[Arny Krueger]

I want the video-equivalent of that.

Describe what that means in terms of the visual representation of the
actress. Do you simply want her to to moving more slowly?

 

[David McCall]

I want the video-equivalent of that.

The equivalent of audio pitch shifting in video is audio pitch shifting.

If I understand, you want the video to stay the same, but
you want the pitch of the actress's voice to be much lower.

This would be a matter for audio software whether it is
done by a plug-in in an audio program or a video editing program
it makes no difference. It is an audio function, and
has nothing to do with video.

David

 

[isw]

so what is the "video-
equivalent" to a real-time pitch shifter?

I wish I knew. This is so interesting for me yet so difficult for me
to answer.

What is the "video-equivalent" to a real-time pitch shifter if the
video is B&W? Since I've been giving wrong answers to my questions,
I'll definitely need guidance.

I do know that video-frequency [in B&W video, not color] has two
elements:

1. Temporal frequency

Frame rate.

2. Spatial frequency

An example of this is ferinstance if there is a white picket fence in
the image, then the "spatial frequency" there is related to the spacing
of the pickets. Every part of the image has associated spatial
frequencies, and they exist in all directions, not just horizontal or
vertical. A higher limit on spatial frequency is associated with
"sharpness" of the image. Eyes tend to be more sensitive to horizontal
spatial frequency -- horizontal sharpness is more important than
vertical.

#1 only applies if the video consists of changing visual signals [such
as a movie or show]

#2 applies to all video signals -- including still images.

Those two are absolutely, totally, independent, for any video imaging
technique in use today.

Changing temporal frequency (usually called temporal *resolution*) is
easy; just change the rate you crank the camera -- or projector.

Changing the spatial frequency involves something like zooming in
(throwing away parts of the image), or zooming out (making up parts that
were not in the original, if you do it at the projector).

Note: actually *changing* the SF is not the same as merely altering the
amplitudes of some of the components; reducing or eliminating the higher
spatial frequencies "softens" an image, making it fuzzy.

Isaac

 

[Jerry Avins]

Then he retracted it:

I want the video-equivalent of that.

Don't tell me what you don't want. Describe what you do want.

Jerry

 

[Ron N.]

Then he retracted it:


Don't tell me what you don't want. Describe what you do want.

One video-equivalent is possible, but probably
looks like crud. Take the 8 DCT coefficients per
block, add them pairwise and stuff them into the
bottom 4 DCT coeffs, zeroing the top 4. You've
shifted all DCT frequencies down by about 2X, and
you end up with a blurry looking result after
you've assembled all the macroblocks. Artifacts
that can fool the ear are really obvious to the
eyes. A runaway AI experiment may have neither.

YMMV.

 

[Radium]

Describe what you do want.

I would like to downshift the temporal and spatial frequencies of a
video signal w/out any low-pass filtering [spatial or temporal],
making the video signal longer, cutting out any parts of the video or
the images that make up the video signal, adding any parts to the
video -- or the video's images -- that weren't originally there, or
changing the size of the images in the video signal. How do I
accomplish this?

 

[Steve Roberts]

I would like to downshift the temporal and spatial frequencies of a
video signal w/out any low-pass filtering [spatial or temporal],
making the video signal longer, cutting out any parts of the video or
the images that make up the video signal, adding any parts to the
video -- or the video's images -- that weren't originally there, or
changing the size of the images in the video signal. How do I
accomplish this?

It would be a lot better if you just told us the effect you are trying
to achieve, rather than spouting technical terms that you don't
understand.

"Downshifting the spatial frequencies" means zooming into the picture.
you cannot do this "without... changing the size of the video signal".

Likewise, "downshifting the temporal frequencies" means slowing the
clip down - again, you cannot do this whilst satisfying the other
conditions you stipulate.

Steve

The Doctor Who Restoration Team Website
http://www.restoration-team.co.uk

 

[Ron N.]

Describe what you do want.

I would like to downshift the temporal and spatial frequencies of a
video signal w/out any low-pass filtering [spatial or temporal],
making the video signal longer, cutting out any parts of the video or
the images that make up the video signal, adding any parts to the
video -- or the video's images -- that weren't originally there, or
changing the size of the images in the video signal. How do I
accomplish this?

Well, you can't do that the way audio pitch shifting does it,
because audio pitch shifting cuts parts out or adds parts
(using either time or frequency domain techniques).