SMPTE 352 Payload Identification

The SMPTE 352 payload identifier is inserted into the ancillary data and carries information to identify such things as the video format and scanning method, interface standard, and aspect ratio for the current video signal. Some upstream devices will insert this information, and other may not. This can result in the SMPTE 352 payload identifier appearing and disappearing as you transition between video signals, causing problems for downstream devices such as monitors.

The SMPTE 352 payload identifier is inserted after the passing or stripping of the ancillary data by the switcher.