GenMotion and DePan plugins for global motion compensation

[scharfis_brain]

I have no time right now.

Why aren't you trying it out yourself?

[Chainmax]

Because like I said several times before on this thread, the docs are not clear enough in that regard, and the two framerate examples are too different for me to extract a common principle that would allow me to build a function with your suggestion.

[scharfis_brain]

what about trail & error then? That is what I do, when something isn't clear to me.

I remember made a similar conversion function when depan came out
(50 -> 300 -> 59.94 fps)

And the docs are clear IMO.

hint: leave out the selectevery - line.
Its job will be done by changefps afterwards.

[Chainmax]

It's not like I haven't been trying, but whatever.

[Fizick]

Chainmax,
Do you clear understand my third (simplest) example, which is in my post:
http://forum.doom9.org/showthread.ph...636#post840636

If not, other discussions is useless.
And did you try this doubler? Do you like it results at 30 fps (smooth)? If not, you must not spend you time with 24 fps.

[Chainmax]

I understand that example, but it only interleaves one component instead of two and it results in 30fps. I need either 23.976 or 29.97 fps output without having to resample/repitch audio.

[krieger2005]

You must find two numbers (not floats). The first one is the factor how much more picture you want to get an (not-float frame-rate) (let's say in your case 7992, because 15*7992=119880fps (or 999 -> 15*999=14985)). The second factor defines which frames of this 119880 you want have in your movie (in your case: 5000, because 119880/23.976=5000 (or 625-> 14985/23.976=625)). And then you have your 23.976fps.

So, in first case you must find a factor, to push up your framerate to a number (not float) framerate, which can be can be devided in the second step by a number (not float) to get 23.976. These two numbers must be as low as possible. Here 999 and 625 would work. This mean an interleave of 999 frames, where you take 625 of it.

[Alain2]

Originally Posted by Chainmax

I understand that example, but it only interleaves one component instead of two and it results in 30fps. I need either 23.976 or 29.97 fps output without having to resample/repitch audio.

krieger2005 is right, and this is working only for decimal numbers, its not possible to change from a decimal framerate to a float framerate 24000/1001 using discrete numbers of intermediate interpolated frames ; but why can't you just interpolate to 24fps and then slow down to 24000/1001? I don't think you will notice the pitch change, and it will but easier to implement (15*8=120=24*5, thus interleave 7 frames between original ones, and select 5)

[Chainmax]

It's just that I was already trying to make a 5.1 mix of the mono track and having to resample/repitch means I'll have to do it all over again...*sigh*

Fine, I cave .

[edit]Not good. Using DePan creates huge black borders. What other alternatives do I have?


One more thing then: I'm now trying to have a small 15fps clip converted to 23.976fps but have it play at half the speed. I tried this:

fps3to5()

AssumeFPS(23.976)

SelectEven()

ChangeFPS(23.976)

But it doesn't seem to play at half speed. What am I doing wrong?

[johnmeyer]

You could try MotionPerfect from Dynapel. They have a free trial, I believe.

[scharfis_brain]

Not good. Using DePan creates huge black borders.

It has parameters to avoid that!

I repeat mysel. it is possible to do your task
pseudocode may be like this:

input=xxxsource("blah")

vectors=depanestimate(input, bla bla bla)

input_1_of_10 = input
input_2_of_10 = input.depan(+1/9)
input_3_of_10 = input.depan(+2/9)
.
.
.
interleave(input_1_of_10, input_2_of_10, ...)
changefps(23.976)


WHAT is so HARD about this task?!?
That is basically typed from my mind.

[videoFred]

Originally Posted by scharfis_brain

WHAT is so HARD about this task?!?
That is basically typed from my mind.

Hello Scharfis,

It's simple for you....

But you and some other members here have this special mathematic talent.
Be happy with it, it's a gift! I admire this talent very much!

But we, mortal people , do not have this talent.
You must understand this.
So it would be good if someone would explain more about this.

Fred.

[scharfis_brain]

what is so hard about simple multiplication and division? and also some calculations with the rule of three?

pupils are learning this in 5th grade...

[videoFred]

Originally Posted by scharfis_brain

what is so hard about simple multiplication and division? and also some calculations with the rule of three?

pupils are learning this in 5th grade...

It's not about the multiplication and division, but where and how to use it.
Working with frames, fields, frame rates etc can look very complicated if you are not used to do it.

Fred.

[Fizick]

Take a white paper and draw a time graphs of shifted frames. It must help.

[Chainmax]

Thanks for your example scharfis_brain, I made a 16-step function that extrapolates to 240.002fps, then I use AssumeFPS(239.76) and set the final framerate with ChangeFPS. Motion appears to be acceptably smooth and as far as I can see there are zero artifacts. I am extremely happy and I apologize if I came out as too insistent. I have but two more questions:

1) Will using ChangeFPS(23.976) and then using pulldown or ChangeFPS(29.97) directly make any difference in motion fluidity in the end result mpeg2? Empirically, both seem pretty much equal to me, but I'd like to know a theoretical reason.

2) Would using SelectEvery yield better results than using ChangeFPS?

[scharfis_brain]

you don't need assumefps follower by changefps.

1)just use changefps(23.976) and become happy.
you will not notice the small error of 23.976 <-> 24.000 fps.
but do NOT use changefps(29.97 ) after changefps(23.976) it will make your video jerky.
either use 23.976 fps MPEG2 with pulldown, or go straightforward to 29.97 fps and encode it as 29.97 fps MPEG2

2)selectevery only can reflect integer decimations, while changefps can do arbitrary decibmations.

[Chainmax]

Originally Posted by scharfis_brain

...
but do NOT use changefps(29.97 ) after changefps(23.976) it will make your video jerky.
either use 23.976 fps MPEG2 with pulldown, or go straightforward to 29.97 fps and encode it as 29.97 fps MPEG2
...

Oh, you misunderstood me. What I meant is the second thing: either ChangeFPS(23.976)+Pulldown or directly ChangeFPS(29.97). The former is probably better anyway because the intermediate huffyuv file will occupy much less. Again, thanks for your advice .

[scharfis_brain]

go directly 29.97.

this won't introduce telecine judder.

[Chainmax]

Ok. The final MPEG2 was done extrapolating to 240.002fps, then using AssumeFPS(239.76) and ChangeFPS(29.97). If I mux that with the original audio, will there be any noticeable A/V asynch or will it be ok?