Ancillary data (which includes audio, teletext, captions, or metadata) is digital data embedded in a video stream. Because video over an AXI4-Stream interface is not packetized to carry video and non-video data, ancillary data must be deembedded or discarded by the input interface and transmitted from front-to-end using a separate (AXI or non-AXI) auxiliary channel, as seen in This Figure .
When video frame rates change, buffering, re-sampling, and other processing may be required on ancillary data. This must be done separately from the Video over AXI4-Stream interface by deembedding the ancillary data before the frame rate change, processing it, and reembedding it into the video stream after the frame rate change.