lws-rtc-camera plugin

Overview

This plugin implements a WebRTC camera integration within libwebsockets. It manages V4L2 device capture, multimedia encoding, and secure routing to an lws-webrtc-mixer endpoint. The plugin encapsulates complex multimedia pipelines behind a simple operational API that the application can trigger dynamically.

Important: This plugin requires protocol_lws_auth_device_client to be enabled to operate securely. The authentication plugin handles the RFC 8628 Device Authorization Flow to securely pair headless cameras with the mixer and acquire the necessary access tokens required by protocol_lws_rtc_camera during the attachment phase.

PVOs

The plugin is configured via Protocol Vhost Options (PVOs) to exchange ABI structures between the application and the plugin.

PVO name	Type	Description
`lws-webrtc-ops`	`struct lws_webrtc_ops **`	Pointer to receive the underlying `protocol_lws_webrtc` ops, allowing this plugin to bind to the WebRTC subsystem.
`lws-rtc-camera-ops`	`struct lws_rtc_camera_ops **`	Pointer to where the plugin should write its operational API struct (`cam_ops`). The application invokes this to trigger camera attachment/detachment.
`app-ops`	`struct lws_rtc_camera_ops *`	(Optional) Pointer to the application's callback structure to receive notifications on camera state changes (e.g. `state_cb`).

lejp-conf Example

Below is an example of configuring the camera plugin through JSON:

json

{
	"vhosts": [{
		"name": "my-camera-vhost",
		"ws-protocols": [{
			"lws-rtc-camera": {
				"status": "ok",
				"lws-webrtc-ops": "my_webrtc_ops_ptr",
				"lws-rtc-camera-ops": "my_cam_ops_ptr",
				"app-ops": "my_app_ops_ptr"
			}
		}]
	}]
}

Note: Since the PVO values must resolve to memory pointers for the ABI exchange, dynamic resolution or native C instantiation is typically required in practice.