Posts Tagged ‘ audio recording’



Digital Video Recorder Surveillance

Written By:
Thursday, September 15th, 2011

Digital Video Recorder or DVR surveillance means that the activity being captured by the system’s cameras is being recorded by the DVR.  The following article explains the significance of the DVR to a camera security system and how it works.

A basic digital video security camera system is a component system that consists of three major components:

1)    One to many cameras;

2)    A DVR or Digital Video Recorder; and,

3)    A monitor or monitors

For digital video recorder surveillance the system operates in the following manner.  The digital video camera converts light energy into electrical energy which can be measured and is used to create digital video data.  This data is sent to the DVR.  As previously mentioned, the DVR is a digital video recorder, just like the hard disk drive or HDD of a personal computer.  However, in security camera systems, the DVR normally contains a processor, just like the processor in a Personal Computer or PC.

However, the processor in a DVR is a highly specialized piece of electronic circuitry.  Unlike the PC processor, the security camera DVR processor is manufactured to handle specific functions of security camera systems such as digital video file production, camera control, and recording of digital video files.  It uses a specific utility called a COmpression/DECompression or CODEC program to process the digital video file from the digital video data sent to it by the video camera.

Digital video is basically nothing more than a series of digital photographs taken in rapid succession.  Typically, high quality digital video is about 30 digital photographs taken within on second, also referred to as 30 frames per second or 30 fps.  When you think of the file size from just one high quality digital photograph, you can imagine how enormous a digital video file that takes 30 fps for 24 hours could be.

That’s why the DVR’s processor uses a CODEC to create the digital video file.  It uses special programming that shrinks the size of the file without sacrificing the high quality of the image.  CODECS change from time to time as different approaches and technologies make each CODEC better and more efficient.  One of the most popular and recent CODECs is called the H.264 CODEC.

The digital video recorder surveillance system create, process, and store digital video files that can be viewed instantly (live) on monitors or stored for later viewing on monitors or for archiving.  Many DVRs also have additional storage options such as CD/DVD writers or USB Flash drive connectivity to copy portions of video to portable media.  This may be necessary to give insurance companies, police departments, as evidence, etc.

The DVR may also contain other specialized features.  One common feature of many modern DVRs is Internet connectivity.  The DVR may contain its own Web server technology and programming so that it may be connected to any broadband Internet service and instantly become accessible anywhere in the world there is broadband Internet accessibility.

Most DVR and security camera systems come in 4, 8, or 16 channels.  This means that the DVR can handle 4, 8, or 16 separate camera inputs at one time.  Security systems requiring more than 16 cameras simply use additional DVRs to expand the number of cameras needed.

Highly specialized digital video recorder surveillance cameras may have highly specialized DVRs.  Portable systems, systems that are used for a small amount of time, systems that have self contained cameras and DVRs all in one unit may utilize different digital storage methods for the DVR.  For example, school bus DVR and security camera systems often use a Compact Flash Card or similar portable storage medium instead of a full sized hard disk drive as the DVR.

Is a DVR necessary in a security camera system?  No, not necessarily, but a system with just a monitor and no DVR will not be able to record the video so that it may be reproduced for later use.  A baby monitor is usually a good example of this.  On the other hand, a retail store facility would not realize the full potential of protection without a DVR and security camera system.

Other DVR and security camera systems functions pertaining to the DVR may include audio recording, various output display resolutions as well as connectors, remote control, e-mail and smartphone notification, and mouse and/or keyboard control.

 

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Digital Recording Device

Written By:
Friday, September 2nd, 2011

A digital (audio) recording device, according to the U. S. Code of Regulations (Title 17, Chapter 10, Subchapter A, paragraph 1001), “is any machine or device of a type commonly distributed to individuals for use by individuals, whether or not included with or as part of some other machine or device, the digital recording function of which is designed or marketed for the primary purpose of, and that is capable of, making a digital audio copied recording for private use…”

Huh?  Let’s try this again.  A digital recording device is any device that records in a digital (binary) format.  There are all kinds of digital recording devices.  Since the technological advancements that have come with the computer age, many other industries have borrowed the same technology but may have modified it slightly to meet their specific needs.

As far as the digital video security and surveillance camera industry goes there are basically two digital recording devices that immediately come to mind.  One is the digital phone/room recorder and the other is the Digital Video Recorder or DVR.

Security Camera King offers two different digital phone/room recorders, product# DPR-N88 and product# DPR-N308.  These two recorders are audio digital recording devices.  They work by recording to a storage medium a stream of discrete numbers that represent the changes in air pressure or sound.  In contrast, analog sound is created from a continuous wave that represents the changes in air pressure or sound.

