SDI to IP Bridge Brings Genlock Into The AV Rack

PlexusAV confirmed global availability of its P-AVN-6-S transceiver in the last week of October, and the specification list reads like a summary of every argument the industry has had about signal transport since 2019. It is an IPMX-certified unit with dual SFP28 cages that take 10GbE or 25GbE for uncompressed video, and it can also run JPEG XS so that a 4K flow fits on ordinary 1GbE infrastructure. On the baseband side it offers native 12G-SDI input and output plus an HDMI loop for local monitoring, converts PTP timing to genlock so that SDI outputs stay locked to the IP plant, supports SMPTE ST 2022-7 hitless redundancy across independent primary and secondary paths, and carries no additional software licences for ST 2110 or IPMX operation. Further products in the same family are promised for ISE 2027.

The two-speed design is the part worth copying into a specification. A production core built on 25GbE can move 4K at 60 frames per second with no compression at all, while the same box drops to JPEG XS when the destination is an enterprise switch and existing cabling. That mirrors how real facilities are built: a small number of high-bandwidth links where the cameras and processors live, and a much larger number of modest links out to confidence monitors, green rooms, overflow rooms and signage. The trade-off has to be stated honestly, because a 1GbE pipe is a constrained pipe. JPEG XS keeps latency to a handful of lines rather than frames, but fitting 4K60 into a gigabit means choosing chroma sampling and bit depth that the uncompressed path never has to consider, and 12G-SDI itself tops out just under 12Gbps, which is enough for 4K60 in 4:2:2 at 10 bits and not enough for everything a 25GbE link will carry.

Genlock is the quiet feature that decides whether such a device is usable. Facilities that grew up on baseband expect every SDI output to reference house black burst or tri-level sync; facilities that have moved to IP expect a PTP grandmaster and boundary clocks. A box that terminates both worlds has to translate between them continuously, and when that translation drifts the symptom is not a lost picture but a one-frame offset that only appears when a director cuts between an IP source and a baseband source on the same wall. Redundancy raises a similar practical bill: ST 2022-7 duplicates the stream across two physically separate paths, which means two switch ports, two cable routes and two sets of configuration that must be documented, not just a checkbox on a datasheet. Licence-free operation is a genuine procurement advantage across twenty endpoints, but it only counts once the diversity and timing requirements are priced in.

Amtune builds the layer that sits either side of such a bridge. Our AV over IP decoders terminate networked streams at displays and confidence positions, seamless hybrid matrices keep baseband routing deterministic where a show depends on it, and converters and scalers reconcile the frame rates, colour spaces and EDID profiles that accumulate wherever IP and baseband meet. For OEM customers we design around the timing and redundancy requirements of the host platform rather than adding them afterwards. Project enquiries at sales@amtune.com.