drc-encode

CLI tool for making movies easier to hear by adding a balanced stereo track optimized for lower-volume playback.

This project is based on the work shared by Reddit user smernt in the r/PleX thread.

The goal here is to make that workflow easier to use as a simple command-line tool.

The current processing settings are based on my personal preference. Over time, the tool will be expanded to support more variations like the ones smernt showed in that post.

This tool exists because movies with 5.1 or 7.1 audio are often difficult to use in apartments, shared homes, or while children are sleeping. Dialogue can be too quiet while music and action scenes jump out too loudly.

Requirements

• ffmpeg must be installed and available in your PATH
• macOS, Linux, or another environment that can run Bash and FFmpeg

Check that FFmpeg is installed:

ffmpeg -version

If that command fails, install FFmpeg first, then run drc_encode again.

Installation

Make the script executable:

chmod +x drc_encode

You can run it from the project directory:

./drc_encode movie.mkv

Or move it somewhere in your PATH so you can run it from anywhere:

mv drc_encode /usr/local/bin/drc_encode

Then run it like this:

drc_encode movie.mkv

Usage

Run the script directly:

./drc_encode <input-file> [language-code]

Examples:

./drc_encode movie.mkv
./drc_encode movie.mkv eng

What It Does

• Creates a new stereo AAC track from the first audio stream
• Raises quieter parts of the soundtrack and evens out volume swings so dialogue is easier to hear and loud scenes are less jarring
• Copies existing video streams
• Copies existing audio streams
• Copies existing subtitle streams
• Writes the output as <original-name>_Stereo_DRC.<ext>

If encoding succeeds:

• the original input file is deleted
• a matching .srt file is renamed to match the new output filename

Notes

• The optional language-code is written to the new DRC audio track metadata
• If no language code is provided, the new track is titled 2.0 Stereo DRC
• If a language code is provided, the new track is titled <language-code> 2.0 Stereo DRC