Video Relay: Protocols, Configuration and Usage Examples

Video relay plays a key role in delivering online content to viewers. This technology allows you to receive a video stream from a source and distribute it to multiple devices through the internet in real-time. Thanks to relay technology, it becomes possible to organize broadcasts of sporting events, concerts, webinars, and video conferences, reaching a large audience.

Video relay solves several important tasks at once. First, it ensures the scalability of broadcasting, allowing video to be transmitted to a large number of viewers without excessive load on the signal source. Second, relay technology minimizes delays, which is critical for real-time broadcasts. Third, it adapts video quality to the available bandwidth of each viewer, which guarantees optimal viewing on various devices and under different network conditions.

Compared to other methods of video delivery, video relay has a number of advantages. It provides more efficient use of network resources, flexibility in adapting to different broadcasting conditions, and interactivity due to low latency. Because of this, relay has become the main method of organizing streaming broadcasting in various fields, which we will discuss in this article.

Contents

• Fundamentals of Video Relay Technology
• Application of Video Relay in Various Industries
• Technical Aspects of Relay Configuration
• The Future of Video Relay
• Conclusion
• Frequently Asked Questions (FAQ)

Fundamentals of Video Relay Technology

Video relay is a technology that allows you to receive a video stream from a source and distribute it in real-time to multiple devices over a network. The basic principle of relay is that the incoming video stream from a camera, encoder, or other source device is received by the relay server, which then repackages and transmits this stream to multiple clients connected to the server.

Various data transmission protocols play an important role in the video relay process:

1. HLS (HTTP Live Streaming) - a protocol developed by Apple that allows delivering video and audio content through a regular web server to various devices, including mobile phones, tablets, computers, and smart TVs. When using HLS, the video stream is divided into small fragments (chunks) typically lasting from 2 to 10 seconds and packaged in MPEG-TS format. The video fragments and corresponding playlist (m3u8) are served via a web server using the HTTP protocol. This approach provides adaptive streaming and allows the client application to automatically select the optimal video quality depending on the network bandwidth.
2. RTMP (Real-Time Messaging Protocol) - a protocol originally developed by Macromedia (now Adobe) for transmitting audio, video, and other data between Flash Player and server. RTMP uses a persistent TCP connection to minimize delays. Therefore, it is often used for organizing live broadcasts where low latency is critical. However, due to the discontinuation of Flash support, the RTMP protocol is gradually giving way to other protocols such as HLS and WebRTC.
3. RTSP (Real-Time Streaming Protocol) - a protocol for controlling real-time data delivery, developed by IETF (Internet Engineering Task Force). RTSP provides the ability to remotely control the stream, allowing the client to perform actions such as play, pause, rewind. The media stream itself is usually transmitted using RTP (Real-time Transport Protocol) protocols over UDP. RTSP is often used in IP cameras and video surveillance systems.
4. WebRTC (Web Real-Time Communication) - a modern protocol and set of technologies for organizing the transmission of streaming audio and video data between browsers or other compatible applications using peer-to-peer technology. WebRTC provides low latency, adaptive bitrate, and data encryption. WebRTC implementation is built into most modern browsers, making it an attractive solution for real-time web applications.

It's important to understand the difference between live streaming and video relay. In live streaming, video is captured in real-time, encoded, and immediately sent to viewers, usually with minimal buffering on the client and server side. In the case of relay, the incoming stream can be buffered on the server to compensate for possible short-term problems with the network or signal source. Also, during relay, the video stream can be re-encoded into other formats and bitrates to adapt to different broadcasting conditions and device types.

Depending on the broadcasting scenario, video relay can be organized in the following modes:

• Unicast - when the video stream is delivered individually to each viewer via a separate connection. Unicast provides flexibility and interactivity but requires more resources from the server with a large number of viewers.
• Multicast - when video is simultaneously transmitted to a group of recipients, which significantly reduces the network load. However, multicast usually works only in managed local networks and is not supported by internet providers.
• Broadcast - broadcasting video to all network nodes, even if they did not request this stream. Broadcasting is used in over-the-air and cable television but is not used for video relay over the internet.

Thus, Unicast is the main mode when organizing relay over HLS, RTMP, RTSP, and WebRTC protocols.

Table 1: Comparison of broadcasting modes

Application of Video Relay in Various Industries

Video relay technology finds wide application in various fields of activity where it is necessary to deliver video content in real-time to a large audience.

In media and entertainment, relay is used to organize online broadcasts of sports competitions, concerts, TV shows, and other mass events. Thanks to adaptive streaming and scalability, viewers can enjoy watching on any device with optimal quality, corresponding to the bandwidth of their internet connection. For example, broadcasts of the Olympic Games or World Cup football championships gather a multi-million audience worldwide, and relay ensures the possibility of reliable video delivery to everyone.

