VirtualDub introduces speckling when using Inverse Telecine

[bugmenot]

I'm trying to use the Inverse Telecine option to bring a 29 FPS AVI down to 23.97 FPS. Most of the time, stripes appear, but I've had a bit more success using the "reconstruct from fields - manual" option. However, using this option occasionally introduces speckling where there's no speckling in the original. Does anyone have a solution to this?

[pijetro]

I'm trying to use the Inverse Telecine option to bring a 29 FPS AVI down to 23.97 FPS

The obvious question is "Is your source Telecined to begin with?".

[bugmenot]

I'd assume so, using the Inverse Telecine option brings the framerate down to 23.97 from 29 FPS without a noticeable change in the speed of the video. The only downside is the occasional speckling and occasional striping of the burnt on subs.

[FulciLives]

If you got burned in subs and if this is from an "imperfect" source ... I wouldn't even bother trying to do an IVTC as the process is very tricky and you can do more harm than good.

- John "FulciLives" Coleman

[bugmenot]

I have a high quality source, hence why I don't want any of it to degrade. I've got the smoothness perfect, I've got the audio perfect. Now I just need a solution to this little speckling problem. Unless someone else can suggest a different way of un-pull downing a 29 FPS video to 23.97 FPS?

[FulciLives]

Well you could try decomb which is an IVTC for AviSynth.

- John "FulciLives" Coleman

[bugmenot]

Erm... Got a guide for that?

[FulciLives]

Erm... Got a guide for that?

Look on DOOM9 plus make sure you read the docs that come with decomb.

The main AviSynth webiste:
http://www.avisynth.org/

Here is where you can get decomb (along with other AviSynth filters):
http://www.avisynth.org/warpenterprises/

Also there are some amazing experts on using AviSynth over on the doom9 forums but if you ask too much of a newbie question it might get ignored.

- John "FulciLives" Coleman

[bugmenot]

Ah, eliteists are they? I'll see what I can work out.

[pijetro]

Why are you so bent on removing the Telecine?? Especially if it's gonna be for TV viewing??
I've done it many times, but the pattern was obvious, and it was straight forward.
But if there's any sign of headache, then forget it...

[bugmenot]

Hmmmm, excuse my AVIsynth newbieness, but I'm having a bit of trouble with it. I've made an .avs with the code (with help from Doom9):
LoadPlugin("D:\Program Files\AviSynth2\plugins\Decomb521.dll")
AviSource("CORRECT PATH TO VIDEO IS INDEED INSERTED HERE. NO REALLY.")
Telecide(guide=1,gthresh=50,chroma=true,threshold= 30)
Decimate(cycle=5)
BicubicResize(512,384,0,0.5)
When I try to open the file in VirtualDub, I get the message "Avisynth open failure. LoadPlugin: "D:\Program Files\AviSynth2\plugins\Decomb521.dll" is not an Avisynth 1.0 plugin" Little help?

[bugmenot]

pijetro: Because it's much smoother to convert a 23.97 FPS video to 25 FPS. If I slow down a 29 FPS video to 25 FPS, it looks like it's running in slo-mo.

[pijetro]

Because it's much smoother to convert a 23.97 FPS video to 25 FPS. If I slow down a 29 FPS video to 25 FPS, it looks like it's running in slo-mo.

Alrighty, you've got a good reason..

Be careful which version of AVISynth you've got..
The 1.0X series can't use the plugins that the 2.5X series uses...
If you've correctly put the DLL into the Plugin folders, then you don't even need to type the LOAD PLUGIN command...
The Telecide function is part of the Decomb package Plugin....

avisource("F:\Bobloblaw")
Telecide()
Decimate()
assumefps(25,true)
BicubicResize(720,576)
resampleaudio(48000)

I hope this one works for you...

[bugmenot]

I've got avisynth 2, I don't know why it's mentioning v1.0.... By the looks of your script, it's going to turn it into a 25 FPS video. Is it still going to perform the un-pull down operation? My plan was to create a 23.97 FPS video then use AVIFrate to speed it up. It's worked with videos that were naturally 23.97 FPS.

[pijetro]

I've got avisynth 2, I don't know why it's mentioning v1.0....

The differences between versions 1.0x and 2.0x are subtle..
If you're using 2.5x, then AVISynth's internal structure is different..
U need to be careful what Plugins belong to what versions of AVISynth..

Anyways:

By the looks of your script, it's going to turn it into a 25 FPS video.

As per your original request.

Is it still going to perform the un-pull down operation?

Yes, the Telecide() pre processes, and deems what's removable, and Decimate() removes every fifth frame..
The () function at the end of a line simply uses the defaults (which should be okay usually )..

Simply drop the script into VirtualDub, and click the File Information, and see what it's showing you...

