cpiped

cpiped captures an audio stream and outputs it to a pipe

cpiped was born to capture line-in audio from a sound card and send it to forked-daapd. On sound detection, it runs a simple script to start playing the associated pipe in forked-daapd.

Contents

• Contents
• Features
• Getting Started
  • Prerequisites
  • Installation
• Usage
  • Options
  • Env variables
• ToDo(s)
• Acknowledgments
  • Top contributors:

Features

• Buffering to handle clock mismatch
• Command execution on sound and silence detection
• User defined noise threshold
• Different sample rate handling
• Multiple instances running in parallel thanks to parametrized pid

Getting Started

Prerequisites

cpiped relies on ALSA lib as only prerequisite

• Debian

  sudo apt install -y libasound2-dev

Installation

1. Clone the repository

   git clone https://github.com/ale275/cpiped.git

2. Make cpiped

   cd cpiped
   make

3. Install cpiped

   sudo install cpiped /usr/local/sbin/

Usage

cpiped is an application meant to be run from command line or demonized

cpiped [-s arg] [-e arg] [OPTIONS] FIFO

FIFO: path to the named pipe where sound will be written

Options

Option	Description	Type	Default	Range	Required?
-d	ALSA capture device in hw:<card>,<device> format.	string	'default'		No
-f	ALSA capture device sample rate in Hz.	integer	44100	16000 - 192000	No
-b	Buffer size in seconds.	float	.25	.1 - 5.0	No
-s	Command to run, in background, when sound is detected.	string			Yes
-e	Command to run, in background, when silence is detected.	string			Yes
-t	Silence threshold expressed as signal power.	integer	100	1 - 32767	No
-D	Daemonize.	bool			No
-p	Path to pidfile.	string	'/var/run/cpiped.pid'		No
-v	Log verbosity. (-vv and -vvv for higher verbosity levels)	bool			No

Env variables

On start cpiped will set the following env variables

• CPIPED_SR audio capture sample rate in Hz
• CPIPED_SS audio capture sample size in bit(s)
• CPIPED_CC audio capture channel(s) count

Those variables are visible by the sound and silence detect commands

ToDo(s)

• Improve Makefile to create dedicated build folder
• Improve Makefile to add install directive

See the open issues for a full list of proposed features (and known issues).

Acknowledgments

• cpiped original code of cpiped by b-fitzpatrick
• NDpiped modified version writing the buffer only when sound was detected
• maweki cpiped fork for parametrized pid file

Top contributors: