Subtitle Translator AI

Translate subtitles to any language using AI. Supports OpenAI, Anthropic, Gemini, and Kimi.

Quick Start

# Clone and install
git clone https://github.com/morphaxl/subtitle-translator-ai.git
cd subtitle-translator-ai
pnpm install

# Set your API key (pick one)
export OPENAI_API_KEY=sk-...
# or ANTHROPIC_API_KEY, GEMINI_API_KEY, KIMI_API_KEY

# Translate!
pnpm run translate movie.srt --to Spanish

Features

• Multi-provider - OpenAI, Anthropic, Gemini, Kimi
• Auto-detection - Picks provider from API key automatically
• Multi-format - SRT, VTT, ASS/SSA
• Video extraction - Extract subtitles from MKV/MP4
• Batch processing - Translate multiple files at once
• Whisper support - Free local transcription (generates subtitles from audio)

---

Translation

Translate Subtitles

pnpm run translate <input> [options]

Options:
  -t, --to <lang>          Target language (default: Hindi)
  -f, --from <lang>        Source language (default: English)
  -p, --provider <name>    openai, anthropic, gemini, kimi
  -o, --output <path>      Output file path
  -b, --batch-size <n>     Subtitles per batch (default: 500)

Examples

# Translate to Turkish
pnpm run translate movie.srt --to Turkish

# Use specific provider
pnpm run translate movie.srt --to Japanese --provider anthropic

# Different source language
pnpm run translate spanish.srt --from Spanish --to English

Providers

Provider	Default Model	Pricing
OpenAI	gpt-4o-mini	Per token
Anthropic	claude-3-5-haiku	Per token
Gemini	gemini-2.0-flash	Per token
Kimi	kimi-for-coding	Per request

Set API key via environment:

export OPENAI_API_KEY=sk-...
export ANTHROPIC_API_KEY=sk-ant-...
export GEMINI_API_KEY=AIza...
export KIMI_API_KEY=sk-kimi-...

---

Extract from Video

Extract embedded subtitles from MKV/MP4/AVI:

# List subtitle streams
pnpm run extract movie.mkv --list

# Extract stream 0
pnpm run extract movie.mkv --stream 0

# Extract all streams
pnpm run extract movie.mkv --all

---

Whisper Transcription

Generate subtitles from audio/video using Whisper (runs locally, free):

# Install Whisper first
pip install -U openai-whisper

# Transcribe video to subtitles
pnpm run transcribe movie.mp4

# Use better model
pnpm run transcribe movie.mp4 --model medium

Note: Whisper can only translate to English. For other languages, transcribe first then use AI translation.

---

Complete Workflow

MKV → Translated Subtitles

# 1. Extract subtitles
pnpm run extract movie.mkv --stream 0 -o movie.srt

# 2. Translate
pnpm run translate movie.srt --to Turkish

Video Without Subtitles → Translated

# 1. Generate subtitles with Whisper
pnpm run transcribe movie.mp4

# 2. Translate
pnpm run translate movie.srt --to Hindi

---

Batch Processing

# Create config
pnpm run init

# Edit jobs.yaml, then run
pnpm run batch

jobs.yaml:

defaults:
  from: English

jobs:
  - input: movie.srt
    to: Spanish
  - input: movie.srt
    to: French
  - input: movie.srt
    to: Japanese

---

Installation

# Required
pnpm install
brew install ffmpeg  # or: apt install ffmpeg

# Optional (for Whisper transcription)
pip install -U openai-whisper

API Keys

• OpenAI: https://platform.openai.com/api-keys
• Anthropic: https://console.anthropic.com/settings/keys
• Gemini: https://aistudio.google.com/apikey
• Kimi: https://kimi.com/coding/profile

License

MIT