Subtool

Subtool is a command line utility for editing subtitle files (.srt only for now). It provides functionalities to clean up descriptive subtitles, analyze and remove unwant subtitles, and translate subtitles (via Deepl API only for now).

Story

I am a big fan of JAV, unfortuantely, I does not know much about Japanese, so I have to rely on subtitles to understand the story. However, I found recent ASR (speech to text) AI is good enough to help me. I have tested Google Cloud speech to text, and OpenAI's Whisper, GCP is better than Whisper, but it more expensive, $1 per hours and I can run Whisper locally with Macbook or use cheap whiisper provinder ($0.1 per hour). My workflow is pretty easy:

Firstly, extract audio from video with ffmpeg:

ffmpeg -i <video> -vn -y <name>.mp3

Then use ASR to generate srt file. For Whisper, generate SRT is good enough, but for GCP, need to enableWordTimeOffsets, enableAutomaticPunctuation and use WordInfo to generate srt file.

then use subtool to clean up the subtitle file, in order:

1. remove descriptive subtitles: usually useless
2. analyze repeat: some lines are repeated, it is usually useless
3. translate to languge I want

Installation

First, ensure that Go is installed on your system.

Install binary

go install github.com/charleshuang3/subtool

From Source

Clone the repository and use go build to build the tool:

git clone https://github.com/charleshuang3/subtool
cd subtool
go build

Usage

Subtool provides several commands with different functionalities:

Remove Descriptive Subtitles

Removes descriptive subtitles (e.g., sound effects):

./subtool remove-descriptive-subtitle -i <input_file>

Analyze Repeat

Analyzes subtitle files to identify repeated lines:

./subtool analyze-repeat -i <input_file>

Remove Unwanted Subtitles

Removes subtitles considered unwant based on a file contains unwanted sub, you can use analyze-repeat's output, 1 per line:

./subtool remove-unwant -i <input_file> --unwant <unwant_file>

Translate Subtitles via Deepl

Translates the subtitles using the Deepl API:

./subtool translate -i <input_file> [--deepl-key <deepl_key_file>]