Submerger

Submerger is a simple tool designed to merge subtitles from two different files into a single output file. It's especially useful for language learners who want to watch content with subtitles in multiple languages simultaneously.

The tool offers two main functionalities: Direct merging of two subtitle files for quick, one-time use, and a more advanced recursive search feature that scans entire directories for subtitle files matching specific language preferences.

Features

• Merge two subtitle files into one output file.
• Customize subtitle color and position for the second subtitle track.
• Recursively search directories for subtitle files to merge based on language markers.
• Supports both .srt and .vtt subtitle formats for inputs, only outputs .srt however.

Installation

Cargo

Installation

To install using cargo:

cargo install submerger

Building

One way to build this project is using Rust.

Note: You must build using rust nightly!

Clone the repository:

git clone https://github.com/rasmus-kirk/submerger.git
cd submerger

Build the project:

cargo build --release

Nix

Note: Nix flakes must be enabled!

Installation

nix profile install github:rasmus-kirk/submerger

Building

This project has a nix flake, so it can be built using nix:

nix build github:rasmus-kirk/submerger

Running

If you just wish to run the program using nix:

nix run github:rasmus-kirk/submerger -- --help

Developement Shell

To enter a developement shell with the correct rust-toolchain and rust analyzer using nix:

nix develop github:rasmus-kirk/submerger

If you use a shell other than bash:

nix develop github:rasmus-kirk/submerger -c $SHELL

Usage

You can either merge two files directly or recursively search a directory for matching subtitle pairs.

1. Merging Two Subtitle Files

Merge two subtitle files into a single output:

submerger simple [OPTIONS] <SUB1> <SUB2> <OUT>

Required:

• <SUB1>: Path to the first subtitle file
• <SUB2>: Path to the first subtitle file
• <OUT>: Output file where the merged subtitles will be saved

Optional:

• --color <COLOR> Sets the color for the second subtitle track
• --position <POSITION> Sets the position of the second subtitle track (default: top-center)
• --log-level <LOG_LEVEL> Sets the level of logging [default: warn] [possible values: error, warn, info, debug, trace]
• --help Print help

Example

submerger simple movie.en.srt movie.ja.srt merged.srt --color "#fbf1c7" --position top-center

2. Recursive Subtitle Merging

Search a directory for subtitle files matching given language codes and merge them:

submerger recursive [OPTIONS] <SUB1_LANG> <SUB2_LANG> <PATH>

Required:

• <SUB1_LANG>: Language code for the first subtitle file (e.g., en for English)
• <SUB2_LANG>: Language code for the second subtitle file (e.g., ja for Japanese)
• <PATH>: Root directory to recursively search for subtitle files

Optional:

• --out-ext <OUT_EXT>: The file extension for the output file (e.g. file.en.srt -> file.merged.srt if set to merged.srt) (Default: srt)
• --vtt: Also match and convert VTT files. Note, this will not output VTT files, only SRT is supported as output (Default: true)
• --color <COLOR>: Sets the color for the second subtitle track
• --position <POSITION>: Sets the position of the second subtitle track (Default: top-center)
• --log-level <LOG_LEVEL>: Sets the level of logging (Default: warn)

How it works

• The program reads both subtitle files and assigns different positions and colors to the second subtitle track (if configured).
• When merging recursively, the program looks for matching subtitle files based on the provided language codes (e.g., en, ja).
• If hearing-impaired subtitles are found (e.g., en.hi), they will be preferred only if normal subtitles (en) aren't available.
• The merged subtitle output file will contain both sets of subtitles and be written as ORIGINAL_FILE_NAME.OUT_EXTENSION$ in the directory where the matching subs were found.

Example

submerger recursive en ja ./movies --color "#fbf1c7" --position top-center

License

This project is licensed under the MIT License. See the LICENSE file for details.