SCTE Message Processing Options - AWS Elemental Live

This is version 2.18 of the AWS Elemental Live documentation. This is the latest version. For prior versions, see the Previous Versions section of AWS Elemental Live and AWS Elemental Statmux Documentation.

SCTE Message Processing Options

The Options

The processing possibilities for SCTE messages include the following.

Automatically Convert SCTE-104 Messages

SCTE-104 messages in the input are automatically converted to SCTE-35 messages during processing of the input. No setup is required for this processing.

Line Up SCTE Messages to Use Blanking and Blackout of Output Content

The “cue out” and “cue in” instructions in SCTE-35 messages line up with specific content in the video, audio, and closed captions streams. You can set up to blank out this content in the output.

  • The content for ad avails is blanked out using the Ad avail blanking feature.

  • The content for other messages is blanked out using the blackout feature.

Your desired behavior must be set up in the event or profile.

SCTE-35 Pass-through

You can include SCTE-35 messages in the output data stream in any TS output. Your desired behavior must be set up in the event or profile.

Manifest Decoration

You can set up SCTE messages with manifest decoration with these options:

  • HLS and HDS outputs can be set up so that their manifests include instructions that correspond to the original SCTE-35 message content.

  • MS Smooth outputs can be set up to include these instructions in the sparse track.

  • RTMP outputs can be set up to include these instructions in the data stream (because RTMP outputs do not have manifests).

Conditioning by a POIS

Optionally, SCTE-35 messages (including those converted from SCTE-104) can be diverted to a POIS server for ESAM conditioning. This conditioning is in addition to all the other processing (manifest decoration, blanking and blackout, and passthrough).

POIS and ESAM conditioning are described in POIS Conditioning.

Insert SCTE-35 Messages into Content During an Event

The AWS Elemental Live REST API includes commands to insert SCTE-35 messages into the content while the AWS Elemental Live event is running.

You can insert using the AWS Elemental Live REST API. AWS Elemental Live makes no distinction between these messages and those that were in the original input. So, for example, if manifest decoration is enabled and you insert a message during encoding, that new message is represented in the manifest.

Default Behavior of SCTE-35 and SCTE-104 Messages

The default handling of SCTE-35 and SCTE-104 messages in AWS Elemental Live includes the following:

  • No manifest decoration: You do not convert any SCTE-35 messages to event information in any output manifests or data streams.

  • No passthrough: You do not pass through SCTE-35 or SCTE-104 messages in any data stream outputs.

  • No blanking: You do not blank out video content for any events: you leave the content as is.

If you desire the default behavior as described , you have the information you need for processing SCTE messages and do not need to read the remainder of this guide.

About Timecode Configuration and Timers

The event or profile includes a timecode configuration field that identifies the source for timecode stamps to be inserted in the output. The source for these stamps may be a timecode embedded in the input or may be a source external to the input (for example, the system clock or a specified time). The following graphic shows where the timecode configuration fields are in the event.


                  The file images/timecode-config.png.

Before starting the transcode, the transcoder gets the timecode from the source.

After the initial sampling, AWS Elemental Live calculates the timecode of every frame and attaches it to the output. The timecode stops advancing if there is no output. So, for example, if the input fails at 10:55:03:009, the timecode at that point is 10:55:009. If the input restarts 3 seconds later, the timecode of the next frame may be 10:55:03:012. The timecode will not be 10:55:06:009.

Given the importance of accurate times with SCTE-35 messages, ensure that the Network Time Protocol (NTP) is configured on the node.