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Virtual Linear Playlists and Smartstart

Use a virtual linear playlist to simulate a linear stream experience that allows viewers to stream one or more asset(s) in sequence.

Which solution should I use to stream VOD assets?

Use one of the following solutions to allow your viewers to stream VOD assets:

  • Smartstart: Use Smartstart to generate a virtual linear experience for a single asset.

  • Virtual Linear Playlist: Use a standard virtual linear playlist to generate a virtual linear experience for multiple assets.

  • Comma-Delimited VOD Playback URL: List all of the desired assets within a playback URL.

  • Live Channel: Schedule VOD assets within a live channel.

Advantages

A virtual linear playlist provides the following advantages over a comma-delimited VOD playback URL:

  • Faster player load times
  • Higher monetization

How does a virtual linear playlist provide better performance?

  • Comma-Delimited VOD Playback URL: A standard VOD playback session requests ads and inserts them into the manifest upon initiating playback. Playback will not start until the manifest is finalized. The amount of latency that this causes varies according to the number of assets in the comma-delimited VOD playback URL and their duration.

  • Virtual Linear Playlist: A virtual linear playlist requests ads and inserts them into the manifest when a playback session approaches an ad break. This eliminates or reduces ad request timeouts, stale ads, and the unnecessary depletion of ad inventory.

Smartstart

Smartstart provides a virtual linear experience for a single asset through the use of a virtual linear playlist that only contains that asset.

What are the differences between Smartstart and a standard virtual linear playlist?

Smartstart, which is a specialized version of a virtual linear playlist, provides an efficient method for creating a virtual linear experience for a single asset. Additionally, it creates a virtual linear playlist whose ID matches the asset it contains. This simplifies playback setup by allowing you to leverage asset IDs when generating playback URLs for Smartstart-enabled assets.

Virtual Linear Playlist Management

Use virtual linear playlists to provide a virtual linear experience for one or more asset(s). View and manage your virtual linear playlists from the Playlists page.

Key Information

  • A virtual linear playlist's Require a token for playback option determines whether playback requires a digital signature.

  • The enforcement of Studio DRM is determined by the manner in which the Require studio approved DRM for playback option is configured on:

    • The virtual linear playlist

    • Each asset associated with the desired virtual linear playlist

      Disable Studio DRM protection for the entire virtual linear playlist viewing experience through the following steps:

      1. Disable the desired virtual linear playlist's Require studio approved DRM for playback option.
      2. Add the following query string parameter to the playback URL: `drm_optional=1'

  • Restrict a virtual linear playlist to assets that have been encoded with the same codec (i.e., AVC or HEVC).

  • A virtual linear playlist supports the following types of ads:

    • Pre-roll ads: Add the following query string parameter to the playback URL: ad.preroll=1

    • Post-roll ads: Add the following query string parameter to the playback URL: ad.postroll=1

    • Ads between assets: You may insert ad placeholders within your virtual linear playlist by adding ad breaks.

      <Info>Adding an ad break will automatically append it to your virtual linear playlist. Drag the ad break's icon <Image inline src="/images/uplynk/drag-icon.png" alt="Revert" /> to the desired position.</Info>

<Info>Alternatively, you add ad breaks through the [Virtual Linear Playlist API](https://docs.uplynk.com/reference/virtual-linear-playlist) by defining the ad dictionary between the desired assets.</Info>

    • Embedded ads: Determine whether an asset's ad breaks will be honored and their duration through the Embedded Ad Break Duration option.

  • Playback URLs are provided on the desired playlist's Playback tab.

  • Preview playback by clicking the preview player that appears on the right-hand side of the window. By default, this preview player displays the playlist's poster image.

Create a Virtual Linear Playlist

  1. Navigate to the Playlists page: From the main menu, navigate to Content > Playlists.

  2. Click + Create Playlist.

  3. In the Playlist Name option, assign a name to the new playlist.

  4. Click Create & Edit.

  5. Perform the following steps to determine how ads embedded within assets will behave:

    • Enable: Set the Embedded Ad Break Duration option to the durations, in seconds, for each ad break within an asset.

    • Disable: Set the Embedded Ad Break Duration option to 0.

  6. Verify that the Active option is set to Yes.

  7. Use the Repeat option to determine whether the playlist will repeat when a viewer reaches the end of the playlist. Enabling this option will cause it to repeat indefinitely.

