AVB Output Streams

The AVB streams leaving the 12Mic are described as "output streams". In this case, the device acts as a talker. The talker defines the presentation time and therefore the latency across the network. This is set per default to 2 ms. See AVB Network Latency for details on AVB latency.

The output streams of the 12Mic are by default empty, containing a clock signal but no audio signal. To send audio with AVB, a routing must be created for each outgoing stream.

To establish a connection between a talker and a listener, an ATDECC controller is required. The 12Mic does not include an ATDECC controller.

Outgoing AVB streams are monitored by the device. The possible states of the color indicator bar of each output stream are the following:

Description Indicator Possible solution

Disabled

grey

Create routing

Disabled

orange

Create connection with ATDECC controller

Streaming/Transmitting

green

SR mismatch

red

Verify that the sample rates of talker and listener are identical

Waiting

yellow …​

Wait for listener to be ready

Listener Fail

red

Verify proper listener configuration

No Bandwidth

red

Use faster network speed (1 GBit/s instead of 100 MBit/s)

Domain Boundary

red

Reconnect all devices and reboot switch

Internal Error

red

Reboot device

Change AVB Output Stream Size and Format

Each of the eight outgoing AVB streams can have a size of 1-8, 12 or 16 channels in AM824 and AAF stream formats, or 0 channels in CRF Media Clock stream format.

To change the amount of channels and its format in the outgoing AVB stream on the device:

  1. Select the configuration of the corresponding AVB Stream tab in the OUTPUT section.

    w12 330 2T 2

  2. Use the button next to Stream format

    w1A 330 2T 1

  3. Rotate the encoder to configure a new stream size and stream format and confirm by pressing the encoder again.

To change the amount of channels of the outgoing AVB streams:

  1. Connect the device by USB or network cable and open the web remote.

  2. Open one of the outgoing AVB Ports.

  3. Select the configuration within the AVB output port to open the outgoing stream settings.

  4. Adjust output streams as necessary and click OK.

Changing a stream size briefly interrupts all outgoing AVB streams.

Adjusting the Network Latency

The default presentation time offset of 2 ms for outgoing streams can be changed when lower latencies are required.

Reducing the offset to a lower value can prevent audio to be played out depending on the network.

This setting can only be accessed on the web remote (see web remote), where it can be found in the outgoing stream settings.

To adjust the presentation time offset:

  1. Connect the device by USB or network cable and open the web remote.

  2. Open one of the outgoing AVB Ports.

  3. Select the configuration within the AVB output port to open the outgoing stream settings.

  4. Choose the desired units: ms, µs, ns, or samples (default).

  5. Adjust the presentation time offset by entering values for each stream or for all streams at once and press OK.

    wAL 330 4T 1
Values will be rounded to the nearest 100ns.
Changing the presentation time offset briefly interrupts all incoming and outgoing AVB streams.