Accordingly, a standard way of archiving and copying data to PC in the majority of cases is by connecting recorder’s analogue output to the input of video capture card and saving video stream in the file with software developed by third party. Some devices can be connected via LAN and software to copy data via network. And only in some models the HDD is directly connected to PC and software to view and copy files.

Usually when you connect the HDD removed from the video recorder to PC, you can see an empty disk (not containing any information – form the OS point of view). At the same time any record to it (initialization by OS tools, formatting etc.) will lead to data corruption and inability to access recorded images even from the video recorder.

It is difficult to name the way the data is stored on video recorders a file system. Data is arranged not in the shape of files but like records. Records are accessed through tables containing data of record, its location on disk and size. If the recorder works with several cameras, the records from different cameras are mixed, i.e. they can be located irregularly, depending on the event (triggered movement detector, timer and so forth).

On top of that, because of using hardware image encoding-decoding tools the video on the storage media is stored in an unusual for a PC user format – stream of frames formed by hardware codec. At the same time the codec can be compatible with of the common compression methods (MPEG, H.264), as well as proprietary, which doesn’t have much software implementation.

Listed above peculiarities create certain complications in case of recovery from this type of devices. Leaning back on our experience in such cases we think it appropriate to inform our clients of the following:

• We have studied the structure of these devices with the purpose to develop a software specifically to retrieve information directly from faulty and working HDDs in a convenient for user format and within shortest period of time. At present, such possibility exists for many home recorders and some security video recorders (for example, Cpcam MPEG-4 DVR, AVTech MPEG-4 DVR). In this case the presence of device is neither required during the recovery stage nor to view the information recovered. The required fragments will be converted into any standard format convenient for the customer.

• In case if we know nothing about the device, we may require to study the disk’s structure. For that purpose it is also advisable to provide a software that came along with the product since it may contain, for example, a codec necessary to convert the image retrieved into a usable format. If such codec is at hand, the presence of device is not required.

• In case there is no chance to convert the recorded video stream (the device uses hardware codec which was not implemented in software), then the device itself has to be provided along with storage media. In this case image will be relocated in the file via video capture card. For instance, such necessity appears for video recorders AVTech with proprietary wavelet encoding (AVC-776, AVC-777).

More detailed information, time and cost of recovery can be obtained after our experts perform diagnostics of the device. All works are done in accordance with information safety techniques, no writing to original disk is performed, all changes are made to copies only. We guarantee the confidentiality of your information through full sector-by-sector wiping off of copies we made during the recovery.