Summary

Recommendation ITU-T H.721 describes and specifies the functionalities of the Internet protocol television (IPTV) terminal devices for the IPTV basic services defined in Recommendation ITU‑T H.720. This Recommendation is targeted at IPTV terminal devices capable of receiving linear television (TV) service and video-on-demand services, with additional data content (such as text) using a managed content delivery network. The service definition takes into consideration conditions on content delivery such as quality of service (QoS). The expected types of IPTV terminal devices are set-top boxes and digital TV sets with embedded IPTV capabilities.

The second edition introduced support for high efficiency video coding (HEVC), dynamic adaptive streaming over HTTP (DASH), MPEG-4 audio lossless coding (ALS), MPEG-4 advanced audio coding (AAC), DTS-HD, timed text markup language (TTML), MPEG media transport (MMT) and several corrections and clarifications.

The third edition introduces support for new technologies such as timestamped fragmented time-length-value (TFT).