7
Restrictions when operating MPEG-4 images
There are following restrictions when "MPEG-4" is selected for the
image compression method on the setup menu. ("NW camera"
under "Camera")
1.
When displaying live images
(1) Black screen may be displayed for the first few seconds (*)
when the following operations are performed while displaying
live images.
⋅
When MPEG-4 live images are displayed (by switching
camera channel, etc.)
⋅
When MPEG-4 image is enlarged (or when enlarged
MPEG-4 image is resized to the original size)
(2) It may take several seconds (*) for refresh interval of MPEG-4
image when displaying images on a 4-screen.
Example:
When "3 seconds" is selected for the refresh
interval on the camera, MPEG-4 image will be
refreshed in 3 seconds intervals.
2. When displaying images sequentially
When "MPEG-4" is selected for the image compression method of
the camera selected for a camera channel on the setup menu, the
respective sequence step will be skipped.
3. When playing recorded images
(1) Displayed playback time may be fast for several seconds (*)
when the following operations are performed while playing
recorded images
⋅
When MPEG-4 recorded images are played (by changing
camera channel, etc.)
⋅
When MPEG-4 image is enlarged (or when enlarged
MPEG-4 image is resized to the original size)
(When operating to zoom in/out a paused MPEG-4
recorded image, image of several seconds later than the
displayed image may be enlarged.)
⋅
When the [PLAY] button is clicked again while playing
MPEG-4 image
⋅
When the first frame is displayed by clicking the [NEXT
IMAGE] button during pausing
(2) Playback may be performed in several seconds intervals (*)
when the following operations are performed while playing
MPEG-4 image. Refer to the Operating Instructions (PDF file)
for further information.
⋅
Reverse playback ([REV PLAY])
⋅
Fast playback/fast reverse playback ([FF] / [REW])
⋅
Reverse frame playback ([PREV IMAGE])
Example:
When "3 seconds" is selected for the refresh
interval on the camera, MPEG-4 image will be
played in 3 seconds intervals.
(3) When two records are played sequentially, the last few frames
of the former record and the first few frames of the next record
may be displayed overlapped.
(4) When playing MPEG-4 image by designating time and date,
playback may start from a point several seconds before or
after the designated time and date or from the first frame of
the next record.
4. When recording images
(1) Time and date displayed on the recording event list (actual
start time of recordings) may not exactly indicate the actual
time of recording trigger (event occurrence time, start time of
the schedule recording, etc.), and also the recording duration
may be shortened for seconds worth two times of the refresh
interval set on the camera.
Example:
When the set recording duration and the set
refresh interval of the camera are 10 seconds and
1 second respectively
10 - (1 x 2) =
8
(sec)
The minimum actual recording duration is
8
seconds.
(2) When pre-event recording is set to be performed, pre-event
recording duration may be longer than the set duration.
Example:
Depending on the size of the image data, pre-
recording duration may be around 10 seconds
even when setting 5 seconds for the pre-event
recording duration.
5. When copying images
Copying may start from a point several seconds (*) later than the
designated start time when copying MPEG-4 images. To copy the
desired images for sure, designate start time several seconds earlier
than the time when the desired images are recorded, and set time
range for copying longer than the refresh interval set on the camera.
6. When downloading recorded images
Download of recorded images may start from a point several
seconds (*) earlier than the designated start time. Set time range for
download longer than the refresh interval set on the camera.
7. When transmitting images recorded at an event
occurrence to the FTP server
Duration of images to be transmitted to the FTP server, which are
recorded at an event occurrence, may not be exactly the same as
the duration set for "Duration-Pre" and "Duration-Post". Set
"Duration-Pre" and "Duration-Post" longer than the refresh interval
set on the camera.
8. Other
MPEG-4 images will not be attached to alarm mails.
Even when images are to be transmitted to the FTP server
periodically, MPEG-4 images will not be transmitted.
* Time (seconds) differs depending on the refresh interval set on
the camera (0.2 - 5 seconds). To shorten time lag, set the refresh
interval on the camera shorter. Refer to the operating instructions
of the camera for how to configure the refresh interval.
Содержание WJND400 - NETWORK DISK RECORDER
Страница 73: ...4 ...
