movie flicker

    Feb 23 2006 | 6:33 pm
    Hello List,
    I am trying to create a patcher where I can mix two effects on one qt movie. The problem I am having is, when I send two patch cords to the jit.pwindow, it causes it to flicker, but when I send them separately everything is allright. So what am I missing here? Any thoughts?
    Here is my basic patcher:

    • Feb 23 2006 | 6:41 pm
      You can;t send 2 video streams to the same pwindow like that. It's simply displaying one stream or the other. Video doesn't mix the way MSP audio does by sending multiple patch coords to the same inlet. You have to explicitly mix them with something like jit.xfade or the other myriad techniques.
    • Feb 23 2006 | 7:05 pm
      That makes totally sense now:/
      Thinking I have 5 differents effects to be mixed, can you suggest which way should I follow in this scenario? Thank you very much!
      best ilteris.
    • Feb 23 2006 | 7:16 pm
      It depends on what you want to accomplish. If you want to mash all 5 together, that's going to take some doing. If you want to smoothly mix between the 5, there are any number of ways of doing this. I tend to use a video buffer connected to an input switch that does fading between input streams which includes all of the effects as well as a feedback stream. On the output of the buffer, I usually have some kind of alphablend.
      good luck, wes
    • Feb 23 2006 | 7:37 pm
      If you are merely trying to mix 5 inputs equally, something like this will work:
      Cheers, Andrew B.
    • Feb 23 2006 | 9:11 pm
      Thanks guys! Andrew your solution worked like a charm ty. It is slow though, I think it is a cpu intensive thing that I am trying to accomplish, it is a weekly project so it is all good! thanks again.
    • Feb 23 2006 | 9:50 pm
      hello, the reason that it is slow is that jit.expr always converts data to float32 before processing. This is going to create a bottleneck if you are using 5 char inputs. You could easily break the expression up into cascaded jit.op objects for better performance with char data:
    • Feb 24 2006 | 1:31 am
      yummy! Thank you very much Andrew! I truly appreciate it.
      best ilteris.