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Most 10 questions to choose a Video Data Logger

This artical was created by Racelogic. It’s a bit outdated, but it still contains useful information, and I post it as it might be helpful to those who are planning to purchase Video Logger. ^^

The benefits of using data logging in motorsport are well known, but it’s only in the last few years that systems have started synchronising video as well. With the increasing number of systems available all with different features it can be confusing deciding which one is best. This is why we have compiled a list of 10 things you need to consider when purchasing a video enhanced data logger.

  1. How easy is it to fit?
  2. How reliable and accurate is the GPS data?
  3. What is the video quality?
  4. How is the data and video recorded?
  5. Will it work in all conditions to ensure no data loss?
  6. Can you get your own graphics and logos onto the video?
  7. Can it record lap times and provide predictive lap times?
  8. How flexible and easy to use is the analysis software?
  9. Can it record other data from your car?
  10. How good is the technical support?

  1. How easy is it to fit?
    Systems that require lots of modules and sensors, or have specific mounting or heat requirements, are far less convenient to fit in your car, especially if you ever need to move it. When choosing a video system you need to think about how suitable it is for your particular car. If you drive a single-seater for instance, you don’t have much spare space! Systems which require special mounting on a flat surface will be more difficult for you to fit in your car. Conversely, if you drive a saloon or even a road car that you also take on track, you need a system that can fit in a glove box or under a seat and be uninstalled easily.
    The video recorder is also sometimes supplied as an additional unit which needs to be plugged into the main control unit, making mounting the system more of a challenge and potentially reducing reliability. Some systems use a GPS engine which has a slower update rate (more on this later) and supplement this with accelerometers to increase accuracy. The downside of this is that the unit has to be fitted in a certain orientation in order to work properly, adding to the fitting time. It can also lead to unintentional errors in the data if the system is not fitted securely or at a slight angle. Ease of installation and use is important – we’d recommend having a look at the manual for the system before purchasing. A huge manual often makes for a confusing product!

    Racelogic’s Answer
    Each Video VBOX unit comes with a one page quick start guide to get you up and running as soon as possible. You can also refer to our easy to follow online manual for more in depth information, or type your question into our active customer forum. If this still doesn’t answer your question, our six dedicated support staff are waiting for your call!

  2. How reliable and accurate is the GPS data?
    A key element in GPS video loggers is the quality of the satellite signal. It is important to be able to use an external GPS antenna so you can fit it in an optimal position for the best satellite reception. GPS antennas need a ‘ground plane’ to operate correctly. On a car with a metal roof this is achieved by placing the antenna in the centre, but for cars without large areas of flat metal, a plate of metal, foil, or aluminium tape about the size of a DVD case is required to get the most reliable data.
    The GPS update rate is also important as this sets the resolution of the data points and the accuracy of the lap timing. A minimum for track driving should be 10 times a second, which provides plenty of information for comparison between laps or different drivers. The dynamic response of the GPS is also important – if there is a lot of smoothing for
    example, this introduces lag into the data and makes it very difficult to reliably compare braking points.


    Racelogic’s answer
    We make high accuracy VBOX data loggers for every car and tyre manufacturer in the world, allowing them to test at up to 2cm accuracy. The GPS engine inside Video VBOX gives a true position, velocity and acceleration update 10 times a second (10Hz), which provides smooth movement to the speedometer and track-maps on the video.
    Position is accurate to 0.5 metres lap to lap, speed is accurate to 0.2km/h and acceleration is accurate to 0.5%.
    Many other systems use a slower (4 or 5 times a second) update rate resulting in delayed graphics and crucially reduced lap timing accuracy. Other systems make up this deficit by using accelerometers, but this means you have to mount the box in certain orientations making it liable to suffer from roll, pitch and incline induced errors. As well as this accelerometers are only used to measure velocity, with inaccurate position data readings meaning displayed driving lines cannot be trusted to the same degree.
    At Racelogic we also make a sophisticated GPS simulator called LabSat, which we use to test Video VBOX. This allows us to optimise and improve the position, velocity accuracy and dynamic response in great detail, with every Video VBOX made being tested and calibrated using this method. This is a great advantage over all other manufacturers. If you want to rely on the speed measured by your data logger, Video VBOX can give you that confidence.

