Development of a methodology to test video codecs used in teleconferencing

The purpose of this report is to define a test methodology for the evaluation of motion television codecs for teleconferencing applications. The results of this evaluation will serve as a guideline for the future preparation of specifications for codecs of this type. The principle characteristics of the codecs include the following: (1) utilize digital communication channels, (2) operate at a data rate of 1.544 Mbps, (3) provide color capability, and (4) provide motion capability. The specific objective of the tests describes is to rank the codecs tested in order of performance. The reason that new tests are being developed is that there are presently no agreed upon test procedures for that purpose. The tests described will utilize a specifically prepared video tape containing still and motion sequences designed specifically for the evaluation of this type of codec. These sequences will be passed through the codecs and the output recorded on video tape. The evaluation and grading of each codec will be on a subjective, comparative basis.