Milestone Basis+ 6.5 - Manual (Page 59)

Milestone XProtect Basis+ 6.5; Administrator’s Manual
Audio Source Administration
Important Information about Using Audio
If you use audio sources (i.e. microphones and/or speakers) on your XProtect Basis+ system, note
the following:
• Audio from microphones is recorded even when video is not: When a microphone is
enabled (see Microphone Settings Window described on page 59), audio from the
microphone will be recorded whenever the associated camera is online (i.e. transmitting
data to XProtect Basis+; see Camera/Alert Scheduler Window on page 64), 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.
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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.
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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 records, and consequently a larger portion will be
available for storing video.
Thus, a camera database’s maximum video storage capacity may in some cases be halved
when an associated audio source is enabled.
Note: Above examples are simplified. Since databases also have a maximum limit of 40
GB of data, the exact available video storage capacity will also depend on GOP/JPEG and
audio kilobyte size.
Tip: The Archiving feature (see page 101) enables you to store recordings beyond the
capabilities of cameras’ databases.
Microphone Settings Window
The Microphone Settings window lets you change basic settings for a microphone.
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