  3. What is the video quality?
    The quality of the video is important, not just so you can clearly see what is happening on the track, but also so you can show the video to others and even use it for promotional purposes.
    HD – You may think High Definition is the way to go. However be warned: the vast majority of consumer HD cameras use a ‘Rolling shutter’ as opposed to Standard Definition cameras which use a ‘Global shutter’.
    A ‘Rolling shutter’ means that the image is captured in a rolling fashion down the image. Any movement during the capturing of the video frame will create distortion and loss of quality. This effect is made even worse when these HD cameras are used in motorsport due to the high speeds and vibration involved. It creates a ‘jello’ like effect which often
    ruins the video. We would therefore recommend that you steer clear of HD systems in motorsport until a reliable motorsport ‘Global shutter’ system has been developed. *Racelogic already launched HD Model ‘VBOX Video HD2’
    See this video ‘https://youtu.be/F_6c0AL_57E‘, which shows an example of the wobble effect on a rolling shutter. The rolling shutter is on the right, and you can see how the image is distorted (because the sensor scans from top to bottom). The Global shutter on the left does not suffer the same problem and creates higher quality, more reliable footage. The rolling shutter camera is a Sony NEX VG10 and the Global shutter image on the left is a prototype HD bullet camera currently in development.

    Video Format
    There are a number of standard definition formats: PAL (UK and Europe), NTSC (USA and Japan) and VGA (generic computer format). PAL is the highest resolution at 720 pixels by 576 pixels, followed by NTSC (720×480) and lastly VGA (640×480). With videos now being commonly viewed on computers, it is important to go for the highest resolution you can – with PAL videos also playable through any computer or TV setup.

    Camera Resolution
    The camera resolution is equally as important, with cheap cameras having fewer active pixels in the sensor and a lower signal bandwidth. Generally, the higher the number of ‘lines’ in the camera is, the better the quality. The best cameras have around 550-580 lines

    Picture in picture
    An important feature is a second camera or ‘Picture in picture’. The most obvious benefit of aiming a camera at the driver is to see their steering inputs and focal point (i.e. where they are looking), as these can be the differences between a quick driver and his team mate. The other benefit is to be able to see who is driving. If you have different drivers in the same car, it can be sometimes difficult to work out who was driving when.

    Racelogic’s answer
    High video quality has been built into Video VBOX’s design from its conception. MPEG-4 compression is used to gain the best balance between quality and bandwidth, using about half the storage space as MPEG-2 for the same quality of
    output. When considering a system, take a close look at its full resolution output. The high quality offered by Video VBOX is the reason why it is used in many high profile applications such as the BMW, Porsche and Audi driver training centres and the Australian GT Championship – all of whom have separately evaluated and chosen what they consider to be the best quality video system in the market.
    The videos recorded by Video VBOX are in .avi format, meaning they can be played in any standard media player and uploaded directly to YouTube without the need for conversion. The quality of cameras is also a major factor in video output. We have spent a long time researching and then defining the specification for our own bullet cameras. They are not standard off the shelf items and have gone through a process of optimisation and rigorous testing to ensure they produce the best possible picture in the highest possible resolution. Our cameras use the Sony HQ1 chipset with 550/580 lines of resolution at 720×576 pixels.
    For a comparison see the resolution test below. The image on the left was taken using a competitor’s ‘550’ line bullet camera, while the clearer one on the right was taken with a camera used by Racelogic. Where the cameras may both operate at a resolution of 550 lines,
    the filters and electronics reduce the quality considerably on the competitor product – clearly highlighting the work we have done to optimise the quality of our cameras.


  4. How is the data and video recorded?
    There are various different flash memory devices you could use to record video. The most popular and readily available are Secure Digital (SD) cards and USB sticks. Compact flash can also be used, but this technology is being phased out in favour of the smaller SD cards which can be used in a greater range of devices.
    The ability to record on USB memory sticks can be a big advantage as it makes your system more versatile for use in track days, corporate events and driving schools.
    Using USB sticks make it easy to distribute your footage, as it can just be plugged into any computer without the need for an external card reader. If you want to upload video to sites such as YouTube, it is important that the video is in a standard video file format that will allow you to do this without any need to transcode the video – which can be a lengthy process.

    Racelogic’s answer
    Video VBOX systems use SD cards as standard to record all video and data up to a maximum card size of 32GB. With half an hour worth of footage per GB of storage space, you can fit a lot of action on just one card!
    USB memory sticks can also be used with a simple adaptor cable (which can also be used as a remote start/stop logging switch and preview monitor connection) connected to your Video VBOX, which makes recording data very convenient. Footage from Video VBOX can be uploaded to websites such as YouTube with no need to edit or change settings, making it easy to share your video with others.

