- How can YAFO afford to offer such
a competitive price?
Because YAFO is a manufacture's direct shop.
- Should I use DVR-card with PC or
DVR as the surveillance host?
The advantage of PC + DVR-card:
- Better picture quality and more detailed functions especially
at "remote access".
- Longer storage time due to better compression algorithm.
- It is a more affordable solution if you already have a reliable
PC.
- The PC can be used for other purposes too.
The advantage of DVR:
- Practical functions for an easier operation.
- Reliable and steady system compared to "Windows environment".
- It costs less than a DVR-card +PC.
- Click here for more
info.
- What is "Real Time"?
Real Time Displaying/Recording is defined as displaying or recording
a video sequence at 30 frames per second. At this rate the individual
frames are indistinguishable by human eyes and therefore it is
referred as continuous streaming. However, a more expensive DVR-card,
computer and a hard disc with a larger capacity is required to
carry out surveillance monitoring at such a high standard. Under
normal conditions 3-5 frames/sec is a reasonable number.
- What is motion detector mode?
By activating this mode, you can extend your recording time up
to around 4 times your normal recording time. It'll write no
data or fewer data onto your hard disc when no motion is detected.
It is still does a full time recording except it lowers the recording
FPS when the image remains still. This method can efficiently
decrease the hard disc wastage since the repeated image data
is not constantly being written.
- How much hard disc space do I need?
Let's take a DVR-card with 4 security cameras installed as an
example. If each security camera records at 6FPS full time over
an one month period it usually takes up to around 96GB of hard
disc space. DVR uses up approximately 120GB of hard disc a week
. When the capacity of a hard disc is insufficient, the system
will overwrite the old data with the new ones. For example, the
video file on 16th November may be overwritten by the video file
on 16th December. There are several capacity saving method provided:
I. Reduce the recording FPS: The space usage will be halved
if the recording FPS is adjusted from 6FPS to 3FPS . Adjusting
the recording quality will provide a similar result however at
a price of poor image quality.
II. Activate "Motion Detector Record": It will greatly
increase your recording time since it decreases records FPS automatically
at still images. How much longer you can record depends on your
FPS settings and how often motion is detected. But from our experience,
a 4 times the normal recording time is a reasonable figure.
III. Setup recording schedule: Enables recording automatically
at certain periods of time.
- What is required for remote access?
Dial-up modem, fixed or time-counted ADSL or Cable Modem connection.
The IP address of the destination host is required for remote
access. A remote computer has to type in this IP address to start
the connection. The connection program can be IE browser.
- Is it a waste of system resource
if I only connect 1 ~ 3 security cameras on a 4 port DVR-card?
YAFO-I series uses "dynamic sharing". Take YAFOI-4 for example.
If this card is runs at 40FPS with four security cameras attached,
then each security camera is only getting 10FPS. On the other
hand, if you only have two security cameras attached then each
runs at 20FPS . In other words, the less security camera you
attach to this DVR-card the smoother the video sequence you'll
get.
- What are the connection terminals
of DVR-cards, DVRs and security cameras? Can they be joined together
with Coax cable or 2-in-1 wire?
It depends. When the card and line terminals are different, a
connector can be added between them. Unless the connection distance
is more than 100M or electromagnetic irradiation is nearby otherwise
RG59U Coax is not necessary (it is expensive and difficult to
install). 2-in-1 wire does the job. We sell all kinds of 2-in-1
wires that comes with cable clippers and an adapters.
- Is it difficult to install DVR-Cards?
It will not be a problem if you are familiar with assembling
a computer provided that we offer you professional assistance
as well. YAFOI-4 and YAFOII-4 runs smoothly on most PC s (Intel
P3 or above). For other DVR-cards please use Intel P4 or equivalent
CPU and chipsets.
- What is the difference between
"Display Image" and "Record Speed"?
Displaying speed is the speed of displaying on a monitor. Recording
speed is the speed which the security camera is filming at. Adding
more security cameras will decrease the speed of "Display Image"
and "Record Speed".
Take YAFOI-8 as an example: The system shows 20 FPS for displaying
speed and 20FPS for recording speed, how the different numbers
of security camera load will effect the value. The result is
shown in the following table.
- Will remote access work when the
host is connected to a Router?
Yes! Provided that the DMZ or Virtual Server in the Router is
opened to the the host computer, it will function properly. The
settings will be different for different models so please refer
to your instruction manual.
- What resolution is the digital
video?
Usually it is set at 640x480, but it is adjustable.
- How fast is the network transmission?
The faster network transmission the more fluent the video will
be! Generally, one picture per second is what dial-up network
can achieve. However broadband connections like ADSL or Cable
Modem has distinct bandwidth speed which result in different
transmission speeds. Details are specified in the specifications
of the cards.
- Are the images viewed via the
internet same as the images being recorded?
Certainly not. To transmit images via the web the system must
compress the image files to save the bandwidth. The downside
to this is the loss of quality. The recorded uncompressed since
it is not required to be transmitted through the internet. Hence
the recorded images will look much nice then the images transmitted.
- Does "remote access" include internet
video recording?
Yes. Our product provides "remote record" function if it is remote
accessible (Some DVR doesn't support "remote access" ). The video
files will be saved in host computer rather then the remote computer.
- Can recording and viewing be done
simultaneously?
The answer is "yes" for all DVR-cards and "no" for all DVRs unless
it is specified.
- How many security cameras and
hosts can remote user view at the same time?
YAFO-I series can connect up to 4 hosts and view 16 security
cameras. The hosts from different locations around the world
can be connected at the same time. YAFO-II, III, IV series is
even more powerful, it supports viewing 16 to 160 locations.
- Will time also be recorded?
Certainly. Users are able to jump to certain points of time.
For example, when 2005/10/10 AM 1:00:21 ~1:30:30 is searched,
the server will play the video for that period of time. This
why digital era is so great.
- What are encoding formats for
video recording?
The encoding format for DVR-card is MPEG4. DVR series uses motion
JPEG encoding which is a extended mode of JPEG. They can be converted
into AVI or MPEG files for display on other computers.
- Can the images be printed out
with certain parts magnified?
Limited to DVR-card only. If you want to print out DVR images,
it has to be transferred onto a PC first.
- What should I do in back-lighted
situations?
Basically, users should try to avoid such a condition. However
you can try turning on BLC with the more advanced security cameras.
If this does not solve the problem, you can try to turn off AES
and adjust the level or exposure manually. The principle is that
the bright background and dark object will cause auto diaphragm
errors, therefore the manual diaphragm setting should solve the
problem. Please refer to the diagram here.
- What should I do when the colors
is fluttering especially when shooting under fluorescent lamps?
This is so-called "Color Rolling". This problem seems to be more
serious among the advanced security cameras. There are some manners
of avoiding such a problem and they are shown as below:
A. Move the security cameras away from the fluorescent light.
B. Use lower rank (middle luminance) security cameras.
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