Forums > Jitter

jit.brcosa

August 2, 2011 | 9:19 pm

I am constructing a reasonably complex jitter patch processing live HD video. It’s working, except that my frame rate is very low (8-10 fps, which won’t do). Tinkering with the patch I discovered the culprit was the jit.brcosa object: take it out and the framerate doubles. Only problem is: I need it. I’ve been trying to make a series of jit.op objects to replace it (which seems to be much lighter on my processor; fps stays high) but I can’t quite get the same effect. I am wondering if there is a jitter expert out there who can advise me. I am using the jit.brcosa object for two things:
1. I make a ‘posterized’ negative image by pushing contrast to -4.
2. I sometimes make the image black and white by pushing saturation to 0 (I know, that’s clunky, but it works).
Anyone know how to do this with jit.op (or any other jitter object)? I can do the negative, but I can’t seem to get the contrast.
I tried jit.rgb2luma for the desaturation, but it crashes the patch if I interpolate the final jit.window, which i like to do.
Anyone know why the jit.brcosa object is slowing me down so much?
Any other suggestions?
I’m all ears
Thanks
Knud
ps. the final patch will run on a new i5 Macmini (which I haven’t been able to test yet), but I’m building it on a 2008 MacPro with 2 x 2.66 GHz Dual-Core Intel Xeon processor and 8 GB of memory. I checked out the patch’s performance on a new i7 Macbook Pro and the frame rate doubles to 15-17 fps.


August 2, 2011 | 10:01 pm

try getting into gl land…shaders might be your friend in this case…in your examples folder there are examples for different color effects. There is not a specific example one for brcosa, but you should be able to figure out the right thing.

Go to examples-> jitter examples -> render -> slab helpers -> colors to find some of the pertinent ones


August 2, 2011 | 10:01 pm

try getting into gl land…shaders might be your friend in this case…in your examples folder there are examples for different color effects. There is not a specific example one for brcosa, but you should be able to figure out the right thing.

Go to examples-> jitter examples -> render -> slab helpers -> colors to find some of the pertinent ones


August 2, 2011 | 11:31 pm

Yes!
GL does have a brcosa: Much better! I’m up to 15 fps (on my old machine) and the video looks super crisp by comparison to what I had before. Beautiful.
You’re a genius Laserpilot. Thanks. I can go to bed now.
At last!


August 2, 2011 | 11:31 pm

Yes!
GL does have a brcosa: Much better! I’m up to 15 fps (on my old machine) and the video looks super crisp by comparison to what I had before. Beautiful.
You’re a genius Laserpilot. Thanks. I can go to bed now.
At last!


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