RTMPd

RTMPd is a daemon, or background process, that implements the Real-Time Messaging Protocol (RTMP). RTMP is a network protocol designed for real-time audio, video, and data communication over the internet. RTMPd typically acts as a server, accepting incoming RTMP connections from clients such as media players or broadcasting software.

When a client connects to RTMPd, it can initiate a stream. This stream can be either live, meaning real-time content is being sent, or recorded, where pre-existing media is played back. RTMPd handles the negotiation of connection parameters, the establishment of communication channels for audio, video, and data, and the management of these streams. It can receive streams from publishers and relay them to multiple viewers, functioning as a media server.

Key functions of RTMPd include stream publishing, where a source sends media to the server, and stream playback, where clients receive the media from the server. It also supports features like metadata exchange, bandwidth control, and session management. RTMPd is often used in conjunction with streaming platforms and content delivery networks (CDNs) to facilitate live broadcasting and video-on-demand services. While RTMP itself is not encrypted by default, RTMPd can often be configured to work with TLS/SSL for secure transport, known as RTMPS.