VirtualDub introduces speckling when using Inverse Telecine

[pijetro]

Bugmenot wrote:

FulciLives: I want it to be an AVI, which will eventually end up as an MPEG-2 when I encode it.

Your file should be an .AVI to begin with..By resaving it as .AVI and encoding again, you're gonna lose quality...
The script program should open up your original file, and send it to CCE or Tmpgenc and feed it unmolested..

If your screenshot was an unadulterated .AVS script, then i would try a BilinearResize...

[vhelp]

Give up on it.

Here here. I agree. Give up on it. You simply *can not* undo a bad
Telecined source. Cartoons are NORTIOUS for this. IMHO, the best
method for these types of Cartoons is to just encode FULL. That is,
at 29.970 fps and get just increase your bitrate some.
.
You'll get:

* smooth video play, and
* possibly better quality (if bitrate raised high enough)


Now, On to your IVTC method ...

I think that you got it a littel wrong there.
I've used this method lots of times, and with perfect results - every time.
But, your source has to be perfect 3:2 pulldown, else it will fail, fail,
fail - every time.
.
I'm always advancing my IVTC process and methods, and time allows me to
research and take a trip through "trial 'n error" scenarios.. a pains taking
process. But I do it for the love of this HOBBY. Course.., I've sense
found an even better solution to my IVTC process.. no longer performed inside
vdub anymores. And, definately *not* inside an AVIsynth script either!
Anyways.
.
Because your source is Cartoon, and (IMO) a broken Telecine source, you cannot
use the 3:2 method built-in to vdub, w/out issues in your final source file.
You've proven this in your pic above.

But, to be *open* and helpful in the IVTC method above.., the proper way to
use this (the next time you have a perfect Telecine (aka, 3:2 pattern through
out your video source) is to observe these steps. Trust me.., you *WONT* go
wrong here.

Step A - - Field Order TOP ...

First, make sure your source is observing the correct Field Order. The wrong
one will cause failure of IVTC.
Two, your captured source must *NOT* have any droppped frames.

If your avi is NOT from a DV device, the field order is TOP. You must there
fore, make the following settings under - Video / Frame Rate..

  -- Source Rate Adjustment --
  (o) No change
  -- Inverserse telecine (3:2 pulldown removal) --
  (o) Reconstruct from fields - manual
  Offset: [3 ]
  [ ] Invert Polarity

.. or ..

Step B - - Field Order bottom ...

If your avi is from a DV device, the field order is BOTTOM. You must there
fore, make the following settings, noting the "Invert Polarity" flag:

  -- Source Rate Adjustment --
  (o) No change
  -- Inverserse telecine (3:2 pulldown removal) --
  (o) Reconstruct from fields - manual
  Offset: [3 ]
  [x] Invert Polarity

When saving a DV file into a new DV file, remember two things:

1 - its re-compressing the source again, to DV. Yes. Recommpressing.
2 - choose a Canopus codec and save it as such (if you have one installed - if
.... not, get one and install it)
.... .
.... The reason I suggested a Canopus codec, (in short) is because TMPG
.... has special provisions for *THIS* codec ONLY (and assuming you turn this
.... feature on in TMPG. Anything else, and it's up to the GODS to deside what
.... makes or breaks your final MPEGs ..that's if you notice anything odd


I think that about raps it up for IVTC inside vdub.

Good luck,
-vhelp

[bugmenot]

Your file should be an .AVI to begin with..By resaving it as .AVI and encoding again, you're gonna lose quality...
The script program should open up your original file, and send it to CCE or Tmpgenc and feed it unmolested..

If your screenshot was an unadulterated .AVS script, then i would try a BilinearResize...

Well, when the video isn't speckled, it looks great, especially with my PAL and S-video cable (you NTSC users have NO idea how good this setup looks :P) and I had indeed re-encoded.
vhelp: that seems like an awful lot of messing around for something that feels like a small error in something I'm doing. If the video was speckled all the time, I'd be looking into that sort of thing, but it's only in a few places, so it's all rather confusing I've just now noticed that my trial of DivX pro has expired, which in turn has taken it off the "slow" setting, I wonder if this might be causing the problem.... I've asked a few of the people at the VD forums, and they seem to think it might be a bitrate problem. I'll try upping it and see what happens...

[Nelson37]

Bugme- you need to Isolate and Identify. By combining several processes, it becomes impossible to determine exactly which one is causing the problem.

Edit a short segment which shows the problem, IVTC and save as uncompressed (or Huffy) AVI. See if this shows the problem. Also check this section of the original for Telecine pattern irregularities, this is most likely the issue.

If the problem does not show up in this uncompressed AVI, then it MUST be your encode method.

[vhelp]

@ bugmenot

By the looks of things, it seems evident that you are capturing your video
source to divX and THEN you are encoding it to MPEG.

Therefore, I would say that the "speckles" you are experiencing is due to
the divX encoding properties you are using.
.
Try capturing w/out a divX codec. Perhaps Huffy or MJPEG, or even uncompressed.
.
Then try your hand at encoding (including your IVTC process) and see what
your new results are.

-vhelp

[bugmenot]

Well, I tried upping DivX's bitrate, and that's done the trick. My DivX pro trial had run out too, so slow encode had turned off too, so that wouldn't be helping. I'm going to do a little more testing and see if it's really been solved I'm totally writing a guide about this, us PAL users need a guide to making silky smooth DVDs!

[junkmalle]

Well, I tried upping DivX's bitrate, and that's done the trick. My DivX pro trial had run out too, so slow encode had turned off too, so that wouldn't be helping. I'm going to do a little more testing and see if it's really been solved I'm totally writing a guide about this, us PAL users need a guide to making silky smooth DVDs!

I IVTC (manual setting) all the time with VirtualDubMpeg and have never seen anything like the problem in your sample. What other filters are you using? Are you resizing? Deinterlacing? Maybe your bitrate is just too low.

[pijetro]

Pijetro wrote:

If you're using Vdub to encode to DivX, then you should be using Fast Recompress option..
Plus, your bitrate could be slow..