    Unbroken video and data

    Whether you’re recording a few laps of a track or test day, or doing the Nurburgring 24 hours, you want to be able to access your video and data easily. After feedback from endurance racing drivers using Video VBOX for as much as 25 hours at a time, we made sure that the recorded video and data is still simple to manage even after long sessions.
    Large video files are split into chunks (2GB in size) – in order to conform to the SD card file structure – but the data file remains as one continuous file. We have developed the internal buffering algorithms to ensure you don’t lose the video as the files are segmented on the SD card, allowing you to get uninterrupted video and data logging from our system.
  5. Will it work in all conditions to ensure no data loss?
    If you’re using a video data logger to analyse your driving or vehicle setup, accuracy and reliability are likely to be the most important requirements. It can be very frustrating to come into the pits after a good test session, or race, only to find out that the video hasn’t been recorded for some reason.
    This is much more common than you would think, with a number of factors leading to a loss of video. When choosing a video logger there are some features to look out for which reduce the risk of this happening.

    Memory Quality
    Not all flash memory cards (SD, Compact Flash, USB Sticks etc.) are created equal. There are fast cards and slow cards, and cards which have a fragmented file structure. Recording video requires a good quality card, if the recording system cannot write to the card fast enough then you may experience video loss. By monitoring the write speed of the card, some video systems can dynamically reduce the quality of the video if it detects a poor card, resulting in slightly lower quality video, but most importantly, no loss of data.

    Power Interruptions
    Power interruptions are most commonly caused when the engine is started. Sometimes this is because the cigar lighter is disconnected during this period, but most commonly it is because the battery voltage drops as the starter motor kicks in. This can be enough of a voltage drop to reset the video logger. This often causes the file system on the card to be corrupted and can lead to video loss. This can happen when leaving the garage (if the driver stalls), or if the car spins on the circuit and the engine cuts.
    Good video loggers have an internal ‘Tank circuit’. These keep power to the unit for a long enough period of time to overcome this problem, retaining any video which was being recorded when the power interruption occurred.

    Racelogic’s answer
    We have developed a number of features which ensure our system will operate reliably in motor racing conditions.


    Built in battery tank circuit

    Poor connections and voltage fluctuations are a common reason for lost or damaged data and video. A unique feature fitted to every Video VBOX Pro and Video VBOX Lite as standard is a small internal battery which provides backup power for 15 seconds after the power input voltage has dropped below a safe threshold. If the power does not return, the Video VBOX automatically closes the current video file to prevent any loss of data due to file or card corruption. This is vitally important should you ever need to start the engine whilst it is recording, as the vehicle battery voltage will always drop below a safe threshold.
    This means your Video VBOX will keep working and you won’t lose video or corrupt the SD card. It also works when you are using an external battery pack; if the battery runs out the tank circuit kicks in and saves your file. If you stall or spin out, all your video remains intact. It is also common to pull into the pits after some laps and switch the engine off
    without thinking. While many video data systems are able to avoid corrupting the SD card, they often lose the video footage. The Racelogic tank circuit ensures that all your video and data is safely saved.

    Dealing with variations in SD card and USB stick quality

    SD memory cards and USB sticks vary enormously in access speed and reliability. You can buy what appears to be exactly the same media from the same company, but the hardware inside is often completely different.

    To deal with this, Video VBOX uses an in-house developed routine to continuously monitor the speed of the SD card (or USB stick). In a process known as dynamic bit-rate throttling, the system will lower the video quality when it detects bottlenecks are occurring, speeding it back up again whenever possible and ensuring the highest available video quality is achieved without file corruption.

    This is critical to reliable operation of a video logger and ensures that changes in media quality will not result in a loss of video.

    Rugged construction

    Video VBOX Lite is made of a tough ABS plastic case with locking mini din connectors, while Video VBOX Pro is cased in
    anodised aluminium with locking Lemo connectors. Whilst Video VBOX Pro has been designed to withstand heavy use on a daily basis, both systems are durable and rugged, made to exacting standards. There are no mounting requirements, meaning that your unit can be stored anywhere. However, Video VBOX is only resistant to condensation and not water. It is therefore recommended to mount your Video VBOX in a glove box, under a seat or in a waterproof
    box if you are using it in an open top vehicle. The bullet cameras, however, are waterproof, so these can be used effectively in open top and single seater race cars.
    Racelogic are an ISO 9001 qualified company, supplying calibrated GPS test equipment to almost every single motor
    manufacturer, tyre company and car magazine for the last 10 years. We therefore take our quality procedures very seriously.
  6. Can you get your own graphics and logos onto the video?
    Being able to see your position on the circuit, current speed, acceleration, vehicle data, or any number of other parameters overlaid on the video footage, is not only entertaining but useful for analysis. You can get a lot of information just by looking at the video with graphic overlay even before delving into the data.
    It can also be important for many users that company graphics, team artwork and sponsors logos can be overlaid on the video for promotional purposes. There are two types of graphical overlay processes: Post-processed and Real-time.

