FreeLCS Free Loudness Correction Server
[FAQ] [Features] [User Manual] [Downloads]
[Changelog]
FreeLCS stands for Free Loudness Correction Server.
FreeLCS lets you automatically correct audio files to EBU R128 target
loudness level -23 LUFS. Beginning from version 3.6 it is also possible to
change the target loudness in range of -31 LUFS to -12 LUFS.
The software lets you easily set up a server that shares one of it's folders
to the network. Users of your network can then drop audio files to the
server for automatic loudness correction. For each processed file the server
also creates a loudness history graphics file which shows loudness
variations inside the file.
The software is very fast even on modest hardware giving 15 times faster
than realtime processing (16 bit stereo files, TruePeak measurement turned
on) on a server with one Intel Core 2 Duo processor, 4 GB Ram, 3 internal
Sata disks in software RAID 0.
FreeLCS uses other open source programs to get the job done (Linux,
libebur128, gnuplot, FFmpeg, sox, mediainfo). All software is free and Open
Source.
More detailed information can be found in FAQ,
Features and User
Manual.
Latest news:
2025.10.28 FreeLCS 3.12 released.
- This release supports Debian 13, Ubuntu 24.04.
- FFmpeg has a built in lookahead limiter (called alimiter)
and since Ubuntu 24.04 it supports channel counts more than two.
FreeLCS 3.12 uses alimiter and 4 x oversampling for TruePeak limiting
where needed. It gives a much better than before protection against
distortion when using target loudness higher than -23 LUFS (for
example -16 LUFS for social media).
- FFmpeg is now always installed since it is required for Truepeak
limiting.
- Configfile format changed from pickle to json. This makes it kind of
human readable.
2025.09.15 FreeLCS 3.11 released.
- This release supports Debian 13, Ubuntu 24.04.
- Windows 11 24H2 and windows 10 does not allow smb - mounts without a
password anymore. You can either configure windows to allow it again or
start to use a username and password with the FreelCS - mount. Discussion
of these options is here.
- Debian 13 comes with FFmpeg 7.1.1 and there was a small change in the
way it reports channel counts. Adjusted FreeLCS to these changes.
2024.05.25 FreeLCS 3.10 released.
- This release supports Debian 12, Ubuntu 24.04.
- This is basically the same as release 3.9 since there was no need to
do changes. Most changes in FreeLCS are driven by changes in programs
FreeLCS uses (libebur128, mediainfo, FFmpeg, sox, etc). This year
there weren't any breaking changes in any of these programs.
Older news can be found here.
- Automatically loudness corrects audio files to conform with EBU R128
loudness recommendation.
- Very easy to use, just drop in your file and copy back the loudness
corrected version.
- Creates loudness history graphics that allows the user to see how
loudness varies inside a file (example picture below).
- Supports channel counts from mono to 5.1.
- Supports EBU TruePeak measurement.
- Uses a protective TruePeak limiter to keep peaks in the allowed range
where needed.
- Takes advantage of multiple processor cores to run calculations
simultaneously.
- User is able to define how many audio files are processed at the same
time, limited only by available cpu processing power and hard disk
bandwidth.
- Supports writing loudness measurement results to a machine readable
file.
- Modest hardware requirements, runs fine with only 4 GB of ram.
- Can be run inside a virtual machine, no need for physical hardware.
- Fast processing. On typical hardware you can expect processing to be
10 - 20 faster than realtime.
- It is possible to chabge target loudness in the range of -31 LUFS to
-12 LUFS making it possible to adjust loudness to a level that is more
compatible with internet media sites (Youtube, Spotify, etc) and mobile
devices.
- Cleans up automatically by deleting all files after a set time delay.
- Sends possible error messages to the admin by email.
- The wide range of FFmpeg supported formats can be processed.
- Support for multistream files, all audio streams are extracted and
processed individually.
- Extract audio from wrappers containing both video and audio.
- Remix audio from MXF files to required mixes before loudness
processing.
- All software is free and Open Source. Install in as many computers as
you like.
- Runs on the free Linux operating system, no need to pay for
proprietary os installation.
- Easy to integrate in many workflows.
- Written in Python 3.
- More specific information can be found in the FAQ.
Click here to go
to the download page (User manual is included in the download)
Click here to go to the User manual.
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