Figure 33: Audio Control Packet Format - Tektronix WFM5200 User Manual

Display Information
Audio Control The Audio Control Packet Display allows you to view information on audio frame
number, sampling frequency, active channels, and relative audio-to-video delay of
each channel, as encoded in the audio control packet metadata. (See Figure 33.)

Figure 33: Audio Control Packet format

For SD signals, transmission of audio control packets is optional for 48 kHz
synchronous operation and required for all other modes of operation (since
it contains the information as to what mode is being used). Where frequent
switching is planned, receiving equipment can be designed to add or drop a
sample following a switch in the four out of five cases where the sequence is
broken. The challenge in such a system is to detect that a switch has occurred.
This can be facilitated by use of the data block number in the ancillary data format
structure and by including an optional frame counter with the unused bits in the
audio frame number word of the audio control packet. (See Figure 34.)
For HD signals, the audio control packet carries additional information used in
the process of decoding the audio data and has a similar structure to standard
definition.
The elements of the Audio Packet display vary depending on the monitored
signal. (See Figure 35.)
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