The impact of bitrate and GOP pattern on the video quality of H.265/HEVC compression standard

Multimedia services have increased sharply in recent years, especially in the video domain. This trend raises the demand for video quality assessment. The main factors affecting the video quality are compression technology and transmission link. H.265/High Efficiency Video Coding (HEVC), which serves as the latest video coding standard, has shown significant improvements on the video compression when compared with the last video coding standard H.264/MPEG-4 AVC. This paper evaluates the video quality under H.265/HEVC compression standard and studies the relationship between the video quality and the bitrate under different group of pictures (GOP) patterns. The evaluation is done for four video sequences using objective metrics. Experiments demonstrate that higher bitrate will lead to better video quality under the same GOP pattern. Also, the video quality will improve as the size of GOP increases while maintaining the number of B-frames. Meanwhile, the effectiveness of the compression also depends on the content and dynamic condition of the video sequences.