Duplicate PGCs in Robot4Rip

[Staz]

I am backing up a DVD of mine that contains 6 TV episodes on it.

When I open robot4rip I see 2 PGC's exactly the same Under each VTS.
Why is this and is it OK to just select one of these duplicate PGC's in Robot4Rip and continue as normal. What is the correct method for handling this situation?

Another thing is that the result for my compressibility check I get 22% when using the resolution 512 * 368. I have to lower my resolution to rediculously low amounts to get in the 40 - 60 % range. Can anyone help out here?

Thanks in Advance
Staz

[manono]

Hi-

What is the correct method for handling this situation?

Pick one of the PGCs and go on from there. Maybe it's multi-angle, with the credits in 2 different languages. By choosing the first angle, it's usually English (where I am anyway).

Can anyone help out here?

That's a pretty low percentage all right. And I agree that you don't want to lower the resolution. I can only suggest either a larger file size (what did you set it at?), or some heavy filtering (which may or may not be a good idea, depending on what the source looks like).

Is this PAL or NTSC? Can it be IVTC'd, or are you already doing that?

[Staz]

Thanks for the reply Manono. :)

I am encoding a TV episode (23 mins long) from a DVD to a XVID of 175 megs in size. I'm in PAL territory and the source is interlaced so I am using the deinterlace filters. First encode attempt I used the "FieldDeinterlace" method for deinterlacing and the next method I used "tomsmocomp". Both of these encodes were done at 544x300 resolution (which meant that only a percentage of 19.2 % in the compressibility test).

The encode with the "Fielddeinterlace" method ended up with a bitrate of 947 kbps and the "tomsmocomp" method ended with a bitrate of 949 kbps. I just woke up so will check out the visual difference in the encodes soon. With such a low compressibility check result these are fairly good resulting bitrates?

In your opinion what is the best method for deinterlacing and should I be getting such rediculously small compressibility percentages?

Thanks
Staz

[manono]

Hi-

With such a low compressibility check result these are fairly good resulting bitrates?

The bitrate is fixed, when the filesize, audio, and video length are the same. Increase the file size (233 MB or 3 episodes per CD, for example) to raise the bitrate. It doesn't have anything to do with compress test results.

In your opinion what is the best method for deinterlacing

I prefer KernelDeint or TDeint.

...should I be getting such rediculously small compressibility percentages?

I agree that it's a very low percentage for that resolution and bitrate, but it's not unheard of. I guess these things just don't compress well.

[piscator]

@staz. Are you absolutely sure the source is interlaced? I'm also in PAL territory and I've yet to find a DVD that is interlaced. And I've made backups of quite a few TV episode DVD's.

Even if DVD2AVi/DGIndex tells you the source is interlaced, it probably isn't. You always have to verify it visually. You know, you get those artifacts with stripes. And even if you get that, the frames are probably phase shifted. I've had a few situations in which this was the case and I remember getting ridiciously low comp. results, though not as low as you have.

Try the following filter to reorder the fields. It worked on quite a few of my episode DVD's.
Telecide(order=1,post=0,guide=2)

greetz,
Piscator

[Staz]

Originally posted by piscator
@staz. Are you absolutely sure the source is interlaced? I'm also in PAL territory and I've yet to find a DVD that is interlaced. And I've made backups of quite a few TV episode DVD's.

Even if DVD2AVi/DGIndex tells you the source is interlaced, it probably isn't. You always have to verify it visually. You know, you get those artifacts with stripes. And even if you get that, the frames are probably phase shifted. I've had a few situations in which this was the case and I remember getting ridiciously low comp. results, though not as low as you have.

Try the following filter to reorder the fields. It worked on quite a few of my episode DVD's.
Telecide(order=1,post=0,guide=2)

greetz,
Piscator

Thanks for the reply Picastor :)

I am certain that I do have an interlaced source. The horizontal lines are very obvious in the preview window of GK and I have dealt with interlaced extras before when making DVDR backups, that look exactly the samex as this. Will this Telecide method still work and if so how do I use it?

Thanks
Staz

[manono]

Piscator made a very good suggestion. To do it, open the .avs to edit it. Near the top, where the LoadPlugIn for the Decomb.dll is located, remove the "#" from the left. Then further down where the Telecide line is located, replace what's there with his setting (also making sure that the "#" is removed). Save it, open it in VDubMod, scroll to a place where there's movement, and start advancing one frame at a time. If the interlacing is gone, then his suggestion made a huge difference, as you had the not uncommon problem for PAL people of "shifted fields". If you still see interlacing, then you really did have a truly interlaced source, and nothing was lost but 5 minutes of your time. If it's still interlaced after adding Telecide to your script, undo the changes that you made, and go ahead and deinterlace.

