Video Phase - Brainstorm SR-112 Owner's Manual

SR-112 User Manual (Rev 4.01)

10.2. VIDEO PHasE

For time code to be synchronous with video, each word of time code must line up
exactly with the video frame it describes. This is essential for video editing.
Per sMPTE specifications, the first transition of bit 0 of the codeword must occur
at the reference point of the video frame with which it is associated. This video
reference point is defined differently depending on the system:
For digital television systems with rates up to 50 or 60 Hz, see 10.3 below.
Video Phase Display
To monitor the sync between time code and video go to the "Video Phase" page
on the LCD display by tapping the [UP] or [DOWN] key.
With synchronous code, the display should read: "000.0º". In the real world howev-
er, things are different and phase will often be slightly off. so long as you are within
a few degrees and that number remains constant, you should have no problems.
Video Phase LED
The Video Phase LED lights up to indicate that time code is out of phase with
video, which means that time code is running at the right speed and is resolved
properly but that there is an offset between the two signals.
By default, the sR-112 considers time code in phase with video if the phase is within
+ or - 20º. If required, this window can be changed by adjusting the "Out Of Phase
Threshold" in menu 07. The range is from 0º to 99º (see page 9).
Video Drift LED & Error Message
The Video Drift LED indicates that time code is not synchronous with video.
When the 'drifiting' state is triggered, the Video Drift LED lights up and a new 'DRIFT'
error message is displayed on the 7-segment display:
The "drifting" state remains in place until either the input time code (or video)
goes away, or an "error clear" is requested (by pressing any key).
- In analog television systems, it is the start of the vertical sync;
- In digital television systems, it is the start of the video frame;
- In 525/59.95 systems, it is the start of line 4;
- In all other systems, it is the start of line 1.
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