Weird distortion and artifacts

[rcmcdonald91]

I'm running 6 RTSP streams using VLC (rpisurv3). I'm assuming this is a resource consumption issue, but when I use raspi2png to grab a screenshot , I see some pretty interesting distortions. Is there anything that can be done to mitigate this? I've tried bumping gpu memory to 512, dispmanx_offline=1, etc...no significant change. rpi4 4GB. The output looks fine on the hdmi display.