The bench test 2: We’re getting there!

It looks as though we are finally getting there! We have had relatively few quibbles regarding the picture performance of hard disk drive (HDD) digital video recorders but when it comes to ease of set-up and use, archiving facilities and secondary features, just about every machine we have looked at has been found wanting in one way or another. The AurorAcorD digital video recorder and multiplexer from Vicon could mark an important milestone in the development of this crucial technology; it sets a new benchmark for digital video recorders and comes tantalisingly close to solving almost all of the gripes and glitches we have associated with earlier products.

Most of the HDD recorders we have seen appear to have been designed by computer engineers with either scant knowledge or an apparent disregard for what has gone before – analogue VCRs have been the backbone of video surveillance for the past quarter of a century. While there is no denying that digital video recording requires installers and operators to adapt, there is surely no reason to ignore tried and tested ways of working nor to make the transition more difficult than it has to be. At first glance the AurorAcorD’s core specification doesn’t look significantly different to the half a dozen HDD video recorders we have looked at in the past year. The HDD recorder and 16-channel multiplexer provide full duplex operation so it can simultaneously record and play back. It comes in a variety of configurations, our test sample (AURFCD80) was fitted with an 80Gb hard drive which, using the ‘normal’ factory default settings for picture quality and sensitivity, provides a recording time of around 14 days, using a proprietary video compression system. Models with 40, 120 and 160Gb drives, and proportionately longer or shorter recording times are also available.

All variants are fitted with a floppy disk drive for exporting still images or short video recordings from a single camera channel; our test machine was also equipped with a CD-RW drive for making longer video archive recordings of as many camera channels as required. Monitor display formats include single screen, picture-in-picture, quad, 3x3, 4x4, mixed border, mixed half, mixed quad and split. Each camera has an associated alarm input and for good measure there is also full motion sensing on each camera channel, digital pan/tilt and 16x zoom, mechanical PTZ control, networking and PC control facilities. The AurorAcorD has one other important extra, rarer than hen’s teeth on HDD recorders: an audio recording channel. This is something we have campaigned for since the first digital video recorders appeared five or six years ago. It is a genuinely useful facility, though it could have been better implemented on the AurorAcorD. Basically there is no loop-through facility, which means you can’t easily monitor what’s being recorded; it is not a big deal but it does make wiring unnecessarily complicated.

The archiving facility could also have been better thought out. There is no problem with exporting stills and short clips, lasting between two and seven minutes, to floppy disk since it uses standard image and motion video (AVI) formats, which means they can be viewed on any PC with suitable software. However, video footage (up to 12 minutes of all 16 channels) archived on CD-R/RW media can only be replayed on AurorAcorD. Vicon has missed a trick here by not making disks readable on a PC, even if it means installing specialist software or better still, loading a viewer utility onto the CD-ROM. That is really as bad as it gets, it’s all good news from now on. The unit is housed in a black rack-mountable case measuring 483 x 292 x 89mm. On the back there’s a slightly unusual arrangement with the video inputs and outputs. Inputs are handled by four groups of four BNC sockets; the loop-throughs are carried on two 15-way D-Sub sockets. The alarm inputs and output share a single 37-way D-sub. It has one high-impedance (600 Ohm) audio input with variable AGC, suitable for a microphone and two line-level audio outputs (one on the front) using minijack sockets. The main display video monitor output is configured for both composite video and VGA. Additionally there is spot monitor output showing a single image or sequence from any designated camera. Finally there are three RJ45 connectors, one on the front for serial communications or an optional keyboard and two on the back, also for serial comms, with a PC or for PTZ telemetry. On the front panel there are two rows of camera selectors with LED indicators along the bottom left side. These also double up as controls for the mechanical PTZ. Above that is the CD-RW drive-loading tray. In the middle is the floppy drive slot and below that a cluster of four ‘cursor’ type buttons to control record/playback and menu functions.

On the right side there are two rows of buttons for controlling various functions including display format, digital zoom, alarm reset, picture freeze, menu set-up and a useful on-screen ‘Help’ system. Up in the top right hand corner there is a jog/shuttle dial for controlling playback speed and direction.

