HDMI 1.4 provides resolution to 4K × 2K (3840×2160p at 24 Hz/25 Hz/30 Hz and 4096×2160p at 24 Hz, which is means it is viable for use for digital theatres). 1.4 has an an HDMI Ethernet Channel (HEC), which means you can forge a 100 Mb/s Ethernet connection between two HDMI connected devices.
1.4 provides an Audio Return Channel, 3D Over HDMI, a Micro HDMI Connector, increased colour support, and an Automotive Connection System.
HDMI 1.4 supports a number of stereoscopic 3D formats including field alternative (interlaced), frame packing (a full resolution top-bottom format), line alternative full, side-by-side half, side-by-side full, 2D + depth, and 2D + depth + graphics + graphics depth (WOWvx), with additional top/bottom formats added in version 1.4a .
HDMI 1.4 needs 3D displays to support the frame packing 3D format at 720p50 and 1080p24 or 720p60 and 1080p24.
HDMI 1.4a furthers its predecessor cable with the ability to support two 3D formats for broadcast content.
HDMI 1.4a includes obligatory 3D formats for broadcast, game, and movie content.