RTMP vs SRT vs NDI for Video Streaming

[Everlasting Summer 20]

"RTMP" (Real-Time Messaging Protocol), "SRT" (Secure Reliable Transport), and "NDI" (Network Device Interface) are three different protocols used for streaming and broadcasting video over a network. Each has its unique features, advantages, and use cases:

1. RTMP (Real-Time Messaging Protocol):

   • Purpose: Initially developed by Macromedia, RTMP is widely used for streaming audio, video, and data over the Internet, typically from a media server to a flash player.
   • Key Features:
     • Low latency.
     • Adaptive bitrate streaming, which adjusts the video quality according to the viewer's bandwidth.
   • Usage: Commonly used for live streaming on platforms like YouTube, Facebook Live, and Twitch.
   • Limitations:
     • Being an older protocol, it lacks some modern features like error correction.
     • Many platforms are moving away from RTMP in favor of newer protocols.

2. SRT (Secure Reliable Transport):

   • Purpose: Developed by Haivision, SRT is designed for secure and reliable transport of high-quality, low-latency video across the public Internet.
   • Key Features:
     • High performance in poor network conditions.
     • Supports encryption for secure transmission.
     • Error recovery and jitter control, ideal for unstable networks.
   • Usage: Used in broadcasting where quality and security are paramount, especially over unpredictable networks.
   • Advantages Over RTMP: Offers better security, error correction, and is more suited for unstable network conditions.

3. NDI (Network Device Interface):

   • Purpose: Developed by NewTek, NDI is used for sharing video sources over a local network in real-time.
   • Key Features:
     • High-quality video with low latency.
     • Allows multiple video systems to communicate over a local area network.
   • Usage: Widely used in broadcast studios and live event production, where multiple video sources need to be shared and managed over a network.
   • Advantages:
     • Flexibility in connecting multiple devices and sources.
     • High-quality video suitable for professional production environments.
   • Limitations:
     • Primarily designed for use within a local network and not over the public Internet.

So:

• RTMP is a more traditional protocol best suited for live streaming to large audiences over the Internet.
• SRT excels in secure and reliable delivery of high-quality video over potentially unstable networks.
• NDI is ideal for high-quality, low-latency video sharing within a local network, especially in professional production environments.