Demystifying Video Streaming Latency: A Comprehensive Guide

Latency in Video Streaming

Understanding and managing latency is paramount in delivering video content efficiently, especially in time-sensitive scenarios like sports broadcasting. This guide focuses on the contribution side of a video pipeline, highlighting key terms and shedding light on the Zixi protocol’s approach to latency.

Key Terms:

• Round-Trip Time (RTT): Time for a packet to travel from sender to receiver and back
• Jitter: Variation in packet arrival times
• Inter-Packet Arrival Time (IAT): Time between packets
• Automatic Repeat Request (ARQ): Re-requesting of packets by the receiving device
• Forward Error Correction: Extra packets to rebuild broken ones
• TCP: Transmission Control Protocol
• UDP: User-Datagram Protocol

Understanding Latency

Latency measures the time packets spend on a network or between sender and receiver devices. It’s both a measurement and a tool, representing the time a packet waits in a receiver’s buffer. While network latency is often beyond control, adjusting the buffer size on the receive device is crucial.

Configuring Latency

Buffer size configuration, labeled as Input buffer, Dejitter buffer, Smoothing buffer, or simply Latency, controls how long packets are stored before release. It’s a static setting, impacting stream reliability and efficiency. Striking a balance is crucial, avoiding early handoffs during network noise and minimizing buffer wait times.

The Role of the Buffer

The receiver’s buffer is pivotal for stream repair, providing a smooth handoff, enabling packet re-requesting, and facilitating packet repairing with Forward Error Correction (FEC). Proper sizing and protocol selection are essential. Unlike other protocols, Zixi protocol has both ARQ, FEC, and features dynamic latency which automatically optimizes buffer size based on network conditions.

TCP vs. UDP and Streaming Protocols

Protocols like RTMP (TCP) and Zixi (UDP) differ due to foundational protocols. TCP ensures ordered, uncorrupted packet delivery, controlling latency. UDP, a quicker but connectionless protocol, requires additional features for reliability. Zixi’s incorporation of ARQ, FEC, and dynamic latency makes it a recommended choice for optimal performance.

Conclusion

Latency can impact event success, especially in sports. Understanding latency dynamics, network capabilities, and selecting the right protocol are crucial. Zixi offers a comprehensive solution, ensuring low latency and reliability at scale. Contact us to discover how Zixi can address your latency and reliability challenges.