Object-Based Rate Adjustment for HEVC Transrating

This paper proposes an adaptive transrating algorithm for HEVC (High Efficiency Video Coding) coded videos. Higher bitrates are assigned to identified significant video object blocks and lower bitrates are assigned to the other regions to improve users' viewing quality. The depth information of CUs (Coding Units) of the original high-quality coded video is used for selecting significant video object blocks. Rate adjustment is realized by adjusting the weight of average bitrate and consequently the QP (quantization parameter) in the LCU (Largest Coding Units) level. Experimental results reveal that the proposed object identification method is sufficiently accurate. With a negligible BD-rate increase, the proposed method implemented in single frames increases the PSNR by 0.22 dB in object blocks.