Volume Relative (VR) is an informal percentage unit of measurement based on Loudness Units Full Scale (LUFS). It is read similarly to Volume Unit (VU), with the target 100% = -6 LUFS.

lufs_to_vr.sh

#!/bin/bash

#===========================================
#  LUFS to Volume Relative (VR) Converter
#  Simple implementation based on formula:
#  VR = 9.09 * LUFS + 154.54
#===========================================

script_name="${SCRIPT_ALIAS:-$(basename "$0")}"

show_usage() {
    local message="
    Usage: $script_name <LUFS_value>
    Example: $script_name -14
    "
    echo -e "$message"
}

if [ -z "${1:-}" ]; then
    show_usage
    exit 1
fi

LUFS="$1"

# Validate if input is a number
if ! [[ "$LUFS" =~ ^-?[0-9]+([.][0-9]+)?$ ]]; then
    echo -e "
    Error: Invalid LUFS value. Must be a number.
    "
    exit 2
fi

# Calculate VR
VR=$(awk "BEGIN { printf \"%.2f\", (9.09 * $LUFS) + 154.54 }")

# Output result
echo -e "
    Input: $LUFS LUFS
    Volume Relative (VR): $VR %
"

vr-bashrc-alias.sh

alias vr='SCRIPT_ALIAS=vr /home/gusmd/.config/bash/lufs_to_vr.sh'

vr_vs_lufs_graph.png