title: How to disable/enable HDMI on Raspberry Pi?
body: <p>So I can use "tvservice -o" to turn off the HDMI on the raspberry Pi, and "tvservice -p" to turn it back on. After turning it back on I apparently need to do "fbset -depth 8 &amp;&amp; fbset -depth 16" to re-enable the frame buffer and then force an X11 redraw.</p>
  
  <p>My question is, how do I do this in C? I have an X11 application and I can manage the X11 redraw no problem, but how do I disable/re-enable HDMI in C, and how do I re-enable the frame buffer after re-enabling HDMI?</p>
  
  <p>To give background, I have a headless application running as a sort of media server, controlled by an Android app. Currently I am permanently disabling the turning off of HDMI after a timeout. However to save energy I would like to disable the HDMI when the app is not in use, and then turn it back on and display the RPi application on screen using libcec to determine when the TV is using the RPi's HDMI connection to turn HDMI on and off.</p>