A Docker Mod for the LinuxServer.io Lidarr Docker container that uses ffmpeg and a script to automatically convert downloaded FLAC files to MP3s. Default output quality is 320Kbps constant bit rate.

NOTE: This mod supports Linux OSes only.

Development Container info:
Production Container info:

Installation

Pull the linuxserver/lidarr docker image from Docker Hub:
docker pull linuxserver/lidarr:latest

Configure the Docker container with all the port, volume, and environment settings from the original container documentation here:
linuxserver/lidarr

Add a DOCKER_MODS environment variable to the docker run command, as follows:

Stable release: -e DOCKER_MODS=linuxserver/mods:lidarr-flac2mp3

Example Docker CLI Configuration

docker run -d \
  --name=lidarr \
  -e PUID=1000 \
  -e PGID=1000 \
  -e TZ=America/Chicago \
  -e DOCKER_MODS=linuxserver/mods:lidarr-flac2mp3 \
  -p 8686:8686 \
  -v /path/to/appdata/config:/config \
  -v /path/to/music:/music \
  -v /path/to/downloads:/downloads \
  --restart unless-stopped \
  ghcr.io/linuxserver/lidarr

Example Synology Configuration

Start the container.

After the above configuration is complete, to use ffmpeg, configure a custom script from Lidarr's Settings > Connect screen and type the following in the Path field:
/usr/local/bin/flac2mp3.sh

Example

This will use the defaults to create a 320Kbps MP3 file.

For any other setting, you must either use one of the included wrapper scripts or create a custom script with the command line options you desire. See the Syntax section below.

Usage

New file(s) with an MP3 extension will be placed in the same directory as the original FLAC file(s) and have the same owner and permissions. Existing MP3 files with the same track name will be overwritten.

If you've configured Lidarr's Recycle Bin path correctly, the original audio file will be moved there.
NOTE: If you have not configured the Recycle Bin, the original FLAC audio file(s) will be deleted and permanently lost.

Syntax

Note: The Arguments field for Custom Scripts was removed in Lidarr release v0.7.0.1347 due to security concerns. To support options with this version and later, a wrapper script can be manually created that will call flac2mp3.sh with the required arguments.

The script accepts three command line options:

[-d] [-b <bitrate> | -v <quality>]

The -b bitrate option sets the output quality in constant bits per second (CBR).
The -v quality option sets the output quality using a variable bit rate (VBR) where quality is a value between 0 and 9, with 0 being the highest quality.
See the FFmpeg MP3 Encoding Guide for more details.
If neither -b nor -v options are specified, the script will default to constant 320Kbps.

The -d option enables debug logging.

Examples

-b 320k        # Output 320 kbit/s MP3 (non VBR; same as default behavior)
-v 0           # Output variable bitrate, VBR 220-260 kbit/s
-d -b 160k     # Enable debugging, and output 160 kbit/s MP3

Included Wrapper Scripts

For your convenience, several wrapper scripts are included in the /usr/local/bin/ directory.
You may use any of these scripts in place of the flac2mp3.sh mentioned in the Installation section above.

flac2mp3-debug.sh        # Enable debugging
flac2mp3-vbr.sh          # Use variable bit rate, quality 0

Example Wrapper Script

To configure the last entry from the Examples section above, create and save a file called flac2mp3-custom.sh to /config containing the following text:

#!/bin/bash

. /usr/local/bin/flac2mp3.sh -d -b 160k

Make it executable:

chmod +x /config/flac2mp3-custom.sh

Then put /config/flac2mp3-custom.sh in the Path field in place of /usr/local/bin/flac2mp3.sh mentioned in the Installation section above.

Note: If you followed the Linuxserver.io recommendations when configuring your container, the /config directory will be mapped to an external storage location. It is therefore recommended to place custom scripts in the /config directory so they will survive container updates, but they may be placed anywhere that is accessible by Lidarr.

Triggers

The only events/notification triggers that have been tested are On Release Import and On Upgrade

Logs

A log file is created for the script activity called:

/config/logs/flac2mp3.txt

This log can be downloaded from Lidarr under System > Log Files

Log rotation is performed, with 5 log files of 1MB each kept, matching Lidarr's log retention.

NOTE: If debug logging is enabled, the log file can grow very large very quickly. Do not leave debug logging enabled permanently.

Credits

This would not be possible without the following:

Lidarr
LinuxServer.io Lidarr container
LinuxServer.io Docker Mods project
ffmpeg
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