Basically using a simple set of the numbers 1 and 0 (called binary or digital format) just about anything that is recorded as an analog set can be converted to digital.  There are several advantages to digital recording devices.  First and foremost is that digital recording does not degrade in quality over time like analog recordings do.  Another advantage of digital recordings is that, thanks to the ever increasing technology of the computer industry, more data can be stored digitally than can be done by an analog medium.

While digital audio recording record the changes in sound, digital video stores information that represents the changes over time in chroma and luminence for video.  Once again, the older (analog) method of recording video was, like analog audio, the creation of a continuous wave.

The security camera industry reaped the biggest benefit from the “computer age” when they started using digital recording devices called DVRs (which are also the second type of digital recording device referenced above).  In the security camera industry the main digital recording device is the DVR.  There are several types of DVRs which use several different methods for storage as a digital recording device.

The most common digital recording device for full size commercial or residential security camera systems is the Hard Disk Drive or HDD.  The DVRs HDD is a non-volatile (will not lose recorded information when power is disconnected), random access digital recording device.  Security Camera Kings systems’ HDD storage options ranges from 500 Gigabytes (GB) to 8 Terabytes (TB).

The HDD consists of rotating rigid platters (disks) on a motor driven spindle.  Digital data is magnetically written to or read from the platter by read/write magnetic heads.   These heads are extremely close to the platters but they never touch them.  As a result when the heads are directed to read or write the platter spins and the head either searches and reads for magnetic changes on the platter or writes magnetic changes on the platter which is literally a series of 1s and 0s.

There are other types of digital recording devices too.  For example, Security Camera King’s product# HC-SUNGL-DVR are sunglasses with the camera and DVR included and built into the glasses.  Of course, in this case the digital recording device is not an HDD but an electronic circuit designed for digitally recording the video and audio.  These sunglasses not only have 4 GB of storage built-in, but the DVR can also accept Micro SD Expansion memory cards of up to 8 GB.

Well hopefully this article has given you enough knowledge about digital recording devices that you’ll know what to look for and how they work.  If you have any additional questions about digital recording devices and how they may apply to you please contact one of Security Camera Kings security experts today.

 

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Night Vision Wireless Security Camera

Written By:
Tuesday, January 25th, 2011

Tired of not being able to see things that go “bump” in the dark? If that’s the case, you need a night vision wireless security camera. These cameras take advantage of the latest technology in digital camera security systems, are easy to install, and are reasonably priced as well.

Can a night vision wireless security camera actually “see” in the dark? Well, indirectly the answer is yes. Although the camera doesn’t actually “see” in the dark, it uses infrared illumination to light the target area of the camera. This infrared illumination is actually invisible to the human eye, so we can’t see it, but the camera can. Before we get ahead of ourselves let’s back up and start at the beginning.

There are many types of digital video security cameras based on appearance and function. The night vision wireless security camera is one of those types that contains highly specialized features for highly specialized applications. Some of the other optional features that are available include the following:

• Pan-Tilt-Zoom or PTZ. This feature allows the camera to move “left and right” and “up and down” which greatly increases the field of vision of the camera. This camera can also “zoom in” on objects to enlarge their view.
• Motion Detection. Camera can come equipped with motion detectors that turn the camera recording on only when motion is detected.
• Audio Recording. Sounds can also be recorded as well as conducting two-way audio communication.
• Internet Protocol or IP ready. Cameras can connect to and use the Internet for networking.

Let’s keep the “focus” (pun intended) on a night vision wireless security camera. First, the camera operates by transferring light images into electronic impulses that can be measured to create digital video images. In digital video language, this transferring of images is normally referred to as “capturing.”

The night vision wireless security camera captures images by using a very special electronic sensor. There are actually two different types of sensors and although they capture images in a slightly different way, they both produce the same end result (a digital video image.) One of the sensors is a Charged Coupled Device or CCD and the other is a Complimentary Metal Oxide Semiconductor or CMOS.

It just so happens, that both CCDs and CMOSs are inherently sensitive to not only the spectrum of electromagnetic radiation we call “visible light” but are also sensitive to infrared radiation or “invisible infrared light.” (We call it invisible because as mentioned earlier, the human eye cannot see it.) Specifically, most night vision wireless security cameras are inherently sensitive to a band of infrared radiation called “near infrared radiation” or for our purpose, we’ll call infrared illumination.

So where does the infrared illumination originate? There are some small amounts that are emitted (or radiated) from objects, especially heat and light sources. However, a night vision wireless security camera normally provides its own illumination using an array of infrared Light Emitting Diodes or LEDs that surround the camera lens or are right next to it pointing in the direction of the camera’s field of vision.

