Comment:Resize Filters

[Tuning]

I'm currently using GKnot 0.28.5.2 with it's codecpack 1.4.The question is this: The resize filters are not up to requirement.I think the sharpest resize filter is lancazos -> but whenever i used lancazos the object edges are not smooth(steps like artifact),but if i used the bilinear and bicubic variety the edges are smooth but the complete video is smoother than before or the details which i previously got was diminished !.And i could not understand how the downloaded movies looks good(doesn't show such artifacts).So is there any combination in GK settings by which better detailed, and smooth curvey edges movies can be made.Any information regarding use of resize filters is appreciated.Thanks.
:confused:

[manono]

Hi-

I can't say that I've noticed those things about LanczosResize, and I use it almost exclusively. Have you tried Sharp Bicubic (BicubicResize(xxx,xxx,0,0.75)) and found it to be too smooth also? Anything unusual about your .avs's? Are you using really low resolutions? Are you using other filters along with it that may account for this? For example, Warpsharp or other sharpeners can produce what you describe.

Oh, and we don't mention downloaded movies around here. You might see this Sticky (http://forum.doom9.org/announcement.php?s=&forumid=6) for clarification.

[Tuning]

I have tried sharpbicubic also.But it also found similar artifact of smoothing videos.And i a'm currently mentioning 2hr movies with mp3 sound on single cd @ resolution 608x272.As in case of d/l movies it was an example or the video of referrence with same resolution time and approximate length.only a refference view.The DVDs i'm using are NTSC ones with interlace.But for progressive video i found the lancazos filter is upto right.:(

[manono]

Hi-

The DVDs i'm using are NTSC ones with interlace. But for progressive video i found the lancazos filter is upto right.

I'm sorry, but I didn't understand that. Are you saying that you have the aliasing-jaggie-stairstep problem with deinterlaced material, but not with IVTC'd material? Then it would stand to reason that the problem is with the deinterlacer, or with deinterlacing in general. You might try out the KernelDeInt deinterlacer, as I believe it to be better than anything else out there. You can find it here (http://www.avisynth.org/~warpenterprises/).

Now, if you've seen other people's versions of the same movies (that's how you say it), and they're better than yours, and don't display the stairstep problem, then I conclude either that they have a telecined version from a different region, or, more likely, films that you thought should be deinterlaced can be IVTC'd to look much better. Maybe this Tutorial (http://www.doom9.org/ivtc-tut.htm) will help teach you which movies can be IVTC'd, and which must be deinterlaced. Just because DVD2AVI tells you it's 100% NTSC, or is interlaced, doesn't mean that it can't be IVTC'd. In fact, most movies like that can be IVTC'd. If those other movies are 23.976fps and yours are 29.97fps and deinterlaced, then that would be confirmation of my suspicions.

And if I've misunderstood you, or not given you enough credit for what you know, then please forgive me. :)

[Tuning]

All the videos mentioned as NTSC has been IVTC'd based on the tutorial u just mentioned(Actually i had the whole doom9's guides on Hard disk and doubts were clarified as soon as happened).Here what i mean progressive is that movies with 23.976 as original framerate and doesn't found to be interlaced.But every movie trancoded of NTSC was found to have the problem.And I have tried these movies on different windowsXps(new installations).All produced similar results.I tried the neutral bicubic and IVTC once -> the edges were smooth but video became more smoother.Then I tried lancazos and IVTC .The pictures were more detailed but edges had steps artifact.Can u explain how the "aliasing-jaggie-stairstep problem " ocuurs and may be i could find some means by which it can be remedied.Thanks Manono:D

[len0x]

What you decribed in the first post is very common if you're dealing with very noisy source. Lanczos as being the sharpest filter abviosly will introduce "steps-like artifacts" on such source unless you put 2-3 times more bitrate (although this will not help a lot) on it or use filters to remove noise.

As you mentioned 2h movie with such resolution and noisy source - will look horrible on just one CD...

[manono]

Hi-

Well, I did misunderstand you. I'm not sure I can help much, though. But here's what I know about the subject. I think it's a source problem, and people that have made better versions of the same movie might have access to a better source.

When you have a movie that has been encoded as Interlaced (100% NTSC and shows as Interlaced in the DVD2AVI Preview), it is usually also widescreen letterboxed (DAR=4:3), instead of being encoded as Progressive (can be Force Filmed in DVD2AVI), and anamorphic widescreen (DAR=16:9). If it's been encoded as 4:3, a lot of picture information is missing when compared to a 16:9 DVD. This can result in the stairstepping you mentioned. The thing I hate the most about this kind of movie is the "shimmer" or "flashing" you get with thin lines. If you freeze the video, you can see that this shimmer is caused by the lines being jagged, or aliased. But if I'm not mistaken, you can see the same problem in the vob files, and there's not much you can do about it.

