Video Transport Detector Ports

The RX section of the UHD-SDI core has an SDI transport format detector. This function examines the timing of the video transport in the SDI data streams and determines which video format is being received. The operation of this function is not dependent on the presence of ST 352 payload ID packets. This function determines the transport format, not the picture format.

Usually these are the same, but not always. For example, when 1080p 50 Hz video is transported on 3G-SDI level B-DL, the video transport is actually 1080i 50 Hz - the transport is interlaced, but the picture is progressive.

The rx_t_family output port provides a 4-bit code indicating which video format family of the transport in the SDI signal. The encoding of this output port is shown in the following table. The transport detection unit also determines whether the SDI transport is interlaced or progressive and reports this on the rx_t_scan output port.

The transport detector also determines the frame rate of the transport in the SDI signal. The rx_t_rate_out port indicates the frame rate of the transport signal as shown in the following table. The encoding of the frame rate matches the encoding used in the picture rate field of SMPTE ST 352 video payload ID packets. However, the rx_t_rate_out shows the transport frame rate, not the picture rate. The rx_t_rate_out port value is always the frame rate, even for interlaced transports.