AWS Lambda Function for Video Transcription

This project is an AWS Lambda function that transcribes videos using OpenAI's Whisper API. The transcription results are generated as an SRT file and uploaded back to an S3 bucket.

Requirements

• AWS Lambda: Executes the function.
• OpenAI Whisper API: Processes audio transcription.
• AWS S3: Stores and retrieves files.

Supported File Formats

• MP4 (video/mp4)
• MP3 (audio/mpeg)
• WAV (audio/wav)

Setup

1. Create an AWS Lambda Function

• Create a new AWS Lambda function.
• Upload the index.mjs file as the function's source code.

2. Add Required Layers

• Include layers for AWS SDK and Axios from the project files.

3. Configure Memory and Timeout

• Increase memory allocation to 2048MB.
• Set the timeout limit to 5 minutes.

Usage

The function accepts the following parameters:

{
  "file_name": "example_video.mp4",
  "user_id": "6790a64b87c2387f93afd485",
  "words_per_line": 3, // max 5
  "punctuation": true,
  "consider_punctuation": true
}

Parameter Descriptions

• file_name: The name of the file to be processed.
• user_id: The user ID, used to determine the file path.
• words_per_line: Specifies the number of words per subtitle line.
• punctuation: Determines whether punctuation marks should be included.
• consider_punctuation: Specifies whether punctuation should be considered when generating subtitles.

Example Output

The following data represents execution time and memory usage for a 4MB video file:

START RequestId: da692ecb-b3f1-4a92-8c34-ded39595029a Version: $LATEST
2025-03-19T11:37:19.734Z	da692ecb-b3f1-4a92-8c34-ded39595029a	INFO	s3-fetch: 470.787ms
2025-03-19T11:37:22.908Z	da692ecb-b3f1-4a92-8c34-ded39595029a	INFO	whisper-api: 3.173s
2025-03-19T11:37:22.909Z	da692ecb-b3f1-4a92-8c34-ded39595029a	INFO	srt-generation: 0.909ms
2025-03-19T11:37:22.974Z	da692ecb-b3f1-4a92-8c34-ded39595029a	INFO	s3-upload: 65.06ms
2025-03-19T11:37:22.974Z	da692ecb-b3f1-4a92-8c34-ded39595029a	INFO	total-execution: 3.711s
END RequestId: da692ecb-b3f1-4a92-8c34-ded39595029a
REPORT RequestId: da692ecb-b3f1-4a92-8c34-ded39595029a	Duration: 3717.83 ms	Billed Duration: 3718 ms	Memory Size: 2048 MB	Max Memory Used: 144 MB	Init Duration: 853.54 ms	

Diagram

The project's workflow diagram is shown below: