- Why does the unit reboot when I insert a CF card?
- How do I reset the unit completely?
- Why does the picture look better on my TV compared with the computer?
- What does “interlaced mean”?
- What is a PIP?
- How much graphics can I have on the screen at once?
- Why do you use the extension .VD4 for the video files?
- What are Chapters and use of them?
- What are the other files used for and what happens if I loose them?
- What specification of PC is required?
- How to improve Performance of the PC software?
- Can I use my video editing software to change edit the video files and add titles etc…?
- Why do I get jaggies?
- How to check the CPU load, and free buffers (using the analysis software)?
- My files take ages to load… what can I do to improve this?
- How long can I record video for?
- What happens when my card if full?
- I’ve done a long recording and I’ve got multiple 4GB files, what’s going on?
- Why not use NTFS?
- How is the video/audio recorded?
- What is alpha blending?
- Can the VIDEO4 be used as a standalone data logger?
- Can the VIDEO4 be used to play the video back in the car?
- What types of video camera is the VIDEO4 compatible with?
- What resolution does the VIDEO4 record at?
- Why doesn't the VIDEO4 use MPEG4 or H.264?
- What type/size of flash memory can the VIDEO4 use?
- What format is the recorded data in?
- What format is the video recorded in?
- How many video channels can the VIDEO4 record?
- Is the VIDEO4 waterproof?
- Is it upgradeable?
- What specification of PC is required?
- How do I transfer the video and data onto my PC?
- Why don’t the values on the VIDEO4 and the Analysis software match exactly?
- Why isn't my video smooth during playback?
1. Why does the unit reboot when I insert a CF card?
Once a new CF card is inserted, the VIDEO4 needs to load the file system, analyse errors on each file and proceed with firmware/overlay copy process based on the newly inserted card. To complete this task correctly, the VIDEO4 needs to reset itself and boot the system from the beginning.
2. How do I reset the unit completely?
- Take a formatted CF card and place two blank files named to COPYBA.CMD and FORMATB.CMD. These files can be created using an empty notepad document.
- Insert the disk and power on the VIDEO4 unit.
- The existing firmware files will copy to a folder named “INTERNAL” and the VIDEO4 will reset completely.
- Update the firmware again on VIDEO4 (see Update VIDEO4 with new firmware)
3. Why does the picture look better on my TV compared with the computer?
Televisions (Both PAL & NTSC types) are capable of displaying YUV422 images directly. Those have built-in functions for filtering and smoothing images that are coming from standard cameras. However the PCs are incapable of displaying YUV graphics directly. To display graphics on a PC monitor, it is required to convert YUV images to RGB format. This conversion can add distortion to the image that may affect the overall quality of the picture when viewed on a PC.
4. What does “interlaced mean”?
Interlace is a technique of improving the picture quality of a video signal primarily on CRT devices without consuming extra bandwidth. Interlaced scan refers to one of two common methods for "painting" a video image on an electronic display screen (the second is progressive scan) by scanning or displaying each line or row of pixels. This technique uses two fields to create a frame. One field contains all the odd lines in the image; the other contains all the even lines of the image. A PAL based television display, for example, scans 50 fields every second (25 odd and 25 even). The two sets of 25 fields work together to create a full frame every 1/25th of a second, resulting in a display of 25 frames per second
5. What is a PIP?
PIP stands for Picture in Picture. This is a very useful feature which embeds video images (mostly resized to smaller sizes) on to another full screen video. With PIP, user can see recordings from many cameras at once on the same video output. In VIDEO4, all four video inputs supports PIP so that the user can place them in any combination using RT VIDEO4 Configuration Tool. In addition to resizing of PIP images, the user can crop margins, add a nice border in any colour and even mirror the image.
For example, we can design an Overlay file by placing a windscreen camera as the background, camera focusing at pedals as a ¼ PIP on a side and the view from a camera facing backwards can be made to look like the actual rearview mirror by placing it over the actual rearwiev mirror, mirroring the image, and adding a border.
