Many　fast　integer-pixel　motion　estimation　algorithms　have　been　developed　for　the　High　Efficiency　Video　Coding　Standard,　however　the　speed　of　sub-pixel　motion　estimation　still　has　room　for　improvement.　A　fast　sub-pixel　motion　estimation　algorithm　is　proposed　in　this　paper　to　speed　up　the　sub-pixel　search　process.　First,　the　proposed　scheme　skips　sub-pixel　search　process　in　smooth　prediction　units.　Then　a　fast　sub-pixel　search　algorithm　based　on　texture　direction　analysis　is　proposed　to　further　reduce　the　computational　complexity　of　sub-pixel　motion　estimation.　The　simulation　results　show　that　compared　with　the　Full　Sub-pixel　Search　(FSPS),　the　encoding　complexity　of　the　whole　motion　estimation　process　can　be　reduced　by　an　average　of　40.9%　with　negligible　coding　performance　loss.