MagicSub

AI-Powered Subtitle Translator

This script provides a simple tool for translating SRT subtitle files using the OpenAI GPT-3.5-turbo API. It supports merging short subtitle segments, ensuring translations are coherent, and processing subtitles efficiently with retry logic for API failures.

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Features

• Text Translation: Translates text from one language to another using OpenAI's GPT API.
• Subtitle Merging: Merges subtitles with short time gaps or excessive length to ensure cohesive translation.
• Error Handling: Implements retry logic for API errors, falling back to the original text after multiple failures.
• SRT Processing: Reads and parses SRT subtitle files, translates their content, and outputs the translated subtitles to a new file.

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Requirements

• Python 3.7+
• OpenAI API Key
• Installed Python packages:
  • openai
  • srt
  • asyncio
  • re

Install dependencies using pip:

pip install openai srt

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Usage

1. Setup

1. Add your OpenAI API key in the script:

   openai.api_key = "your_openai_api_key"

2. Update the paths to your input and output SRT files:

   input_srt = "path/to/your/input.srt"
   output_srt = "path/to/your/output.srt"

2. Run the Script

Run the script in your terminal:

python script_name.py

3. Output

The translated SRT file will be saved to the specified output path.

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Code Overview

1. Translation Functionality

The translate_text_async function uses OpenAI's GPT API to translate text asynchronously. The translate_text function wraps it for synchronous use.

• Parameters:
  • text: The text to translate.
  • source_language: The source language (default: Japanese "ja").
  • target_language: The target language (default: Chinese "zh").
  • max_retries: Number of retries for failed API calls (default: 3).

2. Subtitle Merging

The merge_subtitles function combines consecutive subtitles with short gaps (max_gap) or excessive combined length (max_length) to ensure better translation.

• Parameters:
  • max_gap: Maximum gap in seconds to merge subtitles (default: 2).
  • max_length: Maximum character length for combined subtitles (default: 500).

3. SRT Translation

The translate_srt function reads the input SRT file, merges and translates subtitles, and writes the result to an output SRT file.

• Parameters:
  • input_file: Path to the input SRT file.
  • output_file: Path to save the translated SRT file.

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Example

Input Subtitle (Japanese):

1
00:00:01,000 --> 00:00:04,000
こんにちは、世界！

2
00:00:05,000 --> 00:00:07,000
これはサンプル字幕です。

Output Subtitle (Chinese):

1
00:00:01,000 --> 00:00:07,000
你好，世界！这是一个示例字幕。

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Error Handling

1. API Failures: The script retries API calls up to 3 times. If all retries fail, the original text is returned.
2. File I/O Errors: Handles errors in reading/writing files gracefully.

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Notes

• The OpenAI GPT API may incur usage costs. Ensure your API key has an active quota.
• The script is optimized for translating SRT files with simple text. Complex formatting or edge cases may require adjustments.

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Feel free to clone and modify this repository for your subtitle translation needs! 😊