recommended filters for slightly noisy dvds?

[chsmn]

Sorry if this has already been covered in another post(i did look around abit first), point me in the right direction if it has.

I'm fairly new to gknot and have already done a few good encodings with it but only from very clean sources using no external filters. What I want to know is what avisynth filters(combinations of and settings) do you experienced users find works the best with DVDs that have a slight noisy/grainyness to them that may have been added just for film effect. Is it only nessesary to worry about this for 1cd rips?
The reason I'm asking this is because i'm trying to get the best possible quality with Fellowship of Ring Extended addition (3.5hours) on 3 cds with ac3 included. I did some small experimental ecodes using the temporalsmooth filter that gknot recommends for low noise but the results were unsatisfactory. The detail was a bit worse and the color seemed slightly geen compared to the same ecode i did without temperalsmooth. I have the avisynth that gknot .27 comes with so filters need to be compatible(unless you think I should get a newer version).

Any help would be GREATLY appreciated.

[manono]

Hi-

N_F did an exhaustive series of tests comparing the various denoisers here (http://forum.doom9.org/showthread.php?s=&threadid=51181). He was comparing speed and compression. You'll have to make your own judgement as to which are better. The filters used are for AviSynth 2.51, but most are available for 2.08 (the one in GKnot 0.27). If you need to know where to get some of these filters, then check WarpEnterprises' page here (http://www.avisynth.org/~warpenterprises).

[N_F]

Are you sure you really need a noise filter for FotR? It's rarely I see a DVD more clean than that.

[chsmn]

Thats just what I'm trying to contemplate, I'm just trying to get some opinions to help me decide. By the way, what would be the best resize filter to use if the resolution is 640 x 2?? at 1050kbs?

[kaitsuburi]

Originally posted by chsmn
By the way, what would be the best resize filter to use if the resolution is 640 x 2?? at 1050kbs?

LanczosResize all the way, unless you are really pressed for compressibility. It is great for sharpness and since you already have a clean source it's going to look great :)

[chsmn]

Is this filter built into avisynth 2.08? If so is this what gknot uses when you select the sharp resizing option?

[kaitsuburi]

Here's a quote from avisynth.org:

LanczosResize is an alternative to BicubicResize with high values of c about 0.6 ... 0.75 which produces quite strong sharpening. It usually offers better quality (fewer artifacts) and a sharp image.

Lanczos was created for Avisynth because it retained so much detail, more so even than BicubicResize(x,y,0,0.75). As you might know, the more detail a frame has, the more diffiult it is to compress it. This means that Lanczos is NOT suited for low bitrate video, the various Bicubic flavours are much better for this. If however you have enough bitrate then using Lanczos will give you a better picture, but in general I do not recommend using it for 1 CD rips because the bitrate is usually too low (there are exceptions of course).

Yes, I think LanczosResize is built into Avisynth 2.08/2.51 (definitely the latter). Regarding gknot, it really depends on what version you are using (it is default in the latest alphas IIRC). To check, in the preview window, click on "Save & Encode", that gets you to an option screen, click on "Edit" on the bottom and that will show you the avisynth script that gknot has generated for you. The active options will have the # before them removed...

Hope this helps.

-kaitsuburi

[kaitsuburi]

Oh, and I think bitrates over 900 can be considered "safe" to use lanczos, in a general scenario of course. When you have a very noisy source, lanczos doesn't seem to produce as nice results as with a clean one. In your case, you should definitely try it out...

-kaitsuburi

[chsmn]

Thanks. Btw, do you know if it's even possible to make a 2.1GB avi file that I can play back off my HD or split up onto cds if need be? I remember readimg something about avi's limit being 2GB.

[kaitsuburi]

I think the limitation you are referring to applies only if you are using a file system other than NTFS (WinXP, WinNT and Win2k can use it; Win9x and WinMe are limited to either FAT or FAT32, which have the 2GB upper limit). So check the file system on your drive/partition. Otherwise, I don't think there should be problems with a 3CD avi file, but don't quote me on this -- I very rarely make .avi files that big (unless I capture from DV, but that's a whole different story). I have heard of people experiencing delays when playing 2+ GB .avis on older machines though.

-kaitsuburi

[N_F]

In Gordian Knot 0.28 beta lanczos resize exist as default option on the savs .avs window.

A general suggestion for FotR SE. The credits are huge, IIRC they are over 20 minutes long. If you encode credits separately with constant quality you can increase the bitrate for the movie considerbly.

I encoded FotR SE to 2 CD's some monhts ago and I was perfectly happy with the quality. Though that was with ogg, if you want ac3 then it's probably a good idea going for 3 CD's.

[Acaila]

Or use the 2-channel AC3 track that comes with the Extended version :). I only have two speakers so that enabled me to have perfect audio at a small size (on 2 CD's).
And I agree with N_F, encoding the credits at a low bitrate is a must.

[chsmn]

I compared a clip done with Lanczo's to one done with a sharp bicubic resize and the first looked so much sharper, lucky it was recommended or I would have never tried it.

Before I used gKnot I use to never include credits b/c I didn't think they were worth losing quality over. With the separate encoding option in gknot though, i always include them using the default quant of 20.

Maybe I was not looking hard enough but I didn't see any 2ch ac3 track on the one I have. It's 5ch ac3, DTS, French and 4 or so comentaries.

[frodoontop]

Or don't encode the credits at all. Ever met someone who after a movie of 3 hours had the wonderfull idea to watch all the credits?

By the way, I don't think you need any filters for Lord of the Rings. Certainly not if you're aiming for 3 CD's. I have it with maximum quality fit on 2 CD's with a resolution of 512x288 and having cut off the credits, but retaining the sound. For this movie I used BicubicResize(512,288,0,0.5)

[chsmn]

The credit music is sometimes pretty good and it makes a good ending to a movie even if you only watch 30seconds before you switch it off.