mod-host

About

mod-host is an LV2 host for JACK, controllable via socket or command line

Currently the host supports the following LV2 features:

• lv2core
• atom
• buf-size
• event
• log
• midi
• options
• parameters
• patch
• presets
• state
• time
• uri-map
• urid
• worker

mod-host is part of the MOD project.

Building

mod-host uses a simple Makefile to build the source code. The steps to build and install are:

make
make install

You can change the base installation path passing PREFIX as argument of make.

Dependencies:

libjack-jackd2  >= 1.9.8
liblilv         >= 0.14.2
libreadline     >= 6.2
lilv-utils      (optional)
fftw            (optional)
hylia           (optional)

On Debian-based Linux distributions (Ubuntu, Mint, etc) most of these can be installed with:

sudo apt install libreadline-dev liblilv-dev lilv-utils libfftw3-dev libjack-jackd2-dev

For Hylia, please go to https://github.com/falkTX/Hylia to install from source.

Running

For developing start it like this:

$ ./mod-host -n -p 5555 -f 5556

mod-host does not startup JACK automatically, so you need to start it before running mod-host.

If you run mod-host without options the process will be forked and it can only be controlled through the socket. The default socket port is 5555, this can be changed by passing the option -p (or --socket-port) to mod-host.

The other way to control mod-host is the interactive mode, in this case the commands must be provided on the shell prompt. The interactive mode has autocomplete, therefore, you can always type [TAB] twice any time you want a hint.

Note: When you are in the interactive mode, socket communication won't work.

Options

-v, --verbose
    verbose messages

-p, --socket-port=<port>
    socket port definition

-f, --feedback-port<port>
    feedback port definition

-i, --interactive
    interactive shell mode

-n, --nofork 
    run in non-forking mode

-V, --version
    print program version and exit

-h, --help
    print help and exit

Commands (or Protocol)

The commands supported by mod-host are:

add <lv2_uri> <instance_number>
    * add an LV2 plugin encapsulated as a jack client, in activated state
    e.g.: add "http://lv2plug.in/plugins/eg-amp" 0
    instance_number must be any value between 0 ~ 9990, inclusively

remove <instance_number>
    * remove an LV2 plugin instance (and also the jack client)
    e.g.: remove 0
    when instance_number is -1 all plugins will be removed

activate <instance_number> <activate_value>
    * toggle effect activated state
    e.g.: activate 0 1
    if activate_value = 1 activate effect
    if activate_value = 0 deactivate effect

preload <lv2_uri> <instance_number>
    * add an LV2 plugin encapsulated as a jack client, in deactivated state
    e.g.: preload "http://lv2plug.in/plugins/eg-amp" 0
    instance_number must be any value between 0 ~ 9990, inclusively

preset_load <instance_number> <preset_uri>
    * load a preset state of an effect instance
    e.g.: preset_load 0 "http://drobilla.net/plugins/mda/presets#JX10-moogcury-lite"

preset_save <instance_number> <preset_name> <dir> <file_name>
    * save a preset state of an effect instance
    e.g.: preset_save 0 "My Preset" "/home/user/.lv2/my-presets.lv2" "mypreset.ttl"

preset_show <preset_uri>
    * show the preset information of requested URI
    e.g.: preset_show "http://drobilla.net/plugins/mda/presets#EPiano-bright"

connect <origin_port> <destination_port>
    * connect two jack ports
    e.g.: connect "system:capture_1" "effect_0:in"

disconnect <origin_port> <destination_port>
    * disconnect two jack ports
    e.g.: disconnect "system:capture_1" "effect_0:in"

disconnect_all <origin_port>
    * disconnect all connections of a jack port
    e.g.: disconnect_all "effect_0:in"

bypass <instance_number> <bypass_value>
    * toggle effect processing
    e.g.: bypass 0 1
    if bypass_value = 1 bypass effect
    if bypass_value = 0 process effect

param_set <instance_number> <param_symbol> <param_value>
    * set the value of a control port
    e.g.: param_set 0 "gain" 2.5

param_get <instance_number> <param_symbol>
    * get the value of a control port
    e.g.: param_get 0 "gain"

param_monitor <instance_number> <param_symbol> <cond_op> <value>
    * monitor a control port according to a condition
    e.g: param_monitor 0 "gain" ">" 2.5

patch_set <instance_number> <property_uri> <value>
    * set the value of a control port
    e.g.: patch_set 0 "gain" 2.5

patch_get <instance_number> <property_uri>
    * get the value of a control port
    e.g.: patch_get 0 "gain"

licensee <instance_number>
    * get the licensee name for a commercial plugin
    e.g.: licensee 0

monitor <addr> <port> <status>
    * open a socket port for monitoring parameter changes
    e.g: monitor localhost 12345 1
    if status = 1 start monitoring
    if status = 0 stop monitoring

