Axis Communications AXIS 223M - Manual (Page 24)

24 AXIS 223M - Audio
Audio Channels
Audio mode - The Half-duplex mode transmits and receives audio in both directions, but
only in one direction at a time. This means that you must select when to receive or
transmit audio with the push-to-talk button. To speak, press and hold the button (check
that the microphone is not muted). When finished, release the button and you will receive
audio from the other end of the connection.
Note that the push-to-talk button is configured from AMC. It is also possible to configure
the push-to-talk button so that it toggles between speaking and listening modes.
When selecting the Simplex - Network Camera speaker only mode, the speaker connected
to the camera will play audio, but no audio will be transmitted from the camera to other
web clients. This could be used to provide spoken instructions to a person seen in the
camera. This mode requires you to use the push-to-talk button.
Simplex - Network Camera microphone only mode transmits audio only from the AXIS
223M to web clients. It will not receive audio from any other web clients. This can be used
in remote monitoring, web attractions etc., to provide live audio, as well as video, of a
monitored situation.
When using half-duplex, the Send the sound from the active client to all other clients
option transmits the audio signal from the client that is talking to all the other clients.
Audio Input
Audio from a connected microphone or a line source can be connected to the Audio in
connector of the AXIS 223M. The audio source must be set to Microphone or Line
depending on the connected device.
The Enable microphone power option provides DC power for an external microphone. If
using a small electret condenser microphone such as a clip-on mic or a PC microphone,
this option needs to be enabled.
Note:
To use a high impedance dynamic microphone, DC power should not be enabled. DC power will not harm
the microphone, but if you are uncertain, try switching it off and on. The default value is DC power enabled.
To use a professional microphone requiring 48V phantom power, you need an external power supply and
must use a balanced-unbalanced converter (audio transformer) in between.
If there are problems with the sound input being too low or high, adjust the input gain for
the microphone connected to the AXIS 223M.
Select the desired audio Encoding format: AAC, G711, G726.
Select the desired Sample rate (the number of samples of a sound that are taken per
second). The settings depend on the available bandwidth and the required audio quality,
i.e. 16kHz produces better sound but requires more bandwidth.