scope:

This standard is the North American adaptation for Domestic-International interfaces of the ETSI ETS 300 174 standard for the coding and transmission of digital component televisionsignal at a bit rate of 45 mbits/s. It provides a detailed description of the digital coding algorithm to be implemented in equipment designed to terminate digital transmission systems when those systems are employed to carry ITU-R 6012 digital television video signals, AES/EBU digital audio signals and ancillary signals such as SMPTE time-code, and SMPTE machine control. Each television signal is formatted to be compatible with the North American DS-3 transport network. The video conding algorithms are based on a hybrid predictive/transform scheme incorporating arrangements for variable word-length coding (VLC), synchronization, and video framing. Provision is made for the transmission of audio and teletext services to accompany the video and for the application of scrambling for conditional access.

Purpose
 
 The prupose of this standard is to provide a common framework for coders and decoders to transmit ITU-R 601-2 television signals between the North American and International telecommunications networks by providing linkage to the ITU-R 723 and ITU-T J.81 recommendations and the ETSI ETS 300 174 standard.

NOTE It should be recognized that due to the application of this standard for the interworking internationally with ETSI 300 174 it is useful to provide the details fo encoder implementations as seen by ETSI and the ITU. In the original development of the coding system structure by ETSI and the ITU there was a paining of the specifications between the encoder and the decoder. New encoding the original pairing structure. The standard will allow for this new technology. Therefore, normative references in the standard to implementation of encoders are optional, and are not intended as limitations on encoder implementations.

Application

This standard provides a framework for interoperability of equipment from various manufacturers and various service providers to ensure uniform application of the coding methods. It also provides a common understanding between suppliers and their customers.