The infrared LEDs use much less electricity than a typical filament light, and the illumination they emit can’t be seen by humans but can be detected by the night vision wireless security camera. There are some camera/systems that do not include LEDs around the lens but may use separate infrared LED “illuminators.” These illuminators can also be used with cameras that do already have LEDs to extend their range.

This brings us to an important point. Since the LEDs provide the illumination for the night vision wireless security camera, every camera has a range. Be certain before purchasing your camera that you know what range you will require and that the camera you are purchasing can capture images within that range.

Finally, as the name indicates, a night vision wireless security camera does not require a video transmission cable to be run from each camera to the DVR as other non-wireless systems do. The camera takes advantage of one of many different types of wireless technologies to send its images via radio waves to a receiver or a DVR with a built-in receiver. One example of this technology is 2.4 or 5.8 MHz technology; the same used for wireless land-line based telephones. Talk about making installation easy!

Contact one of our security experts via our on-line “Live Chat” or via telephone if you have any additional questions concerning a night vision wireless security camera.

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Outdoor Wireless Security Camera 500ft Range

Written By:
Monday, October 18th, 2010

An outdoor wireless security camera 500 ft range is adequate for most commercial and residential applications. This type of camera is easy to install and easy to operate and can be purchased with many optional features that greatly increase its versatility. In the following article we’ll talk a little about wireless security camera technology and some of the additional features that can be purchased for these cameras.

There are a few key factors that separates an outdoor wireless security camera 500ft range from other basic security cameras. First, as its name denotes, this camera is an outdoor camera. Outdoor security cameras are designed to withstand weather and other natural outdoor elements that can damage the camera or affect the working quality of the cameras.

When a security camera is specifically classed as an “outdoor” camera, it often has a rating in the camera specifications that indicates exactly how much protection is afforded to the camera from external objects. This rating, called an Ingress Protection rating or IP code, is an International Electrotechnical Commission (IEC) standard.

The code consists of the capital letters “IP” and two digits. The first digit indicates protection afforded against solids and the second digit indicates the protection afforded against liquids. The first digit’s scale ranges from 0-6 with 6 being the best protection, and the second digit’s scale ranges from 0-8 with 8 being the best protection. A good IP rating is IP65 or IP66.

IP65 means the camera is completely protected from dust and water jets from a nozzle coming from any direction. IP66 means the camera is completely protected from dust and water projected by powerful nets in any direction.

The other key feature of an outdoor wireless security camera 500ft range is that the camera uses wireless technology and has a maximum operating range of 500 feet. Non-wireless digital video security cameras work by creating a digital picture and transmitting the digital video data to a Digital Video Recorder (DVR) or monitor via a coaxial video transmission cable. This cable, usually an RG-59 coaxial cable must be run from each individual camera to the DVR or monitor. Wireless cameras eliminate this video transmission wire.

Outdoor wireless security cameras with a 500 foot range contain the internal circuitry to convert the digital data into a radio waveform that can be sent with out cabling. There are various radio technologies used to do this based on the manufacturer, but some of the more popular are the 900MHz an 2.4 or 5.8 GHz band radio technologies. These are the same sorts of technologies used by land line based wireless telephones.

One word about the camera radio technology. This technology is usually based on range which is defined as the maximum distance between the camera antenna and the receiver (or DVR) antenna based on Line Of Sight or LOS. LOS means this range should be attainable provided there is a clear line of sight between the two antennae, i.e. no objects can impede or block the LOS.

If there is not a clear LOS, it doesn’t mean the camera will not work. Usually, depending on the object(s) such as glass, trees, or walls instead of the camera signal failing, the range is just reduced. How much the camera’s signal is reduced is dependent on the material that the signal must penetrate. For example, it is not uncommon for an outdoor wireless security camera 500 ft range LOS to work at a 200 – 400 foot range through walls.

Digital video security cameras are powered by low voltage Direct Current (DC) electricity. This may occur as a small wire that is run from a power distribution center or a plug-in adapter that can be plugged into the nearest wall outlet. Since wireless cameras have already eliminated the need for a video transmission cable, some manufacturers make models that are totally wireless’ the camera can run off of power from batteries or rechargeable batteries.

There are many cameras with optional features that can be purchased. A few of these features include:
• Audio Recording
• Infrared Night Vision
• Day/night low visible light operation
• Pan-Tilt-Zoom (PTZ) operation
• IP or Internet Protocol ready

This should give you enough working knowledge to help you decide if you need an outdoor wireless security camera 500 ft range. If you have any other questions or would like to make a purchase, contact one our Security Camera King’s security experts today.

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