Development Repository

This is a development and test repository. Visit the production repository and branch for stable/production releases.

About

A Docker Mod for the LinuxServer.io Lidarr Docker container that uses ffmpeg and a script to automatically convert downloaded FLAC (or other format) files to MP3s. Default output quality is 320Kbps constant bit rate. Advanced options act as a light wrapper to ffmpeg, allowing conversion to any supported audio format, including AAC, AC3, Opus, and many others. A Batch Mode is also supported that allows usage outside of Lidarr.

This mod supports Linux OSes only.

Production Container info:
Development Container info:

Installation

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

   1. Add a DOCKER_MODS environment variable to your compose.yml file or docker run command, as follows:

      • Stable release: DOCKER_MODS=linuxserver/mods:lidarr-flac2mp3
      • Dev/test release: DOCKER_MODS=thecaptain989/lidarr-flac2mp3:latest

      Example Docker Compose YAML Configuration

      version: "2.1"
      services:
        lidarr:
          image: lscr.io/linuxserver/lidarr
          container_name: lidarr
          environment:
            - PUID=1000
            - PGID=1000
            - TZ=America/Chicago
            - DOCKER_MODS=linuxserver/mods:lidarr-flac2mp3
          volumes:
            - /path/to/appdata/config:/config
            - /path/to/music:/music
            - /path/to/downloads:/downloads
          ports:
            - 8686:8686
          restart: unless-stopped

      Example Docker Run Command

      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 \
        lscr.io/linuxserver/lidarr

      Synology Screenshot

      Example Synology Configuration
      

   2. Start the container.

2. Configure a custom script from Lidarr's Settings > Connect screen and type the following in the Path field:
   /usr/local/bin/flac2mp3.sh

   Screenshot

   Example Custom Script
   

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

   For any other setting, you must use one of the supported methods to pass arguments to the script. See the Command-Line Syntax section below.

Usage

New file(s) will be placed in the same directory as the original FLAC file(s) (unless redirected with the --output option below) with permissions preserved. Existing files with the same track name will be overwritten. Owner is preserved if the script is executed as root.

By default, if you've configured Lidarr's Recycle Bin path correctly, the original audio file will be moved there.

WARNING: If you have not configured the Recycle Bin, the original FLAC audio file(s) will be deleted and permanently lost. This behavior may be modified with the --keep-file option.

Command-Line Syntax

The Arguments field for Custom Scripts was removed in Lidarr release v0.7.0.1347 due to security concerns.

Options and Arguments

The script may be called with optional command-line arguments.

The syntax for the command-line is:
flac2mp3 [{-b|--bitrate} <bitrate> | {-v|--quality} <quality> | {-a|--advanced} "<options>" {-e|--extension} <extension>] [{-f|--file} <audio_file>] [{-k|--keep-file}] [{-o|--output} <directory>] [{-r|--regex} '<regex>'] [{-t|--tags} <taglist>] [{-l|--log} <log_file>] [{-d|--debug} [<level>]]

Table of Command-Line Arguments

Option	Argument	Description
-b, --bitrate	<bitrate>	Sets the output quality in constant bits per second (CBR). Examples: 160k, 240k, 300000 Note: May not be specified with -v, -a, or -e.
-v, --quality	<quality>	Sets the output variable bit rate (VBR). Specify a value between 0 and 9, with 0 being the highest quality. See the FFmpeg MP3 Encoding Guide for more details. Note: May not be specified with -b, -a, or -e.
-a, --advanced	"<options>"	Advanced ffmpeg options. The specified options replace all script defaults and are sent directly to ffmpeg. The options value must be enclosed in quotes. See FFmpeg Options for details on valid options, and Guidelines for high quality audio encoding for suggested usage. Note: Requires the -e option to also be specified. May not be specified with -v or -b. WARNING: You must specify an audio codec (by including a -c:a <codec> ffmpeg option) or the resulting file will contain no audio! WARNING: Invalid options could result in script failure!
-e, --extension	<extension>	Sets the output file extension. The extension may be prefixed by a dot (".") or not. Example: .ogg Note: Requires the -a option to also be specified. May not be specified with -v or -b.
-f, --file	<audio_file>	If included, the script enters Batch Mode and converts the specified audio file. WARNING: Do not use this argument when called from Lidarr!
-o, --output	<directory>	Converted audio file(s) are saved to directory instead of being located in the same directory as the source audio file. The path will be created if it does not exist.
-k, --keep-file		Do not delete the source file or move it to the Lidarr Recycle bin. Note: This also disables importing the new files into Lidarr after conversion.
-r, --regex	'<regex>'	Sets the regular expression used to select input files. The regex value should be enclosed in single quotes and escaped properly. Defaults to [.]flac$.
-l, --log	<log_file>	The log filename Default of /config/log/flac2mp3.txt
-t, --tags	<taglist>	Comma separated list of metadata tags to apply automated corrections to. See Metadata Corrections section.
-d, --debug	[<level>]	Enables debug logging. Level is optional. Default of 1 (low). 2 includes JSON and FFmpeg output. 3 contains even more JSON output.
--help		Display help and exit.
--version		Display version and exit.

If neither -b, -v, -a, or -e options are specified, the script will default to a constant 320Kbps MP3.

Technical notes on advanced options

The -a option effectively makes the script a generic wrapper for ffmpeg. FFmpeg is executed once per track with only the loglevel, input filename, and output filename being set. All other options are passed unparsed to the command-line.

The exact format of the executed ffmpeg command is:

ffmpeg -loglevel error -nostdin -i "input.flac" ${options} "output.${extension}"

Technical notes on regular expressions

By default, the script only matches and interacts with FLAC files (specifically, files ending in ".flac"). The -r option allows the script to match on a user specified regular expression (i.e. "regex") pattern.

