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.

Message type Id	SCTE-35 segmentation type	Start blacking out	End blacking out
splice insert	Any	Not a trigger	Not a trigger
time signal	Provider advertisement, Distributor advertisement, Break	Not a trigger	Not a trigger
	Chapter Start	Start blacking out
	Chapter End		End blacking out
	Network End	Start blacking out
	Network Start		End 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 strength hierarchy shown in the following table. 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.

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