because I believe the built-in deinterlacer kicked in and deinterlaced the video on-the-fly. VLC and the other DShow players played it back as-is, which is why you saw the interlacing.

Your 2 options are:

1) Encode as interlaced. Set ffdshow to decode your video and deinterlace during playback. Deinterlacing options are available under ffdshow video decoder configuration -> Deinterlacing.

2) Like neuron2 said, use a good AviSynth deinterlacer and deinterlace before encoding.

I recommend #2, because you will get a better quality picture for a fixed filesize if you deinterlace before encoding. But it requires more effort than #1. Upto you.

When it comes to video compression and encoding - quick 'n dirty efforts will look quick 'n dirty too - keep that in mind.

Prodoc · 6th July 2006, 17:06

Quote:

Originally Posted by unskinnyboy

Your 2 options are:

1) Encode as interlaced. Set ffdshow to decode your video and deinterlace during playback. Deinterlacing options are available under ffdshow video decoder configuration -> Deinterlacing.

2) Like neuron2 said, use a good AviSynth deinterlacer and deinterlace before encoding.

Doesn't AviSynth only produce an AVI output? Suppose I wouldn't use any filters and the movie isn't interlaced, would the video quality, when saving it as an AVI through AviSynth, be identical to remuxing to MPEG as I did untill now?

Which deinterlacer is recommended? I read on the AviSynth site that there's one included by default and a few 3rd-party plugins.

unskinnyboy · 6th July 2006, 17:20

No. AviSynth produces *uncompressed* output. It is upto you to use whatever encoder you want (which takes an avs input) and save it to whatever format you want - MPEG, AVI, whatever.

Which deinterlacer is recommended? The deinterlacer which will work for you is recommended.

Jay Bee · 6th July 2006, 17:43

If you don't want to lose quality you should just keep it interlaced. Any decoder that plays interlaced VOB files properly should have no problem with interlaced MPEG files. Try Nvidia Purevideo decoder or DScaler 5 (free).

manono · 7th July 2006, 13:37

Based on what he's said so far, we still don't know if it's just telecined film, or perhaps phase-shifted PAL video. Sure, it could be pure interlace, but if there's any reencoding to be done, it would certainly be worthwhile to find out. An unprocessed vob sample would help us find out, if Prodoc doesn't know how to figure it out himself.

Prodoc · 8th July 2006, 11:39

Would it help if I said it's the official Shrek 2 DVD (PAL), no rip, of which I need a sample? Are there DVD's being released with telecined film or phase-shifted PAL video?
I can provide a sample if I figure out how to create an unprocessed vob sample since the files are rather big.

manono · 8th July 2006, 12:16

That rules out telecine, but it ups the chances tremendously that it's just phase-shifted.

To make a sample, open a vob in DGIndex, find a place with movement, and use the "[" and "]" buttons to mark off a small section. Then go File->Save Project And Demux Video. Upload that.

In the meantime you might try:

Telecide(Post=0)

on it to see if that makes it progressive again.

6th July 2006, 15:04	#1 \| Link
Prodoc Registered User Join Date: Dec 2005 Posts: 7	Lossless VOB to MPEG interlace issues. Hi, I've been playing with DGMPGDec, VobEdit and PgcDemux in combination with ImagoMPEG-Muxer to be able to convert VOB files to MPEG files without loosing quality. The reason I used the mentioned programs is because I need a plain and simple program to convert the stuff because I sometimes need to do this in a hurry. Having to start 'scripting' first will be too much of a hassle imo. Today I ran into a VOB file which has interlaced video. After the conversion I get to see artifacts in VLC and Windows Media Player, WMP Classic plays it fine. In VLC I have to set a deinterlace option manually which isn't a clean solution. What are my options to solve the interlace problems? The way I see it is that I'll have to deinterlace the video to make sure it will play fine in most players (VJ purposes), don't I? The programs mentioned above don't have a deinterlace option as far as I can tell. Is there a clean and simple program that can deinterlace the VOB right away when converting? Will I loose any/much video quality in the process? Preferably a all-in-one program would be handy, I'm already using 2 programs to do the trick, I hope it's not required to use a third program/step to deinterlace the video?

6th July 2006, 16:36	#4 \| Link
unskinnyboy Registered User Join Date: Feb 2004 Location: NTSC R1 Posts: 2,054	It is probably interlaced. The "artifacts" you saw after the conversion is interlacing. You didn't see the "artifacts" in MPC because I believe the built-in deinterlacer kicked in and deinterlaced the video on-the-fly. VLC and the other DShow players played it back as-is, which is why you saw the interlacing. Your 2 options are: 1) Encode as interlaced. Set ffdshow to decode your video and deinterlace during playback. Deinterlacing options are available under ffdshow video decoder configuration -> Deinterlacing. 2) Like neuron2 said, use a good AviSynth deinterlacer and deinterlace before encoding. I recommend #2, because you will get a better quality picture for a fixed filesize if you deinterlace before encoding. But it requires more effort than #1. Upto you. When it comes to video compression and encoding - quick 'n dirty efforts will look quick 'n dirty too - keep that in mind. __________________ I encode, therefore I am. Doom9 Toolbar Extension for Firefox [v3.1]

6th July 2006, 17:20	#6 \| Link
unskinnyboy Registered User Join Date: Feb 2004 Location: NTSC R1 Posts: 2,054	No. AviSynth produces uncompressed output. It is upto you to use whatever encoder you want (which takes an avs input) and save it to whatever format you want - MPEG, AVI, whatever. Which deinterlacer is recommended? The deinterlacer which will work for you is recommended. __________________ I encode, therefore I am. Doom9 Toolbar Extension for Firefox [v3.1]

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6th July 2006, 15:10	#2 \| Link
neuron2 _ Join Date: Jan 2002 Posts: 16,653	Are you sure it is interlaced and not telecined (or phase-shifted PAL)? If so, then use any of the available good Avisynth deinterlace filters. If not, then do IVTC or field matching. Keeping high quality while avoiding "hassle" are likely incompatible goals.

6th July 2006, 17:43	#7 \| Link
Jay Bee Registered User Join Date: May 2006 Posts: 451	If you don't want to lose quality you should just keep it interlaced. Any decoder that plays interlaced VOB files properly should have no problem with interlaced MPEG files. Try Nvidia Purevideo decoder or DScaler 5 (free).

7th July 2006, 13:37	#8 \| Link
manono Moderator Join Date: Oct 2001 Location: Hawaii Posts: 5,713	Based on what he's said so far, we still don't know if it's just telecined film, or perhaps phase-shifted PAL video. Sure, it could be pure interlace, but if there's any reencoding to be done, it would certainly be worthwhile to find out. An unprocessed vob sample would help us find out, if Prodoc doesn't know how to figure it out himself.

8th July 2006, 11:39	#9 \| Link
Prodoc Registered User Join Date: Dec 2005 Posts: 7	Would it help if I said it's the official Shrek 2 DVD (PAL), no rip, of which I need a sample? Are there DVD's being released with telecined film or phase-shifted PAL video? I can provide a sample if I figure out how to create an unprocessed vob sample since the files are rather big.

8th July 2006, 12:16	#10 \| Link
manono Moderator Join Date: Oct 2001 Location: Hawaii Posts: 5,713	That rules out telecine, but it ups the chances tremendously that it's just phase-shifted. To make a sample, open a vob in DGIndex, find a place with movement, and use the "[" and "]" buttons to mark off a small section. Then go File->Save Project And Demux Video. Upload that. In the meantime you might try: Telecide(Post=0) on it to see if that makes it progressive again.