These new DIRECTV HD channels required an H20/HR20 or later model set top box  (STB) capable of supporting the  MPEG-4  standard for HD programming. These models also introduced HDMI support for HDTVs with an HDMI port.
The introduction of these new DIRECTV HD channels necessitated a set-top box that could handle the MPEG-4 standard for high-definition content, as well as supported HDMI connectivity for HDTVs equipped with this feature.