Introduction

This wiki explains the design and implementation of the enable transcriptions for video content.

SB-26446: Enable transcripts for video contentClosed

Key Design Problems:

How to store transcripts files in the system.
Support configuration for transcript file types.
Relation between transcripts files & content.

Solution:

We want to create transcript files as assets in our system. For that, we want to create a new asset primaryCategory with mime-types which are supported to create transcript files.

primary category: Video Transcript

tragetObjectType: Asset

mimeType Supported: application/x-subrip

Currently, we are supporting only a single mimeType. in future, if we want to support multiple mimeType just need to update the primary category definition.

{
  "objectCategoryDefinition": {
    "categoryId": "obj-cat:video-transcript",
    "targetObjectType": "Asset",
    "objectMetadata": {
      "config": {},
      "schema": {
        "properties": {
          "mimeType": {
            "type": "string",
            "enum": [
              "application/x-subrip"
            ],
            "default": "application/x-subrip"
          }
        }
      }
    }
  }
}

We are introducing new metadata property transcripts in the content object. this property will have a list of transcripts files uploaded by users for specific content.

Schema changes:

{
  "transcripts": {
    "type": "array",
    "items": {
      "type": "object"
    }
  }
}

Sample: List of transcripts files uploaded by users for specific content

{
    "result": {
        "content": {
            "identifier": "do_12345678",
            "name": "Video Content",
            "author": "N118",,
            "transcripts": [
                {
                    "language": "English",
                    "languageCode": "en",
                    "identifier": "do_1234",
                    "artifactUrl": "https://dockstorage.blob.core.windows.net/sunbird-content-dock/content/do_11340589048704204811789/artifact/do_11340589048704204811789_1636461247932_sample.srt"
                },
                {
                    "language": "Hindi",
                    "languageCode": "hi",
                    "identifier": "do_5678",
                    "artifactUrl": "https://dockstorage.blob.core.windows.net/sunbird-content-dock/content/do_11340589048704204811789/artifact/do_11340589048704204811789_1636461247932_sample.srt"
                },
            ]
        }
    }
}

We are not maintaining any relations between content & transcripts(assets). we are adding a list of transcripts as metadata to the content.
Transcripts property we are indexing into elastic search as an object. So it will be easy to filter contents based on transcripts language & identifier