How to Pause Ecasound Audio Over Net-ECI

This guide explains how to pause active audio processing in Ecasound using the Network Ecasound Control Interface (Net-ECI). It covers the exact command string required to pause execution, details how Ecasound handles transport states, and demonstrates how to transmit the command over a network connection to control an active audio engine.

The Net-ECI Pause Command

The command string sent over Net-ECI to pause audio processing in an active Ecasound instance is:

stop

When transmitted over a TCP socket connection, the command must be terminated with a standard newline character:

stop\r\n

stop\n

How Ecasound Handles Pausing

Ecasound does not feature a dedicated pause command keyword in its control language. Instead, audio playback and processing are managed using the start and stop transport commands:

stop: Immediately halts audio engine processing. The current playhead and sample position within the chainsetup are preserved in memory rather than reset to zero.
start: Resumes audio processing from the exact sample position where the engine was stopped.

Because stop maintains the active chainsetup, input/output routing, and transport position, sending stop functions as a pause operation. To reset the position back to the beginning instead of resuming, a separate position command (such as setpos 0) must be explicitly issued before restarting.

Protocol and Communication Example

Net-ECI operates over a plain-text TCP socket, running by default on port 2868.

To pause an active instance via an interactive socket connection (such as netcat or telnet):

Connect to the host running Ecasound:
```
nc localhost 2868
```
Send the pause command:
```
stop
```
Verify the engine state by issuing:
```
engine-status
```
The server returns the updated state, confirming that processing has stopped while the engine remains ready to resume.