Loop Audio Indefinitely with Ecasound

While Ecasound does not offer a dedicated command-line flag to loop an input file indefinitely on its own, you can easily achieve continuous playback. Ecasound is designed as a powerful multitrack recorder and processing engine rather than a general media player, meaning native playback looping relies on external standard input piping or scripting via the Ecasound Control Interface (ECI).

The Native Limitation

When running standard commands such as:

ecasound -i input.wav -o alsa

Ecasound processes the audio stream from beginning to end and exits immediately when it reaches the end of the input file. There is no simple --loop or -repeat switch built into the standard command-line syntax to restart the file automatically.

Solution 1: Piping via a Shell Loop

The most direct way to loop an audio file indefinitely from the terminal without writing a complex script is to stream the audio repeatedly into Ecasound's standard input (stdin).

For raw PCM or standard WAV files where the format matches:

while true; do cat input.wav; done | ecasound -i:stdin -o:alsa

Note: With standard WAV files, repeatedly streaming the file header can occasionally cause audible clicks or stream resets between iterations. If you experience glitches, convert the file to raw PCM format first or strip the headers:

while true; do sox input.wav -t raw -; done | ecasound -f:s16_le,2,44100 -i:stdin -o:alsa

Solution 2: Ecasound Interactive Mode (EIAM)

If you are controlling Ecasound interactively or through an automated controller, you can use the Ecasound Interactive Mode (EIAM). In interactive mode, you can issue commands to reset the playback head to the beginning of the file when playback finishes:

  1. Launch Ecasound in interactive mode: 
    ecasound -c -i input.wav -o alsa
  2. Start playback by typing start.
  3. Reset the position back to the beginning at any time by issuing setpos 0 or setpos-first.

Solution 3: Scripting with the Ecasound Control Interface (ECI)

For complex automation, Ecasound provides Python, Perl, and C APIs via ECI. You can write a lightweight script that monitors the playback position or the engine state. When the engine reaches the end of the file or enters a stopped state, the script issues a rewind command (cs-set-position 0) and starts the engine again, creating an automated continuous loop.