Smart deinterlace filters for VirtualDub

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Smart deinterlace filters for VirtualDub

Reply #25 – 2003-11-14 20:42:51

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2. usually less bitrate, since preserving the whole content while deinterlacing generates either extra distortions or extra bits.

What is a reasonable bitrate for full-PAL interlaced capture? I'm experimenting with Xvid at ~2000 kbit which would give me five hours per DVD+R, but the results are not always good. Maybe this is caused by the noise from my capture card?

Smart deinterlace filters for VirtualDub

Reply #26 – 2003-11-15 05:01:15

I recently discovered the PeachSmoother filter for Avisynth, and was blown away! For noisy captures and VHS, this filter can cut your required bitrate nearly in half, and barely increases the encoding time at all. (It also works with interlaced video.) I can't say enough good things about it. Give it a try!

Smart deinterlace filters for VirtualDub

Reply #27 – 2003-11-16 18:02:48

Did you use the default settings? How does this filter compare to 3Dconvolution?

I'm still experimenting, but the quality gain seems to be rather small here...

Smart deinterlace filters for VirtualDub

Reply #28 – 2003-11-16 18:14:49

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Did you use the default settings? How does this filter compare to 3Dconvolution?

Last time I heard of it, it was convolution3d.

Smart deinterlace filters for VirtualDub

Reply #29 – 2003-11-17 02:00:06

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the quality gain seems to be rather small here...

I used it with the default settings, and XviD encoding in 1-pass quantizer mode, but I wasn't aiming to improve the quality (I've come to believe that's kind of an impossible dream). My primary concern was finding a filter to help reduce the bitrate without hurting the quality. The bitrate did reduce by a huge amount when I added PeachSmoother, and I could see no visible artifacts from the filter (unlike some other NR filters). But as always, YMMV...

P.S. I've never used convolution3d, but I will certainly try it.

Smart deinterlace filters for VirtualDub

Reply #30 – 2003-11-17 06:59:48

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P.S. I've never used convolution3d, but I will certainly try it.

Go ahead, there are simple presets for operation with "movieHQ" being the most common. The additional benefit of Convolution3d versus PeachSmoother is that the former supports YV12 colourspace; when doing the encoding in YV12 format (such as DVD-to-MPEG4) you gain about 30% encoding speed.

On the other hand Convolution3d is very slow, so that pretty much negates the speed increase

Smart deinterlace filters for VirtualDub

Reply #31 – 2003-11-17 10:06:32

Thanks for the answers. It seems like this thread develops to a valuable resource.
Anyway, since I didn't want to spend much time on figuring out how avisynth works this time, I did some tests with Vdub Smart Deinterlace filter. I got the best results with these settings:

Frame-nly differencing
Use cubic for interpolation
Motion map denoising
Motion treshold: 8 (higher values resulted in remaining interlace artifacts in low contrast background areas)
Scene change treshold: 100 (no scene changes in the clips I encoded)

As recommended I used XviD. Settings: Quality-based (95%), 1-pass.

Next time I'll probably try avisynth. - Anyway, from my understanding how smart deinterlacing works (motion detection, discard 1 field and interpolate in moving areas, blend fields in still areas) I don't see much room for improvement over the result I got with Smart Deinterlace filter this time.

Smart deinterlace filters for VirtualDub

Reply #32 – 2003-11-17 17:03:15

Well, there is certainly room for improvement. One clear advantage that is very important in this case is that Avinsynth filter can work with a wider range of frames, that is, an Avisynth filter can look at future frames of the video, not only at the previous and current frames.

This is specially useful in deinterlacing.

Then again, I have this information in my head since quite a while, so I might be mistaken, and I would like something about this to be confirmed or corrected

Smart deinterlace filters for VirtualDub

Reply #33 – 2003-11-19 07:31:45

Hello: I got this information sometime ago off doom9's forums, i think before they switched forum software or something. It is a deinterlacing technique posted by an user with the nick "Morello". According to his findings, the following chaining of 2 filters seemed to provide the best results:

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IMO the best/Ultimate settings for deinterlacing are:

1)Area Based Deinterlacer, edge detect 50, threshold 27
+
2)Smart Deinterlacer, fram and field differencing, blend, cubic, motion threshold 20, scene change 100, field swap before and after.

