How to use timelapse from a camcorder.

m4jc wrote on 10/22/2003, 12:00 AM
My miniDV camcorder will take "timelapse" sequences that are really a series of short (~0.5sec) video clips, at some regular interval. When the video is imported, the result is a large number of very short video clips. What I want to do is bring them all into VV4, and take just one frame from each clip. So far, I haven't found an easy/automated way to do that. Any ideas?

Thanks!

Comments

johnmeyer wrote on 10/22/2003, 2:04 AM
If you are good at scripting, you could adapt the script I wrote to trim "n" frames from either the beginning or end of an event. Here's a link to that script:

Delete n frames
Chienworks wrote on 10/22/2003, 8:58 AM
Without scripting, i could suggest this method:

Turn off DV scene detection in Video Capture. This will capture the entire sequence as a single file.
Dump this file onto the timeline, then Ctrl-Drag the end to the left as far as it will go. This will speed it up 4x.
Disable Resampling
Render to a new track.
Delete the original track.
Repeat the speed increase on this new track. It will now be going 16x original speed.
The original clips had approximately 15 frames per section. If you tweak the ending point back to the right just a tad then you should end up close to one frame per original section.
Once again, disable Resampling and render.
SonyEPM wrote on 10/22/2003, 9:00 AM
I demo'd this at Weva- here's my recipe (not the only way to do it):

I shot a timelapse sunrise out my hotel window in Las Vegas(120th floor J-Lo suite at Caesar's*) with a Sony PDX10, using the "interval recording" feature- just parked it on a tripod and let it shoot 15 frames every 2 minutes for 2 hrs.

I captured using clip detection (after trying it as one big clip), then dragged all the 15 frame clips from the media pool to the timeline, auto-overlapping the dropped clips with 5 frame crossfades (see editing prefs).

This looked really nice- no jump between clips as with a cut. A little kiss of motion blur made the car lights smear nicely, but I didn't like what it did to the clouds, so I duped the track and did a soft linear wipe to preserve shaprness in the clouds, (bypassing motion blur on the cloud track).

Once this was all rendered, I did some time-compress on it...more coolness.

(*not really)

RichMacDonald wrote on 10/22/2003, 10:23 AM
I do a lot of this work. As stated, you can "Turn off DV scene detection in Video Capture. This will capture the entire sequence as a single file.". However, the results will be "jerky"; a smooth 0.5sec bit followed by a "jump" to the next smooth bit. Depending on the source, you may have to speed the playback up a great deal before this annoyance isn't noticeable.

For a while I thought about using morphing software to eliminate the jumps. However, there is no automatic way to do this and manual ways are ridiculously time-consuming. (Yeah, like I'm going to draw shapes around all those clouds whizzing by :-)

These days I *do* capture each clip separately, as you are doing now. Then I select them all and drop them on the timeline with a default overlap. The overlap blends the transition between clips and smooths (although not completely eliminating) the jumps. Clouds look fine and its a cool effect as transitory objects "blur in" from nowhere then "blur out" again.

I set my transition period to 1/2 the clip length. So if I am using 0.5 sec clips, I set the transition to 0.25 secs. IOW, the entire sequence is a transition.

Note to Sony: For those of us who take really long exposures, it would be nice to change the default vidcap naming from "clip - XXX" to "clip - XXXX", where XXXX is a 4 digit ordered number, rather than the current 3 digit number. That way, the clips sort correctly.

Note to m4jc: Watch how you select all the clips to get the right sequence. After you have selected all the clips, drag the *first* one onto the timeline. And when you're dragging 1000+ clips, plan on a coffee break between the time when you drop and the time Vegas comes back to life.
johnmeyer wrote on 10/22/2003, 1:16 PM
I have posted a script in the script forum that will keep only the last "n" frames from each event on a selected video track. "n" is usually set to one. This will give you true time lapse from your camcorder "time lapse" captures, with no compromises. The script uses the LAST frame (or frames) from each capture on the theory that the first frames could be slightly "glitchy" due to the startup problems some camcorders experience.

Each captured segment must be in a seaparate file (i.e., make sure "Enable DV Scene Detection" is checked in Vegas Capture).

Here's the link to the script:

Time Lapse Script

Once you have run the script, you can render the video. If you want, you can then take that rendered video and let Vegas speed it up further or slow it down.

Finally, if you really want to get into time lapse, I strongly recommend that you look at purchasing Scenalyzer Live (Scenalyzer) which lets you capture true time lapse directly to your computer or laptop. With this program and a laptop, you can capture flowers growing, and do time lapse that covers several days, weeks, or months (like a building going up).