MPD2CamillaDSPVolume

bitkeeper @ github 2022

Starting from mpd2cdspvolume version 1.0.0 support for camilladsp 1.x is dropped. With that also the command cdspstorevolume is dropped.

Introduction

MPD2CamillaDSPVolume makes it possible to control the volume of CamillaDSP with the volume of MPD.

Features:

• Synchronize the volume of MPD to CamillaDSP
• When alsa_cdsp is used, support the use of volume state file:
  • When alsa_cdsp stop CamillaDSP the state file is writen
  • When the volume is changed, while no music is playing, also the state file is writen.
• Dynamic range of volume curve is configuratable.
• Volume offset is possible to reduce the volume with a constant value.

How it works:

• It listens to MPD Mixer changes.
• When CamillaDSP is running, the changed volume is send to CamillaDSP else to the statefile.

Requires:

• Add in alsa_cdsp config for the cargs the argument to the correct statefile -s <path_t_your_statefile> to start camilladsp with the correct statefile.
• Use the same statefile with mpd2cdspvolume.

Files

From source

File	Description	Packed as
mpd2cdspvolume.py	mpd volume to camilladsp syncer	/usr/local/bin/mpd2cdspvolume
etc/mpd2cdspvolume.conf	tmpfs files to created	/usr/lib/tmpfiles.d/mpd2cdspvolume.conf
etc/mpd2cdspvolume.service	systemd service file	/lib/systemd/system/mpd2cdspvolume.service
etc/mpd2cdspvolume.config	mpd2cdspvolume config file*	/etc/mpd2cdspvolume.config
etc/postinstall.sh	runned as part of deb install	na

*) contains dynamic_range and volume_offset

Run-time created/used state files

File	Description
/var/run/mpd2cdspvol/mpd2cdspvol.pid	Contains PID of mpd2cdspvolume. Path is in a temp.fs and is created on boot by usr/lib/tmpfiles.d/mpd2cdspvolume.conf
/var/lib/cdsp/statefile.yml	Contains the volume_state as required by camilladsp. Path is postinstall.sh (typical runned on deb install time)

Install

As source

Checkout the repository from github

git clone https://github.com/bitkeeper/mpd2cdspvolume.git
cd mpd2cdspvolume

mpd2cdspvolume is a python script and requires to dependencies:

pip install -r requirements.txt

Copy the scripts to a convient location like:

sudo cp mpd2cdspvolume.py /usr/local/bin/mpd2cdspvolume
sudo chmod a+x /usr/local/bin/mpd2cdspvolume
sudo chmod a+x /usr/local/bin/cdspstorevolume
sudo cp etc/mpd2cdspvolume.conf usr/lib/tmpfiles.d/

When alas_cdsp is used prep the volume state file:

sudo mkdir -p /var/lib/cdsp
sudo chown -R mpd /var/lib/cdsp

Commandline use

usage: mpd2cdspvolume [-h] [-V] [-v] [--mpd_host MPD_HOST] [--mpd_port MPD_PORT] [--cdsp_host CDSP_HOST] [--cdsp_port CDSP_PORT] [-s VOLUME_STATE_FILE] [-p PID_FILE] [-c CONFIG]

Synchronize MPD volume to CamillaDSP

optional arguments:
  -h, --help            show this help message and exit
  -V, --version         show program's version number and exit
  -v, --verbose         Show debug output.
  --mpd_host MPD_HOST   Host running MPD. (default: 127.0.0.1)
  --mpd_port MPD_PORT   Port user by MPD. (default: 6600)
  --cdsp_host CDSP_HOST
                        Host running CamillaDSP. (default: 127.0.0.1)
  --cdsp_port CDSP_PORT
                        Port used by CamillaDSP. (default: 1234)
  -s VOLUME_STATE_FILE, --volume_state_file VOLUME_STATE_FILE
                        File where to store the volume state. (default: None)
  -p PID_FILE, --pid_file PID_FILE
                        Write PID of process to this file. (default: None)
  -c CONFIG, --config CONFIG
                        Load config from a file (default: None)

example:

sudo -H -u mpd bash -c "/usr/local/bin/mpd2cdspvolume --verbose --pid_file /var/run/mpd2cdspvol/mpd2cdspvol.pid --volume_state_file /var/lib/cdsp/statefile.yml --config /etc/mpd2cdspvolume.config"

This will run the program as user mpd and with --verbose show output of the actions.

alsa_cdsp support

When also alsa_cdsp is used, alsa_cdsp start and stop camilladsp on source change like samplerate. Also when music is pauzed camilladsp is stopped. moOde is an example that uses alsa_cdsp

To preserve the volume settings of camilladsp alsa_cdsp a way of using a volume state file:

• camilladsp gets and argument at startup with the used statefile

When MPD volume changes are made, while the music isn't playing or camilladsp isn't active, the volume setting is writen to the state file instead.

To use the state file with alsa_cdsp edit the config and add the vol_file and camilla_exit_cmd arguments.

For example with moOde add following lines to /etc/alsa/conf.d/camilladsp.conf:

   cargs [
        -p "1234"
        -a "0.0.0.0"
        -s "/var/lib/cdsp/statefile.yml"
   ]

To make this work the user of the process who is running should have the rights to send a signal to mpd2cdspvolume.

mpd2cdspvolume as service

For more convenience mpd2cdspvolume can also be runned as service. Example service script is provided. Tune it to your own use.

If you use alsa_cdsp run it as the same user as from the process that runs alsa_cdsp/camilladsp. This allows sending signals without additional configuration.

build debian package

With the script builddep.sh you can build a debian package for mpd2cdspvolume. This requires that you have fpm installed. And to the system where the package should be installed also the following packages should be present:

• python3-mpd2
• python3-camilladsp