Examining IPMX: Pivotal Documents Determining the Evolution of Audio-Video Transmission via Internet Protocol

In a recent project, a system designer and field technician were tasked with upgrading and expanding an existing AV system. The goal was to integrate legacy baseband equipment with new IPMX endpoints, transforming the system into a modern, efficient solution for audio-visual (AV) needs.

The heart of this transformation lies in the IPMX standard, a developing solution for AV-over-IP that aims to redefine how such systems are thought about and implemented. Rooted in the SMPTE ST 2110 and AES67 standards, and the Video Services Forum (VSF) TR-10 and Advanced Media Workflow Association (AMWA) NMOS specifications, IPMX offers a promising future for seamless, interoperable AV transport and control in professional environments.

One of the first challenges encountered was the integration of the break room's new panel, which displayed a mix of digital signage and over-the-air content, including HDCP-protected content. To handle this content mixing while maintaining HDCP compliance, the team employed the HKEP protocol, detailed in TR-10-14 (draft available soon!).

The digital signage system in the project included older monitors encased in custom cabinets, leading to an EDID-related challenge. However, the advent of NMOS IS-12 enabled seamless compatibility issue resolution, avoiding the need to replace custom-encased monitors or devise makeshift solutions for configuring the new gateways.

The system also needed to support PTP for minimizing latency for Image Magnification (IMAG) and some of the equipment used AES67, which doesn't support asynchronous sources and requires PTP. Thankfully, the TR10-1 specifications made PTP requirements less concerning than in straight SMPTE ST 2110 networks.

However, the team faced an issue with the audio and video being out of sync. After investigating, it was found that the HDMI switch in the breakroom was sending out strange audio info frames with large LATENCY values. To compensate for this, the Link Offset Delay property was used to delay the video enough to sync with the audio.

Finding devices that support all three protocols (IPMX, AES67, and ST 2110) is easy, simplifying the connection of asynchronous AV sources into the auditorium's synchronous live production system. The older monitors' capabilities remain unclear due to the absence of available datasheets, but NMOS IS-11's connection negotiation capabilities allow for multicasting to the new and older monitors, ensuring compatibility across the board.

The secure huddle room presented a unique challenge, requiring all content traffic to be encrypted. This introduced the Privacy Encryption Protocol (PEP), outlined in TR-10-13, which ensures multi-vendor, interoperable encryption for video, audio, and USB traffic.

In this project, the practical application of TR-10 and NMOS specifications within the IPMX framework was evident. The article focuses on this real-world scenario, offering insights into the benefits and challenges of implementing IPMX in a professional AV environment. With final testing scheduled for later this year, the future of IPMX looks promising for streamlined, efficient, and secure AV solutions.

Examining IPMX: Pivotal Documents Determining the Evolution of Audio-Video Transmission via Internet Protocol