[bugmenot]

Ah, so it'll un-pull down the video to 23.97 FPS then speed it up it 25 FPS? That's handy. Hmmm.. Still having a few problems. I'm going to "open video file" in VD, and when I open the .avs file, it tells me "Avisynth open failure: AVIsource autodetect: couldn't open file"
*EDIT* Oops, it was because I'd forgotten to add the .avi to the file path. Now it says "avisynth open failure: script error: there is no function named "telecide""

[pijetro]

You need to properly install the Decomb.dll plugin...

Here's one of many possible plugin pages..
Again, read the documentation, and how it pertains to your version of AVISynth..
http://www.avisynth.org/warpenterprises/

[bugmenot]

Ah, that's got it, seems I did indeed have the wrong version of the decomb plugin :/ Let's see how this one turns out. Do you think it's best for VD to do the resizing or the encoding program?

[FulciLives]

Ah, that's got it, seems I did indeed have the wrong version of the decomb plugin :/ Let's see how this one turns out. Do you think it's best for VD to do the resizing or the encoding program?

If you are using AviSynth scripting then there is no need to use VirtualDub unless you need to edit your input file in which case that can be done with VirtualDubMod but in the end you still will be inputing the AviSynth AVS script directly into your encoder.

- John "FulciLives" Coleman

[bugmenot]

What?! How? And how would I set compression codecs and what not? I just ran the script in VD, it did the pull down removal, and changed the framerate to 25 FPS, but it still had the speckling in the same places as when I use VD's Inverse Telecine. If VD is the cause of the speckling, then this would be one way around it! So tell me, how do I have AVIsynth do the encoding like you said?

[pijetro]

Once i got the basics of AVISynth, i never looked back on VirtualDub filters..

[FulciLives]

What?! How? And how would I set compression codecs and what not? I just ran the script in VD, it did the pull down removal, and changed the framerate to 25 FPS, but it still had the speckling in the same places as when I use VD's Inverse Telecine. If VD is the cause of the speckling, then this would be one way around it! So tell me, how do I have AVIsynth do the encoding like you said?

What is your target format? A DVD or a SVCD or a VCD or a DivX / Xvid etc. ?

- John "FulciLives" Coleman

[pijetro]

If VD is the cause of the speckling

Unfortunately, i don't think this is a correct statement..It's got something to do with your source.

how do I have AVIsynth do the encoding like you said?

You don't. AVISynth acts as a tool that grabs each frame, and feeds it to an encoder.Hence the term frameserver.The advantage, is that the encoder doesn't have to calculate the resize..AVISynth feeds it a cleaned and refined frame..
This could be done by dropping the .AVS file into CCE (for MPEG2), or by dropping the same .AVS file into Vdub for encoding to whatever compression you desire (DivX seems popular)..

[bugmenot]

FulciLives: I want it to be an AVI, which will eventually end up as an MPEG-2 when I encode it.
pijetro: Yeah, that's why I thought it was strange. Perhaps FulciLives will elaborate. And for the record, I've looked at the same scene in my source again and again, it's totally clean. Most of the pull down removed video looks perfect, it's just these few scenes and I have no idea what's causing it.

[bugmenot]

Here's some screenshots to give you an idea on the problem I'm having:

One on the top is what the normal AVI looks like, the one on the bottom is what the one that's had the pull down removal looks like. Note how blurry, speckled and blocky it is.

[FulciLives]

Animation is the hardest type of video when it comes to performing IVTC because you almost never have a perfect 3-2 pattern 100% through out.

Give up on it.

There are other ways to convert 29.970fps video to 25fps video.

Look up Xesdeeni's guide.

- John "FulciLives" Coleman

[bugmenot]

But I bet that would introduce jumpy panning, which was the whole reason why I've been trying to set it to 25 FPS. But, since only about 5% of my videos are 29 FPS, I might just cut my losses and stick with what I've got. Unless someone has any better suggestions?

[junkmalle]

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.

[bugmenot]

I'm using no filters. I'm just opening the video in VirtualDub, then setting the inverse telecine to "reconstruct from fields - manual" then setting no audio, compressing it with DivX 5.2.0 set to "slow" and finally saving it. BTW, what's VirtualDubMpeg? Some sort of VD mod?

[pijetro]

BTW, what's VirtualDubMpeg? Some sort of VD mod?

It lets you work with MPEG2 structure, whereas VirtualDub is an .AVI editor (Mpeg1 also)..

then setting no audio, compressing it with DivX 5.2.0 set to "slow"

Wait a minute, i thought you were compressing to Mpeg2
If that's the case, then you're recompressing unnessecarily..
If you're using Vdub to encode to DivX, then you should be using Fast Recompress option..
Plus, your bitrate could be slow..
Anyways, if it's an .AVI your saving to, then who cares about the 25 fps playback??
If it's native 23.976, then keep it that way..

We're running around in circles...