Milestone XProtect Express 2014 - Manual (Page 56)

Milestone XProtect ® Express 2014 Administrator's Manual
www.milestonesys.com 56 Advanced configuration
Advanced configuration
Hardware devices
About hardware devices
You add cameras and other hardware devices, such as video encoders, to your system through the
Add Hardware Devices... wizard (see "Add hardware wizard" on page 40). If microphones or
speakers are attached to a hardware device, they are automatically added as well (if your XProtect
version supports this).
About microphones
In your system, Microphones are typically attached to hardware devices, and therefore physically
located next to cameras. Operators, with the necessary rights, can then listen to recordings through
the XProtect Smart Client (provided the computer running the XProtect Smart Client has speakers
attached). You manage microphones on your system, meaning you can always manage the
microphones attached to cameras, not microphones attached to XProtect Smart Client operators'
computers.
If you have added more microphones to your system than you need, you can hide the ones you do not
need by right-clicking the relevant microphone or speaker and select Hide. If you need the hidden
microphone again, you can right-click the overall microphone icon and select Show Hidden Items.
About recording audio
If you record audio, it is important that you note the following:

Your system only records incoming audio (from microphones). The system does not record
outgoing audio (from speakers).

Audio recording affects video storage capacity. The system records audio to the associated
camera’s database. Therefore, it is important to bear in mind that the database is likely to
become full earlier if you record audio and video than if you only record video. The fact that the
database becomes full is not in itself a problem since your system automatically archives data
if the database becomes full. However, you may need additional archiving space if you record
audio.
o Example: If you use MPEG4, each one-second video GOP (Group Of Pictures) are stored
in one record in the database. Each second of audio is stored in one record in the
database. This reduces the database’s video storage capacity to half its capacity, because
half of the database’s records is used for storing audio. Consequently, the database runs
full sooner, and automatic archiving takes place more often than if you were only recording
video.
o Example: If you use 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. In extreme cases, this
reduces the database’s video storage capacity to half its capacity, because half of the