Horizontal scrolling is jerky

[MrChristmas2000]

I have a grid that is 8 strings of 108 RGB pixels each folded in half to give me 16 strings of lights on a Horizontal matrix. The starting point is the top right.

When I do scrolling text on that grid the text is very jerky and there are random flashes of all white pixels.

I am running Nutcracker > Falcon FPD > Falcon 8 > Strings.

Other effects do not seem to exhibit this jerky action.

[sean]

what version of xlights?
what hardware are you using? controller and lights
post your xlights_rgbeffects.xml and your sequence.xml file.
do all of the various text effects show this? (left, right, up, down)
is it affected by the speed slider?

thanks
sean

[JonB256]

Check that Sparkles is off for the flashes of white.

[MrChristmas2000]

The flashes have stopped. Didn't do any thing except switch out my two E1.31 dongles, My Falcon FPD and my Lynx Ether dongle.

Now I have determined the jerky action is actually being generated in Nutcracker it's self.

Here is a video of what I am seeing.

https://www.youtube.com/watch?v=udpb-xcIt9s

The version of Nutcracker is 3.4.12.

The specifications of the computer it is running on is:
Intel Core i7 CPU 3.20GHz
16GB installed RAM
64bit Windows 7 Ultimate.

[Greg.Ca]

I also occassionally see jerkyness but so far it's just on my monitor. I'm starting to think thqt the video card might be a factor. By moving the speed slider to just a certain point, I get terrible jerkyness. But by moving the slider either faster or slower, the jerkyness goes away. Video card?

[JonB256]

I also occassionally see jerkyness but so far it's just on my monitor. I'm starting to think thqt the video card might be a factor. By moving the speed slider to just a certain point, I get terrible jerkyness. But by moving the slider either faster or slower, the jerkyness goes away. Video card?

When you move the speed slider and things get smoother, it means that you found a frame rate multiple that works better. One piece of software is working at one set of "frames per second" and your video card at another speed - there will be bad matchups.

But, your actual matrix or tree should not see that same conflict. xLights outputs at 20 Frames per second. Everything is converted to that frame rate for output. While 30 fps or 40 fps or even 60 fps would be smoother, it would be at a huge bandwidth cost for current hardware.

I'm certain the frame rates will go up in the future, but it will be on newer hardware.

[JonB256]

... Now I have determined the jerky action is actually being generated in Nutcracker it's self.

Tom, I have found that there are certain "speeds" of scrolling text that flicker badly across my matrix. There are frequency multiples that will not work quite right on a specific matrix, primarily due to the "pitch" or pixel distance of your matrix. If there is a refresh (20 frames per second) that exactly coincides with your text moving from one pixel to the next, it can make the text seem to flash or blink or jerk (pick a term).

Two solutions - add a LOT more pixels to reduce the pitch, or bump the speed up or down slightly.

The term "resonance" may be applicable. Certain speeds of text will "resonate" and be jerky. Most will not.