Monitoring The Audio Buffer Tracking - evertz 7700 Manual

8.4.8. Monitoring the Audio Buffer Tracking

Video
Audio buffer
This item displays the status of the audio tracking buffer. It can be one of these
states:
•
Emptying (-1%)
•
Emptying (-30 ppm)
•
locked
•
Filling (30 ppm)
•
Filling (1%)
1% filling or emptying will have a slight pitch change that is near the edge of
human perception for normal audio program material. This mode will be
engaged when a large amount of delay needs to be changed quickly (video
frame drops/repeats).
30ppm filling or emptying will be used to make minor delay buffer changes.
"Locked" will indicate that the video and audio buffers match.
The delay of the audio through the audio buffer always tracks the video except
when the video frame synchronizer drops or repeats frames of video or the user
supplies a different phase of input video. Unfortunately, at these boundary
conditions, we cannot simply drop or repeat sections of audio. A rate
conversion process is used to fill or empty the buffer to the desired level. The
process must be spread out over a period of time so that the action is not
audible.
This indicator is mainly used at the Evertz factory and may also be useful to
monitor in order to help in debugging system issues.
Revision 1.0.4
7700 MultiFrame Manual
7736CD2 Dual Composite Decoder
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