ffmpeg-album-normalise/scan.py

53 lines
1.8 KiB
Python
Executable File

#!/usr/bin/env python3
# ffmpeg-album-normalise: Normalise music album-by-album using FFmpeg loudnorm
# Copyright © 2019 Lee Yingtong Li (RunasSudo)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
import argparse
import json
import os.path
import subprocess
import sys
parser = argparse.ArgumentParser(description='Scan audio files for loudness')
parser.add_argument('filename', nargs='+', help='Input files')
parser.add_argument('--levels', '-l', default='levels.json', help='levels.json output file')
args = parser.parse_args()
levels = {}
if os.path.exists(args.levels):
with open(args.levels, 'r') as f:
levels = json.load(f)
for filename in args.filename:
print(filename)
if filename in levels:
continue
proc = subprocess.run(['ffmpeg', '-i', filename, '-filter:a', 'loudnorm=print_format=json', '-f', 'null', '-'], capture_output=True, encoding='utf-8')
if proc.returncode != 0:
print('FFmpeg error')
sys.exit(1)
data_str = proc.stderr[proc.stderr.index('{', proc.stderr.index('Parsed_loudnorm_0')):]
data = json.loads(data_str)
levels[filename] = data
with open(args.levels, 'w') as f:
json.dump(levels, f)