Asset Upload Options


This guide will help you customize manual upload asset options for the Admin UI.

Opencast event media packages reference several different types of assets. These may include video file tracks, metadata catalogs, image files and class handout notes. Some assets are automatically created through workflow events. Others need to be manually attached to the mediapackage. An example of automatically created assets are navigation slides. An example of a manually attached assets are handout notes.

This guide describes how to customize the Admin UI to support new asset upload options.

Default Setup

Out of the box, Opencast provides preconfigured asset and source upload configuration. The configuration is a listprovider properties file:


Two source types are enabled by default for use in the Admin UI.

   "id":"track_presenter", "type":"track", "flavorType":"presenter",
   "flavorSubType":"source", "multiple":false, "displayOrder": 1}

   "id":"track_presentation", "type":"track", "flavorType":"presentation",
   "flavorSubType":"source", "multiple":false, "displayOrder": 2}

Source upload options as displayed in the Admin UI Create event: assetUploadSource

Asset flavor and sub-flavor are used by default Opencast workflows. When you add new asset types, you may need to adjust workflows to process the new asset flavor.

These workflow variables are avaiable to workflows started by the create event or add asset action:

Variable Name Type Description
uploadedSearchPreview boolean true if manually uploaded preview image, false otherwise. Used to prevent image extraction overwrite in compose operation
downloadSourceflavorsExist boolean true if download-source-flavors variable exists, false otherwise. Identifies existence of download-source-flavors var for tagging
download-source-flavors comma separated list A convenience variable that lists manually uploaded asset flavors.

Example of variables in a workflow:

    <!-- Tag any optionally uploaded assets -->
      description="Tagging uploaded assets for distribution">
        <configuration key="source-flavors">${download-source-flavors}</configuration>
        <configuration key="target-tags">+engage-download</configuration>

How to Enable Preconfigured Asset Options

Catalogs and attachments can be added to new and existing events. Source tracks are uploaded as new events. Some predefined catalog and attachment examples are commented out in the properties file. You can uncomment any of these to make them upload options in the Admin UI. The workflow ng-publish-uploaded-assets will automatically distribute, publish, and archive uploaded assets on existing events.

# Attachments and catalogs upload options are for new and existing events.
# Only one file can be uploaded for each of these options, the uploaded file replaces existing elements of the same
# type and flavor in the mediapackage.
# EVENTS.EVENTS.NEW.UPLOAD_ASSET.OPTION.CAPTIONS_DFXP={"id":"catalog_captions_dfxp", "type": "catalog",
#     "flavorType": "captions", "flavorSubType": "timedtext", "displayOrder": 2}
#     "type": "attachment", "flavorType": "text", "flavorSubType": "webvtt", "displayOrder": 3}
# EVENTS.EVENTS.NEW.UPLOAD_ASSET.OPTION.CLASS_HANDOUT_NOTES={"id": "attachment_class_handout_notes",
#     "type": "attachment", "flavorType": "attachment", "flavorSubType": "notes", "displayOrder": 4}
# EVENTS.EVENTS.NEW.UPLOAD_ASSET.OPTION.SMIL={"id":"catalog_smil", "type":"catalog", "flavorType": "smil",
#      "flavorSubType": "smil", "displayOrder": 5}
#     "type":"attachment", "flavorType": "presenter","flavorSubType": "search+preview", "displayOrder": 6}