Files are passed to the script with the full Linux path intact. (Ex: /path/to/audio/a-ha/Hunting High and Low/01 Take on Me.mp3). Craft your regular expression with this in mind.

Escaping special regular expression characters (like a dot .) requires a double backslash or a character class. A character class (i.e. [.]) is recommended because backslashes can be stripped by the bash shell and getting this right can be confusing.

For example, to convert all audio files to AAC audio files, use the following options:

-a "-y -map 0 -c:a aac -b:a 240k -c:v copy" -e m4a --regex '[.][^.]*$'

Regular expression syntax is beyond the scope of this document. See this tutorial for more information. Regular expression patterns may be tested here.

Examples

Command-line Examples

-b 320k        # Output 320 kbit/s MP3 (non-VBR; same as default behavior)
-v 0           # Output variable bitrate MP3, VBR 220-260 kbit/s
-d -b 160k     # Enable debugging level 1, and output a 160 kbit/s MP3
-r '[.][^.]*$' # Convert any file to MP3 (not just FLAC)
-a "-c:v libtheora -map 0 -q:v 10 -c:a libopus -b:a 192k" -e .opus
               # Convert to Opus format, 192 kbit/s, cover art
-a "-vn -c:a libopus -b:a 192K" -e .opus -r '[.]mp3$'
               # Convert .mp3 files to Opus format, 192 kbit/s, no cover art
-a "-y -map 0 -c:a aac -b:a 240k -c:v copy" -e m4a
               # Convert to M4A format, using AAC 240 kbit/s audio, cover art, overwrite file
--file "/path/to/audio/a-ha/Hunting High and Low/01 Take on Me.flac"
               # Batch Mode
               # Output 320kbit/s MP3
-o "/path/to/audio" -k
               # Place the converted file(s) in the specified directory and do not delete the original audio file(s)

Wrapper Scripts

To supply arguments to the script, you must either use one of the included wrapper scripts, create a custom wrapper script, or set the FLAC2MP3_ARGS environment variable.

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.

List of scripts

flac2mp3-debug.sh        # Enable debugging, level 1
flac2mp3-debug-2.sh      # Enable debugging, level 2
flac2mp3-vbr.sh          # Use variable bit rate MP3, quality 0
flac2opus.sh             # Convert to Opus format using .opus extension, 192 kbit/s, no covert art
flac2alac.sh             # Convert to Apple Lossless using an .m4a extension

Example Wrapper Script

To configure an 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.

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.

Environment Variable

The flac2mp3.sh script also allows the use of arguments provided by the FLAC2MP3_ARGS environment variable. This allows advanced use cases without having to provide a custom script.

For example, the following value in your docker run command would convert any .mp3 to Opus:

-e FLAC2MP3_ARGS='-a "-vn -c:a libopus -b:a 192k" -e .opus -r "[.]mp3$"'

Make sure to correctly use quotes and/or escape special characters when using this method. (See regular expression notes above.)
In Docker Compose, the previous command would need an extra $ to match the end-of-line:

environment:
  - FLAC2MP3_ARGS=-a "-vn -c:a libopus -b:a 192k" -e .opus -r '[.]mp3$$'

Synology Screenshot

Example Synology Configuration

The environment variable settings are only used when no command-line arguments are present. Any command-line argument will disable the use of the environment variable.

Triggers

The only events/notification triggers that are supported are On Release Import and On Upgrade

Batch Mode

Batch mode allows the script to be executed independently of Lidarr. It converts the file specified on the command-line and ignores any environment variables that are normally expected to be set by the music management program.

Using this function, you can easily process all of your audio files in any subdirectory at once. See the Batch Example below.

Script Execution Differences in Batch Mode

Because the script is not called from within Lidarr, expect the following behavior while in Batch Mode:

• The filename must be specified on the command-line
  (The -f option places the script in Batch Mode)
• Lidarr APIs are not called and its database is not updated.
  This may require a manual import of converted music files or an artist rescan.
• Original audio files are deleted.
  The Recycle Bin function is not available. (Modifiable using the -k option.)

Batch Example

To convert all .FLAC files in the /music directory to Apple Lossless Audio Codec (ALAC), enter the following at the Linux command-line:

find /music/ -type f -name "*.flac" | while read file; do /usr/local/bin/flac2mp3.sh -f "$file" -a "-c:a alac" -e m4a; done

Metadata Corrections

This feature is not meant for general purpose use. It is only documented here for completeness.

Metadata Tag Details

List of supported tags and metadata corrections that are applied:

Tag	Original	Correction
title	Parenthesis for live|remix, etc. "()"	Square brackets "[]"
disc	1	1/1
genre	/Pop/	"Pop"
	/Indie/	"Alternative & Indie"
	/Industrial/	"Industrial Rock"
	/Electronic/	"Electronica & Dance"
	/Punk|Alternative/	"Alternative & Punk"
	/Rock/	"Rock"

Logs

By default, 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. The log filename can be modified with the --log command-line option.

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

If debug logging is enabled with a level above 1, the log file can grow very large very quickly and is much more likely to be rotated. Do not leave high-level debug logging enabled permanently.

Uninstall

To completely remove the mod:

1. Delete the custom script from Lidarr's Settings > Connect screen that you created in the Installation section above.
2. Stop and delete the Lidarr container.
3. Exclude the DOCKER_MODS environment variable from your compose.yaml file or the docker run command when re-creating the Lidarr container.

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Credits

This would not be possible without the following:

Lidarr
LinuxServer.io Lidarr container
LinuxServer.io Docker Mods project
ffmpeg
Icons made by Freepik from Flaticon