Subtitle removal

Prerequisites

• To use the subtitle removal node in a workflow, you must enable ApsaraVideo VOD and Intelligent Media Services (IMS) and subscribe to the standard edition. For more information, see subscription-based billing.

Benefits

Two versions of subtitle removal are available:

• Advanced (Recommended): Seamlessly removes subtitles and resolves mosaic and shadow artifacts for a more natural-looking video. To enable this version, use the ModelId parameter. For more information, see ModelId parameter.

• The advanced version uses a superior algorithm, but it processes videos more slowly and costs more than the basic version. Choose the version that best fits your business needs.

Billing

Subtitle removal in ApsaraVideo VOD workflows is powered by Intelligent Media Services (IMS). You must purchase an IMS subscription service and pay usage fees. For more information, see Subtitle removal.

Usage

Step 1: Configure the workflow

You can create workflows only in the ApsaraVideo VOD console.

1. Log on to the ApsaraVideo VOD console.

2. In the left-side navigation pane, choose Configuration Management > Media Processing > Workflows.

3. Click Add Workflow Template and enter a name for the workflow.

4. On the workflow editor page, click the + icon to the right of the Start node to add a subtitle removal node.

5. Configure the following parameters in the right-side panel:

   • Node Name: Enter a custom name for the subtitle removal node.

   • Sample Material: A sample video used to configure subtitle settings. This video is not processed by the workflow. Supported formats are MP4, WebM, MOV, and M3U8.

   • Recognition Area: The default area is the bottom 1/4 of the video. You can also manually select an area.

   • Algorithm Version: Two versions are available: Basic and Advanced.

     • Advanced (Recommended): Seamlessly removes subtitles across multiple time ranges and resolves mosaic and shadow artifacts for a more natural-looking result. To enable this version, set the ModelId parameter. For more information, see ModelId parameter.

     • Basic: The output may contain mosaic or shadow artifacts, and the restoration quality is average.

   • Time Range: You can specify a custom start time and end time.

     Note

     • You must specify the start and end times as a pair.

     • The start time cannot be later than the end time.

     • If you do not specify a time range, the entire video is processed by default.

     • The advanced version supports up to five time ranges, while the basic version supports only one.

6. After you finish the configuration, click OK. The system generates a workflow ID. Record this ID for use when uploading videos. The new Subtitle Removal workflow template appears in the template list on the Workflow Management page with a status of Enabled. In the Actions column, you can click Details to view the configuration or Disable to disable the template.

Step 2: Trigger the workflow

You can trigger this workflow during or after video upload.

Step 3: Query results

{
  "RequestId": "****20b48fb04483915d4f2cd8ac****",
  "JobId": "****20b48fb04483915d4f2cd8ac****",
  "FunctionName": "VideoDetext",
  "Input": {
    "Type": "OSS",
    "Media": "oss://example-bucket/input.mp4"
  },
  "Output": {
    "Type": "OSS",
    "Media": "oss://example-bucket/output.mp4",
    "OutputUrl": "http://example-bucket.oss-cn-shanghai.aliyuncs.com/output.mp4"
  },
  "Status": "Success",
  "CreateTime": "2024-09-24T06:17:09Z",
  "FinishTime": "2024-09-24T06:17:31Z",
  "OutputFiles": ["output.mp4"],
  "OutputUrls": ["http://example-bucket.oss-cn-shanghai.aliyuncs.com/output.mp4"],
  "Result": {}
}