  8. Click Save Playlist.

  9. Click the Entries tab.

  10. Add assets to the playlist by performing these steps:

  • Click + Assets.

  • Find the desired asset and then mark the checkbox that appears directly to the left of it.

  • Repeat the previous step as needed.

  • Click Add to Playlist.

  1. Add ad breaks to the playlist by performing the following steps:

    • Click + Ad Break.
    • From the Duration (seconds) option, indicate the duration, in seconds, of the ad break.
    • Click Add. The ad break will be appended to your playlist.
    • Reposition the ad break by dragging the move icon Revert to the desired position in the playlist.
    • Repeat Step 12 as needed.

  2. Click Save Playlist.

Duplicate a Virtual Linear Playlist

This feature allows you to copy an existing playlist's entries and settings while leaving the original playlist unchanged.

  1. Navigate to the Playlists page: From the main menu, navigate to Content > Playlists.

  2. Click the row of the playlist.

  3. Select Duplicate from the top right corner.

  4. Enter a name for the new playlist.

  5. Click Duplicate.

  6. Optional. If you selected the Edit after duplicate option, make your changes to the playlist.

  7. Click Save.

Modify a Virtual Linear Playlist

  1. Navigate to the Playlists page: From the main menu, navigate to Content > Playlists.

  2. Click on the desired playlist.

  3. Perform one of the following actions:

    • Add one or more asset(s) to the playlist.
    • Remove one or more asset(s) or ad break(s) from the playlist.
    • Update an ad break's duration.
    • Modify how ads embedded within assets will behave.

  4. Enable or disable a playlist through the Active option, which can be found on the Details tab.

  5. Determine whether the playlist will repeat when a viewer reaches the end of the playlist through the Repeat option.

Add Assets to Playlist

  1. Click the Entries tab.

  2. Click + Assets.

  3. Find the desired asset and then mark the checkbox that appears directly to the left of it.

  4. Repeat the previous step as needed.

  5. Click Add to Playlist.

  6. Click Save Playlist.

Remove Assets from Playlist

  1. Click the Entries tab.
  2. Mark the checkbox next to each desired asset or ad break.
  3. Click Remove.
  4. Click Save Playlist.

Update an Ad Break's Duration

  1. Click the Entries tab.
  2. Mark the checkbox next to the desired ad break.
  3. Click Remove.
  4. Click + Ad Break.
  5. From the Duration (seconds) option, indicate the duration, in seconds, of the ad break.
  6. Click Add. The ad break will be appended to your playlist.
  7. Reposition the ad break by dragging the Revert icon to the desired position in the playlist.
  8. Click Save Playlist.

Modify Behavior of Ads Embedded in Assets

  • Enable: From the Details tab, set the Embedded Ad Break Duration option to the durations, in seconds, for each ad break within an asset.

  • Disable: From the Details tab, set the Embedded Ad Break Duration option to 0.

Delete a Virtual Linear Playlist

  1. Navigate to the Playlists page: From the main menu, navigate to Content > Playlists.
  2. Click on the desired playlist.
  3. Click Delete Playlist from the bottom right corner.
  4. When prompted, confirm deletion by clicking Delete.

Virtual Linear Experience

Simulate a more authentic virtual linear experience by implementing the following components:

  • Timeline - Set up a timeline by including timeline metadata through the dmm.schemas.top query string parameter and then using this metadata to construct the timeline within your player.
  • Seeking - Use the plts (i.e., playlist timestamp) query string parameter within the playback URL to seek to a specified position in the playlist.

Timeline

Implement a timeline within your player by leveraging content duration and ad break location information provided within a timeline Dynamic Manifest Marker. A Dynamic Manifest Marker dynamically provides different types of metadata (e.g., timeline and ad break information) within the manifest file.

Add a Timeline Dynamic Manifest Marker

To add a timeline Dynamic Manifest Marker to the top of a manifest file, include the following query string parameters in the playback URL:

&dmm.schemas.top=timeline&pltl=1

Sample playback request:

https://content.uplynk.com/playlist/10c5467d77c54dc4b739db2cd832143a.mpd?dmm.schemas.top=timeline&pltl=1

Sample playback request (Smartstart):
https://content.uplynk.com/playlist/12d5e67d77c54dc4b739fb2cd835944c.mpd?dmm.schemas.top=timeline

Sample representations of timeline metadata for HLS and DASH are provided below.

