audio-river/doc/configFile.md

River configuration file

@tableofcontents

Objectifs:

• Understand the architecture of the configuration file.
• all that can be done with it.

Basis:

The river configuration file is a json file. We use @ref ejson_mainpage_what to parse it then we have some writing facilities.

River provide a list a harware interface and virtual interface.

The hardware interface are provided by @ref audio_orchestra_mainpage_what then we will plug on every platform.

The file is simply architecture around a list of object:

{
	"speaker":{
		
	},
	"microphone":{
		
	},
	"mixed-in-out":{
		
	},
}

With this config we declare 3 interfaces : speaker, microphone and mixed-in-out.

Harware configuration:

In every interface we need to define some Element:

• "io" : Can be input/output/... depending of virtual interface...
• "map-on": An object to configure airtaudio interface.
• "frequency": 0 to automatic select one. Or the frequency to open harware device
• "channel-map": List of all channel in the stream:
  • "front-left"
  • "front-center"
  • "front-right"
  • "rear-left"
  • "rear-center"
  • "rear-right"
  • "surround-left",
  • "surround-right",
  • "sub-woofer",
  • "lfe"
• "type": Fomat to open the stream:
  • "auto": Detect the best type
  • "int8",
  • "int8-on-int16",
  • "int16",
  • "int16-on-int32",
  • "int24",
  • "int32",
  • "int32-on-int64",
  • "int64",
  • "float",
  • "double"
• "nb-chunk": Number of chunk to open the stream.

Generic configuration file use

You can specify a generic configuration file foir a user in the path ~/.local/share/audio-river/config.json

The default config file is:

{
	microphone:{
		io:"input",
		map-on:{
			interface:"auto",
			name:"default",
		},
		frequency:0,
		channel-map:[
			"front-left", "front-right"
		],
		type:"auto",
		nb-chunk:1024,
		mux-demux-type:"float"
	},
	speaker:{
		io:"output",
		map-on:{
			interface:"alsa",
			name:"default",
		},
		frequency:0,
		channel-map:[
			"front-left", "front-right",
		],
		type:"auto",
		nb-chunk:1024,
		volume-name:"MASTER",
		mux-demux-type:"float"
	}
}

If the pplication start with no name it try to load this file and if it fail it load the internalversion of a basic file