# DASH ad markers
Ad markers

MediaTailor 

AWS Elemental MediaTailor uses SCTE-35 cue-out markers to identify ad avails in the DASH manifest using the following logic: 
+ **Multi-period DASH**: MediaTailor inserts ads for the first `Event` in each `Period` that contains either `SpliceInsert` or `TimeSignal` cue-out markers. MediaTailor ignores additional `Event` markers in the `Period`.
+ **Single-period DASH**: MediaTailor inserts ads each `Event` in the `Period` that contains either `SpliceInsert` or `TimeSignal` cue-out markers.

By default, AWS Elemental MediaTailor manages DASH manifests as multi-period manifests. You can change your configuration to handle single-period DASH manifests from your origin server. For information, see [Creating an MediaTailor playback configuration](configurations-create.md).

The following sections provide additional detail about DASH ad marker handling and provides decorated manifests from the origin.

## DASH origin manifest XML requirements


Ad markers in DASH manifests from the origin must be formatted properly for MediaTailor to identify ad breaks. The following topics describe these formatting requirements in clear XML.

### `SpliceInsert` in clear XML


`SpliceInsert` ad markers in clear XML must contain the following:
+ `EventStream` must have the following attribute: `schemeIdUri=urn:scte:scte35:2013:xml`
+ `Event` must hold `scte35:SpliceInfoSection` 
+ `scte35:SpliceInfoSection` must hold `scte35:SpliceInsert` 
+ `scte35:SpliceInsert` must have the following attribute: `outOfNetworkIndicator="true"`

**Example `SpliceInsert` in XML**  
In the following example, required SCTE markers are in bold.   

```
<Period start="PT444806.040S" id="123586" duration="PT15.000S">
  <EventStream timescale="90000" schemeIdUri="urn:scte:scte35:2013:xml">
    <Event duration="1350000">
      <scte35:SpliceInfoSection protocolVersion="0" ptsAdjustment="180832" tier="4095">
        <scte35:SpliceInsert spliceEventId="4026531855" spliceEventCancelIndicator="false" outOfNetworkIndicator="true" spliceImmediateFlag="false" uniqueProgramId="1" availNum="1" availsExpected="1">
            <scte35:Program><scte35:SpliceTime ptsTime="5672624400"/></scte35:Program>
            <scte35:BreakDuration autoReturn="true" duration="1350000"/>
        </scte35:SpliceInsert>
      </scte35:SpliceInfoSection>
    </Event>
  .
  .
  .
</Period>
```

### `TimeSignal` in clear XML


`TimeSignal` ad markers in clear XML must contain the following:
+ `EventStream` must have the following attribute: `schemeIdUri=urn:scte:scte35:2013:xml`
+ `Event` must hold `scte35:SpliceInfoSection`
+ `scte35:SpliceInfoSection` must hold `scte35:TimeSignal`
+ `scte35:SpliceInfoSection` must also hold `scte35:SegmentationDescriptor`
+ `scte35:SegmentationDescriptor` must have the following attribute, where the value is a valid [Cue-out numbers](#dash-signal-xml-values): `segmentationTypeId="xx"`
+ `scte35:SegmentationDescriptor` must hold `scte35:SegmentationUpid` 
<a name="dash-signal-xml-values"></a>
**Cue-out numbers**  
The following are supported cue-out numbers for the `segmentationTypeId`.


| Segmentation message | segmentationTypeId value | Hexadecimal value | 
| --- | --- | --- | 
| Distributor advertisement end | 51 | 0x51 | 
| Distributor advertisement start | 50 | 0x32 | 
| Distributor placement opportunity end | 55 | 0x37 | 
| Distributor placement opportunity start | 54 | 0x36 | 
| End break | 35 | 0x23 | 
| Provider advertisement end | 49 | 0x31 | 
| Provider advertisement start | 48 | 0x30 | 
| Provider overlay placement opportunity end | 57 | 0x39 | 
| Provider overlay placement opportunity start | 56 | 0x38 | 
| Provider placement opportunity end | 53 | 0x35 | 
| Provider placement opportunity start | 52 | 0x34 | 
| Start break | 34 | 0x22 | 