This is a serious problem in my region (R1), where many films, particularly Asian films, and even more particularly Hong Kong films, are released on DVD with these bad transfers. And it is also true that these same films are released on DVD in other parts of the world with good 16:9 anamorphic transfers. There are many people in my country that buy region-free DVD players just so they can import better quality DVDs of their favorite movies from other parts of the world. Here's a thread listing movies available only as 4:3 transfers in the US, but with anamorphic 16:9 transfers available in other parts of the world:

http://www.dvdtalk.com/forum/showthread.php?threadid=312339

Maybe some of your movies are on that list. I noticed that len0x also answered while I was typing, and maybe he is helping with your problem.

Also, if you're using Decomb to IVTC, you might have to tweak your settings to make sure that good progressive frames aren't being deinterlaced. That can also lead to the problem.

[Tuning]

May be u are right the video source is the problem.Some rips made from better quality DVD9 dics are found to have diminished artifacts.The other ones are low in quality and have the artifacts.So most of DVDs available in this region are of this poor type.There for can any developer suggest a new resize filter that can reduce this artifact while maintaining the sharpness of Lanczos.Or here is another suggestion :Can the resizing part of VdubMod/NanDub can be manually selected with out using GKs inbuit resize filters(may be in any of future versions).with using GK de-interlacers.Thanks. :D

[len0x]

why don't you just use noise-removal filters prior resizing
(i.e. deen, c3d, fluxsmooth)? I don't have much experience with them but there are ppl here who can suggest what to use...

[bond]

if lanczos isnt sharp enough just dont resize ;)
in matroska you can define the playback resolution...

[manono]

Hi-

Can the resizing part of VdubMod/NanDub can be manually selected with out using GKs inbuit resize filters

No. To use the VDub resizers, you have to encode in Full Processing Mode directly in VDubMod, and not in Fast Recompress through GKnot. But as far as I know, the VDub Resizers aren't any better than the ones available through AviSynth. You could try, though. Make your .avs like usual in GKnot and save it, delete the Resize line, open the .avs in VDubMod, set it for Full Processing, and then Resize and Encode directly in VDubMod. I suppose you could import the VDub filters into the .avs, but I never bothered learning how to do that.

Your comment about DVD5 .vs DVD9 got me to thinking. I saw an imported but official (not bootleg) release of the Japanese film Battle Royale recently. It's an action packed 2 hour movie. It was encoded as Interlaced, but was Anamorphic 16:9 and only on a DVD5, instead of a DVD9, as it should have been. It didn't have the stepping artifacts, but it was full of compression artifacts, including blocks and color smearing. Sad.

[Tuning]

Quote:# manono
Your comment about DVD5 .vs DVD9 got me to thinking. I saw an imported but official (not bootleg) release of the Japanese film Battle Royale recently. It's an action packed 2 hour movie. It was encoded as Interlaced, but was Anamorphic 16:9 and only on a DVD5, instead of a DVD9, as it should have been. It didn't have the stepping artifacts, but it was full of compression artifacts, including blocks and color smearing. Sad.
----------------------------------------------------------------
I got the very first appreciation in forum from u.(since aug 2003).Thanks manono for all your comments and instructions.May i ask u a simple one :the avisynth's use of filters named link etc(additional filter pack ).Is this increases encoding quality/Speed.

[manono]

Thanks for the kind words, Tuning.

I'm not sure I understood the question, but I'll go ahead and answer what I think you were asking (didn't work too well last time :)).

The use of AviSynth 2.5x (2.52 now), combined with the use of VDubMod and the Mpeg2Dec3.dll allows for much faster encoding than before (AviSynth 2.08 and VDub). It's something like 25-30% faster. The reason for this increased encoding speed is because no color conversions are necessary. DVDs are in YV12, and you can now keep it in that colorspace all the way through, where before you had to convert to YUY2 (and back?). Keeping within the same colorspace also, in theory, means for better quality. But I must confess that I can't see any difference in quality. But I definitely see more speed. And this is also much faster (50%?) than the "old days" when we had to use a VFAPI and encode using Full Processing Mode, and converting to RGB.

You can find more information about this in the AviSynth FAQ (http://www.avisynth.org/index.php?page=Section+1%3A+About+AviSynth#q1.7) (Q1.12).

And if you were asking about the use of the imported VDub filters, then I think you will lose at least some of the speed increase, but like I said, I've never used them. I have everything I want in AviSynth.

[Tuning]

I was reffering to the Support utilities(Software on doom9.org) "Avisynth Extension plugin package - Avisynth, AvisynthEx and Link2 in one package".These found to be trial versions.Does the use of these increases Speed/Quality.Thanks.
:cool:

[manono]

Damn! Guessed wrong again. :)

But sorry, I don't know anything about AvisynthEx and Link2. Perhaps someone else can help.

[Wilbert]

1) link2 is an avi-wrapper (with limitations). Look around for "makeAVIS", a free replacement of link2 (url is given in the YV12 faq).

2) AviSynthEx: has the internal filter "IPCSource", which is used to frameserve from Adobe Premiere to TMPGEnc/CCE/whatever. Also in this case a freeware replacement is available: "PluginPace frameserver" (see also YV12-faq).