Time Division Multiplexing (TDM) Video and Data Streams into a 1.5Gb/s HDTV Stream

This paper describes a new standard, SMPTE 346M that defines the time division multiplexing (TDM) of various standard-definition digital video and generic 8-bit data signals over a single high definition serial digital interface (SMPTE 292M). The objective of this single High Definition Multiplexed Interface is to use a single physical link to transmit, distribute, route and switch a complete family of existing 10-bit video formats and various data formats. — Active video and vertical blanking areas in the HD SDI stream are time divided into multiple channels. The standard uses 19 time-interleaved channels. The header data of the first channel is reserved to indicate the data valuation of the remaining 18 channels. — A single video or data stream is multiplexed into one or more channels of the total 18 data channels. A control packet is multiplexed into horizontal ancillary data space of the luminance parallel data area after the switching point of the HD stream for each video or data stream. The control packet indicates how and which TDM channels are used for this video or data stream. It also contains a stream clock reference signal (SCR) for clock recovery of the original clock signal. — According to the standard, multiple video or data streams could be multiplexed into and demultiplexed from a single HD SDI stream with a total delay of less than 4 us which is the time of the horizontal ancillary data space of the HD stream with additional processing delay. — A comparison between SDTI and TDM is made, pointing out the advantages and disadvantages of each type of interface.

Published

2000-10

Content type

Original Research

DOI

10.5594/M00146

ISBN

978-1-61482-933-1