Set-up & operation: It has several unique features: one of the most impressive is the highly intuitive control system. We suspect this is the first HDD recorder we’ve tested that we were able to get up and running without once having to refer to the instructions. Either we are getting smarter (unlikely) or manufacturers such as Vicon are putting a bit more effort into their product’s user interfaces. It is virtually ready to go straight out of the box, the only preliminaries being to set the time and date on the main menu. Pressing the menu button brings up seven options. Number one is Easy Set-up with the aforementioned time and date adjustments; item two is the Main Menu, which has eight sub-menus (Display Setup, Camera Set-up, Serial Port Setup, Time/Date, Record/Playback Set-up, System Set-up and Disk Functions). Menu 3 deals with camera calibration, menu 4 is for Saving and Restoring system settings, menu 5 sets the OSD operating language, menu 6 displays a list of 14 occasionally useful FAQs (frequently asked questions) and menu item 7 covers the system details (drive capacity, software version number etc). All of the most interesting items are to be found on the main menu. The Display Set-up has sub menus for title text and backgrounds.

The Camera Set-up contains the title com-poser, motion sensor configuration and camera calibration utilities. The Alarm, Serial Port and Time/Date set-ups are all fairly straight-forward too but all of the most important video settings are to be found on the Record/Playback menu. These include the recording rate (from one to 15fps and 25fps) and sensitivity (five modes: lowest 8kb/field, low 12kb/f, normal 15kb/f, high 20kb/f & highest 35kb/f). Between them these settings determine image quality and recording duration, in the case of a unit with a 80Gb drive this can be between one and 31 days. The audio recording facility, when enabled, appears to have very little impact on recording times.

The System Set-up menu can be used to password-protect access to most of the recorder’s function including locking the front panel to camera access. This menu also includes the set-up for the schedule timer and a system reset option. Motion detector set-up uses a grid of 12 x 16 targets, which can be individually enabled or disabled using the camera selector buttons.

Sensitivity can be adjusted to minimise false alarms. When activated it can be programmed to carry out a number of responses, from increasing the update rate on the camera concerned to sounding an alarm. Archiving recordings to floppy or CD-R/RW couldn’t be easier, just set the start and end times, pop in a disk and let it get on with it. Other useful extras include a disk space remaining display, simply by pressing the Enter button. In normal operation the unit will default to record mode; pressing the play button on the front panel enables playback. Playback normally starts at the last recorded block, which is typically a few seconds behind what’s being currently recorded. However, to view any other part of the recording simply use the jog/shuttle dial.

Turning the outer shuttle ring shifts the search speed in seven steps in either direction and the display shows the speed as 1x, 2x, 3x, 4x, 5x, 7x and 10x. However, while the lower speeds are probably about right, the 10x speed works on an entirely different time frame and will wind through 10 days of material in a little under 10 seconds. Impressive as this is, it makes finding a particular sequence extremely difficult.

Slow motion replay is also a little awkward, the recorder first has to be put into pause mode (by pressing the Play button) and then the speed can be varied using the jog/shuttle control.

Performance: The manufacturer’s claims for picture quality are not far off the mark. At the highest resolution setting, recordings are indeed superior to analogue S-VHS. Resolution is noticeably up on the 400-lines the analogue tape-based system is theoretically capable of (and that’s on a good day) but the most obvious difference, and a very welcome characteristic of digital recording, is the very low noise level. Colour rendition and contrast balance are not as good as tape however, and it really begins to show up on the lower quality settings when areas of block noise show up, especially in lighter areas of the image. Nevertheless, on the ‘Normal’ settings image quality is very acceptable indeed and noticeably superior to standard VHS. As an added bonus there is no deterioration with repeated playback, and absolute stability when playing in search, still or slomo modes. Audio recording quality is sufficient for recording speech and background sounds but the fact that it records sound at all is something of a breakthrough!

manufacturer says ...
This is an innovative combination of multiplexer and digital video/audio recorder which allows 16 channels of video to be recorded to the unit's hard drive in a variety of settings for recording rate, sensitivity and quality. Recording time is maximised by a Wavelet compression algorithm which condenses video information without compromising quality. In addition, the audio utilises a similar codec compression scheme to optimise recording times and limit the effective bandwidth to 6 KHz.

AurorAcorD can be fitted with one or two hard drives or one hard drive and a CD-R/W drive. The hard drive stores the motion video with audio in a proprietary format along with alarm, time and titling information for each camera. AurorAcorD features full telemetry control (PTZ). Using front panel keys, it can remotely control up to 16 camera domes/PTZ drives using RS-422/485 protocol.

Display options include play back through a VGA monitor output or a standard digital BNC output. The VGA output provides a horizontal resolution

of 720 pixels (540 TV lines) and the

digital BNC output provides 640 pixels (480 TV lines).