shell-scripts/normalize - master - telnov.ob/cerberus

shell-scripts/normalize
96 строк3 KB
Daniel J Wilcox
normalize
08 фев 2026, 21:53
08 фев 2026, 21:536125b69
#!/bin/sh

#===============================================================================
# normalize audio levels (2-Pass loudnorm)
#===============================================================================

#===============================================================================
# script usage
#===============================================================================

usage() {
echo "Usage: $(basename "$0") -i input -t -3.0 -o output
-i input
-t target lufs tp
-o output"
exit 2
}


#===============================================================================
# check number of arguments passed to the script
#===============================================================================

[ $# -gt 0 ] || usage


#===============================================================================
# getopts
#===============================================================================

while getopts ':i:t:o:h' opt; do
  case ${opt} in
     i) input="${OPTARG}";;
     t) target="${OPTARG}";;
     o) output="${OPTARG}";;
     h) usage;;
     *) usage;;
  esac
done


#===============================================================================
# variables
#===============================================================================

# setup output defaults
input_name="${input%.*}"
input_ext="${input##*.}"
audio_default="${input_name}-normalized.${input_ext}"

# lufs settings
target_i="-16"
target_tp="-3.0"
target_lra="11"

#===============================================================================
# Analyzing file
#===============================================================================

echo "+ Pass 1: Analyzing file for -16 LUFS target..."

measurements=$(ffmpeg -hide_banner -i "${input}" -af "loudnorm=I=${target_i}:TP=${target:-${target_tp}}:LRA=${target_lra}:print_format=json" -f null - 2>&1)

# Extracting variables using a more robust awk pattern matching
measured_i=$(echo "${measurements}" | awk -F'"' '/input_i/ {print $4}')
measured_tp=$(echo "${measurements}" | awk -F'"' '/input_tp/ {print $4}')
measured_lra=$(echo "${measurements}" | awk -F'"' '/input_lra/ {print $4}')
measured_thresh=$(echo "${measurements}" | awk -F'"' '/input_thresh/ {print $4}')
target_offset=$(echo "${measurements}" | awk -F'"' '/target_offset/ {print $4}')

# Safety check: If we didn't get data, stop here
if [ -z "${measured_i}" ]; then
    echo "Error: Could not analyze audio. Check if ffmpeg is installed."
    exit 1
fi


#===============================================================================
# Applying normalization
#===============================================================================

echo "+ Pass 2: Applying normalization (Source: ${measured_i} LUFS)"

# Pass 2: Applying the 2-pass linear normalization
ffmpeg -hide_banner \
-stats -v panic \
-i "${input}" -af \
"loudnorm=I=${target_i}:TP=${target:-${target_tp}}:LRA=${target_lra}:\
measured_i=${measured_i}:\
measured_tp=${measured_tp}:\
measured_lra=${measured_lra}:\
measured_thresh=${measured_thresh}:\
offset=${target_offset}:\
linear=true" \
-ar 48000 \
"${output:-${audio_default}}"