X Error of failed request: BadMatch (invalid parameter attributes) ffmpeg error

Question

I'm getting the following error message in ffmpeg:

X Error of failed request:  BadMatch (invalid parameter attributes)
  Major opcode of failed request:  140 (MIT-SHM)
  Minor opcode of failed request:  4 (X_ShmGetImage)
  Serial number of failed request:  11
  Current serial number in output stream:  11

I turns up when I run the bash function mentioned in a forum post about streaming in Linux.

What does it mean and how can I fix it?

Solution

It looks like you're trying to record a streaming video by playing it while ffmpeg records your screen to a file.

I think the problem is that

INRES="1920x1080"

doesn't match your actual screen resolution. When recording your X display (-f x11grab), if you mess up the input screen resolution, ffmpeg gives such a nasty error message. You need to change this line to match your monitor's actual resolution.