monitor_output <instance_number> <param_symbol>
    * request monitoring of an output control port (on the feedback port)
    e.g.: monitor_output 0 "meter"

midi_learn <instance_number> <param_symbol> <minimum> <maximum>
    * start MIDI learn for a control port
    e.g.: midi_learn 0 "gain" 0.0 1.0

midi_map <instance_number> <param_symbol> <midi_channel> <midi_cc> <minimum> <maximum>
    * map a MIDI controller to a control port
    e.g.: midi_map 0 "gain" 0 7 0.0 1.0
    a non-standard midi_cc value of 131 (0x83) is used for pitchbend

midi_unmap <instance_number> <param_symbol>
    * unmap the MIDI controller from a control port
    e.g.: midi_unmap 0 "gain"

monitor_audio_levels <source_port_name> <enable>
    * monitor audio levels for a specific jack port (on the feedback port)
    e.g.: monitor_audio_levels "system:capture_1" 1

monitor_midi_program <midi_channel> <enable>
    * listen to MIDI program change messages (on the feedback port)
    e.g.: monitor_midi_program 0 1

set_midi_program_change_pedalboard_bank_channel <enable> <midi_channel>
    * set the MIDI channel which changes pedalboard banks on MIDI program change. <midi_channel> is in the range of [0,15].
    e.g.: set_midi_program_change_pedalboard_bank_channel 1 5 to enable listening for bank changes on channel 6

set_midi_program_change_pedalboard_snapshot_channel <enable> <midi_channel>
    * set the MIDI channel which changes pedalboard snapshots on MIDI program change. <midi_channel> is in the range of [0,15].
    e.g.: set_midi_program_change_pedalboard_snapshot_channel 1 4 to enable listening for preset changes on channel 5

cc_map <instance_number> <param_symbol> <device_id> <actuator_id> <label> <value> <minimum> <maximum> <steps> <extraflags> <unit> <scalepoints_count> <scalepoints...>
    * map a Control Chain actuator to a control port
    e.g.: cc_map 0 "gain" 0 1 "Gain" 0.0 -24.0 3.0 33 0 "dB" 0

cc_unmap <instance_number> <param_symbol>
    * unmap the Control Chain actuator from a control port
    e.g.: cc_unmap 0 "gain"

cc_value_set <instance_number> <param_symbol> <value>
    * set the value of a  mapped Control Chain actuator
    e.g.: cc_value_set 0 "gain" 2.5

cv_map <instance_number> <param_symbol> <source_port_name> <minimum> <maximum> <operational-mode>
    * map a CV source port to a control port, operational-mode being one of '-', '+', 'b' or '='
    e.g.: cv_map 0 "gain" "AMS CV Source:CV Out 1" -24.0 3.0 =

cv_unmap <instance_number> <param_symbol>
    * unmap the CV source port actuator from a control port
    e.g.: cv_unmap 0 "gain"

cpu_load
    * return current jack cpu load

load <file_name>
    * load a history command file
    * dummy way to save/load workspace state
    e.g.: load my_setup

save <file_name>
    * saves the history of typed commands
    * dummy way to save/load workspace state
    e.g.: save my_setup

bundle_add <bundle_path>
    * add a bundle to the running lv2 world
    e.g.: bundle_add "/path/to/bundle.lv2"

bundle_remove <bundle_path> <resource>
    * remove a bundle from the running lv2 world
    e.g.: bundle_remove "/path/to/bundle.lv2" ""

feature_enable <feature> <enable>
    * enable or disable a feature
    * feature can be one of "aggregated-midi", "freewheeling" or "processing"
    * the "aggregated-midi" feature requires the use of jack2 and mod-midi-merger to be installed system-wide
    e.g.: feature_enable link 1

set_bpm <beats_per_minute>
    * set the global beats per minute transport value
    e.g.: set_bpm 120

set_bpb <beats_per_bar>
    * set the global beats per bar transport value
    e.g.: set_bpb 4

transport <rolling> <beats_per_bar> <beats_per_minute>
    * change the global transport state
    e.g.: transport 1 4 120

transport_sync <mode>
    * change the transport sync mode
    * mode can be one of "none", "link" or "midi"
    e.g.: transport_sync "midi"

output_data_ready
    * report feedback port ready for more messages

help
    * show a help message

quit
    bye!

For each effect added one client on JACK will be created. The names of clients follow the standard: effect_\<instance_number>

If a valid command is executed a response is given as following:

resp <status> [value]

If status is a negative number an error has occurred. The table below shows the number of each error.

A status zero or positive means that the command was executed successfully. In case of the add command, the status returned is the instance number. The value field currently only exists for the param_get command.