Digital Workshop

Hi,

for live presentation i'd like to have smooth backward on video :
- i create a 3d animation (example : a car in 3d that turn around itself)
- i export that 3d animation in avi format (or mpeg)
- in opus i'd like to have a slider that allow me to control the rotation of the car interactively . Actually i can do that when the animation play forward ( i just play and pause) but if i want the animation to play backward (i use seek backward) this animation is not smooth
If you can implement for a next version a function that can make a video playing backward that could do what i'd like.

If somebody have another idea...

benoit

Sounds like it might be a job for QuickTime VR.

i use "rendered video" in opus because i want my video to have a transparent background. Another example is with chart : i make animated chart and import them in opus and make its background transparent. The animation work fine in normal play but... not in reverse play. It seems to me that you can't have transparent background with quictime vr ?

Thank you
benoit

I just mentioned it because you said you were rotating an object - which seems to be one of the commonest uses of Quicktime VR. Just thought it might solve your problem better than trying to play video backwards.

Video files are designed to play forwards. To attempt to play backwards would require a lot more of the CPU and hard disk/CD drive, and it's going to struggle to do it smoothly. You'd be much better off having either a second video that was the first video backwards, or including that section backwards later on in the same video and seeking to that (hope that makes sense ).

Benoit

Presuming you made the video, could you just use your editing software to run the video backwards? (This would be either by setting the speed of the whole file to -100%, or applying a Reverse Direction move, depending on your software)

Then you could just export this as a second mpg file, and run the second video clip in Opus to make the video appear to go backwards.

I too use the Rendered Video a lot, to blend smaller clips of video better into a larger graphic screen. Also I can then add captions that go partly over the video to highlight key points... these are much better quality than if they were rendered within the video itself.

I attach a screen shot of a programme we completed today as an example.... not a good quality grab, and only at 50% size (the presentation is 1024x768), but it gives the right idea.

... and good luck with your backwards video!

Linda

Any Mpeg file is especially hard to run backwards. The nature of Mpeg is that each frame only updates the information that has changed since the last frame. Ony 1 frame in many has complete information. There are few complete frames compared to total frames. Since each frame depends on what was in the frame before it, it can never really look good and smooth backwards. With a lot of special processing like what is built into high end DVD players it can look OK but not great and not fluid.

AVI or quicktime is better backwards but because it is a bigger file it is harder on the processing system. You will find it's success is also very dependent on the quality of the video card thus making it unpredictable on different computers. Still not the way to go.

I have had pretty good success with flash video which doesn't mind going backwards at all. I use Sorenson to convert. Very good output.

thank for all your answer.

I 'll use another video mpeg file for reverse video (make with my editing video software).

for Opus team : i don't know what do you think that opus future is but think about 3d presentation tool (manipulate or animate 3d object within opus). I find that there is a lack of 3d integration in presentation tool (except perhaps for director an liquid media) ... It depends on what your majority of your customer are but i am sure that those that make live presentation or sales Cd-Rom could find with this tool another reason to stick with opus.

Benoit