The need for standardization emerged with the fast development of video streaming technologies. MPEG Dynamic Adaptive Streaming over Hypertext Transfer Protocol (MPEG DASH) is a standard for adaptive video streaming. Applications developed in compliance with MPEG DASH ensure smooth playback to end-users while being hardware agnostic, cost-efficient, and easy to maintain. The client side of the MPEG DASH system houses the adaptation logic which has been investigated intensively over the last several years. The server side stores representation sets of video sequences as well as accompanying Media Presentation Description and initialization file. Compared to the client side, the server side has not been yet sufficiently explored.

Although there are some papers investigating the parameter selection for representation sets, most solutions are proprietary, do not take into account the content, and do not give the comprehensive methodology and its notation that can be applied to other codecs and encoder parameters. Also, most of the currently available solutions are costly and require large computational power. This article provides a comprehensive analysis and methodology for selecting the most appropriate spatial resolution switching points, which define the bitrates where switching to the higher spatial resolution is optimal. Furthermore, it presents a spatial resolution selection model for the estimation of switching points, which considers the spatial and temporal activity of video sequences. With the developed model, the optimal representation selection process is simplified and the segmentation process in MPEG DASH is improved. The methodology proposed for the development of this content-dependent spatial resolution selection model can be used for encoders and coding parameters not covered by the presented research.

Quality of the video sequences segmentation using the proposed switching points were tested using two different test cases for network conditions and two different adaptation algorithms: Basic Adaptation algorithm and Segment Aware Rate Adaptation algorithm. The streamed videos that used the proposed segmentation have achieved better SSIM (Structural Similarity Index) results in 83.33% of cases in comparison to the videos that used segmentation presented in the relevant literature.

随着视频流技术的快速发展，出现了对标准化的需求。MPEG 动态自适应流超文本传输​​协议 (MPEG DASH) 是自适应视频流的标准。根据 MPEG DASH 开发的应用程序可确保向最终用户流畅播放，同时与硬件无关、经济高效且易于维护。MPEG DASH 系统的客户端包含在过去几年中已被深入研究的适配逻辑。服务器端存储视频序列的表示集以及伴随的媒体表示描述和初始化文件。与客户端相比，服务器端还没有得到足够的探索。

尽管有一些论文研究了表示集的参数选择，但大多数解决方案是专有的，没有考虑到内容，也没有给出可应用于其他编解码器和编码器参数的综合方法及其符号。此外，大多数当前可用的解决方案成本高昂并且需要大量的计算能力。本文提供了选择最合适的空间分辨率切换点的综合分析和方法，这些切换点定义了切换到更高空间分辨率的最佳比特率。此外，它提出了一种用于估计切换点的空间分辨率选择模型，该模型考虑了视频序列的空间和时间活动。随着开发的模型，简化了最优表示选择过程，改进了MPEG DASH中的分割过程。为开发这种依赖于内容的空间分辨率选择模型而提出的方法可用于本研究未涵盖的编码器和编码参数。

使用所提出的切换点的视频序列分割的质量使用针对网络条件的两种不同测试案例和两种不同的自适应算法进行了测试：基本自适应算法和分段感知速率自适应算法。与相关文献中使用分割的视频相比，使用建议分割的流视频在 83.33% 的案例中取得了更好的 SSIM（结构相似性指数）结果。