Provided are techniques for low complexity video coding. For example, a video coder may be configured to calculate a first sum of absolute difference (SAD) value between a coding unit (CU) block and a first corresponding block in a reference frame, and define branching conditions for branching of CU sizes based on the first SAD value, the branching conditions including a background condition and/or a homogeneous condition. The video coder may be configured to detect the background condition if the first SAD value of the CU block is less than a first threshold background value, and detect the homogeneous condition if a second SAD value of a sub-block of the CU block is between upper and lower homogeneous threshold values based on the first SAD value. The branching of the CU sizes may be based on detecting the background or homogeneous conditions.