Most non-Apple smartphones have micro-USB ports for charging, and most made in the past few years also support sending an HDMI signal through this port, either via MHL [1] or SlimPort (notably, Nexus 4). All it takes is a $10 adapter cable rather than a $40 SoC transcoding things.
1: http://en.wikipedia.org/wiki/Mobile_High-Definition_Link#Mob...