In the field of video surveillance and security, video relay allows transmitting images from multiple surveillance cameras to security control panels, situation centers, or mobile devices of security personnel. The video streams can be transmitted both over a local network and through the internet, which enables remote monitoring of facilities. Using low-latency protocols, such as WebRTC, ensures prompt response to emerging incidents.

Educational institutions and online platforms use relay for organizing distance learning, conducting webinars, online lectures, and presentations. Thanks to the possibility of integration with learning management systems (LMS) and collaboration tools, video relay allows creating an interactive educational environment where students can not only watch video in real-time but also participate in discussions and ask questions to the teacher.

In the corporate sector, video relay is in demand for conducting video conferences, remote meetings, webinars, and broadcasts of corporate events. The use of relay became especially relevant in the context of the mass transition to remote work. Company employees can connect to video conferences and meetings from their workplaces, from home, or on the go, using laptops, tablets, and smartphones. This format of interaction increases team engagement and the efficiency of collaborative work.

Video relay plays an important role in organizing internet television services (IPTV) and providing video on demand (VoD) on connected TVs and mobile devices. Providers of OTT services (Over the Top), such as Netflix, Hulu, Amazon Prime Video, use relay to deliver video content to their subscribers. Adaptive streaming and optimization of video delivery through CDN networks (Content Delivery Network) allow ensuring high quality and availability of the service even with a large number of simultaneous viewers.

As we can see, video relay is a universal tool for organizing online broadcasts of various scales and purposes. The possibility of flexible configuration of broadcasting parameters, integration with web technologies and automation tools makes relay an attractive choice for media and entertainment companies, educational platforms, the corporate sector, and OTT service providers.

Technical Aspects of Relay Configuration

For successful configuration of video relay using Flussonic Media Server, it is necessary to perform a series of technical steps and take into account the specifics of the particular project. Let's consider the main stages of server configuration and recommendations for performance optimization.

Installation and Basic Configuration of Flussonic Media Server:

1. Download the Flussonic Media Server distribution and install it on a Linux-controlled server, following the instructions from the documentation.
2. After installation, open the Flussonic administration web interface, which is available by default at http://your_server:80.
3. Perform the initial server setup, setting the administrator password and network settings.

Configuring Input and Output Streams:

1. In the Flussonic web interface, go to the "Media" section. Here you can add new incoming streams, specifying their URL and protocol (RTMP, RTSP, UDP, HLS, etc.).
2. For each incoming stream, specify the relay parameters: outgoing protocols (HLS, RTMP, WebRTC), path for archive storage, DVR settings, and other options.
3. Save the settings and start the relay.

Real-time Stream Transcoding:

1. Flussonic supports transcoding incoming streams into various formats and with changes in video parameters (resolution, bitrate, codec).
2. To configure transcoding, create profiles with the desired parameters in the Transcoder section of the web interface.
3. Apply the transcoding profiles to incoming streams to ensure video adaptation to the characteristics of the network and viewer devices.

Performance Optimization:

• Use server equipment with sufficient computing power and RAM. A processor with support for Intel Quick Sync Video or NVIDIA NVENC technologies will reduce the load during video transcoding.
• Ensure high bandwidth of the server's network connection, especially on the outgoing channel.
• Configure buffering of incoming streams using the RTMP protocol to compensate for possible short-term signal losses from the source.
• To distribute the load between servers, use load balancers and caching systems such as AWS Elastic Load Balancer or Nginx.

Bandwidth Management and Failure Prevention:

• Set limits on the maximum number of simultaneous viewer connections and total outgoing bitrate to avoid server overload.
• Use adaptive streaming (HLS, MPEG-DASH) for automatic adjustment of video quality to the network bandwidth on the viewer's side. This will help avoid buffering and playback interruptions.
• Implement a monitoring system for server and network health to promptly identify and address potential problems.

Table 2: Recommended hardware settings for video relay

By following these recommendations and relying on the detailed documentation of Flussonic Media Server, you will be able to configure effective and stable video relay, adapted to the needs of your project. If necessary, contact Flussonic technical support for additional consultations.

The Future of Video Relay

Video streaming technologies are rapidly developing, opening new possibilities for relay and content delivery to viewers. Let's consider some key trends and promising directions that will determine the future of video relay.

One of the main trends is improving video quality and transitioning to higher resolutions such as 4K and 8K. As network bandwidth and playback device performance increase, the demand for ultra-high-definition content will grow. This will require relay service providers to modernize infrastructure and implement new encoding technologies such as H.265/HEVC and AV1, which provide efficient video compression while maintaining high quality.

Another important direction of development is the application of artificial intelligence (AI) and machine learning in video relay. AI algorithms can be used for automatic optimization of video quality depending on network conditions and viewer device characteristics, ensuring the best user experience. In addition, AI will help in content personalization, automatic metadata creation, and smart video indexing for improved navigation and search.

