Digital program insertion (DPI) allows cable headends and broadcast affiliates to insert locally generated commercials and short programs into remotely distributed regional programs before they are delivered to home viewers.[1]
Digital program insertion also refers to a specific technology which allows an MPEG transport stream to be spliced into a currently flowing MPEG transport stream seamlessly and with little or no artifacts. The controlling signaling used to initiate an MPEG is referred to as an SCTE-35 message. The communication API between MPEG splicers and content delivery servers or ad insertion servers is referred to as SCTE30 messages.[1]