Triggers for blackout - AWS Elemental MediaLive

Triggers for blackout

The blackout feature is triggered only by time_signal messages of segmentation type Other. It is not triggered by splice_insert messages of any segmentation type, and is not triggered by time_signal messages of any type except Other.

SCTE-35 messages of type ID "splice insert" and messages of type ID "time signal" can both include "Other" time_signal messages. Therefore, when enabling blackout, the ad avail mode is not relevant. Blackout works the same with either mode.

The segmentation ID triggers blackout based on “events,” as shown in the following table.

SCTE-35 segmentation type Blacked out
Chapter Start Start blacking out
Chapter End End blacking out
Network Start End blacking out
Network End Start blacking out
Program Start Start blacking out
Program End End blacking out
Unscheduled Event Start Start blacking out
Unscheduled Event End End blacking out

For example, if the blackout feature is enabled, then blanking always occurs when a Program Start message is encountered and always ends when a Program End message is encountered.

Note that the triggers for blackout on a Network event are different from the other events:

  • With Network, blanking starts when the Network End instruction is encountered.

  • With other events, blanking starts when the "Event Start" instruction is encountered.

End event trigger hierarchy

Events have the following "strength hierarchy."

SCTE-35 segmentation type Strength
Network 1 (Strongest)
Unscheduled Event 2
Program 3
Chapter 4 (Weakest)

A blackout can be ended only by an event of equal or greater strength than the event that started it.

For example, if the blackout is started by a Program Start, it can be ended by a Network Start, an Unscheduled Event End or a Program End. It cannot be ended by a Chapter End. MediaLive ignores the “end blackout” instruction implied by the Chapter End.