6. How much graphics can I have on the screen at once?
For the convenience of the user, the number of graphical objects that can be added to an Overlay file is not limited in VIDEO4. However the user must aware that there will be frame drops (missing frames) in the file with a complicated Overlay file. User can notice the CPU load while recording with the Overlay file by using RT VIDEO4 Controller Tool. In case the CPU Load of the VIDEO4 unit exceeds 100% with the Overlay file, the graphics need to be reduced to avoid frame drops.
7. Why do you use the extension .VD4 for the video files?
VD4 files are created by multiplexing a Standard MPEG2 video stream with a Standard MPEG1 Audio Layer II stream. These files are fully compatible with any PC Media Player available up to date.
However, in addition to the VD4 file, the VIDEO4 unit records data coming from Standard data logging equipments like DL1 in parallel to Video file to make a perfectly synchronized analysis. These files are later used for further analysis by our set of tools including RT Analysis. This combination has made the Video files recorded from a VIDEO4 somewhat different than ordinary MPEG files. So for the ease of identifying the files, we have used a separate extension, VD4, to differentiate it from standard MPEG files.
8. What are Chapters and use of them?
Chapters are used to mark specific locations in a VD4 file. These important locations of the video mostly consist of special events such as over speed, breaking, other specified violations, etc… Overlay file is used to define chapters based on Variable changes. Please refer to RT VIDEO4 Configuration Tool for more information.
DVD Burn software captures Video files along with Chapters and records them on DVDs. DVDs that are recorded with chapters allow the user to jump to the locations designated by these chapters instantly on standard DVD players. The chapter file is saved in a .CHP extension along with the VD4 file.
9. What are the other files used for and what happens if I loose them?
There are a few types of files that are saved along with video in the VIDEO4 unit. They all share the same filename, but the extensions are different to specify each file type.
1. Chapter file (.CHP)
Please refer to “What are Chapters and use of them?“ for more information. If this file is lost, the user will not be able to jump to special locations in the video. However other functionalities are still available.
2. Jump index file (.IDX)
This is used by RT Video Playback Tool & RT Analysis software for fast video frame jumps and scrolling. This is important for large video files. If lost the PC will build this before playing the video, which can take a long time.
3. RT message file (.RUN)
This file contains data from standard data loggers like DL1 that are recorded in parallel to the video. This file is very important as if it is lost all the data recorded with the data logger in that session will be lost.
4. Lap marker file (.LAP)
If there isn’t any matching LAP marker file on the CF card, the VIDEO4 unit will record a LAP file based on the origin location and LAP markers added while recording.
10. What specification of PC is required?
There are few aspects to consider in the PC configuration.
1. Does the PC meet the requirements specified by the Operating System being used?
This is very important as the OS is not guaranteed to be either stable or perform adequately when running with a lower hardware configuration.
2. What is the recommended configuration required by the Race Technology software bundle?
- Windows XP operating system
- Intel Core2Duo 2 GHz with 4 MB Cache(or compatible)
- Intel original motherboard (or compatible)
- 2 GB DDR II/III RAM
- 120 GB hard disk
- Graphics card with 256 MB DRAM
11. How to improve Performance of the PC software?
There are two important points to consider in particular.
1. Run the software on a PC of at least the recommended configuration.
More importantly use a multi-core CPU like Intel Core2Duo which can process few software programs at once rather than a legacy single core CPU like Intel Pentium III. All modern CPUs are multi-core so this point is only relevant for users with old PCs.
Use enough Random Access Memory (RAM) to reduce Virtual memory usage.
2. Enable DirectX and hardware acceleration from the operating system.
This will allow the PC to distribute the workload efficiently between the graphics card and central processor.
12. Can I use my video editing software to change edit the video files and add titles etc…?
This is possible since VD4 files are fully compatible with the MPEG standard. However there can be compatibility issues with RT Analysis and Video Playback Tool. For example, if the number of frames changes, the data file (.RUN) will not be synchronised with the VD4 file any longer. Similarly the Chapter file (.CHP) can be pointing to invalid frames with the same cause.
