Efficient Unequal Error Protection Techniques for Tile-Based Transmission of HEVC Videos

The video bitstream compressed by the efficient high efficiency video coding (HEVC) standard is extremely vulnerable to the channel error. For robust transmission of such compressed videos, techniques can be formed based on the specific characteristics of the compression standard. With the introduction of new coding features in HEVC, such as flexible block partitioning and tiles, unequal error protection (UEP) schemes are proposed in this paper aiming to enhance the quality of the important regions. The proposed algorithms are implemented in two and three-levels. For the two-level UEP, tiles are prioritized based on their motion density, which is defined as the ratio of motion vector magnitudes to the block size in a compressed video frame. Furthermore, a three-level UEP is proposed to improve the protection of low-important tiles, which may include moving objects. For this purpose, clustering algorithms, utilizing kernel density estimation (KDE) and density-based spatial clustering of applications with noise (DBSCAN), are modified based on the motion density of coding tree units (CTUs). Indeed, this represents implementation of an object detection algorithm based in compressed domain. Simulation results confirm that proposed UEP schemes achieve better objective quality compared to conventional UEP and equal error protection (EEP) approaches.