  • HLS version 7 and up - A timeline Dynamic Manifest Marker is added as an #EXT-X-DATERANGE tag at the top of a ray manifest file. The X-DATA attribute contains Base64-encoded timeline metadata.

    Example:

    #EXT-X-DATERANGE:ID="2e64fcbc2c5d4eecbf5fc6bb4c8b2d60:2020-12-18 02:09:28.957000+00:00:playlist",

START-DATE="1970-01-01T00:00:00+00:00",

DURATION=60.3093,

CLASS="urn:uplynk:top-data:playlist:v1",

X-DATA="eyJicmVha3...VwZWF0IjotMX0="

  • DASH - A timeline Dynamic Manifest Marker is added as an EventStream tag at the top of a manifest file.

    Example:

    <EventStream schemeIdUri="urn:uplynk:top-data:timeline" timescale="90000" value="top-data">

<Event duration="5877840" id="5877840" presentationTime="0">{"repeat": -1, "content_duration": 60.3093, "breaks_count": 4, "session_id": "d9cab2afee494db7a0a5b877727ef387", "breaks": [{"id": 1, "offset": 11.0080}, {"id": 2, "offset": 26.0000}, {"id": 3, "offset": 33.0026}, {"id": 4, "offset": 52.0053}]}</Event>

</EventStream>

Sample timeline metadata:

{
	'repeat': -1,
	'content_duration': 60.3093,
	'breaks_count': 4,
	'session_id': 'd9cab2afee494db7a0a5b877727ef387',
	'breaks': [{
			'id': 1,
			'offset': 11.0080
		}, {
			'id': 2,
			'offset': 26.0000
		}, {
			'id': 3,
			'offset': 33.0026
		}, {
			'id': 4,
			'offset': 52.0053
		}
	]
}

Ad Break Dynamic Manifest Markers

A virtual linear playlist allows the player to fetch ads as playback approaches an ad break. Leverage ad break Dynamic Manifest Markers to provide metadata about requested ads.

Add ad break Dynamic Manifest Markers to the manifest file by including the following query string parameter in the playback URL:
&dmm.schemas.breaks=break_info

Sample playback request:
https://content.uplynk.com/playlist/10c5467d77c54dc4b739db2cd832143a.mpd?dmm.schema.breaks=break_info

An ad break Dynamic Manifest Marker may include the following information:

  • Requested ad break duration
  • Actual ad break duration
  • Total duration for all ads
  • Number of ads in the ad break
  • Actual ad break duration status
  • Duration of the current ad
  • Position of the current ad within the ad break
  • Offset, in seconds, of the current ad within the ad break
  • Ad slate
  • Whether ad break information has been received from the ad server and processed

Sample representations of this metadata for HLS and DASH are provided below.

  • HLS Version 7 and Up - An ad break Dynamic Manifest Marker is added as an #EXT-X-DATERANGE tag within a manifest file. The X-DATA attribute contains Base64-encoded ad break metadata. The daterange class for this data is: urn:uplynk:ad-data:break_info

  • DASH - An ad break Dynamic Manifest Marker is reported within an event stream with the following schemeIdUri:
    urn:uplynk:break_info:ad-data

Check the dmm_data_not_ready property to find out whether actual ad break duration is known.

Example (unknown actual ad break duration):

The following sample data indicates that actual ad break duration has not yet been determined:

{
	'break_dur_req': 180.00,
	'break_dur_act': -1,
	'ad_dur': 10010.02,
	'num_ads': 3,
	'ad_slate': 0,
	'dmm_data_not_ready': 1
}

Example (known actual ad break duration):
The following sample data indicates that actual ad break duration exceeded the requested ad break duration by 5.68 seconds:

{
	'break_dur_req': 180.00,
	'break_dur_act': 185.68,
	'ad_dur': 10010.02,
	'num_ads': 3,
	'ad_slate': 0,
	'dmm_data_not_ready': 0
}

Seeking

Define the plts query string parameter within the playback URL to seek to a specific position within the playlist. This seek position is measured from the start of the playlist in seconds.

Sample playback URL:
The following sample playback URL seeks 2 minutes from the start of the playlist:

https://content.uplynk.com/playlist/2e64fcbc2c5d4eecbf5fc6bb4c8b2d60.m3u8?plts=120

Key information:

  • Only content counts towards seek times. Specifically, ad breaks are excluded from this calculation.
  • The plts query string parameter is exempt from digital signatures.

Updated 15 days ago