These are VirtualDub filters, i use Avisynth for other things (like cleaning the video), but you can load most virtualdub filters from avisynth as well, and i use exactly this same method when i need deinterlaced output. I use NTSC, and mostly capture from broadcast or VHS sources.

PS: Capturing at half vertical resolution is the same as dropping a field altogether, and capturing at double speed achieves the same thing of doing a normal capture and apply bob filter afterwards (except you won't need double space when capturing...).

PS2: My hardware is a Hauppauge WinTV-PCI 404 (BT878), i also have a studio DC10 almost new in its box, didn't like it, but i know how to use it... (forces you to use mjpeg and fixed res, like 640x480, at least with the original drivers).

Smart deinterlace filters for VirtualDub

Reply #34 – 2003-11-19 09:15:12

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IMO the best/Ultimate settings for deinterlacing are:

1)Area Based Deinterlacer, edge detect 50, threshold 27
+
2)Smart Deinterlacer, fram and field differencing, blend, cubic, motion threshold 20, scene change 100, field swap before and after.

I just tested these settings and the result was worse IMO than Smart Deinterlacer alone with the settings I used (Remaining visible lines in still/slooow moving areas, stairs in medium moving areas) . I also don't understand the sense of this approach theoretically. What happens should be this (correct me if I'm wrong):

There are 4 cases:

1. 1st filter detects motion, 2nd does too.
=> there's interpolation applied (seems like linear, not cubic resulting in stairs), then blending, resulting in unnecessary vertical smoothening is applied.

2. 1st filter detects motion, 2nd does not.
=> Like 1. but no blending, these areas will be sharper than "1." areas.

3. 1st filter doesn't detect motion, 2nd does.
=> On these hopefully not much moving areas blending is applied which should be OK

4. both filters don't detect motion
=> No processing. Hopefully the movement/brightness change is small enough to avoid visible lines.

This (espacially what happens in 1.) doesn't make much sense IMO. What would be best IMO:
A filter with 2 tresholds:

1. Fast moving areas: Discard 1 field + interpolate (cubic)

2. Medium to slow moving areas: Blend fields

3. No movement: No processing.

Ideally the should be somehow fluent transitions between the three ways of processing.

Smart deinterlace filters for VirtualDub

Reply #35 – 2003-11-19 16:06:10

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It is quite easy to find information on it: behold the wiki!

Broken down. Can anyone point to any other avisynth info?

Smart deinterlace filters for VirtualDub

Reply #36 – 2003-12-07 22:10:54

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I recently discovered the PeachSmoother filter for Avisynth, and was blown away! For noisy captures and VHS, this filter can cut your required bitrate nearly in half, and barely increases the encoding time at all. (It also works with interlaced video.) I can't say enough good things about it. Give it a try!

fcc,now tell everyone who loves peaches the best ( )
(btw.now try to asses the noise manually and enter the numbers into peach settings;

Code: [Select]

#peachsmoother(readout = true, dot = true)  #noise estimation

if you already didn't...i also tried it like _separatefields()-peach-weave_....and I was impressed!)

@avih;how is xvid laced encoding compared to mpeg2?
if it's worthy i'll do the test(fields quality compared),but i'm not quite blown away with ffvfw's laced stuff (although i havent tried recent build of ffvfw)....
in fact i believe mpeg2 looked better...

@all;
vdub users should try graft's "smartdeinterlace" or thalin's "deinterlace area based"
avs users shoudl try graft's kerneldeinterlace....
(i have done quite an extensive tests with lots of screenshots,and these came as winners...MAP was not that good...)
be carefull NOT to use "use chroma" option in smartdeinterlace;it was ment for toons...(if that)

all of these filters are "clever" ie. they leave uncombed parts of the image alone..(to preserve their vertical resolution)

c3d?
don't bother for analog capturings.....very poor temporal denoising component...(last time i tried it..)

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