Reversed video: segment only...

FuTz wrote on 2/4/2003, 1:11 PM
Hi, I'd like to reverse just a part of a shot on the timeline. If I put the whole shot on the timeline and put a velocity envelope to -100, everything's fine except I just want a PART of this action on the timeline. If I go into the trimmer, trim this very part then put it on the timeline to invert it, the velocity envelope seems to calculate the "reverse" option from the whole original shot: this leads to a result I don't want: a reverse clip (same duration of the clip I want) taken somewhere else from the original shot.
How can I reverse just a excerpt taken from a shot?

Comments

Chienworks wrote on 2/4/2003, 1:19 PM
There have been lots of tweaking methods discussed. However, (and i almost hate to admit this), the method i like best is the lowballest. I render out the section i want to reverse into a new file, then load that file into the timeline and reverse it. It's fast, easy, simple, and nearly foolproof.
FuTz wrote on 2/4/2003, 1:54 PM
And do you know if the same thing happens in Vegas 4 ?
Thanks for advice by the way! I would have liked avoiding to render but if that's the way to go... 8..(
jetdv wrote on 2/4/2003, 2:02 PM
You don't need to render anything first. Just do a split where you want the reverse to begin (i.e. at the END of the clip playing forward), Insert a velocity envelope, and set the velocity to a negative percentage. That's all there is to it!
sqblz wrote on 2/5/2003, 4:58 AM
sorry, jetdv, you *may* me wrong. split won't do. The split is not a physical cut to the clip, just a marker.
Futz, please check here:
http://www.sonicfoundry.com/Forums/ShowMessage.asp?Forum=4&MessageID=141675
Tyler.Durden wrote on 2/5/2003, 7:51 AM
This is an interesting issue...

It may be helpful to consider that all velocity envelopes effect playback from the location and setting of the node:

A shot of 5:00 (secs:frames) duration, beginning at 10:00 in the source footage, will run in reverse for five seconds starting at 10:00 and ending at 5:00... if a -100% velocity envelope is applied to the whole event... because the node is automatically placed at the head of the event (at 10:00), and the video runs reverse from there.

This is different from some NLEs that offer taking a defined segment (10:00-15:00)and playing it in reverse.

The important difference being that VEs are very special... know any other NLE that does em? The rule they must follow; is the vector must be applied to the media at the location of the node. That necessitates the node being set to negative at the END of a segment or action; say, a golf-swing or a javelin-catch.



HTH, MPH

Tips:
http://www.martyhedler.com/homepage/Vegas_Tutorials.html
jetdv wrote on 2/5/2003, 9:28 AM
No, I'm not wrong - I do it all the time. Let's see if I can explain it better. Let's say you have a clip of a person catching a ball but you want the ball to fly away from the person. Go to the point in the clip where the person CATCHES the ball (i.e. at the END of the segment you want reversed) and do a split (press "S"). Now, on the segment on the right of the split, insert a velocity envelope and set a negative velocity. The clip on the RIGHT will now BEGIN with the catch and the ball will go AWAY from the person. NO extra rendering required until the final PTT.
sqblz wrote on 2/5/2003, 1:53 PM
jetdv, your hint deserves some trying.
So far, I have always been able to control the right end of my reversed video, and never able to control the left end.
Maybe that's the secret. Thanks.

Oh yes, and Mr.Hedler also did some fine contribution to my referred posting :-)))
jetdv wrote on 2/5/2003, 3:00 PM
Yes, the secret to reversing is START AT THE END. Otherwise, it gets way too confusing real fast.
sqblz wrote on 2/5/2003, 4:11 PM
OK. Been there, done that.
Jetdv, your recipe works.

But ...

I had to go through all *my own* posting again to remember... you know, the BIG problem is not when you have a fixed velocity reverse clip, but when the velocity changes throughout the clip. or even worse, when the velocity changes above and below zero. Then, you loose control.
Please go back and see my original posting, referrenced here above. Then try it for yourself. The title speaks for itself: "Slow down, then reverse".

Like I said then, kinda pushing a boiled spaghetti... never succeeded. Marty came up with a working idea using overlaps, which is an elegant turnaround, though.

(hey, jetdv, YOU were also there, in my original posting ...)

Cheers