Script to export all audio tracks from MKV to separate files

export_audio.sh

#!/bin/bash

# Check if ffmpeg is installed
if ! command -v ffmpeg &> /dev/null; then
    echo "Error: ffmpeg is not installed. Please install it and try again."
    exit 1
fi

# Input file and output directory
INPUT_FILE="$1"
OUTPUT_DIR="$2"

# Validate input arguments
if [[ -z "$INPUT_FILE" || -z "$OUTPUT_DIR" ]]; then
    echo "Usage: $0 <input_file.mp4> <output_directory>"
    exit 1
fi

# Check if input file exists
if [[ ! -f "$INPUT_FILE" ]]; then
    echo "Error: Input file '$INPUT_FILE' not found."
    exit 1
fi

# Create output directory if it doesn't exist
mkdir -p "$OUTPUT_DIR"

# Get the base name of the input file (without extension)
BASE_NAME=$(basename "$INPUT_FILE" .mp4)

# Get the total number of audio tracks in the input file
TRACKS=$(ffmpeg -i "$INPUT_FILE" 2>&1 | grep "Stream" | grep "Audio" | wc -l)

if [[ $TRACKS -eq 0 ]]; then
    echo "No audio tracks found in the input file."
    exit 1
fi

echo "Found $TRACKS audio track(s). Extracting..."

# Loop through each audio track and extract it
for ((i=0; i<TRACKS; i++)); do
    OUTPUT_FILE="${OUTPUT_DIR}/${BASE_NAME}-audio-$((i + 1)).m4a"
    echo "Extracting audio track $((i + 1)) to $OUTPUT_FILE..."
    ffmpeg -i "$INPUT_FILE" -map "0:a:$i" -c:a aac -b:a 192k -y "$OUTPUT_FILE" &> /dev/null
    if [[ $? -eq 0 ]]; then
        echo "Track $((i + 1)) extracted successfully."
    else
        echo "Failed to extract track $((i + 1))."
    fi
done

echo "Extraction complete. Files saved to '$OUTPUT_DIR'."