Grass Valley Imagestore 750 v.3.0.1 - Manual (Page 39)

23
Imagestore 750
User Manual
The compatibility matrix between REF IN type and output video format is shown here:
Adjusting Reference Timing
 Always adjust reference timing off-air because it can result in a loss of picture in downstream
equipment. Errors can occur in the SDI stream as the adjustment is taking place.
The Imagestore 750 has one FIFO on each input for simplified system timing. You can modify the
reference offset using the front panel menu. Select Setup > Reference > Offset.
Then choose either:
Lines/Samples
Lines/uS
Use the front panel arrows to increase or decrease the offset value. For any video standard, the
factory default reference timing is 0 lines plus half the length of a video line. This setting buffers
about half a video line for inputs that are timed to a reference offset of + 0 lines + 0 samples (or
+ 0 lines + 0
ms ).
Reference adjustment affects the line number marking of the output stream. The reference
must be adjusted to match the input signal timing of the local facility. Ancillary data such as
timecode, captions and audio metadata may be missed by downstream equipment if they are
not present on the same line on which they were input. If the output reference timing is not set
correctly, problems might be seen such as:
• Loss of timecode.
• Loss of closed captions.
• Errors in embedded audio.
• Errors in Dolby E streams.
Note that reference adjustment affects the line number marking of the output stream. The refer-
ence must be adjusted to match the input signal timing of the local facility.
An SDI data analyzer is needed to monitor the timing of the SDI input sources and the outputs
with respect to the facility reference.
REF IN Type
52
5i /
59
.9
4
62
5i /
50
10
80i /
5
9
.94
10
80i /
5
0
72
0p /
59.94
72
0p /
50
Ou
tp
u
t V
id
e
o F
o
rm
a
t 525i / 59.94 
625i / 50 
1080i / 59.94  
1080i / 50  
720p / 59.94  
720p / 50  
Table 4-2: Reference In compatibility with Output Video Standard