  Recently, High-Efficiency Video Coding (HEVC/H.265) has been chosen to
replace previous video coding standards, such as H.263 and H.264. Despite the
efficiency of HEVC, it still lacks reliable and practical functionalities to
support authentication and copyright applications. In order to provide this
support, several watermarking techniques have been proposed by many researchers
during the last few years. However, those techniques are still suffering from
many issues that need to be considered for future designs. In this paper, a
Systematic Literature Review (SLR) is introduced to identify HEVC challenges
and potential research directions for interested researchers and developers.
The time scope of this SLR covers all research articles published during the
last six years starting from January 2014 up to the end of April 2020.
Forty-two articles have met the criteria of selection out of 343 articles
published in this area during the mentioned time scope. A new classification
has been drawn followed by an identification of the challenges of implementing
HEVC watermarking techniques based on the analysis and discussion of those
chosen articles. Eventually, recommendations for HEVC watermarking techniques
have been listed to help researchers to improve the existing techniques or to
design new efficient ones.
