Overscan - how to prevent or mitigate it

[muckabout]

I am sure that many Picuntu users encountered the problem where window buttons, status bars and scroll bars are off the screen. This occurs because the typical TV defaults to overscanning. Overscan is where the actual image is larger than the screen it is displayed upon. There are ways to overcome this. On my Sony Bravia you need to set the size to "full" which is to say normal and in the settings for the picture set it to "1:1". The catch is that the input device such as your TV stick has to use the native resolution of the set which in my case is 1920x1080. Anyway this is a bother because the TV always reverts back to overscan whenever you change inputs.

Other TVs allow to set a label on the HDMI input to "PC" which will turn off overscan. Still others have one of HDMI inputs dedicated for PCs and it will not overscan.

The point of all this is a question for the video guru's out there. When I use Android on my TV stick there is no apparent overscan. The status bar is not hidden. Full screen apps all appear normal with everything visible. Does Android size the image to compensate for overscan? Does Android have some sort of a signal on the HDMI to turn off overscan?

[tyeo098]

Hmm.

For me android was always under-scanned. Then when I switched to picuntu it was full-size and I was very happy.

Then again I'm using a computer-monitor with HDMI input.

The default overscan settings of your display isn't the fault of the device

[muckabout]

As far as I know the vast majority of TVs default to overscan. In the days of analogue broadcasts the edges of the picture were very dirty so overscan was adopted to make the crappy edges invisible.

Edit
Your comments make me believe the Android shrinks the image. Computer monitors do not overscan by default.

[czlowiewkzmarsa]

Use this script

http://www.freaktab.com/showthread.php?7948-SCRIPT-Modifying-Display-Scale

I had to logout and log back in to apply settings. Basically what it does is changing values in /sys/devices/platform/rk-fb/graphics/fb0/scale

[muckabout]

Thanks cz
I will try it. I like the idea of putting it in /etc/rc.local.
Ideally it should done without scaling but I am sure the effect probably won't be noticed. I am guessing that the versions of Android that the sellers of TV sticks use probably involves scaling since it is expected that they will be used with TVs more often than monitors.