AWSE SCTE-35 format

AWSE is a format_identifier value used in the SCTE-35 MPU UPID structure. Some AWS Elemental MediaLive features use this format to carry additional information in SCTE-35 splice_info_section messages.

This page describes the binary format of AWSE descriptors, including the versioned envelope structure and registered feature payloads.

Features using the AWSE format_identifier

The following table lists the MediaLive features that append AWSE descriptors to SCTE-35 messages.

AWSE format specification

The AWSE format_identifier provides a versioned, extensible envelope. This envelope identifies the feature that produced the descriptor and carries a feature-specific payload. The following sections describe the outer descriptor structure, the envelope fields, and the registered feature identifiers.

Segmentation descriptor structure

Each AWSE descriptor follows the SCTE 35 segmentation_descriptor() syntax:

segmentation_descriptor {
    splice_descriptor_tag           = 0x02
    descriptor_length               = 15 + segmentation_upid_length
    identifier                      = 0x43554549 ('CUEI')
    segmentation_event_id           = <unique per splice_info_section>
    segmentation_event_cancel_indicator = 0
    program_segmentation_flag       = 1
    segmentation_duration_flag      = 0
    delivery_not_restricted_flag    = 1
    segmentation_upid_type          = 0x0C (MPU)
    segmentation_upid_length        = <varies by feature>
    segmentation_upid               = <AWSE format_identifier + envelope — see AWSE UPID envelope>
    segmentation_type_id            = 0x01 (Content Identification)
    segment_num                     = 0
    segments_expected               = 0
}

The segmentation_upid_type is always 0x0C (MPU). The segmentation_type_id is always 0x01 (Content Identification). The segmentation_upid begins with the format_identifier value "AWSE", followed by the envelope fields described in AWSE UPID envelope.

AWSE UPID envelope

The segmentation_upid begins with a fixed envelope header. This header identifies the format_identifier, schema version, and feature. Depending on the feature, a feature-specific payload might or might not follow. Parsers use the feature_id to determine how to interpret the remaining bytes (if any).

The fields appear in the order shown.

For schema version 1, the envelope header is 9 bytes (4 + 1 + 4). A feature-specific payload might or might not follow the feature_id, depending on the feature. When a payload is present, its length is segmentation_upid_length - 9. The feature defines the payload structure entirely; see the feature's payload reference for details.

Parsers that do not recognize a feature_id should skip the descriptor gracefully.

Feature identifiers

The following table lists the registered feature_id values.