DVR boards suitable for extreme sports environments, surveillance and other design areas
Want to design a DVR? For many applications, using board-level video camera system design has proven to be better than designing from scratch. Designing is easier and faster.
To store video images digitally, designers actually have two options. Either they develop DVRs themselves or rely on investments in other companies that already have the technology. When designing a DVR, all aspects of the application requirements must be considered. Input signal, data rate, physical storage media, and file management are all important factors.
Disadvantages of developing your own DVR
DVR designers should start by evaluating and analyzing their existing applications. This means evaluating the entire process starting from the input signal. In the analog world, the input signal may be S-video, composite video or component video. So the first thing to decide is whether to change the camera to change the signal itself, or whether it is appropriate to convert the above signal to a digital format. Considering the capabilities, cost, and achievable image quality of the most commercially available analog-to-digital converters (ADCs), there are very few situations where the input signal itself is required to be in digital format.
Note that the complexity required to convert an analog signal into a digital format is more complex than simply selecting an ADC. It's easy to underestimate the complexity of decoding analog video into its digital components and then using the output of the video encoder to form a high-quality analog signal. Monolithic analog video decoders and encoders are available from several reputable vendors, and their reference designs are fully parameterized to support discrete components.
However, be aware that this recipe-based solution looks simple, but provides poor results. Traditional composite video has many properties, both good and bad. Common sense about the interdependencies of things like subcarriers, synchronization, luma, and chroma only belongs to a handful of people who are willing to take the time to study the details and spend countless hours witnessing public issues and workspaces during actual video playback.
To maximize image fidelity, DVR designers must be aware of the shortcomings of high-performance device selection and wisely enhance or sometimes abandon discrete filters when applying reference designs to new hardware. During the all-important layout phase, designers must devote their full attention to many details, such as component placement, power supply filtering, and the correct use of analog and digital planes in close proximity to each other.
Data Storage and Compression
The next step for the DVR designer is to determine the amount of data that needs to be stored. This makes video compression decisions very important. Essentially, digital video requires high data rates, and the higher the image quality, the greater the amount of data required. There are many compression formats available today, each with its own pros and cons. The choice of compression technology will directly affect image quality and storage requirements, so it is important to know the level of image quality and integrity required.
Figure 1: Hardware Block Diagram
Designers must also have a deep understanding of the physical storage media, location, and memory capacity of digital cameras. To put it simply, you first need to determine whether the storage medium needs to be pluggable or whether a hot-swappable drive is needed, or whether a built-in hard drive is needed, and whether the operating environment requires solid-state storage media. Will the data need to be downloaded from the device, and if so, what interface will be used?
The choice of storage media type depends largely on how the designer intends to archive new video images. If flexibility is considered, using a standard 2.5" laptop hard drive is a preferable solution, but for more harsh environments, it will be more effective to use off-the-shelf high-density flash memory.
File management may be a problem in video recording One of the most overlooked and misunderstood aspects. What data format should you choose to start with? The most popular - by far the one that can be played directly on any computer - is QuickTime for removable media. The standard PC format file system on the hard disk has unquestionable advantages, especially when files need to be copied for analysis or archiving. Video files can be read directly without special software. < /p>
An optional USB 2.0 interface can be used to connect removable media. This simple plug-in connection can provide high-speed data reading, with data rates up to 800 megabits per second.
USB 2.0 ports are standard on all latest PCs and are widely used in mass storage devices that come with Windows operating systems that directly provide support for USB 2.0.
Figure 2: (Top: Outrider IDE; Bottom: Outrider CF) FFV Outrider products provide two methods to easily remove and transfer recording materials. Outrider IDE uses a laptop's 2.5-inch, 80-GB IDE hard drive, while Outrider CF uses a compact flash memory card.
Board-level DVR solution
A board-level DVR alternative
In addition to the various hidden challenges and R&D costs when developing a DVR system, There are also many practical factors to consider, such as technical support and whether debugged software is already available. Sometimes it makes more sense to invest money in other companies that are already successful, such as Fast Forward Video. The block diagram below shows the core architecture of a certain board-level product of FFV, which is known as Outrider. It's clear that this patent-pending architecture is a successful solution for managing and processing large amounts of data generated by constrained processor usage.
The Outrider DVR is an ultra-compact digital video camera. Its size is only 4.9" x 2.2" x .6". Outrider can record more than two hours of video with a compression ratio of 20:1 using a commercially available small flash memory card. It is easy to plug in and out, transfer or record data. Outrider is compatible NTSC/PAL format, provides composite video, Y/C input and output, scheduled recording function, and can loop record QuickTime files or secure video files that can be played on PC. The camera provides 720 x 486 image pixel resolution, using Scalable motion JPEG compression.