**Example `TimeSignal` in XML**  
In the following example, required SCTE markers are in bold.   

```
<Period start="PT346530.250S" id="178443" duration="PT61.561S">
  <EventStream timescale="90000" schemeIdUri="urn:scte:scte35:2013:xml">
    <Event duration="5310000">
      <scte35:SpliceInfoSection protocolVersion="0" ptsAdjustment="183003" tier="4095">
        <scte35:TimeSignal>
          <scte35:SpliceTime ptsTime="3442857000"/>
         </scte35:TimeSignal>
        <scte35:SegmentationDescriptor segmentationEventId="1414668" segmentationEventCancelIndicator="false" segmentationDuration="8100000" segmentationTypeId="52" segmentNum="0" segmentsExpected="0">
            <scte35:DeliveryRestrictions webDeliveryAllowedFlag="false" noRegionalBlackoutFlag="false" archiveAllowedFlag="false" deviceRestrictions="3"/>
            <scte35:SegmentationUpid segmentationUpidType="12" segmentationUpidLength="2">0100</scte35:SegmentationUpid>
          </scte35:SegmentationDescriptor>
        </scte35:SpliceInfoSection>
    </Event>
  .
  .
  .
</Period>
```

## DASH origin manifest base64-encoded binary requirements


Ad markers in DASH manifests from the origin must be formatted properly for MediaTailor to identify ad breaks. The following topics describe these formatting requirements in base64-encoded binary.

Both `TimeSignal` and `SpliceInsert` ad markers in base64-encoded manifests must contain the following:
+ `EventStream` must have the following attribute: `urn:scte:scte35:2014:xml+bin`
+ `Event` must hold `scte35:Signal`
+ `scte35:Signal` must hold `scte35:Binary` that contains a base64-encoded binary. 

The decoded binary must provide a `splice_info_section` with the same information as what's required for clear XML ad markers.
+ The command type must be either `splice_insert()` or `time_signal()`
+ The additional settings must comply with those described in [`TimeSignal` in clear XML](#dash-signal-xml) and [`SpliceInsert` in clear XML](#dash-splice-xml).

 The decoded binary must provide a `splice_info_section` with the same set of information as the clear XML would provide in a `scte35:SpliceInfoSection` element. The command type must be either `splice_insert()` or `time_signal()`, and the additional settings must comply with those described previously for clear XML delivery. 

The following example shows this option, with the required markers in bold.

```
<Period start="PT444806.040S" id="123586" duration="PT15.000S">
    <EventStream schemeIdUri="urn:scte:scte35:2014:xml+bin" timescale="1">
      <Event presentationTime="1541436240" duration="24" id="29">
        <scte35:Signal xmlns="http://www.scte.org/schemas/35/2016">
          <scte35:Binary>/DAhAAAAAAAAAP/wEAUAAAHAf+9/fgAg9YDAAAAAAAA25aoh</scte35:Binary>
        </scte35:Signal>
      </Event>
      <Event presentationTime="1541436360" duration="24" id="30">
        <scte35:Signal xmlns="http://www.scte.org/schemas/35/2016">
          <scte35:Binary>QW5vdGhlciB0ZXN0IHN0cmluZyBmb3IgZW5jb2RpbmcgdG8gQmFzZTY0IGVuY29kZWQgYmluYXJ5Lg==</scte35:Binary>
        </scte35:Signal>
      </Event>
  .
  .
  .
</Period>
```

The following is the decoded binary for the first event listed in the preceding example. The setting for `splice_command_type` is 5, which indicates `splice_insert`. 

```
{
        "table_id": 252,
        "section_syntax_indicator": false,
        "private_indicator": false,
        "section_length": 33,
        "protocol_version": 0,
        "encrypted_packet": false,
        "encryption_algorithm": 0,
        "pts_adjustment": 0,
        "cw_index": 0,
        "tier": "0xFFF",
        "splice_command_length": 16,
        "splice_command_type": 5,
        "splice_command": {
          "splice_event_id": 448,
          "splice_event_cancel_indicator": false,
          "out_of_network_indicator": true,
          "program_splice_flag": true,
          "duration_flag": true,
          "splice_immediate_flag": false,
          "utc_splice_time": {
            "time_specified_flag": false,
            "pts_time": null
          },
          "component_count": 0,
          "components": null,
          "break_duration": {
            "auto_return": false,
            "duration": {
              "pts_time": 2160000,
              "wall_clock_seconds": 24.0,
              "wall_clock_time": "00:00:24:00000"
            }
          },
          "unique_program_id": 49152,
          "avail_num": 0,
          "avails_expected": 0
        },
        "splice_descriptor_loop_length": 0,
        "splice_descriptors": null,
        "Scte35Exception": {
          "parse_status": "SCTE-35 cue parsing completed with 0 errors.",
          "error_messages": [],
          "table_id": 252,
          "splice_command_type": 5
        }
      }
```