How to speed up video - very much

ingvarai wrote on 1/2/2009, 8:03 AM
I have a clip, about 1 hour long that I want to compress to a 1 minute long video event. How do I do this, what is the preferred way?
Control + dragging the event edge only presses it down to 1/4 of the original time, I want much more than this.
What I want to achieve - you sometime see this when something is contructed ( a house, a bridge etc) . In my case, 1 hour --> 1 minute

PS: The original video is recorded using the normal frame rate for my camera, 50i.

Comments

Chienworks wrote on 1/2/2009, 8:14 AM
Combine Ctrl-dragging with a velocity envelope. Velocity envelopes allow a 3x speed up, so you get 12x. Render this to a new file using low or no compression. If the source is DV and you disable sampling then you can render to DV with almost no quality loss at all.

Place the new file on the timeline and speed up again as necessary. 2 passes let you speed up to 144x, which is more than you need. 3 passes will speed up to 1728x.
rs170a wrote on 1/2/2009, 8:15 AM
Ctrl+drag is one of two ways to do this.
The other is to apply a Velocity envelope which gives you a further 3X increase for a total of 12X.
This brings your 1 hr. down to 5 min.
Render this to a new track and use the Ctrl+drag again to get you very close to your target.

Mike
je@on wrote on 1/2/2009, 9:26 AM
There's a script called, one-frame-from-each-event that has worked well for me in similar situations. Take your clip, break it at the intervals of your choice (1 sec, .5 sec, whatever), then run the script. In my experience, it looks better than velocity envelopes. Your mileage may vary...
ingvarai wrote on 1/2/2009, 10:30 AM
Thanks for the suggestions!
I have tried it, except for the script mentioned, the problem now is that it takes an unacceptable time to render. My 1 hour footages compressed down to about 4 minutes using the approach mentioned above, gives me an extimated render time of more than 40 minutes. Regardless of rendering to MPG or AVI.
I mean .. can't Vegas just take a frame then hop to a frame a suitable interval ahead then render this frame then jump again?

40 minutes to render 4 minutes of video with no FX..?
kairosmatt wrote on 1/2/2009, 12:11 PM
"can't Vegas just take a frame then hop to a frame a suitable interval ahead then render this frame then jump again?"

I think you have to right click on the event and disable re-sampling, then Vegas should do just that.

kairosmatt
je@on wrote on 1/2/2009, 1:56 PM
No render issues when using the script method but it can require a fair amount of time to break your clip at exact intervals - depending on it's length.
Harold Brown wrote on 1/2/2009, 2:38 PM
Buy a Quad!! :)
Tim L wrote on 1/2/2009, 3:39 PM
As a home hobbyist user, I'm usually hesitant to offer advice, but here's an approach I haven't seen mentioned before: use nested veg's. (Please, someone correct me if this is a bad idea...)

I created a new project and loaded in an approximately 1 minute video, then ctrl-dragged this to the left to create about a 15 second video. I saved this as "test1.veg" (no rendering).

I then created another new project, loaded in test1.veg onto the timeline, and ctrl-dragged it to the left for another 4x speedup (a little less than 4 seconds on the timeline now). Again, I saved this veg without rendering, as test2.veg.

I then created another new project and loaded in test2.veg and ctrl-dragged it to be 4x faster again, giving me a clip now < 1 second.

Trying to scrub on this timeline was ridiculous, of course (especially on my lowly P4), but it seems like a way to get multiple levels of speedup without rendering. (For this test I didn't bother with applying the velocity envelope speedup...)

When I did render -- actually just a shift-B render to memory -- it seemed pretty slow. But I also neglected to disable resampling, so I think each frame in the render had been constructed of multiple frames from the source. (A person walking slowly in the original file looks like a blur -- kind of a cool effect anyway.) I'm guessing that disabling resampling in each veg would have Vegas grab just individual frames for the resulting file.

Maybe somebody else can test this or comment on possible pitfalls with this approach?

Tim L
ingvarai wrote on 1/3/2009, 9:38 AM
Harold Brown
> Buy a Quad!! :)
Actually . that's what I have, combined with Vista 64 bit / Vegas 8.1
:-)
ingvarai wrote on 1/3/2009, 9:38 AM
Tim L
> but here's an approach I haven't seen mentioned before:

I will try this later, just a question on the fly: How do I turn off / on resampling?
Chienworks wrote on 1/3/2009, 9:41 AM
Right-mouse-button click on the video clip, choose switches / disable resample.
ingvarai wrote on 1/5/2009, 11:11 AM
Hi Tim L,
I have tested your approach and it works!
I did not even know that it is possible to add one Vegas project to the time line in another Vegas project.