FFV's Outrider product offers two ways to easily remove and transfer recorded material using an 80-GB, laptop-friendly 2.5-inch IDE hard drive. The Outrider CF uses a small flash memory card. This board-level DVR design can meet a variety of challenging application requirements, including portable, vehicle-mounted and remote control applications. Here are three ways FFV's customers use Outrider to meet their unique application needs. An example.
Portable video camera
Portable cameras used in cross-country competitions face many challenges. For example, the movement itself has a lot of vibration, and the camera must survive such harsh conditions. Function properly.
In addition, impacts occur frequently. Not only must the camera be able to withstand the impact, it must also provide flawless, uninterrupted video recording during the process.
For racers equipped with camcorders to capture the action for off-road broadcasts, ruggedness and performance will be the most important factors.
Inertia Unlimited is a supplier of specialized camera systems to network television. , when making a helmet-mounted camera for driver Ryan Clark who participated in the opening ceremony of the Jeremy McGrath Invitational, FFV's Outrider CF DVR was used.
Unfortunately, Ryan Clark crashed during the race. But not only did the helmet camera remain intact, but it also provided uninterrupted, flawless footage.
The Outrider also has several other advantages over the portable tape cameras used by Inertia Unlimited. to 1 pound, which is important because it doesn't bother the rider at all. It also records over two hours of video on a flash drive in QuickTime file format that can be viewed directly on your computer.
In-vehicle Video Cameras
Inertia Unlimited also uses the Outrider CF DVR on their CF solid-state cameras, which are used in vehicles at the CORR Offroad Truck Series competition in Crandon, Wisconsin. Videography.
Inertia Unlimited's CF camera weighs just 0.62 pounds and measures 6" x 3" x 0.82". The housing is anodized aluminum for harsh environments, and the video connectors are compatible with Sony Handycams. Take advantage of FFV Outrider, the camera features 60 frames per second video capture and playback with a resolution of greater than 550 lines at a 4:1 compression ratio. Robustness is also a key indicator in this application. During the CORR race, 26 cameras recorded two extremely powerful G-force impacts directly on the car in QuickTime format, and the impact records were intact.
Remote monitoring
< p>For many law enforcement applications, manual monitoring is unsafe and impractical. For areas such as monitoring illegal activities, property and building protection, and environmental monitoring, as well as intelligence gathering, gang activity recording, and anti-smuggling, non-manual monitoring is often required. systems.The need for logging and remote display around the clock and the need for designers and manufacturers to comply with the requirements of law enforcement agencies have resulted in the need for sophisticated concealed and modular surveillance systems. The second-generation covert deployment system, the Sentinel G2, is a pocket-sized, self-contained portable video surveillance system that can operate for weeks without maintenance.
The G2 system operates in an efficient and unique manner. It takes pictures, wakes up and records when the target enters the monitoring area, and goes to sleep when the target leaves. In addition, it uses wireless means to send a notification to law enforcement agencies to tell them that there is a target in the monitoring area. /p>
The Outrider IDE DVR was selected in the G2 because of its excellent recording capabilities and small size. For non-human surveillance, the camera must be unobtrusive and able to work independently in any environment. weeks. The Outrider's size, weight and low power consumption make the above system possible.
Another important factor in remote monitoring is the quality of the images recorded by the surveillance system. Therefore having the best quality is crucial. Outrider uses motion JPEG technology that provides exceptional image quality in applications such as slow motion, so fast editing, sequential or interactive reproduction requirements can be achieved. Unlike MPEG technology, which compresses differences between different frames without preserving each entire frame, Motion JPEG applies original JPEG still file compression technology to each individual frame of a video or movie sequence, utilizing a pixel block matching system that minimizes image degradation. , videos using motion JEPG compression are preserved in the camera, so users can access every video and every frame. This provides excellent performance to a variety of applications that require clear images and random access to video material. p>
Summary of this article
Developing digital video storage solutions is a complex, time-consuming and cost-intensive task. A practical alternative is to use a board-level DVR solution, such as FFV's Outrider, which is a proven technology that can be customized to suit any application. There is a strong technical guarantee behind the video solutions from FFV. They have more than twenty years of R&D investment experience in designing compact and ultra-reliable products that provide the best image quality. Extensive technical support helps designers achieve their specific application goals. The company's cameras are suitable for a variety of high-end customers including broadcast, military, government agency surveillance, law enforcement and emergency response, as well as challenging applications including portable, vehicle-mounted and remote surveillance. FFV's DVRs have been integrated into camera systems and can be used in different environments, such as racing, presidential planes, deep-sea video cameras, rowing races, and even space.