The SMPTE UHD-SDI core provides hooks in the transmitter to allow the embedding of any type of ancillary data, including audio. Any ancillary data embedded in the SDI data streams is present on the data streams output by the SMPTE UHD-SDI core receiver.
For 6G-SDI and 12G-SDI, the SMPTE UHD-SDI core supports up to 16 elementary (non-multiplexed) data streams. In the SMPTE 6G-SDI and 12G-SDI mapping standards documents, the term data streams refers to both multiplexed and non-multiplexed data streams and care must be used when interpreting these documents to determine how many elementary data streams are used by each mapping method. At this point in the development of the 6G and 12G-SDI standards, the maximum number of elementary data streams that can be multiplexed together into a 6G-SDI data stream is 8 and into a 12G-SDI data stream is 16. As of this publishing, the 16-way interleave of data streams only occurs in dual link 12G-SDI.
Elementary data streams refers to an SDI data stream that is not multiplexed. For example, a HD-SDI signal consists of two elementary data streams, usually referred to as Y and C, that are multiplexed together onto the virtual 10-bit HD-SDI interface. Likewise, a 3G-SDI level A signal also consists of two elementary data streams, called data stream 1 and data stream 2 that are multiplexed together onto the 10-bit virtual 3G-SDI interface. A 3G-SDI level B-DL signal, however, consists of four elementary data streams, a Y and a C data stream for the HD-SDI signals that are aggregated together onto the 3G-SDI level B interface. These four elementary streams get multiplexed in a 4-way multiplex onto the 10-bit virtual 3G-SDI interface.
The SMPTE UHD-SDI core only accepts and outputs elementary, non-multiplexed, data streams on its data stream inputs and outputs. The multiplexing and de-multiplexing of data streams occurs internally to the SMPTE UHD-SDI core. Note that SD-SDI is a special case. The ST 259 standard defines an elementary data stream that actually carries both the Y and C components. This is considered to be an elementary data stream by the SMPTE UHD-SDI core.
The SMPTE UHD-SDI core does not do any video format mapping. The user application must do any necessary mapping of video onto the elementary data streams prior to feeding those streams into to the SMPTE UHD-SDI transmitter and must reconstruct the video image from the elementary streams output by the SMPTE UHD-SDI receiver. For all video formats on SD-SDI and single-link HD-SDI and for 1080p 50, 59.94, and 60Hz 4:2:2 YCbCr 10b video on 3G-SDI level A, no mapping is necessary because there is a one-to-one correspondence between the data streams of these formats and the elementary data streams into and out of the SMPTE UHD-SDI core. For dual-link HD-SDI, 3G-SDI level B-DL, multi-link 3G-SDI, 6G-SDI, and 12G-SDI, mapping of the video formats to and from elementary data streams is required and is not done in the SMPTE UHD-SDI core.