
Io XT/4K Capture, Display, Convert v14.0 46 www.aja.com
Quadrant Mode
In Quadrant Mode you can use four HD or 2K signals (1.5G) to input / output
UltraHD or 4K at 30fps or below, or four 3G signals to enable HFR and / or deep
color. Whether using four 1.5G or four 3G wires, each represents individual
quadrants of the higher definition UltraHD 3840x2160 or 4K 4096x2160 4K
formats. Physical connections of the quadrants will be mapped to the SDI
connectors as shown. Monitoring one of these HD signals on a standard SDI
monitor will display one quadrant of the picture.
Figure 15. Mapping of Quad SDI Outputs
2SI Mode
Two Sample Interleave is an alternative method to organize the data of SDI
UltraHD and 4K formats. Instead of dividing the picture raster into quadrants,
this method samples pixels to create four lower resolution versions of the entire
picture. These are combined later to create the full resolution image.
Figure 16. Mapping of 2SI Outputs
For 2SI UltraHD or 4K SDI video at 30 fps or less, monitoring one of these four
signals on a standard SDI monitor displays the entire picture, but at a lower
resolution. Above 30 fps, 3G bandwidth is required, so a 3G capable monitor is
required.”
NOTE: In some versions of AJA Control Panel, the 2SI method is referred to as ‘425’ which
is a reference to the SMPTE 425 standard which defines this method.
2-Wire and 4-Wire Modes
Using higher data rates, it is possible to carry UltraHD and 4K signals on two SDI
links, instead of four. In this situation, half (two quarters) of the image data is
carried on one link, with the other half carried on the other link. These types of
signals also cannot be viewed on a standard SDI monitor using one connector.
You can choose 2-wire or 4-wire input and output (depending on the type of
signal). If the number of links selected is not sufficient, the number of links is
automatically increased to accommodate the signal. UltraHD or 4K SDI signals 30
fps and below can be input and output simultaneously, using two connectors in
each direction. However, all four connectors are required above 30 fps. You will be
able to either input or output a high frame rate SDI signal, not both at the same