scope:

This document provides a proposed methodology for video quality assessment that can be applied to any multiple bit rate (multi bit rate) adaptive streaming system. The methodology provides a framework for video quality assessment and does not define the specific algorithms to be used for video quality measurement. The recommended reference methodology is designed to be as generic as possible in order to allow the different video quality measurement algorithms to use this methodology as their evaluation platform.

Video quality refers to both subjective and objective quality throughout the document, unless one is explicitly stated.

Purpose

Video quality (VQ) assessment plays an important role in the design and architecture of a video streaming system. One of the trends that emerged in the streaming media industry recently has been the over-the-top (OTT) adaptive streaming video to mobile phones, tablets, and PCs having different display screen sizes. Adaptive streaming techniques dynamically adapt video bit rates for individual display devices during a streaming session, based on the available network bandwidth. Therefore, it is very important to adjust the video parameters appropriately in order to achieve the best video quality on end-user devices. Furthermore, due to the large number of end-user devices having different display properties, a video quality assessment methodology is necessary to build a model for the perceived video quality on the end-user devices. This document describes a methodology to be employed to characterize the effect of the factors influencing the video quality in a multi bit rate adaptive streaming scenario and thereby choose the optimal video parameters to achieve the best video quality.