SMPTE 305M. Allows fasterthan- real-time transfers between various servers and between acquisition tapes, disk-based editing systems, and servers, with both 270 Mb and 360 Mb, are supported. With typical real-time compressed video transfer rates in the 18 Mbps to 25 Mbps range, SDTI’s 200+ Mbps payload can accommodate transfers up to four times normal speed. The SMPTE 305M standard describes the assembly and disassembly of a stream of 10-bit words that conform to SDI rules. Payload data words can be up to 9 bits.

The 10th bit is a complement of the 9th to prevent illegal SDI values from occurring. The basic payload is inserted between SAV and EAV although an appendix permits additional data in the SDI ancillary data space as well. A header immediately after EAV provides a series of flags and data IDs to indicate what is coming as well as line counts and CRCs to check data continuity.