In this paper, we address the issues in designing metrics that are important in evaluating the Quality of Service(QoS) of video transmission. We propose a new metric for video QoS called the weighted cost-satisfaction ratio based on requirements from two perspectives: the user and the service provider. To understand real video workload environments and user behavioral patterns, we obtained and analyzed empirical results from the VOSAIC (video-over-the-Web) system, a hierarchical video-on-demand (VOD) system and a remote VCR system. Based on these results, we define parameters of resource consumption (storage and network bandwidth etc.) and user satisfaction (jitter, synchronization skew) and derive analytical interrelationships among the metric parameters. We also draw an economic relationship between the user-satisfaction and resource consumption factors to solve metric optimization relations. Keywords: QoS, video, resource consumption, user satisfaction, workload.