cCamillaDSP

Companion c++ library for CamillaDSP. This is my attempt at a port of pyCamillaDSP to c++. It should work with CamillaDSP version 1.0.0 and up.

Dependencies

cCamillaDSP requires easywsclient https://github.com/dhbaird/easywsclient and JSMN https://github.com/zserge/jsmn.

Communicating with the CamillaDSP process

This library provides an easy way to communicate with CamillaDSP via a websocket.

TODO

Most of the methods around CamillaDSP configuration management have not yet been implemented.

Documentation from pyCamillaDSP

This has not yet been updated to reflect the port to c++

Simple example to connect to CamillaDSP to read the version (assuming CamillaDSP is running on the same machine and listening on port 1234):

from camilladsp import CamillaConnection

cdsp = CamillaConnection("127.0.0.1", 1234)
cdsp.connect()
print("Version: {}".format(cdsp.get_version()))

Classes

All communication functionality is provided by the class CamillaConnection. The contructor accepts two arguments: host and port.

CamillaConnection(host, port)

Exceptions

The custom exception CamillaError is raised when CamillaDSP replies to a command with an error message. The error message is given as the message of the exception.

Different exceptions are raised in different situations. Consider the following example:

from camilladsp import CamillaConnection, CamillaError
cdsp = CamillaConnection("127.0.0.1", 1234)

myconfig = # get a config from somewhere
try:
    cdsp.connect()
    cdsp.validate_config(myconfig)
except ConnectionRefusedError as e:
    print("Can't connect to CamillaDSP, is it running? Error:", e)
except CamillaError as e:
    print("CamillaDSP replied with error:", e)
except IOError as e:
    print("Websocket is not connected:", e)

• ConnectionRefusedError means that CamillaDSP isn't responding on the given host and port.
• CamillaError means that the command was sent and CamillaDSP replied with an error.
• IOError can mean a few things, but the most likely is that the websocket connection was lost. This happens if the CamillaDSP process exits or is restarted.

Methods

The CamillaConnection class provides the following methods

Basics

Method	Description
connect()	Connect to the Websocket server. Must be called before any other method can be used.
disconnect()	Close the connection to the websocket.
is_connected()	Is websocket connected? Returns True or False.
get_version()	Read CamillaDSP version, returns a tuple with 3 elements.
get_library_version()	Read pyCamillaDSP version, returns a tuple with 3 elements.
get_state()	Get current processing state. Returns a ProcessingState enum value, see "Enums" below.
get_stop_reason()	Get the reason that processing stopped. Returns a StopReason enum value, see "Enums" below.
def get_supported_device_types()	Read what device types the running CamillaDSP process supports. Returns a tuple with two lists of device types, the first for playback and the second for capture.
stop()	Stop processing and wait for new config if wait mode is active, else exit.
exit()	Stop processing and exit.

Config handling

Method	Description
reload()	Reload config from disk.
get_config_name()	Get path to current config file.
set_config_name(value)	Set path to config file.
get_config_raw()	Get the active configuration in yaml format as a string.
set_config_raw(value)	Upload a new configuration in yaml format as a string.
get_config()	Get the active configuration as an object.
get_previous_config()	Get the previously active configuration as an object.
set_config(config)	Upload a new configuration from an object.
validate_config(config)	Validate a configuration object. Returns the validated config with all optional fields filled with defaults. Raises a CamillaError on errors.
read_config_file(path)	Read a config file from path. Returns the loaded config with all optional fields filled with defaults. Raises a CamillaError on errors.
read_config(config)	Read a config from yaml string and return the contents as an object, with defaults filled out with their default values.

Reading status

Method	Description
get_signal_range()	Get current signal range.
get_signal_range_dB()	Get current signal range in dB.
get_capture_signal_rms()	Get capture signal level rms in dB. Full scale is 0 dB. Returns a list with one element per channel.
get_playback_signal_rms()	Get playback signal level rms in dB. Full scale is 0 dB. Returns a list with one element per channel.
get_capture_signal_peak()	Get capture signal level peak in dB. Full scale is 0 dB. Returns a list with one element per channel.
get_playback_signal_peak()	Get playback signal level peak in dB. Full scale is 0 dB. Returns a list with one element per channel.
get_capture_rate_raw()	Get current capture rate, raw value.
get_capture_rate()	Get current capture rate. Returns the nearest common rate, as long as it's within +-4% of the measured value.
get_update_interval()	Get current update interval in ms.
set_update_interval(value)	Set current update interval in ms.
get_rate_adjust()	Get current value for rate adjust.
get_buffer_level()	Get current buffer level of the playback device.
get_clipped_samples()	Get number of clipped samples since the config was loaded.

Volume control

Method	Description
get_volume()	Get current volume setting in dB.
set_volume(value)	Set volume in dB.
get_mute()	Get current mute setting.
set_mute(value)	Set mute, true or false.

Enums

ProcessingState

• RUNNING: Processing is running.
• PAUSED: Processing is paused.
• INACTIVE: CamillaDSP is inactive, and waiting for a new config to be supplied.
• STARTING: The processing is being set up.
• STALLED: The processing is stalled because the capture device isn't providing any data.

StopReason

• NONE: Processing hasn't stopped yet.
• DONE: The capture device reached the end of the stream.
• CAPTUREERROR: The capture device encountered an error.
• PLAYBACKERROR: The playback device encountered an error.
• CAPTUREFORMATCHANGE: The sample format of the capture device changed.
• PLAYBACKFORMATCHANGE: The sample format of the playback device changed.

The StopReason enums also carry additional data:

• CAPTUREERROR and PLAYBACKERROR: Carries the error message as a string.
• CAPTUREFORMATCHANGE and PLAYBACKFORMATCHANGE: Carries the estimated new sample rate as an integer. A value of 0 means the new rate is unknown.

The additional data can be accessed by reading the data property:

reason = cdsp.get_stop_reason()
if reason == StopReason.CAPTUREERROR:
    error_msg = reason.data
    print(f"Capture failed, error: {error_msg})

Included examples:

read_rms

Read the playback signal level continuously and print in the terminal, until stopped by Ctrl+c.

python read_rms.py 1234

get_config

Read the configuration and print some parameters.

python get_config.py 1234

set_volume

Set the volume control to a new value. First argument is websocket port, second is new volume in dB. For this to work, CamillaDSP must be running a configuration that has Volume filters in the pipeline for every channel.

python set_volume.py 1234 -12.3

play_wav

Play a wav file. This example reads a configuration from a file, updates the capture device fto point at a given .wav file, and sends this modified config to CamillaDSP. Usage example:

python play_wav.py 1234 /path/to/wavtest.yml /path/to/music.wav