[Staz]

And it worked! =)

There were two places on the .avs file that I found a Telecide line. One underneath IVTC section and one under Deinterlace section. I edited the one under the Deinterlace section. No interlacing lines when I opened the .avs file in virtualdubmod. I think its great that you can open the .avs in virtualdubmod rather than having to go through an entire encode first and then checking for interlace lines. =)

What is decomb.dll? (I thought it was something to do with interlacing?)

How do I view what DGindex thought of the source.
Eg: Whether it thinks its interlaced or not etc.
Is there some kind of log I can view?

Also what are the benefits of using telecide rather than deinterlacing?
I have encoded all 8 episodes from the DVD, deinterlacing them using the tomsmocomp deinterlacing method. Would I get better results if I used the telecide method instead?

Lastly, is there a good FAQ that explains about "shifted fields" and the "telecide" option. I'm interested in finding more about these. I just straight away assumed I had an interlaced source, now I know its good to check that its not a case of "shifted fields" instead.

Thanks again all the doom9 pros!!

Staz

[manono]

Hi-

Good. I'm glad it worked for you. piscator comes through again. :)

What is decomb.dll

Decomb contains Telecide, Decimate and FieldDeinterlace, and is most often used by NTSC people to perform IVTC. If you didn't understand that, just be thankful you're in PAL land, and don't often have to use it. But it is sometimes useful for PAL people (as it was in your case) to realign the fields, or to remove 1 duplicate frame in 25 in those few cases when NTSC was converted to PAL by adding a frame every second, rather than the more common speedup method.

How do I view what DGindex thought of the source.

Load the vobs and run the Preview. However, it's not going to show you much of interest to help you in the situation you faced. It'll show that the video was encoded as Interlaced (as are most PAL DVDs), but it won't tell you whether or not the video is actually interlaced. There's a distinction between Interlaced encoding, and it being truly Interlaced. Most is encoded as Interlaced, but as piscator noted earlier, very little is actually interlaced. You'll have to depend on your eyes, and running tests, such as the one piscator recommended.

Also what are the benefits of using telecide rather than deinterlacing?

Deinterlace only as a last resort. Even though AviSynth has some very good deinterlacers, inevitably they'll degrade the source to some degree. In your case, Telecide restored the Progressive frames without the need for deinterlacing, and the resulting video quality was the better for it.

Lastly, is there a good FAQ that explains about "shifted fields" and the "telecide" option.

http://www.doom9.org/ivtc-tut.htm#PALTheGoodTheBadAndTheUgly

[Staz]

Thanks Manono!
You have been a brilliant help!

The source quality of my original DVD was really bad. They tried to cram too many episodes onto the one DVD. The quality of the XVID encodes was actually exactly the same as the source even when deinterlacing. In the future if I have a case of "shifted fields" I will definitely use the telecide line in the .avs. I think I might encode a few of the episodes using telecide rather than deinterlacing and compare the results.

Thanks Again
Staz

[piscator]

Originally posted by Staz
The source quality of my original DVD was really bad. They tried to cram too many episodes onto the one DVD. The quality of the XVID encodes was actually exactly the same as the source even when deinterlacing. In the future if I have a case of "shifted fields" I will definitely use the telecide line in the .avs. I think I might encode a few of the episodes using telecide rather than deinterlacing and compare the results.

Great that it worked! :D Like I said, I've yet to find a PAL DVD which is truly interlaced. I assume your compressability checks were much better now? I guess you won't see much quality difference between the Deinterlace method and the Telecide method (since the source material was already crappy). Except, of course, for filesize.

Obviously, using Telecide on a truly interlaced source, such as TV captured output doesn't work.

I've had this "shifted fields" problem with TV episode DVDs only. Especially if the source is crap (seeing macro blocks in shadows, ughhh :scared: ), it always appears to have the "shifted fields".

greetz,
Piscator

[Staz]

Sorry to bother you again manono.

You mentioned you prefer the "tdeint" method for deinterlacing. I am wanting to deinterlace some DV footage that I captured from a DV CAM as I plan to encode it to XVID. How on earth do I use tdeint? (I extracted it). I know it's something to do with .avs scripts. Is it possible to use tdeint in virtual dub or Gordian Knot?

If someone could help out here, that would be awesome!

Thanks
Staz