Recommended Practice for Digital Program Insertion for Cable

Executive Summary

This Recommended Practice is to serve as an informational enhancement to SCTE 35 Digital Program Insertion Cue Message. SCTE 35 is necessarily brief in many areas in order to maintain conciseness and accuracy. This document serves as a companion to SCTE 35 as well as SCTE 104, Automation System to Compression System Communications Applications Program Interface (API).

Scope

This document is an informational companion to SCTE 35. It is not in itself a specification or a standard. The information within is intended as guideline information. Where this document contradicts SCTE 35, SCTE 35 takes precedence.

Benefits

The purpose of this document is to aid splicing equipment designers, ad insertion equipment designers, as well as the purchasers and users of such equipment, such as the networks that originate Cue Messages from their uplink sites. This document is also expected to aid in the system integration of advertising related equipment, both at the Message origination end and at the Message reception end.

SCTE 35 includes content segmentation messages, and this document has been written to aid the users of these messages. Some of the devices that will be interpreting the SCTE 35 commands include transcoders, packagers, network PVR, and other content manipulation, storage and streaming delivery systems.

There may be crucial information within this document for manufacturers of equipment that pass the Cue Message as part of the MPEG-2 transport stream. An example of such equipment is a rate altering re-multiplexer, which performs complex processing of the stream. When the stream is demultiplexed and processed and then re-multiplexed, it is very important to place the Cue Message in the proper position relative to the video service and relative to nearby time-base discontinuities. Such equipment may also be required to alter the Message before retransmission

Improvements in Ad Timing Synchronization

This document makes recommendations on how to maintain proper time synchronization between servers and splicers. These recommendations include the time synchronization method used between servers and splicers, methods for configuring splicer controlled Ad Insertion Systems, and methods for monitoring the proper timing of Cue Messages.

Intended Audience

The primary audience for the document is engineers developing implementations of ad insertion systems either as the provider or as the distributor. The document also provides an informative linkage between