MKV repacker for ffmpeg docker

repack.sh

#!/bin/bash

# Function to display usage information
usage() {
    echo "Usage: $0 [--extension <file_extension>] --audio <audio_directory> --subtitle <subtitle_directory> <source_directory> <destination_root_directory>"
    exit 1
}

# Function to check write permission
check_write_permission() {
    local directory="$1"
    if [ ! -w "$directory" ]; then
        echo "Error: Destination directory '$directory' is not writable."
        exit 1
    fi
}

# Default extension if not provided
extension=".mkv"

# Parse command line options
while [[ $# -gt 0 ]]; do
    case "$1" in
        --extension)
            shift
            extension=".$1"
            shift
            ;;
        --audio)
            shift
            audio_directory="$1"
            shift
            ;;
        --subtitle)
            shift
            subtitle_directory="$1"
            shift
            ;;
        *)
            break
            ;;
    esac
done

# Check if all required options are provided
if [[ -z $audio_directory || -z $subtitle_directory || "$#" -ne 2 ]]; then
    usage
fi

# Source directory containing the files
source_directory="$1"

# Destination directory for processed files
destination_directory="$2"

# Check if destination directory is writable
check_write_permission "$destination_directory"

# Get the permissions of the parent directory
parent_permissions=$(stat -c "%a" "$destination_directory")

# Get the last part of the source directory name
source_dir_name=$(basename -- "$source_directory")

# Check if the destination directory contains the last part of the source directory name
if [[ ! "$destination_directory" == *"$source_dir_name"* ]]; then
    destination_directory="$destination_directory/$source_dir_name"
fi

# Create destination directory if it doesn't exist
mkdir -m "$parent_permissions" -p "$destination_directory"

# Function to auto-detect file extension in a directory
detect_extension() {
    local directory="$1"
    local extension=""

    # Loop through each file in the directory
    for file in "$directory"/*; do
        # Check if file exists and is a regular file
        if [ -f "$file" ]; then
            # Extract file extension, as all after FIRST dot
            extension=$(basename "$file" | cut -d. -f2-)
            # Check if extension is not empty
            if [ -n "$extension" ]; then
                break  # Exit loop once first non-empty extension is found
            fi
        fi
    done

    echo ".$extension"
}

# Detect extensions for audio and subtitle directories
audio_extension=$(detect_extension "$source_directory/$audio_directory")
subtitle_extension=$(detect_extension "$source_directory/$subtitle_directory")

# Loop through each file in the source directory with the specified extension
for file in "$source_directory"/*"$extension"; do
    # Check if file exists
    if [ -f "$file" ]; then
        # Extract filename without extension
        filename=$(basename -- "$file")
        filename_no_ext="${filename%.*}"

        # Your ffmpeg command using the current file
        ffmpeg -i "$file"\
            -i "$source_directory/$audio_directory/$filename_no_ext$audio_extension"\
            -i "$source_directory/$subtitle_directory/$filename_no_ext$subtitle_extension"\
            -map 0:v -map 0:a -map 1:a -map 2:s\
            -codec copy -disposition:a:0 none -disposition:a:1 default\
            "$destination_directory/$filename_no_ext$extension"
    fi
done

Usage examples -
./repack.sh --audio 'Studio Band' --subtitle SUB /data/'Ore dake Level Up na Ken' /xdata
./repack.sh --audio 'RUS Sound'/'[StudioBand]' --subtitle 'RUS Subs'/'[Wakanim]' /data/'[ReinForce] Tatoeba Last Dungeon (BDRip 1920x1080 x264 FLAC)' /xdata

Script can proceed audio or subtitle file naming with addons, f.e. if main file named 'foo.mkv' than audio track may has name 'foo.baz.mka'
Important notes - as destination script use destination ROOT, where NEW identical directory will be created for processed files.