[photo-3d] RE: 3D video editing question

["Marcus Warrington" <marcusw@xxxxxxxxx>]

>i shoot 3d stereoscopic video using a Sony hi8 camcorder and a Nu-View
>lens attachment. 

SNAP.. so do I :)

>I have great pop up, pop out 3d footage. however i cant
>seem to find an editing system that keeps the stereoscopic 3d in the
>editing process .

Strange, I've had no trouble maintaining the stereoscopic effect with
a variety of NLE (Non Linear Editing) packages such as Adobe Premier,
VirtualDub and DC10+ software (all PC not MAC I'm afraid). As long as
the software handles everything at Frame level and maintains field 
integrity then there should be absolutely no problem.

>we have tried the state of the art video editing
>system, Apple G4 with FINAL CUT PRO software. we loose the 3d effect
>when we try to slowmtion, or any editing. 

Ahhh.. I suspect that what your saying is that its not the editing but
the applying of transitions and effects that destroy the 3D. I can
see how this could be true, since many of the effects and transitions
(certainly slow motion) will process at an individual field level(
rather than frame level) and destroy the 3D effect by separating the
stereo pairs. 

With a normal video stream, for example, each video frame holds
two fields, and each field is 1/50th (PAL)  or 1/60th (NTSC) ahead
of the previous one;

AB | CD | EF 

after slowing down by a third this may be converted to ;

AA| AB| BB| CC | CD | EE | EF

This plays back fine (but at a third the speed) since the ordering
of fields is not destroyed.

Doing the same to a 3D Video, where each frame now holds a 
pair of images and effectively each pair is from the same time
slice with each frame 1/25th or 1/30th of a second ahead of the 
previous.

Before:
Aa | Bb | Cc | Dd |

After:

AA | Aa | aa | BB | Bb | bb | CC | Cc

You can see that the majority of frames no longer store the 
correct pair of fields.

>do you know of any video
>editing system that keeps the 3d effect?       thanks

Short answer, yes all of them.. but NOT ALL THE EFFECTS that they can
apply :(
Unless the effect is written to maintain field ordering within each
frame then it WILL destroy the 3D effect.

Marcus Warrington 
MIS Computer Services (UK)


 

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