Summary

Parallel transmission links including codecs are often set up to realize a highly reliable contribution and primary distribution of television programs, in particular of big events such as Olympics and World Cup Soccer. This configuration, however, has the following issues:

1)          The reserve link is totally wasted during normal periods.

2)          Switching to the reserve link should be perfect to avoid a disrupted television program, when a failure occurs in a transmission link.

3)          In addition, objective assessment of received video quality has been strongly demanded in an actual operation of digital television program transmission.

This Recommendation, therefore, recommends a framework for methods that support solutions for these issues. This framework mainly consists of the following three elements:

1)          It reduces coding noise and improves picture quality compared to only one link by outputting the average signal of two links, when both links are normal (Efficiency).

2)          It detects a failure that occurs in one of the two links by monitoring the two links by comparing them (Support of failure detection).

3)          It evaluates the quality of the two decoded pictures by comparing them (Automatic picture quality assessment).

Appendices show examples of methods in this framework. Such methods improve the operational efficiency and reliability of parallel video transmission links.