By Daniel Howard, VQLink, Inc.
Key video quality impairments that impact video networks are described to help MSOs in monitoring and analysis of video quality over their networks. An in-depth discussion and taxonomy are given of video quality compression and network artifacts that are detectable by new, no-reference video quality technology that employs a hybrid of both bitstream and pixel processing and thus provides full video analysis of live and file-based MPEG2 and MPEG4 video content. The importance of measurement accuracy and minimal Type I and Type II errors for detection of these artifacts are developed and specific issues in transitioning from MPEG2 to MPEG4 are addressed with respect to these artifacts. Also discussed is how compression and network artifacts are perceived and detected differently in MPEG2 and MPEG4, and the specific video quality challenges for MSOs using transcoded video. Use cases for accurate measurement and classification of video impairments are given for network capacity planning, verification and maintenance of no material degradation (NMD) constraints, and stream bandwidth reductions for delivery of Internet video. Ultimately, MSOs can use newer video measurement and monitoring technology that provides accurate detection and classification of video quality impairments throughout their network to ensure that they affordably deliver the video quality required to remain competitive.