+
+ +

NOTICE: This software (or technical data) was produced for the U.S. Government under contract, +and is subject to the Rights in Data-General Clause 52.227-14, Alt. IV (DEC 2007). Copyright 2025 +The MITRE Corporation. All Rights Reserved.

+

Media Selectors Overview

+

Media selectors allow users to specify that only specific sections of a document should be +processed. A copy of the input file with the specified sections replaced by component output is +produced.

+

New Job Request Fields

+

Below is an example of a job that uses media selectors. The job uses a two-stage pipeline. +The first stage performs language identification. The second performs translation.

+
{
+    "algorithmProperties": {},
+    "buildOutput": true,
+    "jobProperties": {},
+    "media": [
+        {
+            "mediaUri": "file:///opt/mpf/share/remote-media/test-json-path-translation.json",
+            "properties": {},
+            "mediaSelectorsOutputAction": "ARGOS TRANSLATION (WITH FF REGION AND NO TASK MERGING) ACTION",
+            "mediaSelectors": [
+                {
+                    "type": "JSON_PATH",
+                    "expression": "$.spanishMessages.*.content",
+                    "resultDetectionProperty": "TRANSLATION",
+                    "selectionProperties": {}
+                },
+                {
+                    "type": "JSON_PATH",
+                    "expression": "$.chineseMessages.*.content",
+                    "resultDetectionProperty": "TRANSLATION",
+                    "selectionProperties": {}
+                }
+            ]
+        }
+    ],
+    "pipelineName": "ARGOS TRANSLATION (WITH FASTTEXT LANGUAGE ID) TEXT FILE PIPELINE",
+    "priority": 4
+}
+
+
    +
  • $.media.*.mediaSelectorsOutputAction: Name of the action that produces content for the media + selectors output file. In the above example, we specify that we want the translated content + from Argos in the media selectors output file rather than the detected language from the first + stage.
    • +
  • $.media.*.mediaSelectors: List of media selectors that will be used for the media.
    • +
  • $.media.*.mediaSelectors.*.type: The name of the type of media selector + that is used in the expression field.
    • +
  • $.media.*.mediaSelectors.*.expression: A string specifying the sections of the document that + should be processed. The type field specifies the syntax of the expression.
    • +
  • $.media.*.mediaSelectors.*.resultDetectionProperty: A detection property name from tracks + produced by the mediaSelectorsOutputAction. The media selectors output document will be + populated with the content of the specified property.
    • +
  • $.media.*.mediaSelectors.*.selectionProperties: Job properties that will only be used for + sub-jobs created for a specific media selector. For example, when performing Argos translation + on a JSON file in a single-stage pipeline without an upstream language detection stage, this + could set DEFAULT_SOURCE_LANGUAGE=es for some media selectors and + DEFAULT_SOURCE_LANGUAGE=zh for others.
    • +
+

New Job Properties

+
    +
  • MEDIA_SELECTORS_DELIMETER: When not provided and a job uses media selectors, the selected parts + of the document will be replaced with the action output. When provided, the selected parts of + the document will contain the original content, followed by the value of this property, and + finally the action output.
    • +
  • MEDIA_SELECTORS_DUPLICATE_POLICY: Specifies how to handle the case where a job uses media + selectors and there are multiple outputs for a single selection. When set to LONGEST, the + longer of the two outputs is chosen and the shorter one is discarded. When set to ERROR, + duplicates are considered an error. When set to JOIN, the duplicates are combined using + | as a delimiter.
    • +
  • MEDIA_SELECTORS_NO_MATCHES_IS_ERROR: When true and a job uses media selectors, an error will be + generated when none of the selectors match content from the media.
    • +
+

Media Selector Types

+

JSON_PATH is only type currently supported, but others are planned.

+

JSON_PATH

+

Used to extract content for JSON files. Uses the "Jayway JsonPath" library to parse the expressions. +The specific syntax supported is available on their +GitHub page. JsonPath +expressions are case-sensitive.

+

When extracting content from the document, only strings, arrays, and objects are considered. All +other JSON types are ignored. When the JsonPath expression matches an array, each element is +recursively explored. When the expression matches an object, keys are left unchanged and each value +of the object is recursively explored.

+

JSON_PATH Matching Example

+
{
+    "key1": ["a", "b", "c"],
+    "key2": {
+        "key3": [
+            {
+                "key4": ["d", "e"],
+                "key5": ["f", "g"],
+                "key6": 6
+            }
+        ]
+    }
+}
+
+