EasyNVR, as a pioneer product of video Internetization, has been in development for almost 5 years. During this period, it has undergone many major iterations and optimizations, and has been continuously enriched and improved to achieve the current results:
At the beginning of the design of EasyNVR, we built according to the goal of the video capability platform, connecting the hardware of various manufacturers at the bottom layer and various video scene applications on the upper layer. The capability layer of EasyNVR is like giving a token key. This key can switch all the capabilities of EasyNVR:
So what technology is needed to make a product like EasyNVR? Today we will summarize the dry goods technologies used by EasyNVR:
- EasyOnvifClient performs device discovery and device live streaming address acquisition;
- EasyRTSPClient performs RTSP streaming;
- EasyAACEncoder transcodes security audio such as G.711/G.726 into AAC format;
- EasyRTMP corrects the audio and video streams and pushes them to the EasyDSS streaming server;
- EasyDSS streaming media server performs RTMP/HTTP-FLV/HLS synchronous output, compatible with all terminals;
- Peripheral controls the rhythm of pulling stream -> pushing stream -> forwarding according to the user's interface request;
- Synchronization of each circulation node will do some snapshots, error code recording and external output;
- **AI+** access to various intelligent analysis algorithms;
How to build an edge computing service like EasyNVR
Step 1: Selection of device docking protocol
Whether it uses RTSP or Onvif protocol to fetch from the device, or the national standard GB/T28181 to fetch the stream to the device, it is based on the protocol supported by the device to obtain the audio and video data of the device callback through the protocol process, such as Haikang's NetSDK, national Power grid video platform A/B interface, etc.;
The choice of streaming protocol depends on your own application requirements. For example, if your device only has Hikvision, then you can use Hikvision’s SDK to get the stream, but if your device is available from various manufacturers, and Not fixed, it is recommended to use RTSP, an international standard streaming method.
So, taking RTSP streaming as an example, we have many options in open source or commercial fields, such as ffmpeg and EasyRTSPClient (https://github.com/tsingsee/EasyRTSPClient);
Step 2: Data processing and analysis
After fetching the audio and video stream from the first step, we need to unify the stream Demux into the ES stream for further processing. For example, most of the streams output by the Haikang SDK are PS streams. We need to parse the PS into ES audio and video data. Based on the audio and video data of ES, various operations such as snapshots, video information, transcoding, and video analysis are performed.
Step 3: Push and distribute
After preliminary data processing in the second step, we need to push the ES audio and video data to nginx-rtmp or EasyDSS (www.easydss.com) through librtmp or
EasyRTMP (https://github.com/EasyDSS/EasyRTMP
) Streaming media server performs high-performance distribution and storage, and provides a series of external management interfaces;
Step 4: Interface processing
After completing the above 3 steps, it can only be regarded as running through the entire data process. We also need to control the entire process. For example, when a client requests to watch, we start streaming, transcoding, streaming, and distribution. In the process, when the user stops watching or the server does not keep alive within a period of time, the server stops the entire circulation process.
At the same time, we need to output the process of fetching and recording of a certain device in the form of an interface (refer to the realization of EasyNVR), so that a set of bottom layers can be provided to multiple sites and multiple projects.
Principles of Edge Computing Service Construction
Looking back at the development process of EasyDarwin->EasyDSS->EasyNVR, we basically maintain the development method of first part system, first component and then platform, step by step to consolidate every detail and function point, from the most basic and most compatible audio and video data Pull stream acquisition, to efficient and fully compatible data push, and then to the high-performance distribution of audio and video data by the streaming server, and the entire platform of audio and video playback, the formation of the entire audio and video data transmission link, It is enough to meet the needs of a variety of ever-changing audio and video applications.
Especially in the field of security, its main characteristics are more equipment, fewer users, and high requirements for intelligence. We need to access equipment with multiple different protocols under multiple network environments, such as camera IPC, network hard disk video recorder NVR, hard disk video recorder DVR , GB/T28181 national standard equipment, individual equipment, SIP protocol equipment, etc., which will involve more data transmission and control protocols, such as: RTSP, RTP, Onvif, GB/T28181, SIP, State Grid A/B interface And so on, and the data encapsulation formats of these transmission protocols will be various: ES, TS, PS, PES, what we need to do is to make all these protocols compatible, and provide a unified interface and Compatible audio and video output protocol, build a set of high cohesion, low coupling, easy expansion, interface-friendly video capability platform, so that application system developers can develop various value-added services based on video capability platform Application platform!
In the audio and video applications of traditional security combined with the Internet, it can basically be divided into the following points:
1. Protocol compatible
From the device fetching and data forwarding protocol, we need to involve:
- RTSP fetches the stream;
- Onvif protocol control;
- GB/T28181 protocol control;
- State Grid A/B interface control;
- RTMP push stream;
2. Processing of stream encapsulation
After the audio and video data is obtained through the streaming protocol, we need to perform secondary processing on the packaging format and encoding format of various audio and video data, and output uniformly:
- RTP data analysis;
- PS data analysis;
- RTMP/FLV data package;
3. Distribution and storage of streaming data
Streaming media service is the core part of all video applications. It mainly requires stable, high-performance, and full-platform distribution, and can provide a series of peripheral management services, including recording, retrieval, playback, authentication, etc.:
- High-performance distribution;
- RTMP/HLS/HTTP-FLV synchronous output;
- Recording, retrieval and playback;
4. Audio and video codec
- Video snapshot
- G.711/G.726/PCM transcoding AAC;
- Audio and video decoding and playback
About EasyNVR
EasyNVR can connect high-definition network cameras IP Camera, NVR and other high-definition network cameras in the traditional surveillance industry with RTSP protocol output devices to EasyNVR through simple network camera channel configuration. EasyNVR can pull and convert the audio and video data of these video sources. For RTMP/HLS, full-platform terminal H5 live broadcast (Web, Android, iOS), and EasyNVR can connect the live broadcast data of the video source to a third-party CDN network to achieve Internet-level live broadcast distribution;
Detailed description: http://www.easynvr.com
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