# A Framework for Symmetric-Quality S3D Video Streaming Services
## 5 Conclusions  
In this paper, we propose and analyze the performance of a new encoding framework designed to address the issue of asymmetric image quality between the left and right views in 3D video services while achieving more efficient 3D video encoding. Compared with conventional HEVC and Cross-View SHVC methods, the proposed framework combines the conditional replenishment algorithm and Cross-View SHVC to significantly improve the quality of the right-view video while maximizing encoding efficiency through the use of Video Enhancement Information (VEI) technology. The experimental results demonstrate that the proposed method outperforms HEVC and Cross-View SHVC in terms of bitrate reduction and quality improvement. Specifically, the proposed framework delivers higher \(PSNR\) with lower bitrates, without subjective quality degradation, compared with encoding the right-view video using HEVC and Cross-View SHVC. On average, it achieved a 57.78% reduction in bitrate and a 2.62 dB improvement in \(PSNR\) compared with HEVC and a 45.10% reduction in bitrate and a 1.81 dB improvement in \(PSNR\) compared with Cross-View SHVC. These performance improvements contribute not only to bandwidth savings but also to increased network transfer efficiency. Moreover, the proposed framework has proven to be effective in ensuring quality in 3D video services. When encoding left and right videos at UHD resolution, the proposed structure achieved an average bitrate reduction of 10.53% compared with HEVC and 15.24% compared with Cross-View SHVC while offering a \(PSNR\) improvement of 1.04 dB over HEVC and 1.76 dB over Cross-View SHVC at the same bitrate. Furthermore, it is \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Sequence**} & \multicolumn{3}{c}{**Proposed vs. HEVC**} & \multicolumn{3}{c}{**Proposed vs. Cross-View SHVC**} \\ \cline{3-6}  & & **BDBR (\%)** & **BDSNR (dB)** & **BDBR (\%)** & **BDSNR (dB)** \\ \hline \multirow{6}{*}{Nutjob} & Part 1 & \(-12.36\) & \(1.37\) & \(-19.04\) & \(2.39\) \\  & Part 2 & \(-8.48\) & \(0.72\) & \(-14.51\) & \(1.46\) \\  & Part 3 & \(-11.21\) & \(1.29\) & \(-9.72\) & \(1.17\) \\  & Part 4 & \(-8.92\) & \(0.75\) & \(-14.73\) & \(1.58\) \\  & Average & \(-10.24\) & \(1.03\) & \(-14.50\) & \(1.65\) \\ \hline \multirow{6}{*}{Sweet Rollercoaster} & Part 1 & \(-24.24\) & \(2.38\) & \(-25.05\) & \(2.88\) \\  & Part 2 & \(-6.71\) & \(0.55\) & \(-11.94\) & \(1.13\) \\ \cline{1-1}  & Part 3 & \(0.14\) & \(-0.01\) & \(-7.85\) & \(0.99\) \\ \cline{1-1}  & Part 4 & \(-6.66\) & \(0.57\) & \(-13.41\) & \(1.34\) \\ \cline{1-1}  & Average & \(-9.37\) & \(0.87\) & \(-14.56\) & \(1.58\) \\ \hline \multirow{6}{*}{Secret of the Universe} & \(-11.60\) & \(1.13\) & \(-16.57\) & \(1.98\) & \(-11.60\) \\ \cline{1-1}  & \(-5.86\) & \(0.63\) & \(-12.44\) & \(1.82\) & \(-5.86\) \\ \cline{1-1}  & \(-9.54\) & \(0.86\) & \(-15.03\) & \(1.88\) & \(-9.54\) \\ \cline{1-1}  & \(-20.95\) & \(2.26\) & \(-22.55\) & \(2.57\) & \(-20.95\) \\ \cline{1-1}  & Average & \(-11.99\) & \(1.22\) & \(-16.65\) & \(2.06\) \\ \hline \multicolumn{2}{c}{Total Average} & \multicolumn{3}{c}{\(-10.53\)} & \(1.04\) & \(-15.24\) & \(1.76\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: BDBR and BDSNR of the proposed method (includes total bitrate of hybrid 3 DTV system). well-suited for streaming services, as it allows users to selectively choose from outputs of various quality levels. The proposed framework is designed to output streams at various resolutions, allowing users to choose from different quality levels. This enables high-quality service even in low-bandwidth environments, making it an excellent framework for OTT and broadcast environments. However, it should be noted that additional bandwidth is required, and it cannot be assumed that the left and right views will have 100% identical quality. In the future, as decoder processing power advances, further research should focus on enhancing video quality at the decoder side. Conceptualization, J.L., S.L. and D.K. ; methodology, J.L., S.L. and D.K.