13. Why do I get "jaggies"?
All standard cameras capture video in interlaced format, but the PC has a progressive display so a conversion is necessary, otherwise we will get "jaggies" with movement.
It can depend on the video playback software how good the de-interlacing is and therefore whether “jaggies” are seen or not.
Currently the RT player uses quite simple de-interlacing method that simply filters the 2 fields together into a single frame. This eliminates the "jaggies" at a slight cost of vertical resolution.
Note that if you wish to experiment with different de-interlacing settings they can be accessed from the Decoder Settings in the Race Technology player
14. How to check the CPU load and free buffers (using the analysis software)
With data logged on the VIDEO4 there are a couple of extra channels of data that are available. Typically these do not need to be used, and are mainly used for trouble shooting and development.
The extra channels include:
- the video frame that is associated with that time
- the CPU load expressed as a percentage
Typically this will be about 75%-85% depending on the complexity of the layout, the bit rate, the encoding scheme and the content of the video.
- the number of input audio and video buffers
Typically the unit will have 6 or 7 free buffers, however if the CPU load is very high then it is possible that this will dip down to as low as 2 without any negative impact on video quality.
- The amount of free CF buffer space
This is expressed as a percentage. Typically this will be between 80% and 100%, however if the card is generally slow then it will be lower and if there are problems with the card there maybe brief spikes down to even lower values.
15. My files take ages to load… what can I do to improve this?
The user is most probably using either a legacy USB reader or a USB 1.1 port on the PC. The reader problem can be sorted out by using a new reader with a USB 2.0 interface. If the port of the PC is USB 1.1, then the user might need to upgrade the PC with a USB 2.0 expansion card.
16. How long can I record video for?
See Recording time for different card sizes.
17. What happens when my card if full?
Once the card is almost full (within a few MB) all open files are completed and the recording is stopped. A full card is indicted by flashing the power light.
18. I’ve done a long recording and I’ve got multiple 4GB files, what’s going on?
The maximum file size for FAT32 is 4GB, once a file gets to this size, the recording is paused, the file closed, a new file opened and recording resumed.
19. Why not use NTFS?
The format of NTFS is kept secret by Microsoft and there is currently no practical or legal way of 3rd parties using this format. FAT32 is also simpler to implement on an embedded system.
20. How is the video/audio recorded?
There are 3 components to the video file that is recorded by the VIDEO4:
1. The incoming video is encoded as MPEG2 video stream at D1 resolution. This is exactly the same format and resolution as a DVD. The quality that the video is encoded at is set by the “bit rate”, this is the amount of information that is stored to the memory card and is measured in bits per second (bps). The bps is configurable on the VIDEO4 between 2Mb/s (2 million bits per second or 250kBytes per second, 250kB/s) for a low quality recording, up to 12Mb/s (1.5MB/s) for very high quality. Note that if you are intending to you the DVD burn tool to write your video directly to a DVD, most DVD players only support video files up to about 6Mb/s although this figure does vary depending on the model.
The bit rate that you record at depends on a number of factors:
- How long you want to record at, and the size of your CF card. Clearly the higher the bit rate, the less time that you can record for on a given card
- What the data is to be used for. If the video is for race analysis then typically a low bit rate is used. If the video is for a presentation then typically a higher bit rate is used
- What cameras are used: If low resolution cameras are used, there is very little benefit from recording at high bit rates
- Download consideration: To make use of the video data the video has to be transferred from the memory card to the PC. While the USB2 card readers that Race Technology supply are very fast, long recording at high bitrates result in very large files. This is particularly a consideration when you are using the system at the track where you want to be looking at the video/data as quickly as possible
2. The audio is recorded as an MP2 audio stream. The audio is sampled at 16bit and 48kHz. The bit rate for the audio is set for xxx. Again this was chosen to be common with DVDs. The performance of the audio in practical applications is really dominated by the microphone and making sure that it is protected from wind and isolated from vibration. Somewhat surprisingly, getting good audio is rather more difficult than getting good video in racing and automotive testing applications.
