LibGDX - Making deathcam for game

Currently I’m trying to make deathcam for my game.
When players are dead, I’d like to show them what happened 2~3 seconds before their death

I tried using ScreenUtils.getFrameBufferPixels to take screenshot and use those image as deathcam.
It sorta works but performance is terrible.
Also if I want to draw image as original size, I need to scale Image again.

So I’m trying to get image other way around.
I searched about it and I think i could use framebufferobject but wiki says
“rendering to them every frame, may not lead to the best performance.”
But as I don’t know when player will die, If i want to use framebufferobject I need to render every frame with it.

Is there any other better way to do it? like getting image directly from batch before flushed?.