Query Audio Inputs and Outputs in Ecasound

Ecasound includes a powerful interactive mode (EIAO) that allows you to manage signal routing, inspect system drivers, and control processing in real time. This article explains how to start Ecasound in interactive mode and use its built-in commands to query currently active audio inputs and outputs, as well as inspect supported audio device drivers and object types.

Launching Interactive Mode

To access the interactive prompt, launch Ecasound with the -c flag from your terminal:

ecasound -c

If you already have a predefined setup or specific input/output devices to test immediately, you can pass them along with the command (for example, ecasound -c -i alsa -o alsa), but launching with -c alone provides an empty session ready for configuration.

Listing Currently Bound Inputs and Outputs

Once inside the interactive interpreter (ecasound'c>), you can query the active chainsetup for assigned inputs and outputs using the audio object list command:

aio-list

This command returns all audio inputs and outputs attached to the current chainsetup. If you need more detailed runtime information about the status of these I/O streams—such as buffer sizes, positions, and operational state—run:

aio-status

Checking Supported Audio I/O Drivers and Formats

To see which audio subsystems (such as ALSA, JACK, OSS, or file handlers like WAV and FLAC) are available for input and output on your installation, query the registered audio object types:

aio-register

This displays a complete list of valid audio object prefixes (e.g., alsa, jack, soundcard, null) that you can use when defining input (-i) and output (-o) targets.

Verifying Chainsetup Routing

To inspect the overall topology and see how inputs and outputs map to individual processing chains:

cs-status

The output details the active setup, selected chains, connected audio inputs, and assigned audio outputs, allowing you to confirm that your inputs and outputs are properly routed before initiating playback or recording with the start command.