This standard specifies a collection of test scenes that have been used for subjective assessment and may be used in future objective assessment of Video Teleconferencing/Video Telephony (VTC/VT). The scenes represent limited examples of the content that may be found in VTC/VT usage. The collection does not constitute a balanced set of scenes in any known way@ and use of the scenes to determine an overall performance assessment is beyond the scope of this standard. Other test scenes may be used in video performance assessment@ but their specification is also beyond the scope at this time. The test scenes identified within this standard are applied at the analog input interface shown in figure 1. Service channel interfaces (analog input and analog output) are between VTC/VT transmission service providers and end-users. Purpose The purpose of this standard is to make available to the industry a collection of video test scenes for the subjective performance evaluation of VTC/VT transmission systems on digital transport. It is intended to provide a common understanding by manufacturers@ carriers@ and their customers; and to aide in the development of objective test methodologies that statistically correlate to the subjective performance. Application The primary application of this collection of test scenes is in the assessment of VTC/VT transmission systems according to standardized methods. Some test scenes have an accompanying audio track@ but the audio must be used carefully if at all because of the variation in master audio quality. Test methodologies and quantitative measurement criteria@ for testing transmission systems@ utilizing these test scenes will be addressed in a separate document.