High Efficiency Video Coding (HEVC) is a new video coding standard that has recently been finalized. Due to its substantially improved performance, it is expected to replace the H.264 video coding standard and to become the most common video coding technique in few years. A major innovation in HEVC is the use of a quad-tree based coding tree block for images. In this representation, an image is first divided into non-overlapping coding units, which can be recursively divided into smaller coding units. This recursive quad-tree decomposition of the image is an efficient representation of variable block sizes, so that regions of different sizes can be better coded. However, the flexibility of the variable block size structure greatly increases the search domain hence the computational complexity of the encoder.
In this project, we developed a simple yet efficient algorithm for selecting a quad-tree representation of images in an HEVC video encoder. This is the most computationally complex part of such an encoder and optimizing it is a must when implementing any practical HEVC encoding system. The efficiency is measured in the total encoding time, the quality of the compressed video and the bit rate.