Description #

The video subtitle translation operator supports extracting subtitles from videos and translating them into multiple languages. Users can choose to recognize embedded subtitles in the video using OCR, or extract audio subtitles using ASR, then refine and translate the recognized subtitles, and output subtitle files in various formats.

Limitations #

• The input video must be accessible by the service and supports http/https and tos://.
• Video duration limit: minimum 10 seconds, maximum 4 hours.
• Supported input video formats: mp4, mov, avi, mkv, flv, webm.
• Supported output subtitle formats: .txt, .srt, .xml, .vtt.

Key features #

• Dual subtitle sources: Supports two methods—recognizing embedded subtitles in the video using OCR and extracting audio subtitles using ASR.
• Multiple accuracy levels: Each subtitle source supports both low and high accuracy configurations to meet different scenario requirements.
• Multilingual translation: Supports subtitle translation in 25 languages, including Chinese, English, Japanese, Korean, French, German, Spanish, and more.
• Multi-format output: Supports simultaneous output of subtitle files in multiple formats.
• Bilingual subtitle recognition: The OCR mode supports recognition of translation-type bilingual subtitles and dialogue-type bilingual subtitles.

Applicable scenarios #

• Video globalization: Enables video communication across different countries, covering short dramas, animation, movies, e-commerce videos, and many other fields.
• Education industry: Translates professional videos and adapts to videos with different accents, expression habits, and complex technical terms.

Advantages #

• Comprehensiveness: Provides diversified subtitle generation methods. For scenarios where there are no subtitles in the video, subtitles can also be generated from audio.
• Accuracy: Offers higher subtitle extraction accuracy, especially in educational scenarios with complex technical terms and strong accent phenomena; provides higher translation accuracy for videos with accents.
• Cost-effective: Offers multiple modes to choose from, providing the most cost-effective solutions for different scenarios.

Description of subtitle sources #

Supported languages #

The following languages are supported for audio recognition and subtitle translation:

Performance description #

• Total processing time is mainly affected by video duration, subtitle source type, number of output languages, and number of subtitle formats.
• Processing time for OCR mode is proportional to video duration and mode accuracy.
• ASR high-accuracy mode requires longer processing time due to refined subtitle editing based on video understanding.
• Translation time is proportional to the number of subtitle lines and the number of output languages.

• Billing standards

  Breakdown	Description of billing standards
  Billing item	Billing is based on the input video duration, and includes two billing items: subtitle recognition fee and subtitle translation fee. The total amount payable is the sum of all billing items.
  Billing type	Pay-as-you-go, unit: CNY/minute, billed hourly based on actual usage.
  Unit price	The unit price for each billing item is tiered based on the input length when calling the model. The unit price varies depending on the input length tier. Video subtitle recognition: The cost for intelligently recognizing subtitles from the input video. The unit price depends on the subtitle source method used. Video subtitle translation: The unit price is fixed, but the total cost also depends on the number of target languages. When using the operator for subtitle translation, if translation into multiple languages is required, a subtitle translation fee will be incurred for each language.

• Billing details
  Billing formula:

  Total Cost = Subtitle Recognition Cost + Subtitle Translate Cost
             = (Subtitle Recognition Unit Price × Input Video Duration)
                   + 
               (Subtitle Translate Unit Price × Input Video Duration × Number of languages to be translated)
  

  Billing item	Unit price
  Subtitle recognition	Video subtitle source method - OCR low accuracy: 0.15 CNY/minute
  	Video subtitle source method - OCR high accuracy: 0.25 CNY/minute
  	Video subtitle source method - ASR low accuracy: 0.015 CNY/minute
  	Video subtitle source method - ASR high accuracy: 1.5 CNY/minute
  Subtitle translation	Fixed unit price: 0.1 CNY/minute/item

• Billing example

  • Example scenario: Input a 5-minute Chinese video, select OCR high accuracy as the subtitle source method, and translate the video subtitles into English and Japanese.
  • Cost details:
    Total cost = 0.25 CNY/minute * 5 minutes + 0.1 CNY/minute/item * 5 minutes * 2 items = 2.25 CNY

Submit #

Interface description #

Invoke the video subtitle translation operator to submit asynchronous tasks, supporting subtitle extraction, translation, and multi-format output.

Request parameters #

Response parameters #

Examples #

Request example

curl --location "https://operator.las.ap-southeast-1.volces.com/api/v1/submit" --header "Content-Type: application/json" --header "Authorization: Bearer $LAS_API_KEY" --data '{
    "operator_id": "las_video_subtitle_translate",
    "operator_version": "v1",
    "data": {
        "video_url": "https://example.com/sample_video.mp4",
        "caption_source": "ocr_high_precision",
        "output_language": ["en-US"],
        "caption_format": [".srt"]
    }
}'

Response example

{
    "metadata": {
        "task_id": "task-20260323153012-abc123",
        "task_status": "PENDING",
        "business_code": "0",
        "error_msg": ""
    }
}

Error codes

Poll #

Interface description #

Query the execution status and results of video subtitle translation tasks.

Request parameters #

Response parameters #

Examples #

Request example

curl --location "https://operator.las.ap-southeast-1.volces.com/api/v1/poll" --header "Content-Type: application/json" --header "Authorization: Bearer $LAS_API_KEY" --data '{
    "operator_id": "las_video_subtitle_translate",
    "operator_version": "v1",
    "task_id": "task-20260323153012-abc123"
}'

Response example

{
    "metadata": {
        "task_id": "task-20260323153012-abc123",
        "task_status": "COMPLETED",
        "submit_time": "2026-07-21T16:04:06+08:00",
        "end_time": "2026-07-21T16:04:06+08:00",
        "business_code": "0",
        "error_msg": ""
    },
    "data": {
        "video_url": "https://example.com/sample_video.mp4",
        "video_duration": 98.4,
        "final_captions": [
            {
                "tos_path": "tos://bucket/captions/20260323/account/trace/en-US_caption_xxx.srt",
                "presigned_url": "https://...",
                "language": "en-US",
                "format": "srt"
            }
        ]
    }
}

Error codes