Nevion AV-3G-XMUX - Manual (Page 28)

Configuration 28
AV-3G-XMUX User Manual Rev. B
LOCK Video input loss of signal
EAV, SAV Video frame format TRS errors
YCS, CCS Ancillary data packet checksum errors
YCRC, CCRC HD line CRC errors
LNUM HD line number errors
NOEDH SD EDH packet presence
FF-CRC SD EDH packet Full frame CRC errors
AP-CRC SD EDH packet Active picture CRC errors
6.4.5 Transport and shuffling of audio groups
The AV-3G-XMUX stereo audio router involves de-embedding, buffering and re-embedding which
introduces a small delay relative to the video signal. The group router is used to avoid this extra
delay. Groups that only pass through the group router are re-embedded in the same video line.
This avoids any extra delay and means that incompatible audio formats (asynchronous audio/
96 kHz audio) may still be transported. The AV-3G-XMUX automatically uses transport mode
whenever possible when controlled with the DIP switches. Shuffling of groups is when existing
embedded audio groups are re-assigned to different groups. Copying of groups is also possible
i.e. Group 1 may be transported to Group 1 and duplicated to Group 2. This function also takes
place in the group router which means that there is no extra delay. There are 8 possible groups
with 3G video but the AV-3G-XMUX has only 4 embedders so the group routing is only possible
on either the low conventional groups or the high 3G groups.
6.4.6 Audio generator
The stereo audio generator is available in the audio router as a source. It is a high purity 1 kHz sine
wave with a 250ms interruption on the left channel every 3 seconds. The audio level may be set to
one of two standards. The two levels are -18 dBFS and -20 dBFS. These two levels correspond to
EBU R68 and SMPTE RP 155.
6.4.7 Mono Audio Shuffler
The audio shuffler is shown in the main GUI as the rectangle labelled ’Mixer’. It has four stereo
outputs which may be delayed as set with the delay controls. The shuffler inputs are mono so each
if the eight inputs may be independantly set with a drop down from any of the mono channels in
the main stereo matrix except the two audio generators.