Supplementary Information

GRIDSHOT® supports embedding of SCTE-35, also known as Digital Program Insertion Cueing Message for Cable, in the channel. SCTE-35 is an additional PID in the MPEG transport stream (MPEG-TS). Channel owners can decide in our GRIDSHOT® scheduling application where the SCTE-35 markers are placed in the schedules.

Although SCTE-35 is an international standard. It’s implementation can have a vendor specific rule set applied. We can apply these specific rule set if we have enough information from supplier. SCTE-35 is more frame accurate than analog cue tune (DTMF). For outputs such as SRT, ASI, IP ASI (multicast / unicast), no additional translation steps are required for the SCTE-35 markers.

* Note that Splice OUT/IN and Cue OUT/IN is used interchangeably and both have the same meaning.

Break communication

The SCTE-35 standard has a comprehensive set of rules to communicate when and how long a break must occur. GRIDSHOT® communicates such breaks using the splice_insert command. 

A break generally has a Splice OUT (exit from main feed) and Splice IN (return to main feed) marker.

Scheduled SCTE-35 markers in GRIDSHOT® produce Splice OUT markers in the Transport Stream embedded with a duration field and with the Auto Return Mode flag enabled. 

According to the SCTE-35 standard the splicer device should respect this flag and implicitly return to the main feed after the specified duration, therefore a Splice IN marker is not required and won’t be included in the Transport Stream. This is our recommended application of the SCTE-35 markers.

Optionally, GRIDSHOT® can embed a combined Splice OUT and Splice IN marker in the Transport Stream.

Actual time of Digital Ad/Program Insertion

When an SCTE-35 marker is scheduled in GRIDSHOT®, the actual time of insertion can be visually different than what is scheduled in GRIDSHOT® because of delays in the distribution chain.

For example, an SCTE-35 Splice OUT marker arrives at 14:09:52 because of the preroll (time before actual splice OUT/IN event) and communicates a Splice OUT at 14:10:00. This allows the downstream splicer device to cut into the channel and insert external content into the signal.

Image 1: Graphical overview SCTE-35 markers synchronization and the effect of distribution delay.

However, it is possible that the customer may see the advertisement starting at 14:10:30 (wall clock) if it is watching the spliced channel output. This is because of the overall signal delay in the distribution chain. GRIDSHOT® playout has about 20 ~ 30 seconds delay due to internal buffering. And the distribution chain may also add more variable delay on top.

Visually the SCTE-35 marker has replaced the range of frames of the playlist item that was supposed to be shown.


Our SCTE-35 markers are tested and verified by engineers from multiple companies and products:

  • Appendix 1: Mediakind RX8200 (minimal required version 8.28.0)
  • Appendix 2: DVBControl DVBAnalyzer

Appendix 1: MediaKind RX8200

The RX8200 from the vendor MediaKind has support for our SCTE-35 markers. The RX8200 requires version 8.28.0 or higher to support the latest SCTE-35 standard revisions.

With the build-in alarm system, you can retrieve signals from the RX8200 when a advertisement event is active. For updates or more information about the RX8200, please contact the support department of MediaKind.

Image A1: Decode tab shows detected Splice Event ID 2 (CUE OUT)

Appendix 2: DVBControl DVBAnalyzer

DVBAnalyzer has a built-in SCTE Viewer that can detect SCTE-35 markers in the Transport Stream.

Image A2: SCTE-35 viewer shows detected Splice Events (CUE OUT)

Contact and Support

Should there be any technical issues or questions regarding the application of SCTE-35 Splice markers please contact theFrontDoor at