View source for Pam rd jackd rivendell daemons

```mediawiki
= Rivendell Daemons, JACK Audio System, and PAM Integration =

In a Rivendell radio automation environment, the '''Rivendell daemons''', the '''JACK Audio Connection Kit (jackd)''', and the '''pam_rd PAM module''' work together to provide user authentication, audio routing, scheduling, recording, and playout services. Rivendell supports JACK as an audio driver and includes PAM integration for multi-user authentication.

== JACK Audio System (jackd) ==

JACK (Jack Audio Connection Kit) is a low-latency audio server that provides a centralized audio routing layer between Rivendell applications and physical audio hardware. Rivendell can use JACK as its primary audio driver.

=== Functions of JACK ===

* Manages audio interfaces and sound devices.
* Provides low-latency audio transport between applications.
* Creates virtual audio ports that applications can connect to.
* Allows multiple applications to share and route audio streams without direct hardware access.

=== JACK Workflow ===

<pre>
Audio Source
     │
     ▼
   jackd
     │
     ▼
Rivendell Application
     │
     ▼
 Audio Output Device
</pre>

For example, audio recorded by RDCatch can be routed through JACK to storage, while audio played by RDAirPlay can be routed through JACK to a broadcast console or transmitter chain.

== Rivendell Daemons ==

Rivendell relies on several background processes (daemons) that provide automation and control services. These daemons run continuously and support the various Rivendell applications.

=== rdcatchd ===

The '''rdcatchd''' daemon is responsible for:

* Managing scheduled recordings. 
* Executing automated recording events. 
* Receiving audio through configured audio drivers such as JACK. 

=== ripcd ===

The '''ripcd''' daemon provides Rivendell interprocess communications and automation services.

Functions include:

* Communication between Rivendell applications. 
* GPIO and automation event handling. 
* Coordination of system-wide control messages. 

=== Other Rivendell Applications ===

Applications that interact with these services include:

* RDAirPlay (On-air playout) 
* RDPanel (Cart wall application) 
* RDLibrary (Audio library management) 
* RDLogManager (Log generation and scheduling) 

These applications communicate with Rivendell services while using JACK for audio transport. 

== PAM Integration (pam_rd) ==

Rivendell includes a PAM (Pluggable Authentication Module) component called '''pam_rd'''. Documentation for this component is distributed as ''pam_rd.txt'' and provides support for authentication and multi-user environments. 

=== Purpose of pam_rd ===

The pam_rd module enables:

* User authentication through the Linux PAM framework. 
* Multi-user workstation support. 
* Integration between Linux authentication and Rivendell user management. 
* Access control for Rivendell applications and services.

=== Authentication Process ===

<pre>
User Login
     │
     ▼
Linux PAM Framework
     │
     ▼
pam_rd
     │
     ▼
Rivendell User Authorization
     │
     ▼
Access Granted / Denied
</pre>

When a user launches a Rivendell application or logs into a Rivendell workstation, the PAM framework invokes pam_rd to validate credentials and determine authorization for Rivendell resources. 

== Relationship Between Daemons, JACK, and PAM ==

The components work together as follows:

<pre>
Operator
    │
    ▼
 PAM / pam_rd
    │
    ▼
Rivendell Applications
    │
    ▼
Rivendell Daemons
    │
    ▼
 JACK (jackd)
    │
    ▼
Audio Hardware
</pre>

* '''pam_rd''' authenticates and authorizes users. 
* '''Rivendell daemons''' perform automation, scheduling, recording, and system coordination tasks. 
* '''jackd''' transports audio between Rivendell applications and audio devices with low latency.

== Summary ==

In a Rivendell installation:

* '''pam_rd''' determines who can access the system. 
* '''Rivendell daemons''' manage broadcast automation functions and interprocess communications.
* '''jackd''' provides the low-latency audio infrastructure used for recording, playback, and audio routing. 

Together, these components provide a secure, multi-user broadcast automation platform capable of professional radio playout and recording workflows.