Fake Slow motion: 30 fps interlaced into 60 frames per second progressive?

[kakomu]

I was hoping I could record a few slow motion scenes for a corny trailer I'm going to make, but, alas, my miniDV camera does not deviate from the standard NTSC 480i.

However, I was wondering if it would be possible to separate each individual field and display it as a separate frame? I'm pretty sure the camera is not performing a 2:3 pulldown or any other such telecine operation. I'm pretty sure it's recording at 59.94 fields per second (interlaced into 29.97 fps).

I'm aware that performing said operation would essentially half the vertical resolution of the video. As such, I'd probably perform a resize to maintain full frame size.

Anyways, is such an operation possible?

[sh0dan]

There are a number of different "bobbers" out there. Do a search for "LeakKernelBob", "mcbob". There are also others, but you should get started there.

[Leak]

Anyways, is such an operation possible?
What you're looking for are bob filters, which do full-rate deinterlacing instead of the half-rate deinterlacing of regular deinterlacers...

Have a look here (http://avisynth.org/mediawiki/External_filters#Deinterlacing), for example (though I miss Tritical's NNEDI in that list...)

np: KLF - 3AM Eternal (Blue Danube Orbital Mix) (Auntie Aubrey's Excursions Beyond The Call Of Duty Part 2 (Disc 1))

[neuron2]

After bobbing, do AssumeFPS(29.97). Then you'll have a slo mo clip.

I like sbdeint() for this.

[kakomu]

What substantial differences exist between the bob filters besides speed? I read that DGBob does file resizing, do all the others?

Finally, when enlarging, should a Lanczos resize suffice, or would a Bicubic resize be better?

[Blue_MiSfit]

The bob filters differ in their sharpness, ability to reduce aliasing, and ability to deal with high motion. That's a gross simplification, but suffice it to say - they're all quite different.

When scaling, you have to try different filters to see what works for you :)

Popular favorites are lanczos, spline16, and bicubic. :)

[Gavino]

Finally, when enlarging, should a Lanczos resize suffice, or would a Bicubic resize be better?
You don't need to resize as the bob filters already produce full frame size (by default). That is their purpose in life.

[kakomu]

You don't need to resize as the bob filters already produce full frame size (by default). That is their purpose in life.

I was hopping for a Bob filter that produces only the half frame so that I could control the resolution after the fact.

[Blue_MiSfit]

Then just separate the fields and compensate for the offset.

Smart-bobbing will probably give you better results :)

[kakomu]

Then just separate the fields and compensate for the offset.

Smart-bobbing will probably give you better results :)

WHich is what I was asking about in the OP. DGBob did an OK job. Avisynth's built in bob filter does shimmer or "vibrate".

Which smart bobbing filter do you recommend that gives me control over the vertical res?

Moreover, I'm not sure how to use McBob's avs file.

[Comatose]

You should just bob it and then resize to whatever you want.

[Blue_MiSfit]

You should just bob it and then resize to whatever you want.

yes

Try

TDeint(mode=1)


TDeint is an overall good smart bobber that can be improved with the usage of other filters like NNEDI and TMM.

"super" TDeint is this:

#Use AssumeTFF or AssumeBFF to set field order first

#Build NNEDI interpolated frames for 60p output
edi=NNEDI(field=-2)

#Build motion mask for 60p output
mmask=TMM(mode=1)

#Bob-deinterlace with TDeint, using the motion mask and NNEDId frames
TDeint(mode=1, edeint=edi, emask=mmask)

#Now you have 60p, so let's do slow-mo
AssumeFPS(29.97)


You could do 23.976 as well for more effect. You could also get even better results by using MVFlowFPS2 from MVTools to interpolate 60p to 120p, and then playing back at 30p or 24p.

AviSynth is very powerful!

~MiSfit

[kakomu]

ONce interpolated from 60p to 120p, is it possible to decimate down to 24p (keep every 5th frame) to give it a "film" look?

[neuron2]

SelectEvery(5,0)

[Atak_Snajpera]

Or ChangeFPS(23.976)

[kakomu]

SelectEvery(5,0)
Thanks.
Or ChangeFPS(23.976)

This would maintain slow motion. I was inquiring about achieving a film look.

[Pookie]

Film look has much more to do with short depth of field than frame rate tricks. I wish it didn't, it would be cheaper.

Have a look at this vid for a demonstration of that:

http://www.vimeo.com/1114483

Apologies if this is OT

[kakomu]

Film look has much more to do with short depth of field than frame rate tricks. I wish it didn't, it would be cheaper.

Have a look at this vid for a demonstration of that:

http://www.vimeo.com/1114483

Apologies if this is OT

I know that when it comes to film cameras, the three main areas of exposure that you have control are aperture, shutter speed and film speed. Near as I can tell, what really makes the film look is a wide aperture (with the aforementioned shallow depth of field) and slow shutter speed so that motion is blurred from one frame to another. Quick shutter speeds will produce far more still images which will have an odd stuttering effect (you can see such an effect in many recent movies).

But, yes, I think that achieving a 24p look from my camera from a 30i source would be a big step toward achieving a desired look.

However, my camera's 30p is also pretty good. Of course, the blur caused by aperture are matters of taste and aren't that necessary especially when you consider sharpness and focus used as an art (think of a frame out of focus that slowly comes into focus). I suppose the biggest tenets of the "film" look is the frame speed, shutter speed and color composition (lighting).

[IanB]

You could do 23.976 as well for more effect. You could also get even better results by using MVFlowFPS2 from MVTools to interpolate 60p to 120p, and then playing back at 30p or 24p.Once interpolated from 60p to 120p, is it possible to decimate down to 24p (keep every 5th frame) to give it a "film" look?SelectEvery(5,0)Or ChangeFPS(23.976)This would maintain slow motion. I was inquiring about achieving a film look.I thought your goal here was Slow motion.

Slow motion effect is achieved by generating extra frames, that correctly represent any motion, using the limited number of frames you originally have, then playing all of all those extra frames at the original speed.

If this is your goal then AssumeFPS() is what you need to be using. Summary :- 30i -> Bob! -> 60p -> AssumeFPS(30) :: 2x slow motion, 30fps.
30i -> Bob! -> 60p -> AssumeFPS(24) :: 2.5x slow motion, 24fps.
30i -> Bob! -> 60p -> MVFlowFPS -> 120p -> AssumeFPS(30) :: 4x slow motion, 30fps.
30i -> Bob! -> 60p -> MVFlowFPS -> 120p -> AssumeFPS(24) :: 5x slow motion, 24fps.
---------
30i -> Bob! -> 60p -> MVFlowFPS -> 120p -> SelectEvery(5,0)/ChangeFPS(24) :: Normal speed, 24fps.

If you want "Film look" at the original rate then see this thread, How to achieve "film look" on PAL DV source. It discusses all of the issues like adding motion blur using generated 120p source decimated down to 24p, etc, etc...

24p, 30i, 60p & 120p in this posts context are 23.976, 29.97, 59.94 & 119.88

[themostestultimategenius]

Moreover, I'm not sure how to use McBob's avs file.

Rename it as MCBob.avsi.

Source
MCBob()
AssumeFPS(24) #Or whatever framerate you want

[Gavino]

Rename it as MCBob.avsi.
... and put it in your plugins directory.

If, for some reason you prefer not to put it there, add
Import("yourfolder\MCBob.avsi") to your script.

[kakomu]

I thought your goal here was Slow motion.
It was. However, in that particular post, I was inquiring about negating frames to play the video at 24fps for at normal speed.