Compact Multifunction Video Recorder
Today the topic of video surveillance and telepresence every day is becoming more and more popular and in demand. At first glance, it seems that the market is filled with video recording, storage and processing products. However, if you want to install a simple uncomplicated surveillance system in your apartment, house, cottage or even in the car, or somewhere else, then searching in stores and on the Internet, you will understand that suitable products that meet the affordable price / ratio (quality + characteristics), quite a bit. What are the most popular characteristics should have a DVR, so that he wanted to put in his facility? Let's try to list them:
- several video channels. Usually about 4 video cameras are enough for a good view of the apartment, or a section of a country house.
- good video quality.
- the ability to record all channels in realtime mode, i.e. at least 25 frames / from each channel.
- at least one channel of audio.
- availability of hard media for long-term storage.
- the ability to remotely view video and control cameras via the Internet.
- USB port for quickly connecting the device to a PC and copying information and other operations.
- RS-232 / RS-485 ports.
- small dimensions. DVD recorders of the size of a DVD player or an old video recorder are already considered quite cumbersome and are mainly suitable for installation at a monitoring station or checkpoint with a permanent operator, but not for home use. In addition, it is not convenient to store, as it takes up too much space.
- the ability to connect from a source of 12 / 24V for use in cars. The presence of overvoltage protection up to several tens of volts, protection against polarity reversal, the suppression of short-term surges.
The above properties of the video recorder are basic. In addition to them, it would be nice to have another option package that could be installed in the registrar at the request of the client without increasing the size, but for an additional fee. These optional properties may include:
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- availability of a wireless communication module (GSM / 3G) for receiving SMS alarms / emergency messages or transmitting video stream (or individual frames) to a mobile phone in case of any event at the facility.
- the presence of a wireless module Wi-Fi to interact with any internal network, or to communicate with a device for visual display of information on the display (tablet computer, i-background, etc.).
- availability of a digital input / output module and a CAN interface for connecting external sensors (for example, alarm systems, shock sensors, door opening sensors, etc.) and for controlling external actuators using discrete signals (turn on the lights, close the doors, turn on the siren , etc.).
Compact multifunctional modular recorder
Currently, over-sized video recording devices are appearing on the market, supporting some of what is listed above. However, among the well-known, the most oversized 4-channel modular device that supports all of these capabilities is likely to be the HDRx4-v01 device from ARMiSoft ( www.armisoft.net ).
The device is in the production stage of the prototype. The main hardware and software parts of the device are tested on the debug board. The prototype will be assembled and tested by mid-December. Components have already been ordered, production of printed circuit boards has been launched. We hope that the prototype, after minor improvements and corrections, will go into series.
The design of the product is modular, which will allow it to be modified for different executions and tasks. The device contains 3 boards: a microprocessor board, a power board, and a wireless communication board. This design will make it easier to implement the option, increases reliability, since the power board and power protection circuits (especially important for transport applications) are separated from the sensitive microprocessor board. Due to the modular development of software and hardware devices, a quick upgrade and repair of the system will be provided if necessary.
The device is designed to register on HDD 2.5 ”audio and video data carrier in real time mode simultaneously from four cameras, as well as to remotely view video and control external devices through communication interfaces.
The device can be used in transport, on mobile installations, on industrial facilities, in houses, apartments, shops, parking lots, etc. The main expectations are connected with the residential sector - apartments, private houses. The presence of communication modules, as well as external peripherals, significantly increases the attractiveness of the device.
The company plans the first series of ready-made devices in early 2014. The output of products will coincide with the seasonal activity of the market.
The purpose of writing this article is to attract interest to this registrar and to all products of the company. More convenient conditions for the purchase of devices in the mode of pre-orders. Specific conditions of supply on pre-orders will be formed after the interest from potential buyers.
| Parameter | Specifications |
|---|---|
| Dimensions (maximum) | LWH: 115x75x35mm |
| Number of video channels 720x576 | four; input connectors MSH, 75 Ohm |
| Number of frames / second 720x576 | 4 x 25 = 100 |
| Number of audio channels | four |
| Ethernet 10/100 | Yes |
| USB 2.0 OTG | Yes |
| GSM / 3G (optional) | Yes |
| Wi-Fi (optional) | Yes |
| CAN bus (optional) | Yes |
| Discrete inputs isolated (optional) | 5 pieces. |
| Discrete outputs isolated (optional) | 6 pieces |
| Nutrition | 12V / 24V DC is implemented on a separate module. Existence of protection against overvoltage, against polarity reversal, suppression of short-term surges |
| Indicator LEDs | 9pcs: 1x each video channel (4pcs.), 2x Ethernet, 1x (two-color) processor status, 1x power status, 1x hard disk status |
3D models
Below are the 3D models of the device board stack. After the assembly of prototypes will be presented photos of the recorder.
Fig.1. View from above. Microprocessor board registrar.
Fig.2. Stack of boards and hard disk recorder. Front view. From left to right: 4 video inputs (MCX-75 connectors), 2 audio stereo inputs (allow you to start 4 channels of audio through a standard 2-> 1 adapter), Ethernet 10/100 input via a standard RJ-45 connector. The SIM card for the wireless module is inserted on the left side into a special convenient slot with a card holder.
Fig.3. Stack of boards. Back view. The installed discrete output / output module is shown. Lower row from left to right: RS-232 / RS-485, discrete I / O connector, micro USB; top row: power connectors, digital inputs / outputs, CAN.
Fig.4. Registrar fee. Bottom view: HDD2.5 hard drive mounted under the board. MMSH connectors for GSM and Wi-Fi antennas are located on the side of the device.
The body of the recorder is assumed to be aluminum. All connectors are equipped with snaps, which provide a reliable connection of external cables to the device. Consider the details listed.
