A visit to the Norbain display at IFSEC 2014
Reminder: I had 5 questions specifically relating to the exporting of evidential video from a Video Surveillance System.
Norbain is one of the UK’s biggest distributors of CCTV, IP, Access Control and Intruder Detection solutions. They also have a number of there own brands. One that I hadn’t seen before was Xeno.
I decided to look at the new XDR-960. So new in fact that I can’t find any details about it on the Xeno website! One of the main reasons I went for this one was that I wanted to highlight to the Norbain staff how difficult it is to establish what appliance is being used when there is no make / model number on the front. The DVR examined here had XENO on the front but no model number.
How easy is it to export evidential video from this device?
It was unfortunate that the device was so new that it’s USB Ports were not functioning! As a result I was promised to have an export sent to me. The interface seemed pretty standard but I will have to have a bit more time with a unit to offer anything constructive. At least it had USB Ports at the front.
How easy is it for me to play the exported footage?
Norbain very kindly sent me an export. The structure looked like this with the .psf file containing the video data.
I quite like the Player_Launcher.exe in the root. This then saves a viewer from having to go into the Player folder and selecting the right file. I know it’s a small matter but it takes any uncertainty away and makes it simpler for the export recipient.
When the player launches, it doesn’t automatically detect the presence of a video file. The video has to be loaded using the Open Icon. When a .PSF File is selected, it will load in and the camera streams will display.
Its a pretty clean interface with very little to distract the viewer. Standard playback controls and a calendar view are the only other interface attributes.
How easy is it to analyse and understand the format of the video?
No details on Milliseconds, Frame Rate, Frame Count, Frame Type, Resolution, Format, VMD etc A right click on the video gives a number of controls and then the Version Number…
Are there any functions to deal with the evidential video within the software?
As can be seen from the two images above, there are options for exporting images and video. The location anything is saved to is set in the options…
As you can see above, there are no drop-downs for still images. When you select the image export, the current frame is saved as a compressed .jpg file.
There is a 70 pixel high black bar added to the bottom of the image where certain text is displayed. Part of that is the recorded resolution of the video. It is interesting then that the presented image itself is 640×480. Are the images being squeezed into a 4:3 Aspect Ratio?
The next problem is interlacing. Below, on the left is the default, interlaced image (screen-grabbed from the player window). If an image is exported interlaced, the jpeg copy also includes the interlacing lines, but they are slightly blurred due to the compression to jpeg. On the right is a zoomed in portion of the image using the built in de-interlacing function. You may be able to see the artefacts down the right side of the leg and the front of the foot.
For video, there are two export formats available; ASF and MP4. On a number of test clips, using the Clip export button on the top of the interface, the result was not readable. I found that it was easier to use the right click option. You have to Click it once to start the capture and then again to finish it. A video file is then created in your saved location.
This has to be done in realtime, which makes it a very slow process. From preliminary tests, the MP4 export appears to be a basic demuxer, rather than a transcode. From analysing the raw data in the MP4 file and searching for it within the original PSF, the data was there.
The Mp4 was a 960×576 H264/AVC format.
Is it possible to deal with the evidential video away from the software?
The video file is read immediately as a 960 x 576 H264/AVC stream. However, due to the two streams being muxed together, it is not easily possible to extract them. As such, the MP4 file, demuxed using the software has to be used. I have not done too much testing but dealing with the interlacing out of the software, and in products like Photoshop or FFmpeg, produced slightly better results as I could decide on what field to use and how to interpolate etc.
1. The player is quick and easy to launch, but it would be handy for the video files to be pre-loaded.
2. No help file or URL to help and information.
3. No information on Export file. Resolution, Frame rate, type, etc etc..
4. Still Images should be uncompressed and at the same resolution to that recorded. If adjustments for Aspect Ratio should be made – this should be clearly documented.
5. Although the ability to transcode a small clip is useful in certain circumstances, the ability to demux the streams to individual native files should be much quicker and simpler.
6. The date and time information should be exportable as a subtitle.
7. The method of de-interlacing should be documented in the help file.
None of the points mentioned above are huge issues. The data is all there, but it’s hidden from the user. The player and interface is simple and fast to use, but analysing and dealing with the video then becomes problematic. Due to the analogue capture and increase in captured resolution provided by the 960H camera’s, the ability to deal with the interlacing, and retain its original format and size, is highly important.
The information provided here has been supplied to assist the video security industry.
If anyone from Norbain / Xeno wants to improve the systems using the information provided, please feel free to get in touch.