5
Restrictions when operating MPEG-4 images
There are following restrictions when "MPEG-4" is selected for the image compression method of "NW camera"
under "Camera" on the setup menu.
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 the image compression method of the camera selected for a camera channel is "MPEG-4", 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 dis-
played 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) for how to control playback.
• Reverse playback
• Fast playback/fast reverse playback
• Reverse frame playback
Example:
When "3 seconds" is selected for the refresh interval on the camera, MPEG-4 image will be refreshed
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 sec-
ond 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 dura-
tion.
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.
