On-Net Surveillance Systems, Inc.
NetDVMS 6.5f User Manual
Input, Events & Output
75
may therefore happen to several drives during the same process. However, that has no impact on how
you find and view archived recordings.
Note: If you use a drive for both recording and archiving, archiving to that drive will only take place
from cameras recording to that drive. In that case, you should select one or more other drives for
archiving, so that archiving from other databases will also take place. Alternatively, you should avoid
using the same drive for both recording and archiving.
Important: If you have more that one surveillance server, each surveillance server must archive to
its own mapped location in order for archiving to work. If you try to archive to the same mapped
location from all the servers, archiving will not work.
Archiving Audio
If audio is enabled on a device, audio from the device will also be archived. If the device is a video
encoder with several channels, audio will be archived with the camera on channel 1.
Audio
If you use audio sources (i.e. microphones and/or speakers) on your NetDVMS system, note the
following:
•
Only audio from microphones is recorded: Only incoming audio, i.e. audio recorded by
microphones attached to cameras, is recorded. Outgoing audio, i.e. what
NetGuard-EVS
operators say when they talk through speakers attached to cameras, is not recorded.
•
Audio from microphones is recorded even when video is not: When a microphone is
enabled (see
Microphone Settings Window
), audio from the microphone will be recorded
whenever the associated camera is online (i.e. transmitting data to NetDVMS; see
Camera/Alert Scheduler Window
), regardless whether video from the camera is being recorded
or not.
Depending on your cameras’ recording settings, this may mean that when you play back
recordings, you may find that there are periods for which you only have audio recordings.
This will also be the case for exported recordings if audio has been included in the export.
•
Audio recording affects video storage capacity: When a microphone is enabled, audio is
recorded to the associated camera’s database. This will affect the database’s capacity for
storing video. A camera’s database can contain a maximum of 40 GB or 600,000 records. It is
thus important to bear in mind that the maximum limit of the database is likely to be reached
earlier if recording audio and video than if only recording video.
o
Example: If using MPEG4, each one-second video GOP (Group Of Pictures) will be
stored in one record in the database. Each second of audio will also be stored in one
record in the database. When this is the case, the database’s video storage capacity
will be reduced to a maximum of 300,000 records, because half of the database’s total
maximum of 600,000 records will be used for storing audio.
o
Example: If using MJPEG, audio is stored in one record for every JPEG for as long as
the audio block size does not exceed the time between the JPEGs. The database’s
video storage capacity can thus in extreme cases be reduced to a maximum of
300,000 records, because half of the database’s total maximum of 600,000 records
will be used for storing audio. If using very high frame rates, where there is less time
between each JPEG, a smaller portion of the database will be used for storing audio
