Did you ever try a smaller GOP after you patched it with the 300 frame interval? -g 1 would give a keyframe every frame so I'm wondering if the -g 100 holdover

Did you ever try a smaller GOP after you patched it with the 300 frame interval? -g 1 would give a keyframe every frame so I'm wondering if the -g 100 holdover might be counterproductive once you'd done your other tweaks. Right now you have an I frame followed by 99 P-frames which could lead to a flake out for 3s if you ever lost an I-frame. The P-frames are more efficient than I-frames, but at 50mbit you don't need to set your compression too aggressively. I think I'd try (and I know your project is done) some flags along the lines of -vcodec libx264 -preset ultrafast -tune zerolatency -g 1 https://trac.ffmpeg.org/wiki/StreamingGuide#Latency https://trac.ffmpeg.org/wiki/StreamingGuide#Latency There's some other tweaks in there for the ffplay side to reduce its latency. Thanks for the nice write up.