3. The video and audio data streams are combined into a single file, this is called “multiplexing”. On the VIDEO4 this multiplexing is done to MPEG1 standards. Note that this MPEG1 multiplexing has nothing to do with the standard the video is encoded to, that is done using the far more modern MPEG2. The multiplexing only adds header and timing information to ensure that the audio and video are correctly synchronized.
21. What is alpha blending?
Alpha blending is an advanced technique that is used to make the displayed graphics partially transparent. For example you can add a dial to the video that is “alpha blended” by 50% which means that when you watch the video you can clearly see the overlaid dial without completely obscuring the picture behind. Alpha blending also improves the look of the overlaid graphics as they can be blended out at the edges. This makes them look smooth and professional. Without this the overlay would look “blocky” rather like “teletext” graphics. The alpha blending on the VIDEO4 supports both a “global” setting for the object which affects the whole object and also “pixel by pixel” blending which allows different pixels in the object to be individually controlled.
22. Can the VIDEO4 be used as a standalone data logger?
No. the VIDEO4 is a video recorder - it accepts data from our range of data loggers and stores this data alongside the video. These include the DL1, DL2, AX22 and SPEEDBOX products.
23. Can the VIDEO4 be used to play the video back in the car?
Yes. The VIDEO4 has a standard composite video output port available.
24. What types of video camera is the VIDEO4 compatible with?
Any standard cameras with a composite output are compatible.
25. What resolution does the VIDEO4 record at?
The VIDEO4 records at D1 resolution; which is the same as that used on DVDs and broadcast video. For PAL this is 720x576 and 25 frames per second and for NTSC this is 720x480 and 29.97 frames per second.
26. Why doesn't the VIDEO4 use MPEG4 or H.264?
MPEG2 was primarily chosen in order to make the VIDEO4 compatible with the DVD standard. Contrary to some reports, MPEG4 does not offer any significant advantage over MPEG2 and hence is not widely used in professional applications. The newer H264 does certainly offer significant benefits in terms of compression, but it is far slower to encode and decode.
27. What type/size of flash memory can the VIDEO4 use?
We use CF cards formatted as FAT32. This makes the files directly readable by Windows. CF format was chosen, as it is available in the largest sizes of all removable media and is also the fastest - this is important for video applications.
28. What format is the recorded data in?
The data is stored in the standard RUN file format, as it is will all our products. The details of this format can be found in the knowledge base on our website.
29. What format is the video recorded in?
The video and audio are stored as a standard MPG file.
30. How many video channels can the VIDEO4 record?
Currently one D1 video channel is recorded, which can contain a main video stream with up to three PIPs overlaid on it. Future firmware may support multiple video streams.
31. Is the VIDEO4 waterproof?
The VIDEO4 Sport enclosure is custom made and of the highest quality, but it is not waterproof. The unit should, therefore, be protected from all normal levels of moisture encountered during standard applications.
The VIDEO4 Pro enclosure is a waterproof. The enclosure is made from CNC machined aluminium and sealed with O-rings and all connectors are sealed to IP66 standards.
32. Is it upgradeable?
Yes. Firmware updates will be available in the future. All firmware updates can be found under downloads and documentation on our website http://www.race-technology.com
33. What specification of PC is required?
Video is demanding on the PCs resources. Our standalone player and analysis software are, however, optimised to minimise the requirements. A modern, entry level PC or laptop is more than adequate.
34. How do I transfer the video and data onto my PC?
Data and Video are read from the CF card using a reader. A good quality USB2 reader is essential for high transfer speeds.
35. Why don’t the values on the VIDEO4 and the analysis software match exactly?
There are 2 reasons why there can be slight differences:
- The time alignment in the overlay is slightly out compared with the GPS data. The GPS data that it outputs maybe up to 0.2 seconds behind the video data.
- 2.The filtering is different in the real time and post-processed cases. In real time we filter the past x samples, in the post-processed (analysis) case we sample x/2 samples ahead and x/2 samples behind, so the “amount of filtering” is the same, but there “phase response” i.e. the delay in the signal is different:
For information on filtering and filter lag click here
36. Why isn't my video smooth during playback?
Please refer the section Video Problems for more information on this.