Intelligent Media Management:Video subtitle extraction

Scenarios

• Multi-language support: Extract subtitles from a video so you can produce multi-language versions, making your content accessible to audiences in different languages.

• Translation and localization: Once subtitles are extracted, translators can work directly with the text to create localized versions that match the cultural and linguistic conventions of a target region.

• Dubbing and speech recognition: Extracted subtitle text provides a script for voice actors to record dubbed audio. It can also serve as training data for speech recognition models.

• Video editing and production: Video editors can extract, review, and refine subtitle text to improve accuracy and readability before publishing the final product.

Supported subtitle types

Step 1: Upload a file

Upload a media file to an OSS bucket that resides in the same region as your IMM project. You can use the OSS console to upload the file.

Step 2: Extract subtitles from the video

Call the CreateMediaConvertTask operation to create a subtitle extraction task.

The extraction process works in four phases:

1. Subtitle format identification: The system identifies the subtitle formats present in the video file, including SubRip Subtitle (SRT), Advanced SubStation Alpha (ASS), Web Video Text Tracks (WebVTT), and embedded subtitle stream formats.

2. Subtitle data extraction: The system extracts subtitle text along with its associated timestamps from the video file. This phase captures all subtitle content, including speaker names, timestamps, and time format information.

3. Text processing: The system performs any necessary processing on the extracted subtitle text. During this phase, redundant information may be removed, formats adjusted, languages translated, and spelling and grammar checked.

4. Output and saving: The processed subtitles are saved in the specified output format (such as SRT or ASS) at the designated OSS location, ready for downstream use, editing, or upload to video platforms.

Extract all subtitles and convert to WebVTT format

• Subtitle format: WebVTT

• Output path: oss://test-bucket/video-demo/subtitle-%d.vtt

• Completion notification: A Simple Message Queue (formerly MNS) message sent to a topic named test-mns-topic

For the sample SDK code, go to OpenAPI Explorer. The parameters in the example are pre-configured in OpenAPI Explorer. Modify them as needed before running the code.

Request parameters

{
  "ProjectName": "test-project",
  "Notification": {
    "MNS": {
      "TopicName": "test-mns-topic"
    }
  },
  "Sources": [
    {
      "URI": "oss://test-bucket/video-demo/test.mp4"
    }
  ],
  "Targets": [
    {
      "Subtitle": {
        "ExtractSubtitle": {
          "Format": "webvtt",
          "URI": "oss://test-bucket/video-demo/subtitle-{streamindex}.{autoext}"
        }
      }
    }
  ]
}

Extract all subtitles and convert to SRT format

• Subtitle format: SRT

• Output path: oss://test-bucket/video-demo/subtitle-%d.srt

• Completion notification: A Simple Message Queue (formerly MNS) message sent to a topic named test-mns-topic

For the sample SDK code, go to OpenAPI Explorer. The parameters in the example are pre-configured in OpenAPI Explorer. Modify them as needed before running the code.

Request parameters

{
  "ProjectName": "test-project",
  "Notification": {
    "MNS": {
      "TopicName": "test-mns-topic"
    }
  },
  "Sources": [
    {
      "URI": "oss://test-bucket/video-demo/test.mp4"
    }
  ],
  "Targets": [
    {
      "Subtitle": {
        "ExtractSubtitle": {
          "Format": "srt",
          "URI": "oss://test-bucket/video-demo/subtitle-{streamindex}.{autoext}"
        }
      }
    }
  ]
}

IMM billable items

For detailed pricing, see IMM billable items.

OSS billable items

For detailed pricing, see OSS Pricing