ffmpeg script for normalizing audio.
This program normalizes media files to a certain dB level. The default
is an RMS-based normalization where the mean is lifted or attenuated.
Peak normalization is possible with the -m option.
It takes any audio or video file as input, and writes the audio part as output WAV file. The normalized audio can also be merged with the original.
- Python
- ffmpeg from http://ffmpeg.org/ installed in your $PATH (3.x or above recommended)
pip install ffmpeg-normalize
ffmpeg-normalize [options] <input-file> ...
Normalization:
-l,--level <level>: dB level to normalize to [default: -26]-m,--max: Normalize to the maximum (peak) volume instead of RMS-b,--ebu: Normalize according to EBU R128 (ffmpegloudnormfilter)-t,--threshold <threshold>: dB threshold below which the audio will be not adjusted [default: 0.5]
Encoding / Format:
-a,--acodec <acodec>: Set audio codec for ffmpeg (seeffmpeg -encoders) to use for output (will be chosen based on format, default pcm_s16le for WAV)-r,--format <format>: Set format / file extension for ffmpeg (seeffmpeg -formats) to use for output file [default:wav]-e,--extra-options <extra-options>Set extra options passed to ffmpeg (e.g.-b:a 192kto set audio bitrate)
File Handling:
-f,--force: Force overwriting existing files-p,--prefix <prefix>: Prefix for normalized files or output folder name [default: normalized]-x,--no-prefix: Write output file without prefix (cannot be used when--diris used)-o,--dir: Create an output folder under the input file's directory with the prefix instead of prefixing the file (does not work if--no-prefixis chosen)-u,--merge: Take original file's streams and merge the normalized audio. Note: This will not overwrite the input file, but output tonormalized-<input>.
General:
-v,--verbose: Enable verbose output-n,--dry-run: Show what would be done, do not convert-d,--debug: Show debug output
Normalize a file and write to normalized-file.wav:
ffmpeg-normalize -v file.mp3
ffmpeg-normalize --verbose *.avi
Normalize a number of AVI files and write to
normalized-<file>.wav:
ffmpeg-normalize -v *.avi
ffmpeg-normalize --verbose *.avi
Normalize a number of MP4 files to -5 dB peak volume and merge the audio
stream back into the MP4 files, in a new directory called
normalized:
ffmpeg-normalize -vuofm -l -5 *.mp4
ffmpeg-normalize --verbose --merge --dir --force --max --level -5 *.mp4
Normalize a number of MKV files and merge the audio back in using the
libfdk_aac encoder with 192 kBit/s CBR:
ffmpeg-normalize -vu -a libfdk_aac -e "-b:a 192k" *.mkv
ffmpeg-normalize --verbose --merge --acodec libfdk_aac --extra-options "-b:a 192k" *.mkv
One user (@pannal) suggested this for an old series with bad sound mixing:
ffmpeg-normalize --verbose --merge --force --acodec libfdk_aac --ebu \
--extra-options "-threads 4 -b:a 224k -filter:a 'compand=0|0:1|1:-90/-900|-70/-70|-30/-9|0/-3:6:0:0:0'" *.mkv
The MIT License (MIT)
Copyright (c) 2015-2017 Werner Robitza
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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