I have a Galaxy Note II, which uses MHL micro USB out to HDMI. I'd like to run the video signal thru a composite video (RCA) converter cable to my old school device. Does Android support this sort of video output conversion natively, or would I need to forget this cable and get an HDMI-to-composite converter box for in the middle?
To use the MHL output of the phone (using micro USB connector) you need to either have a device (such as a TV) that supports MHL directly, or use a dongle to convert MHL to some other standard (such as HDMI, VGA or Composite) that you can use with your device. This is done entirely in the dongle. So as long as your device outputs MHL and you have the dongle, it should work just fine. Currently the only dongles in the market are MHL to HDMI (although there are MHL to VGA and Composite coming to the market soon!). So, you can't wait for the new dongles, you have to get another dongle/box that converts HDMI to Composite and connect it to your MHL-HDMI dongle.