Which recording method suits your surveillance cameras? Recording methods and storage media compared

Surveillance cameras are being installed for many purposes, such as crime prevention, disaster preparedness, and more efficient security work. When considering surveillance cameras, you may wonder what kind of camera to choose and which recording method and storage media suit your company.

There are many types of cameras and storage media, and it is important to choose ones that fit your purpose and installation site. This article explains the differences between surveillance camera recording methods and storage media.

Why surveillance cameras are needed and what they are used for

Surveillance cameras are installed in many places, mainly for crime prevention: commercial facilities, retail stores, transportation infrastructure such as stations, railroad crossings, and vehicles, parks and multipurpose facilities, schools, and shopping streets. They are also increasingly installed along rivers and roads for disaster preparedness, and at large facilities such as factories and power generation infrastructure.

Along with this, surveillance cameras themselves have evolved over time, and their performance and applications have become very diverse.

In places with some of the most advanced security camera technology in the world, such as China and the UK, large numbers of security cameras are installed in urban areas and on public transportation to deter crime, help arrest offenders, and check the circumstances of incidents and accidents. Even in Japan, which is relatively safe, demand for security cameras in towns and cities has been growing in recent years.

Beyond crime prevention purposes such as deterrence and follow-up after incidents, surveillance cameras are now used for more diverse purposes. These include reducing labor and improving efficiency to make up for shortages of security guards who patrol facilities and electrical engineers who carry out regular inspections, and marketing through foot traffic and behavior analysis using image analysis and AI.

As the purposes and locations of surveillance cameras diversify, both the public and private sectors are increasingly using the various kinds of information that camera video provides.

However, many people may not know in detail how video data is actually recorded and stored.

The next section introduces how surveillance cameras record video.

How surveillance cameras record video

There are two main recording methods for surveillance cameras: “recording with data compression” and “mirrored recording.”

Data compression methods for recording

Video data from surveillance cameras is large, so it is usually compressed before recording. There are four standard video compression methods: Motion JPEG, MPEG-4, H.264, and H.265.

Choosing a method with higher compression efficiency lets you reduce storage capacity while keeping image quality.

Compression efficiency increases in the following order.

Motion JPEG < MPEG-4 < H.264 < H.265

Motion JPEG

Motion JPEG compresses each frame of a video with JPEG, an image compression method.

It displays JPEG images (still images) one after another so that they look like a video, on the same principle as a flip book. Because it uses no compression other than JPEG, images do not degrade and can be recorded in high quality. This makes it suitable when you want to check video frame by frame.

On the other hand, it does not compress between frames, so its compression efficiency is lower than the three methods below, and it uses more storage capacity.

MPEG-4

Unlike Motion JPEG, MPEG-4 compresses between frames. It is widely used as a standard video format for internet services and content.

MPEG-4 detects the “changing parts” and “unchanging parts” of video frames and saves the differences. This allows both image quality at or above HD and a high compression ratio. However, the higher the compression ratio, the more the image quality degrades, and fast-moving video can show noise, so care is needed depending on the application.

H.264

H.264, also called “MPEG-4 Part 10 AVC (Advanced Video Coding),” is a video compression method from a newer MPEG standard derived from MPEG-4. Like MPEG-4, it is an international standard for video files. It is used in 1seg mobile TV broadcasting and video media (Blu-ray), and it compresses files to a smaller size than MPEG-4.

H.265

H.265 is an improved version of H.264 and is used by internet video streaming services and others. Its compression ratio is close to twice that of H.264.

The next section explains the storage media used to record surveillance camera data.

Storage media for surveillance camera data

There are four main types of storage media for saving recorded surveillance camera video.

HDD (hard disk drive)

The HDD (hard disk drive) is the main storage medium for surveillance cameras and is widely used because it is suitable for large amounts of data. Because it can store large amounts of data at a relatively low cost, it is also widely used for storing data on PCs and servers and for recording TV. However, HDDs are relatively large and sensitive to vibration.

SSD (solid state drive)

An SSD (solid state drive) is a storage medium that can be used in the same way as an HDD. Because it uses semiconductor memory, it has the following advantages over an HDD.

– Resistant to shock and vibration

– Small size

– Fast processing

– Quiet operation

– Low power consumption

This makes SSDs suitable for outdoor surveillance cameras, for example. Their drawback is that they cost more than HDDs, which makes large-capacity media harder to adopt.

SD cards

An SD card is a removable external storage medium. It is very small and thin, so it is easy to carry, and it is often used in street surveillance cameras. SD cards are also used in smartphones, digital cameras, and portable game consoles.

They are easy to insert and remove and are inexpensive, so they are cost-effective for temporary storage. However, ordinary SD cards are not suited to long-term use, and they have small capacity and break easily.

For recording to SD cards for business use, we recommend SLC or pSLC SD cards, which have higher write endurance limits and can be used for longer periods.

Cloud storage

Cloud storage saves recorded data to the cloud, a storage location on the internet. It has the following advantages.

– No recorder is needed, so you can make better use of the space around the cameras

– No risk of data loss from vandalism, theft, or natural disasters

– You can check recordings from a PC or smartphone

On the other hand, the drawbacks of cloud storage include the need for an internet connection and monthly fees for cloud and communication services.

The next section explains recorders for surveillance cameras.

Recorders for surveillance cameras

Surveillance cameras use recorders to store video. There are two main types.

DVR (digital video recorder)

A DVR stores video from analog cameras connected by cable. Image quality drops because the analog video is converted to digital. Each DVR may need multiple cables for power and video, so with many cameras the wiring becomes complicated, and finding a place to install the DVR can be difficult.

NVR (network video recorder)

An NVR stores surveillance camera video over wired LAN cables or wireless Wi-Fi. It can record and play back video from IP cameras over an IP network, and because the data is digital, image quality is high. An NVR can be installed away from the cameras, so it is easy to add cameras and recorders, and it is well suited to remote monitoring.

Talk to amnimo about choosing the right surveillance cameras

This article explained the technical points to know before introducing surveillance cameras, such as the differences between recording methods and storage media. However, we hear from many customers that it is difficult to choose the surveillance cameras that suit their company.

amnimo offers products for managing surveillance cameras spread across many sites in a unified way. We offer products that send only the data you need from multiple cameras, based on your purpose, so you can monitor video remotely while keeping mobile data costs down.

Security and surveillance cameras: From “install and record” to “use the video data”

Security and surveillance cameras are used in many places in our daily lives. Their role is shifting: they are no longer installed only as a deterrent, but as a source of video data to put to use.

Behind this shift are major advances in camera performance (the eyes), internet, cloud, and wireless communication technology (the nerves), and AI image analysis (the brain).

amnimo offers video solutions that combine IoT gateways and routers that withstand harsh environments with cloud services designed for IoT and camera operations. We provide them to sites in many industries where cameras must run 24 hours a day, 365 days a year.

If you are looking for “a camera system where the right people can see the video they need, when they need it, in real time” or “a camera system that supports AI image analysis and integration with other systems,” amnimo is well suited to your needs.

If you have issues with your current surveillance camera system, or are planning to introduce one, contact us through our inquiry form.