# How schedule actions work
This section describes how MediaLive handles each combination of [action type](x-actions-in-schedule.md) and [start type](sched-timing-types.md).
**Topics**
+ [How input switch actions work](x-actions-in-schedule-ips.md)
+ [How input prepare actions work](x-actions-in-schedule-prep.md)
+ [How image overlay actions work](x-actions-in-schedule-image-overlay.md)
+ [How motion graphics overlay works](x-actions-in-schedule-mg.md)
+ [How SCTE 35 actions work](x-actions-in-schedule-SCTE35.md)
+ [How ID3 metadata actions work](x-actions-in-schedule-id3.md)
+ [How ID3 segment tag actions work](x-actions-in-schedule-id3-segment-tag.md)
+ [How pause and unpause actions work](x-actions-in-schedule-pause.md)
# How input switch actions work
You can set up an action to switch the input that the running channel is ingesting. The channel stops ingesting the current input and starts ingesting the specified input.
The input must already be attached to the channel.
Before you add input switching actions to the schedule, read [Setting up for input switching](scheduled-input-switching.md).
**Input switch with fixed start**
When you create the action, you include a start time. The start time for the action must be at least 15 seconds in the future but not more than 14 days in the future. After that cutoff, MediaLive rejects the request to create the action.
After you have created the action, the action sits in the schedule. Approximately 15 seconds before the start time, the schedule passes the action to the channel. The channel sets up so that the input switches at the specified time.
**Input switch with immediate start**
When you create the action, you set the start type to *immediate*.
For an input switch in a standard channel (a channel with two pipelines), MediaLive internally sets the start time to 10 seconds in the future. This delay ensures that the switch occurs at exactly the same time for the two pipelines.
The schedule immediately passes the action to the channel. The channel immediately starts to switch the input (for a single-pipeline channel), or sets up to switch at the specified time (for a standard channel).
**Input switch with follow start**
When you create the action, you specify the input switch action that you want this action to follow. That *reference action* must be an input switch.
The input for the reference action must have a source end behavior of *Continue*. To find the **Source end behavior** field, go to the **Create channel** page, find the input in the **Input attachment** list, and then find **General input settings**.
After you create the action, the action waits in the schedule. Just before the reference action is due to finish, the schedule passes the action to the channel so that the channel can switch to the new input as soon as the current input has finished.
# How input prepare actions work
You can set up an action to prepare an input that is associated with an immediate input switch, in order to reduce the delay that occurs when MediaLive performs the switch.
The input must already be attached to the channel. However, there is no requirement for the input switch for this input to already exist in the schedule. For example, input X must be *attached *to the channel. You can create action A to prepare input X and later on you can create action B to switch to input X. Or you can create action B and then create action A.
Before you add input prepare actions to the schedule, read [Preparing inputs in AWS Elemental MediaLive](feature-prepare-input.md).
**Input prepare with fixed start**
When you create the action, include a start time. The start time for the action must be at least 15 seconds before the start time of the associated input switch, but not more than 14 days in the future. After that cutoff, MediaLive rejects the request to create the action.
After you have created the action, the action sits in the schedule. Approximately 15 seconds before the start time of the prepare action, the schedule passes the action to the channel. The channel starts preparing the input.
**Input prepare with immediate start**
When you create the action, you set the start type to *immediate*.
The schedule immediately passes the action to the channel. The channel immediately starts the prepare.
**Input prepare with follow start**
When you create the action, you specify the input switch action that you want this action to follow. That *reference action* must be an input switch.
The input for the reference action must have a source end behavior of *Continue*. To find the **Source end behavior** field, go to the **Create channel** page, find the input in the **Input attachment** list, and then find **General input settings**.
After you create the action, the action waits in the schedule. Just before the reference action is due to finish, the schedule passes the action to the channel. As soon as the current input has finished, the channel switches to the new input.
# How image overlay actions work
You can set up an action to insert and remove an image overlay on the video:
+ The activate action inserts an image overlay and activates it so that it is superimposed on the underlying video. If the image overlay information includes a duration, then at the appropriate time the image overlay is removed.
+ The deactivate action removes an image overlay. You therefore use this action to remove a currently running image overlay before the specified duration, or remove it when no duration is specified.
Before you add image overlay actions to the schedule, read [Working with image overlays](working-with-image-overlay.md).
**Global or per-outputs insertion**
There are two ways to insert image overlays:
+ Use the **Static image activate** feature to insert globally: You can create an action to insert an image overlay in every output in every output group in a channel.
+ Use the** Static image output activate** feature to insert per-output: You can create an action to insert an image overlay in specific outputs in specific output groups in a channel.
**Activate or deactivate with fixed start**
When you create the action, you include a start time. The start time for the action must be at least 15 seconds in the future but not more than 14 days in the future. After that cutoff, MediaLive rejects the request to create the action.
After you have created the action, the action sits in the schedule. Approximately 15 seconds before the start time, the schedule passes the action to the channel. At the start time, the channel inserts the image overlay or removes the image overlay from the video.
**Activate or deactivate with immediate start**
When you create the action, you set the start type to *immediate*.
The schedule immediately passes the action to the channel. The channel immediately inserts the image overlay or removes the image overlay.
# How motion graphics overlay works
You can set up an action to insert and remove a motion graphics overlay on the video:
+ The activate motion graphics action inserts a motion graphic and activates it so that it is superimposed on the underlying video. If the image overlay information includes a duration, then at the appropriate time the motion graphic is removed.
+ The deactivate motion graphics action removes an image overlay. You therefore use this action to remove a currently running motion graphics before the specified duration, or remove it when no duration is specified.
