7700 MultiFrame Manual
7736CEM Composite Encoder with Monitoring
Revision 1.5
Page - 25
*Grey background indicates un-implemented or un-tested features
7.5.14. Setting the Colour Field Phase of the Output Video – NTSC Video
Video/SID
With this control, you can set the colour field phase of the output video with
respect to the Genlock reference input when operating in NTSC/525 video
mode.
The correct value for this register will depend on the reference to output video
phase. If the output video is later than the reference video, but less than one
field, then setting this control to "0" will make the output video have the same
colour field relationship to the genlock.
NTSC C phase
0 to 1
0
7.5.15. Setting the Colour Field Phase of the Output Video – PAL-B Video
Video/SID
With this control, you can set the colour field phase of the output video with
respect to the Genlock reference input when operating in PAL-B/625 video
mode.
The correct value for this register will depend on the reference to output video
phase. If the output video is later than the reference video, but less than one
field, then setting this control to "0" will make the output video have the same
colour field relationship to the genlock.
PAL-B C phase
0 to 3
0
7.5.16. Monitoring the Audio Buffer Tracking (-A4)
Video/SID
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 needed 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 to help in debugging system issues.
Audio buffer
