Video surveillance systems are currently undergoing transformation, and more and more traditional analog solutions are being replaced by digital solutions. Compared to analog video surveillance systems, digital video surveillance offers greater flexibility in video content processing or data transmission. At the same time, it has the ability to implement advanced features such as motion detection, face recognition and object tracking. The application of digital systems enables security systems to transmit video over the Internet, so we need to study different video streaming methods on the network. Streaming is the process of playing a file while the file is still being downloaded. Streaming video is a series of "moving images" that are sent in compressed form, which can be started before it is fully received, just like a video clip on a web page.
Here, some of the network protocols used in the video stream are described. The focus is on the features of the most important protocols in video surveillance, including TCP, UDP and RTSP.
Streaming Media Technology Agreement:
A protocol is a rule implemented for a particular technology that is used in streaming technology to carry message packets and communicate only through them. Some of the protocols used in streaming technology are described below:
The SDP, which represents a session description protocol, is used to describe a multimedia session in a format understood by the participants through the network. The purpose of SDP is to convey information about media streams in a multimedia session to help participants join or collect information about a particular session. In fact, the information conveyed by the SDP includes the session name and purpose, the session activity time, the codec format, the media in the session, and the information [address, port, format, etc.] that receives the media. Participants check this information and make a decision to join the session.
SDP is mainly used in large wide area networks [wide area networks] including the Internet. However, SDP can also be used for proprietary LAN [Local Area Network] and MAN [Metropolitan Area Network].
Dynamic Host Configuration Protocol [DHCP] is a network protocol that enables a server to automatically assign dynamic IP addresses to each device connected to the network. With this assignment, new devices can be added to the network without having to manually assign them a unique IP address. The introduction of DHCP facilitates the issues associated with manually assigning TCP/IP client addresses, providing network administrators with flexibility and ease of use.
DHCP is not a secure protocol because there is no build mechanism to allow clients and servers to authenticate each other. Both are vulnerable to deception because one computer can pretend to be another computer.
Real Time Transport Protocol [RTP] is an Internet Protocol standard for managing the real-time transmission of multimedia data over unicast or multicast network services. In other words, RTP defines a standard packet format to provide real-time audio and video over an IP network. RTP does not guarantee real-time delivery of data, but it does provide a mechanism to support streaming data for sending and receiving applications. It is used in conjunction with Real-Time Transport Control Protocol [RTCP] to ensure monitoring data transmission over large multi-cast networks and maintain Quality of Service [QOS]. Monitoring is used to detect any packet loss and compensate for any delay jitter.
RTP is widely used in communications and applications involving streaming media such as telephony or video teleconferencing applications. The recent application of RTP is the introduction of a VoIP [Internet Protocol Voice] system, which has become very popular as a replacement for conventional telephone circuits.
Real-Time Control Protocol [RTCP] is a control protocol that works in conjunction with RTP to monitor data transfers over large multicast networks. Providing feedback on the quality of service provided by RTP is the main function of RTCP.
The RTCP Control Packet is periodically sent to all other participants by each participant in the RTP session. It is important to point out that RTCP carries statistical and control data, while RTP passes data. The RTCP statistics contain sender or receiver reports, such as the number of bytes sent, the packets sent, the lost packets, and the round-trip delay between the endpoints. RTCP provides a way to correlate and synchronize different media streams from the same sender.
The primary protocol in streaming is the Real Time Streaming Protocol [RTSP], which is used to transport stored or live media data over an IP network. It provides client control for random access stream content. The application layer protocol is used to establish and control single or multiple time synchronized continuous media streams, such as video and audio. The RTSP server uses Transport RTP in conjunction with RTCP so that RTP acts as a transport protocol and RTCP will be applied to QOS [Quality of Service] analysis and synchronization between video and audio streams. Therefore, RTSP can control and provide real-time content. RTP and RTCP are independent of the upcoming transport layer and network layer. In fact, RTSP is more than just a protocol, it provides a simple set of basic commands to control the video stream.
RSTP is based on the bandwidth available between the client and the server, so big data can be divided into packet size data. This applies to real-time data feeds as well as storage. Therefore, the client software can play a packet while decompressing the second packet and downloading the third media file. This allows users to instantly hear or view real-time files without having to download the entire media file or feel the interruption between the data files.
Some of the features of the live streaming protocol are as follows:
- RTSP is capable of presenting media streams from different multimedia servers.
- RTSP can control and deliver real-time media between media servers and a large number of media clients.
- Firewall friendly: Both application and transport layer firewalls can be easily handled through protocols.
- RTSP provides on-demand access to multimedia projects, such as stored real-time audio/video files, real-time feeds or stored non-real-time projects.
- New parameters or methods can be easily added in the protocol, so they can be extended.
- There is proper control on the server. The server cannot be streamed to the client in any way, so that the client cannot stop streaming.
- Frame-level precision makes the protocol more suitable for media applications.
- RTSP allows interoperability between client-server multimedia products from multiple vendors.
Hypertext Transfer Protocol [HTTP], an application-level protocol, is a set of rules for transferring files [text, graphics, sound, video, and other multimedia files] over the Web, so the server uses these rules to exchange information. HTTP uses the server – the client model, where the web browser is the client. When the user opens this web browser, an HTTP command is sent to the web server. The browser uses HTTP to communicate with the server via TCP/IP and retrieves web content for the user.
It is worth mentioning that in addition to the context of the World Wide Web, HTTP is also used in distributed collaborative hypermedia information systems.
Real Time Messaging Protocol [RTMP] is used to transport audio, video and metadata over the network. In fact, it is a system that provides on-demand and real-time media to Adobe Flash applications developed by Adobe Systems. RTMP is a TCP-based protocol that maintains persistent connections and allows for low-latency communication. Splitting the stream into segments allows the stream to be transported smoothly while transmitting a large amount of information. RTMP supports video in MP4 and FLV as well as audio in AAC and MP3.
Some of the benefits of RTMP include its ability to stream in real time, allowing people to watch videos while recording video. In addition, it is capable of dynamic streaming, which means that video quality is automatically adjusted to bandwidth changes, and subsequent parts can be found in the video, which is especially useful for longer videos. The player maintains a tiny buffer instead of downloading video during playback, so it uses less bandwidth. The RTMP stream can jump to any location in the video at any point in time, so you can skip to the content you want to view without any unnecessary waiting. When using HTTP, you can only view what is already in the browser cache. When RTMP is used as a protocol, the host needs to install a dedicated server for RTMP.
However, RTMP has several drawbacks: because streaming data to the player, the bandwidth of the connection must be greater than the data rate of the video, so if the connection drops for a few seconds, the stream will be intermittent. Also, since it uses different protocols and ports with HTTP, it is easily blocked by a firewall. The biggest drawback is that RTMP can only be run in Flash, not in HTML5. Here, it can be replaced by other streaming protocols with broader support.
Transmission Control Protocol [TCP] is a popular transport layer protocol that is connection-oriented and provides a reliable byte stream to the top layer, called the application layer. TCP has a positive acknowledgment mechanism and also provides a mechanism to avoid congestion to reduce the transmission rate when the network is overloaded. TCP guarantees that all packets arrive in the correct order without corruption, reordering out-of-order packets and/or queries…Online Dating Program For Men (view mobile),Click here! Online Art Lessons (view mobile),Click here! Astonishing Conversions - Online Allure,Click here!