# The video source track upload options are only for new events.
# Unlike the other assets, multiple source tracks can be uploaded for a single flavor.
# The MULTIPLE_PARTS example shows how to enable choosing multiple source files for a single flavor. In this case,
# a fictional "multipart/part+source".
# EVENTS.EVENTS.NEW.SOURCE.UPLOAD.MULTIPLE_PARTS={"id": "track_parts","type":"track",
#    "flavorType": "multipart", "flavorSubType": "part+source", "multiple":true, "displayOrder": 10}
# EVENTS.EVENTS.NEW.SOURCE.UPLOAD.AUDIO_ONLY={"id": "track_audio","type":"track",
#     "flavorType": "presenter-audio", "flavorSubType": "source", "multiple":false, "displayOrder": 11}
EVENTS.EVENTS.NEW.SOURCE.UPLOAD.NON_SEGMENTABLE={"id": "track_presenter","type":"track",
     "flavorType":"presenter", "flavorSubType": "source", "multiple":false, "displayOrder": 12}
EVENTS.EVENTS.NEW.SOURCE.UPLOAD.SEGMENTABLE={"id": "track_presentation","type":"track",
     "flavorType":"presentation", "flavorSubType": "source", "multiple":false, "displayOrder": 13}

How to Upload Assets in the Admin UI

After enabling an upload option, a new navigation area becomes visible in the "Create event", called "Asset Upload". Assets can be uploaded to new events. The "Asset Upload" navigation disapears for scheduled events. Assets cannot be uploaded for scheduled events until after the scheduled event is processed. assetUpload

The manually uploaded assets appear in the Create event summary assetUploadSummary

To Upload an asset to an existing event, go into the existing event details Assets tab, and click "Add Asset >" link assetUploadExistingEvent

The option selection is the same as for Create event, execpt the "Add Asset" button automatically executes the workflow defined by EVENTS.EVENTS.NEW.UPLOAD_ASSET.WORKFLOWDEFID assetUploadExistingOptions

How to Create a New Asset Option

The following steps will assist you in creating a new asset upload option. As mentioned before, only catalog and attachments can be added to existing events. New source types can be added to new events.


  • Modify etc/listproviders/
  • Add Admin UI translation for the new asset name modules/matterhorn-admin-ui-ng/src/main/resources/public/org/opencastproject/adminui/languages/...
  • Modify your workflow from etc/workflows/...
  • Test your changes

The following steps describe how to change the properties configuration.

Step 1. Determine your new option type and processing needs

There are 3 asset upload types:

  • track is a media source such as video file
  • catalog is an XML formatted metadata file
  • attachment can be any type of file. For example jpeg, pdf, text, etc.

Tracks are usually associated with workflow processing. If you need special processing with your custom track flavors, update or create workflows to work with your new track flavor.

Attachments and Catalogs, such as smil files, can also be used for processing. If you only need to publish manually uploaded assets with a unique flavor, this is already built into the default workflows.

Step 2. Add your new option to the list configuration

You add your new asset upload configuration as a row to this file:


Copy an existing row as a template for your new asset. Retain the property key prefix EVENTS.EVENTS.NEW.SOURCE. or EVENTS.EVENTS.NEW.UPLOAD_ASSET.OPTION.

Your unique asset identifier will follow the last dot after the prefix, in all capital alphabetical characters. Underbars are allowed. CONFIGURATION values are in JSON object format.

Attribute Example Description
id track_presenter One of "attachment" or "catalog" or "track", underbar (_), unique text (no spaces)
type track One of "attachment" or "catalog" or "track" to designate asset type
flavorType presentation The primary flavor type. Used to reference asset in workflows, player, and media module
flavorSubType source The sub flavor type. Used to identify the sub flavor of this flavor type
multiple false true or false, used by the admin UI to enable single or multiple file input selection
displayOrder 32 Integer number, used by the admin UI to sort the display of upload options in the UI

The parameter key is internationalized as the display text in the admin UI ref: modules/matterhorn-admin-ui-ng/src/main/resources/public/org/opencastproject/adminui/languages/

Step 3. Add translation for the new option

The option property key is internationalized for display in the Admin UI. Add a translation for the option property when adding new option, otherwise the Admin UI will display the raw key.

The translation language files are located:



  "EVENTS": {
    "EVENTS": {
       "NEW": {
        "UPLOAD_ASSET": {
            "CAPTIONS_WEBVTT" : "Captions WebVTT",

Now you are ready to test and deploy.