Creating a Time Lapse?

[mojo2185]

I'm filming our schools homecoming dance tomorrow, and I thought that doing a time lapse starting with the empty room, ending with the room filled with everyone, would be a nice touch. For those who don't know, a time lapse is where you start at time 'A' and get to time 'B' very quickly. Basically taking an hour + of video and making it happen in 30 seconds. I'm pretty sure thats what a time lapse is, but if i have the wrong term, please let me know.
Anyway...
How should I do this? Should I take still photos at certian time intervals, or should I just video tape the whole arrival and speed it up?
Any tips/knowledge on this would be extremely helpful!

Thanks!

[Gees]

My understanding of time lapse is it is always photos - or single frames -run together consecutively.

But you could accomplish that with video and just grab certain frames. Whatever is easiest for you.

You'd only need a tripod for whatever camera, as it's always supposed to be from the same, unchanging point of view.

I wouldn't do the speeded up version. That would have more of a comedy effect - unless that's what you're after. Just grab whatever frames contain a change, that you like.

Sounds fun. Good luck with it. :c)

* took 3 tries to fix typos! :cD

[Tommyknocker]

AviSynth and this script.

[Vejita-sama]

Yes I know I should try it out, but do the revese and slow/fast filters change the framerate? I've been looking for an easy method to slow down clips without changing the framerate.

[adam]

As others have already stated, if you can set your camera to take a pic at a set interval, then just do that. Otherwise just let it run recording everything and then just keep only certain frames at an interval. Just do the math. If you want the clip to finish in 1/20th of the time recorded than just keep 1 out of every 20 frames.

[mojo2185]

Thanks for all of the help. Its good to know that stills are used for this, then thrown together. This is good because I only have an hour long tape. If i recorded the people coming, then I'd run out of tape for the rest of the night. The good news is i have a dv camera to use, so i can take stills with it (not sure if i can set it up to do the intervals or not, i'll probably have to do it manually). I'm new to this DV camera, so i'm not sure how the pictures are saved (on the tape? or on the camera then needs to be hooked up to computer to transfer stills?).

Thanks for all the input, you guys gave more than enough advice (but if you have more, keep it coming), so hopefully i can get it to work.

[DivXExpert]

you could capture full video and just decimate it as much as you want, and keep the framerate the same. Unless anyone knows of some software that allows you to use a firewire source and automaticly takes a still frame every set time. Kinda like an automated version of Anasazi (freeware stop motion software).

[adam]

When you take a still shot in a dv camera it captures that 1 frame, and then it repeats is for a few seconds or so depending on the camera. You would access that still the same way you would the video, by transfering it to your pc.

If you are manually going to be taking these pics you are probably not going to have much time for dancing. You'd need to take quite a few stills to make the effect work I'd think. You might consider buying another dv tape, its always a good idea to have at least 2 on you.

[DivXExpert]

whenever I do time-lapse, I just record it full motion to my hard drive directly, then use avisynth to decimate a ton, then keep the framerate the same.

[Tommyknocker]

I would use the decimate procedure myself, but I would crossfades between clips to help enhance the passage of time. Makes for a more surreal effect, and avoid the comedic look of fast motion. And don't forget the tripod!

[DivXExpert]

I thought a tripod was common knowledge.

[Tommyknocker]

One would think so.

[DivXExpert]

There has to be some sort of software that will automaticly take a still when the camera is hooked up through the firewire, every set time.

[Tommyknocker]

I bought two two cameras, one a JVC, the other a Sony. Both offer interval recording. But I think he want to record the whole tape with the arrival of the guests and the ensuing festivites, then edit the video to show the time lapse effect.

[DivXExpert]

I have found a very good and cheap program for time lapse. Its called WinTLV, and it works very well. Its only $20.

[mojo2185]

I bought two two cameras, one a JVC, the other a Sony. Both offer interval recording. But I think he want to record the whole tape with the arrival of the guests and the ensuing festivites, then edit the video to show the time lapse effect.

Either way would be great. If I didnt have to waste a whole tape of everyone arriving, that would be even better though. Its not my camera, so i'm not sure if it can do interval recording, but i'll take a look at it. Either way would be good, but if i could get the camera to do most of the work, that would be a lot easier for me.

Thanks

[DivXExpert]

With WinTLV you don't have to record everything, it automaticly takes a picture every set time.

[Gees]

The poster said the filming is being done for a school dance, probably a rec hall with no PC access. Or are you talking post-filming process with this WinTLV thingy?

[mojo2185]

Ok, filming is done...
I basically have an hour plus of video of people walking in. Now just playing it on fastforward looks really funny and cool, so hopefully the finished product will be even better. I ended up using a non dv camera, I used a camera that uses the hi8 tapes. This is because my DV camera didn't screw in correctly on my tripod
So now i have to take the extra step of importing the footage to the computer, then editing it down to look fast and furious. I'm hoping the hour+ of video won't be as huge as a filesize as I think it will be...
I can use Premiere and Adobe After Effects to edit this, or I could use AVI Synth to cut out the clips. Question is, if i use avi synth, does it reencode the video? Will I get quality loss?

Thanks for all the helpful hints so far!

[DivXExpert]

I would go with AviSynth, and no it does not loose any quality at all.
If you want to be simple you could use the AviSynth command SelectEven() over and over again untill you have got what you want. Or you could use the SelectEvery(blah,blah,blah) command. But make sure you decimate it by like exactly 2, 3, 4, ect. Not like a 2.3, or any fractional decimation, becuase you will get extreamly jerky motion.

Gees, WinTLV does not post-process, its more effeciant to just record one frame every second than to record 30 every second and then delete 29 of them. But I see what you are saying with the no PC access.

[Tommyknocker]

Personally, I would write the following AviScript script once I had the video loaded as AVI (even DV type 2):

a1=AVISource("C:\schooldance.avi")
b1=a1.Trim(1,500)
b2=a1.Trim(701,1200)
b3=a1.Trim(1401,1700)
Dissolve(b1,b2,b3,100)

The values for variables b1, b2, and b3 (the start and end frames) I would get from an application like Virtual Dub mod or the Source Frame function in TMPGEnc. And the "100" value in the Dissolve command is arbitrary, as the number of frames the video clip will use to dissolve to the next clip.

[lgh529]

Why not use Scenealyzer? It has time lapse capture built in.

[DivXExpert]

I find that Scenealyzer has a sort of bloated code. As in how it was programmed. Its sorta of slow and buggy.