For information about preparing the motion graphics asset that the action inserts, see [Working with motion graphics overlays](feature-mgi.md).
**Activate or deactivate with fixed start**
When you create the action, you include a start time. The start time for the action must be at least 15 seconds in the future but not more than 14 days in the future. After that cutoff, MediaLive rejects the request to create the action.
After you have created the action, the action sits in the schedule. Approximately 15 seconds before the start time, the schedule passes the action to the channel. At the start time, the channel inserts the motion graphic or removes the motion graphic from the video.
**Activate or deactivate with immediate start**
When you create the action, you set the start type to *immediate*.
The schedule immediately passes the action to the channel. The channel immediately inserts the motion graphic or removes the motion graphic.
# How SCTE 35 actions work
You can set up an action to insert a SCTE 35 message in the channel. There are three types of actions:
+ Action to insert a splice\$1insert into the channel: a SCTE 35 message with splice\$1command\$1type set to splice\$1insert.
+ Action to insert a time\$1signal into the channel: a SCTE 35 message with splice\$1command\$1type set to time\$1signal.
+ Action to insert a SCTE 35 return-to-network message into the schedule in order to end a splice\$1insert that either has a duration or has no duration.
Before you add SCTE 35 actions to the schedule, read [Processing SCTE 35 messages](scte-35-message-processing.md).
**Insert SCTE 35 message with fixed start**
When you create the action, you include a start time. The start time for the action must be at least 15 seconds in the future but not more than 14 days in the future. After that cutoff, MediaLive rejects the request to create the action.
After you have created the action, the action sits in the schedule. Approximately 15 seconds before the start time, the schedule passes the action to the channel. At the start time, the channel inserts the SCTE 35 message into the stream.
After the channel inserts the message, MediaLive processes the inserted message in the same way as it processes messages that were already in the source content.
**Insert SCTE 35 message with immediate start**
When you create the action, you set the start type to *immediate*.
The schedule immediately passes the action to the channel. The channel immediately inserts the SCTE 35 message into the stream.
After the channel inserts the message, MediaLive processes the inserted message in the same way as it processes messages that were already in the source content.
**Insert SCTE 35 message with follow start**
When you create the action, you specify the input switch action that you want this action to follow. That *reference action* must be an input switch.
The input for the reference action must have a source end behavior of *Continue*. To find the **Source end behavior** field, go to the **Create channel** page, find the input in the **Input attachment** list, and then find **General input settings**.
After you create the action, the action waits in the schedule. Just before the reference action is due to finish, the schedule passes the action to the channel. As soon as the current input has finished, the channel inserts the SCTE 35 message into the stream.
After the channel inserts the message, MediaLive processes the inserted message in the same way as it processes messages that were already in the source content.
# How ID3 metadata actions work
You can set up an action to insert ID3 data in the channel. You can set up an action to insert ID3 data in each segment in the following types of outputs:
+ CMAF Ingest
+ HLS
+ MediaPackage
Before you add ID3 metadata actions to the schedule, read [Inserting ID3 metadata using the schedule](insert-id3-metadata-via-schedule.md).
**Insert ID3 metadata with fixed start**
When you create the action, you include a start time. The start time for the action must be at least 15 seconds in the future but not more than 14 days in the future. After that cutoff, MediaLive rejects the request to create the action.
After you have created the action, the action sits in the schedule. Approximately 15 seconds before the start time, the schedule passes the action to the channel. At the start time, the channel inserts the data into the channel.
**Insert ID3 metadata with immediate start**
When you create the action, you set the start type to *immediate*.
The schedule immediately passes the action to the channel. The channel immediately inserts the data into the channel.
# How ID3 segment tag actions work
You can set up an action to insert ID3 data in each segment in the following types of outputs:
+ CMAF Ingest
+ HLS
+ MediaPackage
Before you add ID3 segment tag actions to the schedule, read [Inserting ID3 metadata using the schedule](insert-id3-metadata-via-schedule.md).
**Insert ID3 segment tags with fixed start**
When you create the action, you include a start time. The start time for the action must be at least 15 seconds in the future but not more than 14 days in the future. After that cutoff, MediaLive rejects the request to create the action.
After you have created the action, the action sits in the schedule. Approximately 15 seconds before the start time, the schedule passes the action to the channel. At the start time, the channel inserts the data into the channel.
**Insert ID3 data with immediate start**
When you create the action, you set the start type to *immediate*.
The schedule immediately passes the action to the channel. The channel immediately inserts the data into the channel.
# How pause and unpause actions work
You can insert an action to pause and unpause one or both pipelines in the channel. The action pauses the specified pipelines and unpauses any unspecified pipelines:
+ Action with *one* pipeline specified–The action pauses the specified pipeline and unpauses the other pipeline.
+ Action with *both* pipelines specified–The action pauses both pipelines.
+ Action with *no* pipelines specified–The action unpauses both pipelines.
**Note**
The pipelines that you don't specify are not left in their current state. They are always set to unpaused.
**Pause or unpause with fixed start**
When you create the action, you include a start time. The start time for the action must be at least 15 seconds in the future but not more than 14 days in the future. After that cutoff, MediaLive rejects the request to create the action.
After you have created the action, the action sits in the schedule. Approximately 15 seconds before the start time, the schedule passes the action to the channel. At the start time, the channel pauses or unpauses the pipelines in the channel.
**Pause or unpause with immediate start**
When you create the action, you set the start type to *immediate*.
The schedule immediately passes the action to the channel. The channel immediately pauses or unpauses the pipelines in the channel.