Question: I am faced with a dilemma where currently a standard typical DVR will not achieve my criteria. I.e. I can only burn a disc onto a DVD giving me a maximum of approx 1-2 hours recording which I need to file.
What I need is eight hours! Can you please tell me if there is a DVR available on the market which will record daily office hours (approx 8) rather than using expensive hard drives?
If such a machine is available what other key features will it possess? I am recording from a three colour camera system and may need a quad unit if the DVR doesn’t have this feature
Any help or ideas would be much appreciated as the nearest machine to my requirement seems to be a domestic 8 hour recorder but I don’t think it will withstand the constant daily use.
Thanks, John (via email)
Answer: Why do you need to create ‘daily’ archives in this way? Most applications call for a minimum archive period at the DVR, after which the data is overwritten. If daily archives are needed, these are usually done over a network to a separate storage device known as a NAS (network attached storage). These can then be RAID configured to ensure that the data is kept secure.
Removable media does tend to be a little limited in size and is often only used for incident archive. Memory sticks are now up to 4Gb and getting larger all the time, but I think larger USB attached hard drives (say 500Gb) would still be his best bet with a single drive providing enough capacity to archive over a week’s footage, instead of just one day. An advantage of a USB hard drive is that it can be over written and re-used, whereas DVDs tend to be locked and used once.
For reference, most 4-channel DVR’s offer a quad screen view as standard with USB ports and internal hard drive options
Jon Hill, Bewator –
Follow up question:
Dear Dr Hill,
Many thanks for your quick response and for the info.I thought you may like to hear more about this unusual request. My Client runs a clinic and is using CCTV instead of a chaperone.He is overly concerned about the possibility of an accusation being brought against him by a client i.e. molestation or similar accusation of which could happen any time even according to him up to or even beyond 3 years. He obviously wants the peace of mind that a daily archive (recorded onto a cd and filed away) may give as opposed to having a massive hard drive back up with a possibility of hard drive failure at some point giving him NO evidence even if mirrored plus obviously the high cost. He did not want to use a system such as a hard drive with recording over as he wants to log each day just in case of that slim possibility of an accusation being brought up against him. Can I just ask, if I may, if you have any further comments to add to this senario?
Kind regards and thanks again,
John harrison
Answer:
Dear John,
Many thanks for providing additional specific details about this scenario. It certainly is an unusual situation if you don’t mind me saying. I have to say that I have never encountered a medical practitioner using CCTV in this way and can only hope that your client makes his patients fully aware that their procedures are being recorded. I do however sympathise with his predicament, considering our current claim culture. Putting the ethics to one side for a moment, I would like to respond to the original question about daily archives.
There are a number of points to consider here. Daily retrieval of archived data from a digital recorder can prove fairly time consuming, especially in a busy medical practice. External Hard drives designed for 24/7 use are now available and are far more robust than they used to be. Another point to consider is that drives generally fail due to heat, wear and tear or general miss-use. External drives if treated properly should last for years. The obvious advantage of using an external drive with vastly more archive space than a DVD would be a significant reduction in man hours with weekly archives possible instead of daily ones. This could still prove to be quite expensive though as you say, especially if your client is serious about archiving data for three years.
Archiving daily to a closed form of storage media such as DVD may be this man’s only option. The problem you identified originally was not having enough space on the disk to archive a full day of footage. I have a few suggestions for you:
1. Try compressing the data to a greater extent. Assuming that the images are being captured either ‘at’ or ‘near to’ real time, the DVR should offer several compression levels – typically low, medium or high. Compressing the data to a greater extent will reduce the file size and may allow you archive more images to a DVD. DVD’s typically allow up to 4Gb of data storage. Be mindful that higher compression levels can sometimes have a detrimental effect on image quality. Best to monitor the results initially. Also try to keep any recordings to an absolute minimum, recording any procedures as an event instead of leaving the camera rolling so to speak.
2. Is the DVR recording MJPEG or MPEG4 format video? File sizes are significantly smaller when using MPEG4 format so double check this. Also check the resolution of each recording. It may be that the resolution can be reduced, depending on the position of the camera and the available light etc.
3. If DVD’s just aren’t working for your client, perhaps he should look at Blue Ray discs? While current optical disc technologies such as DVD, DVD plus or minus R, DVD plus or minus RW, and DVD-RAM rely on a red laser to read and write data, this new format uses a blue-violet laser instead, hence the name Blu-ray. The benefit of using a blue-violet laser (405nm) is that it has a shorter wavelength than a red laser (650nm), which makes it possible to focus the laser spot with even greater precision. This allows data to be packed more tightly and stored in less space, so it’s possible to fit more data on the disc even though it’s the same size as a CD/DVD. The format offers more than five times the storage capacity of traditional DVDs and can hold up to 25GB on a single-layer disc and 50GB on a dual-layer disc.
All things considered, it sounds like the Blue ray option may be your client’s best bet. A word of warning – archiving video data for three years will not be cheap, which ever route is chosen. You will also need to ensure that archived discs are properly encrypted and kept very securely under lock and key. Accusations of molestation are clearly very serious, but data of this kind finding its way into the public domain could prove catastrophic for the doctor and very distressing for the patients. I would strongly recommend that your client ensures that all relevant governing bodies are completely happy with this approach before spending too much money.
I hope this is of help to you.
Very best regards,
Jon Hill.
What might b the cause of a cctv losing video footage at times or recording on and off