New ITU standards to assess quality of adaptive-bitrate video streaming
A new suite of ITU standards provides model algorithms to monitor the quality of video streaming over mobile devices as well as large screens with fixed-network connections. The standards are applicable to both progressive-download and adaptive-bitrate video streaming.
Adaptive-bitrate streaming – where the rate of media delivery adapts to fluctuations in available bandwidth – makes a valuable contribution to interruption-free video streaming, especially for mobile devices moving at high speed, for example in cars and trains, or from outdoor to indoor environments. This adaptive bit rate may however give rise to variations in the audiovisual quality experienced by end-users, variations that industry will monitor and address with the help of the new ITU-T P.1203 suite of standards.
The ITU-T P.1203 suite for “Parametric bitstream-based quality assessment of progressive download and adaptive audiovisual streaming services over reliable transport” was developed by ITU’s standardization expert group for ‘performance, QoS and QoE’, ITU-T Study Group 12.
ITU-T P.1203 describes a set of objective parametric quality-assessment modules, which together form a complete model to predict the impacts on end-user experience resulting from audio and video encodings and observed IP network impairments.
The standards provide models for short-term estimations of video and audio quality, as well as a final integration model to incorporate these short-term estimations into a long-term estimation of audiovisual quality. The standards describe different model realizations for different levels of content encryption and computational complexity.
ITU-T P.1203 currently supports quality estimations for HD video encoded using ITU-T H.264. ITU-T Study Group 12 is extending the standards to provide support for ‘4K’ UHD video encoded using ITU-T H.264, ITU-T H.265 and VP9.
The ITU-T P.1203 suite is structured in line with the functionality of its three modules:
- ITU-T P.1203: Introduction to the ITU-T P.1203 suite
- ITU-T P.1203.1: Module for short-term estimations of video quality
- ITU-T P.1203.2: Module for short-term estimations of audio quality
- ITU-T P.1203.3: Module for audiovisual integration to estimate the quality of viewing sessions between 30 seconds and 5 minutes