    Post Processed

    Post processed systems allow the user to insert graphics after the event. The advantage of post processed graphics is that you can change the graphics at any point. The disadvantage is that the user has to carry out an additional, often time-consuming process. On some systems the graphics can only be seen in a special playback software package, making it impossible to load the video/data combination to YouTube.

    Real Time

    Other systems create and overlay the graphics during recording (i.e. Real-time) which is much easier for the end-user, but lacks flexibility in changing graphics after the event.

    Racelogic’s answer

    Graphics Quality

    Video VBOX produces high resolution graphics in real time using a dedicated 24-bit graphics processor with per-pixel alpha blending (transparency). This means the graphics are recorded directly onto the video instead of having to generate them after the event. You can choose multiple, realistic looking gauges, needles, graphs and text, all updated 25 times a second.

    Setup Software

    The included Video VBOX Setup software enables you to make your own graphic overlay ‘scene’. Creating your own great looking scene complete with gauges and logos is easy. We also have a large free library of professionally designed graphic scenes, making your life even easier! With many other video loggers limited to using a simple straight line as a needle and one simple font, the quality of Video VBOX graphics far exceed our competitors, allowing you to create a much higher spec video and making your footage really stand out from the crowd.
    We have produced some online tutorial videos showing how to set up the graphics on a Video VBOX.
  7. Can it record lap times and provide predictive lap times?
    Instant driver feedback is always useful in motorsport. Lap time read-outs allow you to see what pace you are
    currently running at – providing you with a benchmark to beat – while predictive lap-timing gives you a clear
    indication of where you are losing or gaining time by continually comparing your time with that of your previous fastest lap.
    It is therefore a big advantage if your video logger has the ability to connect to a separate dashboard, or lap-timing
    display, mounted in clear view of the driver. If the video logger you are looking at does have this option, it is also important you understand how it gathers the information displayed. If the predictive lap-timing is based on distance, the prediction displayed gets less and less accurate as you go – potentially ending up 0.5s off the pace by the end of the lap! It is therefore crucial your video logger emits predictive lap timing based on GPS position, continually updating to provide you with an accurate prediction of your current lap time.

    Racelogic’s answer

    Racelogic’s ‘LineSnap’ predictive lap timing uses a high contrast OLED display connected to a Video VBOX, using
    GPS position to compare your previous best with your current lap in real time. It offers unrivalled 0.1s accuracy the entire way around any circuit, including long circuits such as Spa or the Nurburgring, even if you take a completely different line each lap. It also displays your lap time on screen at the end of each lap.
    The technology provides you with accurate, real-time lap comparisons, working at any track without the need for beacons. Helping you to judge the effectiveness of different racing lines or gain immediate feedback on how much time you’re losing/gaining on your current lap, you’ll find yourself constantly trying to beat your previous best time!

  8. How flexible and easy to use is the analysis software?
    Nobody wants to sit down and read a lengthy, boring manual before they can use a video data logger.

    Driver analysis

    There is no reason why the software shouldn’t be easy to use. Most people want to find their fastest lap and compare this with other laps to see where they can gain time.
    You therefore shouldn’t have to spend ages configuring the circuit start line, or manually going through the files to find your fastest lap. Good software will have a built in track database to save you having to set start/finish lines, overlaying and lining up laps automatically and accurately and allowing you to concentrate on the most important task of improving your driving technique.
    If you want to improve lap times as a driver, the software should give you the tools you require to concentrate on the driving aspects rather than focussing on the technical setup of your car.

    Drive Distance vs. Position by GPS

    Another important, but little known feature to look out for, is the way comparison laps are aligned. Traditionally, laps have been aligned using distance (derived from a wheel speed sensor), as accurate GPS was not available in the early days of data logging. However distance is not the best alignment method because it varies from lap to lap. For example, even a professional driver around a short circuit can vary his lap distance by up to 10m from lap to lap. If you are comparing braking points then 10m makes a huge difference! Nowadays without doubt the best way to align laps is to use the GPS position. It does take more software processing power to do this, but it allows you to compare one lap with another without any error. Around long circuits such as Spa or the Nurburgring, GPS position is the only way to compare driving lines.

