Pan crop + slow mo = Stuttery video

DJPadre wrote on 10/6/2006, 12:04 AM
okies, well after years of using this application.. ive finally worked out the problem, but i dont know why it exists...

slow a clip down, and adjust the pan and crop... now render as progressive using interpolate..

stuttery to the s**thouse and back....

Slow the clip.. DONT change and pan crop.. all is good... smooooooth

Pan and crop on its own... SMooooooothhhh...

put the 2 together... and it looks like garbage...

thoughts??

Using V6. Primarily Progressive footage, but i sometimes work with interlaced sources... and this problem is abundant when converting interlaced to progressive...

anyone else have issues like this?? or similar?

Comments

Grazie wrote on 10/6/2006, 12:24 AM
I'm no programmer, but I would think that there is a rate of change being created that is not being interpolated because there is a tertiary rate of change being processed. Sometime back I referenced here an issue with a MASK and GLOW fluttering I was getting.

Tell me, what happens if you do each of these processes in discreet stages?
farss wrote on 10/6/2006, 4:06 AM
I'm with Grazie on this one.
Apart from trying doing it in two steps what about changing the order?

Bob.
technobaba wrote on 10/6/2006, 4:13 AM
I got this also in a similar item where I was slowing and panning. How about motion blur? Is it on? How about that super-sampling you can do on the output vid bus?
DJPadre wrote on 10/6/2006, 10:08 AM
doing it in seperate stages usually works ok but it ads a generation to the DV...

umm.. suspersampling is usually off unless im doing multipass velocity scales, or intense slow mo's. Motin blur defeats the purpose of the detail im trying to represent (ie a footballer diving for a catch just as an example)

I jsut think the engine falls over itself when its asked to slowmo and pan and crop a track.. thing though is that interpolation is on.. and sometimes, even whn slow mo is ISNT being used, and all ive done was reframe a shot (as in raise or lower the frame vertically or shift it horizontally) i sometimes get this as well..

as for teh glow filter, ive learnt that u have to be REALLY careful with it becusae using it with slowmotion creates pulsating and flickering results. I usually render my slowmoo, then add the glow later..

I can prolly do the same with teh pan crop slowmo, but rendering elements out then reimporting them defeats the purpose of an efficient NLE.. reminds me of how Edius works (render and replace)

TheHappyFriar wrote on 10/6/2006, 10:35 AM
don't worry about the adding a generation in vegas. it won't cause a problem (plus it will render a lot faster).