Video delay with increasing delay time

  • Hi,

    has anyone any tips on how I can make a increasing video delay?
    I want to make a delay that starts with just a few frames and ends up with 2 minutes delay after approximately 30 minutes. Is this possible with isadora?
    Thanks Tilo

  • if you can draw it on paper then you can probably make it in Isadora. does the image change from one delay to the next? if its a series of delays, gradually increasing, but always starting from a point that we've already seen, then you could do it with a series of different Video Delay actors and some creative routing using Gates, Triggers and maybe a Selector. If its one video feed that gradually gets slower - like slowing down the playback of a recording - then you could look at the Buffer actor controlled by an Envelope Generator going through a Curvature, although I'm not sure you'll get 30 minutes of video in a Buffer.

  • Tech Staff

    I think you will need to switch between 2 delays. Since it clears the buffer everytime the delay is changed. So I think using multiple and switching between is the way to go. Of course updating the 'hidden' one while playing the other. It's an interesting technical challenge. Will probably take a little experimenting.

  • haha dbini, think I can draw it on paper and I know I could have build it with two VHS players som mechanics and a slow motor ;) Its the one video feed that gradually gets slower i try to make.

    DusX, I tried something similar with capture to disc actor and playing back the recording with increasing delay. It worked, but with black frames between every recording. I will do som testing with 2 video delay actors. Maybe that's the way to go.
  • Tech Staff

    I just realized that the delay actor doesn't support any where near that delay.. hmm I was thinking about the programming/mechanics of it.. and lost sight of the requirements. If it's playing videos.. you could off set the playback on 2 players?

  • Just to put some perspective on this.
    • 30 min = 180 sec
    • 180 sec * 30 fps = 5400 frames
    • 5400 frames * 640 x 480 (resolution) = 1.65 GB
    So, in terms of RAM it's possible. But the problem is the growing length. Isadora's Video Delay actor resets the buffer each time you change the delay, so that's not going to work. Instead you'd have the rather staggering task of setting up 5400 Video Delay actors and using nearly as many Selector actors to get at the frame you wanted. So it's doable, but not very easy.
    Best Wishes,

  • I guess you meant '3 minutes'...

  • Thank you Mark,

    I will do some experiments with the setup. 5400 Video Delay actors sounds like a lot of work ;) I will try something like DusX suggests with two Video Delay Actors. 
    @Stepane_Morisse to clarify eventual misunderstanding. I was hoping to setup a live camera that runs for 30 min (maybe more). Slowly during the 30 min I wanted Isadora to delay the video gradually.
    After 0 min: no delay 
    after 15 min: 1 min delay
    after 30 min: 2 min delay  

  • This page might give you some options, you could look at using syphn to get them into isadora