Number of cameras
The optimal number of cameras used in oversized recorders is 4 pieces ... In stationary use, the cameras can be used both for viewing the area along each side and inside the residential building (apartment, house). For mobile applications, such as cars, buses, motor homes, etc., 4 cameras are also used.
Video quality
Good quality can be ensured not only by using HD video resolution, but also by conventional analog cameras with a resolution of 720x576. Unfortunately, even this video resolution is not supported by all registrars today. It should be understood that the quality of the video depends not only on the characteristics of the recorder - its internal design, the quality of the trace of printed circuit boards, the use of appropriate connectors and video processing algorithms. The quality is also determined by the optics of the camera, its sensor, as well as the proper installation of the video signal transmission medium, i.e. coaxial cables.
In some cases, it is required to get freeze frames when analyzing individual scenes. The use of algorithms that eliminate temporal redundancy between frames (Inter coding), degrades the quality of individual frames. Eliminating spatial redundancy only (Intra coding) increases the amount of data after compression. The user must be able to select the compression mode. The use of the latter compression mode increases the probability of recovery of information in the case of loss or distortion of individual frames in the absence of a time dependence between frames.
Real time recording
There are very few multichannel recorders with small dimensions on the market that can record 720x576 pixels from all cameras in real-time mode, i.e. 25 (frames / s) from each camera. Usually, manufacturing firms indicate the total number of recording frames for all cameras in the sum, and it is, with small dimensions of the recorder, usually less than 100 for 4 channels at the maximum resolution. Low speed video recording can play a negative role in the observation of rapidly developing events.
Audio
Audio input channels are not always required. Often they are not used, even if they are provided. In some cases, the presence of audio recordings that are synchronous with video streams can be claimed.
Information carrier
The information carrier is extremely necessary, because without it the system loses its meaning for autonomous use. Today, recorders use both conventional hard drives and memory cards, or solid-state hard drives. A regular hard disk is the easiest and cheapest way to store recordings per unit of memory. Volumes of modern disks allow you to store videos for weeks, and if the recording goes only by an event, for example, by the movement of an object in the territory, then a 1 terabyte disk for 4 cameras with a resolution of 720x576 each can be enough for a long time.
Solid-state hard drives are rarely used because of their high cost and higher consumption. In the future, they, of course, will be cheaper, but so far they are used in responsible applications, where security is more expensive than the money spent.
Access to video via the Internet
Imagine that you went on vacation and left your home unattended, but under an alarm. A triggered sensor (motion, strike, alarm, etc.) sends a signal to the recorder, which in turn sends you a message on the phone. It becomes possible to observe what is happening in your apartment, house or car from the phone via the Internet and take appropriate actions based on the results of the observation.
Ethernet
The presence of the port allows you to use the device without storage media, only as an IP camera. If the device is running a WEB server, then it becomes possible to view video data and device settings on any platform where modern browsers are supported, without installing additional software.
USB port
This port in USB OTG mode allows you to quickly connect to a personal computer. When connected to a computer, you can make various kinds of recorder settings, as well as copy video data to a computer. In this mode, when connected to a PC, the available files are presented to the user as on a regular USB Flash drive.
RS-232 / RS-485 ports
These ports allow you to build a more complex surveillance system, for example, they allow you to control cameras. If the registrar has an Ethernet port, you can control the cameras via the Internet. Also, based on the RS-485 interface, some higher level industrial protocols are built, for example, ModBus, ProfiBus, which also allows integrating the recorder into a more complex system.
Dimensions
Dimensions often determine one of the main reasons why the user prefers such a product. Who needs devices the size of a DVD player, or a VCR? If you want to install the recorder at home, then most likely it needs to be placed in an inaccessible and hidden place, so the small dimensions can be very useful. If we are talking about the use of cars, then it is on a par with the quality of the video, one of the decisive factors. Multichannel recorder in this case should be compact.
Power supply from 12V / 24V source
Power supply from 12V / 24V - designed for use in the car. For use in homes, will have to purchase a power supply 220V-> 12V / 24V. Also 12V / 24V power supply is possible for industrial use. It is also worth noting that the recorder must be protected from polarity reversal and against high voltage surges, since there is a lot of noise on the power line in the car and the power surges are several tens of volts higher than the onboard nominal voltage.
GSM / 3G wireless module
Of course, this option is not necessary for everyone, but for those who want to build a real security system based on a small box - a video recorder. The advantages of this feature are described above. Ideally, the module supports both GSM and 3G communications. Those. Who needs - can only receive notifications in the form of SMS. Someone also needs to get video from the camera on the phone, so you need a 3G connection.
Wi-Fi Wireless Module
Wi-Fi today allows you to communicate with many mobile devices at a distance of 100m or more. The presence of this type of communication makes it possible to copy information from the recorder to a display device (smartphone, tablet computer, car's GPS navigator) and view it. Suppose the recorder is in your car and you also have a GPS navigator. In the event of any incident, you contact your registrar with the help of a GPS navigator via Wi-Fi, and copy the video onto it for viewing, and right there on site. In this case, you do not need a bulky recorder near the windshield, you have only mini-cameras attached, and the multichannel recorder is hidden under the backseat or in the trunk. Those. the system is very convenient, you do not see the constantly recorded video, you do not need it in the car and only distracts, but in case of which you can always watch it using Wi-Fi.
Module of discrete I / O and CAN interface
The advantages of this option are also described above. It should only be said that such a module allows you to put your car almost under complete control. The main thing is that the number of discrete inputs / outputs was sufficient. CAN-bus allows you to read many parameters of the car, as well as manage some of them.
We are ready to continue the series of articles on issues of interest to readers.
ARMiSoft company ( www.armisoft.net ),
email: habr@armisoft.net
Source: https://habr.com/ru/post/198566/
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