    Racelogic’s answer

    Racelogic’s Circuit Tools analysis software has been designed from the ground up to be used by drivers rather than race engineers. Therefore the steps you need to analyse and compare laps have been reduced to make it quick and easy to use. It has been designed for use on a Windows PC, but can be used on a Mac by dual loading windows and boot camp software.
    The software contains over 230 popular tracks from around the world, automatically detecting which track (and even layout) you have been driving. It sets the start/finish lines and circuit overlay automatically and will display the fastest lap in any session file you load.
    When comparing two or more drivers, Circuit Tools automatically synchronises the video and data from the fastest laps of each driver, allowing instant comparison. You just load the file in and it does the rest, allowing you to concentrate on finding improvements in your lap times.
    Many professional driver coaches use the software on a daily basis and claim it is the most powerful and easy to use data analysis software available. You can read more about using Video VBOX and Circuit tools in track day and racing instruction.
  9. Can it record other data from your car?
    Accurate GPS provides a wealth of data from which to analyse vehicle and driver performance and improve lap times, but sometimes you need more.
    Whether that’s RPM, throttle angle, exhaust temperature or any number of parameters, an important feature of a good video logging system, especially for professional drivers and teams, is the ability to record vehicle data too.
    The best way is to hook into your vehicle’s ECU and use the signals which are already there – or failing that, you may want to fit your own sensors and log these inputs.
    Some systems have built-in CAN and serial inputs for ECU connection. When choosing a video data logger, ask how many CAN channels it has and how easy it is to configure for your car, as they all use different protocols. It is no use having the CAN facility if the data logger manufacturer cannot supply the translation file for your vehicle. Some older racing ECUs have serial interfaces without any CAN facilities.
    Some boxes may also have a built-in analogue/digital interface for your own sensors which can be preferable. Others have a separate input/output module which keeps all of the sensors separate and grouped away from the main logger, which also has its advantages.

    Racelogic’s answers

    External modules


    Designed to provide an easy and useful way of acquiring vehicle information, Racelogic’s Micro Input Module allows you to pick up parameters such as RPM and throttle angle. Once set-up, it synchronises automatically with the GPS data in your Video VBOX. The Micro Input Module has an RPM (digital) frequency input and four analogue voltage inputs. More data is available with the Mini Input Module which accepts eight analogue and two digital inputs.

    CAN

    Racelogic have made it possible to tap into your car’s CAN (Control Area Network) bus. Available in most modern cars, the CAN bus carries information on a variety of parameters around the vehicle. However, each vehicle manufacturer encodes their CAN bus information in a different way, making logging vehicle data difficult. Racelogic have reverse
    engineered
    a huge number of vehicles to obtain the CAN information, making it possible for you to plug straight into the OBD socket or CAN wires to log data.

    All Video VBOX units come with our free CAN database which, if available on your vehicle, allows you to capture RPM, throttle angle, brake pressure or wheel-speeds directly from the CAN bus. You can then view this data alongside your GPS and video. Video VBOX Lite has one selectable CAN channel with the option to upgrade to a total of four. While, Video VBOX Pro has one CAN channel as standard with the option to upgrade to a total of 32.
  10. How good is the technical support?
    There is nothing more frustrating after buying a technical product than finding it difficult to use and the company unresponsive. Before purchasing you need to be sure that the manufacturer and / or its dealers are able – and willing – to help you should any problems arise.
    So what do you need to look for? A friendly, experienced support team (hopefully consisting of more than one expert!) who answer without leaving you on hold, don’t require all your details every time you call, and can explain technical matters in simple terms. It may also be important to be able to speak to someone when you’re at the track.
    In addition, it’s important that the system you choose comes with free software and firmware updates.

    Racelogic’s answer

    Whilst Video VBOX has been designed to be a ‘plug and play’ device, sometimes you might have a problem with your system or want to delve further into its capabilities. If the manual, online tutorial videos, or forum don’t provide the answers you need, you can rely on Racelogic’s team of six qualified customer support technicians and numerous trained dealers in many countries.
    We are motorsport enthusiasts at Racelogic with a number of us regularly attending trackdays or racing at weekends (with varying levels of success!) using our own products. We therefore understand our products and can help you to overcome any problems. We also have a number of Video VBOX dealers who attend trackdays and race meetings who are there on hand to help.
    In addition, we have a busy online forum which you can use to get answers to any questions. Our support staff check the forum every day, so you can be sure that your question or comment will be answered.


    We are always working to improve the software and firmware that goes into Video VBOX and provide every update we release free of charge. If you are unhappy, so are we, so we do everything in our power to ensure every Video VBOX user can get the most out of their system. Our support team is available at support@racelogic.co.uk

    If you’d like to learn even more about your Video VBOX or delve further into the software, we offer free half day training courses for customers at the Racelogic office in Buckingham, UK.

    https://www.racelogic.co.uk/index.php/en/
    https://racelogic.support/
    https://www.vboxmotorsport.co.uk/index.php/en/



    From Racelogic

    20, JAN 2012
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