The future of video relay is also closely linked to the development of 5G networks and edge computing. The ultra-high bandwidth and low latency of 5G networks will open new possibilities for video streaming, especially in scenarios requiring minimal response time, such as cloud gaming, augmented and virtual reality (AR/VR). Edge computing will allow moving video processing closer to end users, reducing the load on central infrastructure and increasing scalability.

Video relay will play an important role in creating "smart cities" and implementing the concept of the Internet of Things (IoT). Thanks to built-in cameras and sensors connected to the network, it will become possible to analyze video streams in real-time to solve various tasks such as traffic management, ensuring public safety, environmental monitoring. Integration of video relay with IoT platforms and data-based decision-making systems will allow creating intelligent and adaptive services on a city scale.

Finally, the development of Web technologies such as WebRTC and HTML5 will contribute to the convergence of traditional broadcasting and online video. Video relay will become even more accessible thanks to the possibility of viewing directly in the browser without installing additional plugins. Integration with web platforms will allow creating interactive and personalized video services, combining the advantages of linear broadcasting and video on demand.

Conclusion

Video relay is a key technology that ensures the delivery of video content in real-time to a wide audience via the internet. Due to its efficiency, scalability, and flexibility, relay has become an indispensable tool in various fields, from media and entertainment to education and video surveillance.

The ability to adapt video quality to network bandwidth and viewer device characteristics makes relay an optimal solution for delivering content to heterogeneous platforms. The use of modern protocols such as HLS, MPEG-DASH, and WebRTC ensures low latency, reliability, and compatibility with a wide range of client applications.

Professional relay solutions, such as Flussonic Media Server, provide a comprehensive set of functions for organizing video streaming of any scale. Thanks to support for multi-format broadcasting, archiving capabilities, built-in mechanisms for content processing and protection, Flussonic allows implementing complex relay scenarios and integrating video services with external platforms and systems.

As technologies develop and the need for quality video content grows, video relay will continue to evolve. Increasing video resolution, applying artificial intelligence, integration with 5G networks and edge computing, as well as convergence with web platforms, open new horizons for the streaming broadcasting industry.

Relying on reliable and scalable solutions such as Flussonic, video service providers will be able to keep pace with technological progress and provide their viewers with innovative, personalized, and convenient services. Video relay will remain the foundation for building modern content delivery systems, ensuring fast, high-quality, and ubiquitous access to video information in the era of digital transformation.

Frequently Asked Questions (FAQ)

How does video relay help reduce the load on the source server with a large number of viewers?

Video relay allows distributing the load among several servers, which reduces the requirements for performance and bandwidth of the source server. Instead of processing requests from all viewers directly, the source server transmits the video stream to the relay server, which, in turn, serves multiple clients.

Thus, the source server can focus on generating the video stream, while the relay server takes on the task of distributing content among viewers. This is especially effective with a large number of simultaneous connections, as the load is distributed among relay servers, preventing overload of the video source.

What is the difference between live video relay and video-on-demand (VOD) streaming?

Live video relay and video-on-demand (VOD) streaming are two different approaches to delivering video content over the internet. In live video relay, content is transmitted in real-time from the source to viewers.

The video stream is generated and sent continuously, and all viewers receive the same playback point at each moment in time. Live video relay is ideal for broadcasting events happening in real-time, such as sports competitions, concerts, or news reports.

In the case of video-on-demand (VOD) streaming, content is pre-recorded and stored on a server. Viewers can choose which content they want to watch and control playback (pause, rewind). Each viewer receives an individual video stream, independent of other viewers. VOD is typically used to provide access to a library of video content, such as movies, series, or educational materials.

Is video relay with adaptive bitrate possible and how does it work?

Yes, video relay with adaptive bitrate (Adaptive Bitrate Streaming) is widely used to ensure optimal playback quality on various devices and under different network conditions. In adaptive relay, the video stream is encoded with multiple bitrates and resolutions. The relay server stores several versions of the same video, each optimized for a specific network bandwidth.

During playback, the client application automatically selects the most suitable version of the video based on current network conditions and device performance. If network bandwidth decreases, the client can switch to a version with a lower bitrate to avoid buffering and playback interruption. When bandwidth improves, the client can switch to a version with a higher bitrate to improve image quality. This process happens dynamically and is imperceptible to the viewer.

Special protocols such as HLS (HTTP Live Streaming) and MPEG-DASH (Dynamic Adaptive Streaming over HTTP) are used to implement adaptive relay. These protocols break the video stream into small segments and create a playlist with information about available bitrates and resolutions. The client downloads video segments as needed, choosing the optimal version based on current network conditions. Adaptive relay provides flexibility and improves playback quality for viewers with different internet connection speeds and on different devices.