The Evertz 7720AD4 is a modular processing card designed for installation within the 7700-series backplane chassis, specifically engineered to de-embed multiple channels of digital AES audio from a serial digital video signal. In broadcast workflows where audio is commonly embedded within the HD-SDI or SD-SDI video stream for transport and switching, this card performs the critical extraction function. It can accept an SDI input, strip out the embedded audio packets, and output them as discrete AES/EBU digital audio streams. The "4" in its designation typically indicates its capacity to output four discrete pairs (eight channels) of AES audio derived from the embedded data within the incoming video signal, providing flexibility for routing audio to separate processors, recording devices, or audio mixing consoles independent of the video path.

The card provides precise control over the de-embedding process. It allows users to select which audio groups or channels within the SDI ancillary data space are to be extracted and mapped to specific AES output pairs. This is crucial for handling complex productions where multiple language tracks, stereo mixes, or discrete audio stems (like dialogue, music, and effects) are embedded together. The de-embedder also typically includes sample rate conversion capabilities, ensuring the output audio matches the required clock reference of the destination audio system, and can apply lip-sync delay adjustment to compensate for any video processing latency elsewhere in the chain. The process is transparent and lossless, preserving the original digital audio quality.

As an integral component of the modular 7700 system, the 7720AD4 benefits from centralized management, redundant power, and hot-swappability. Configuration of its parameters—such as input selection, audio group mapping, and output formatting—is managed via the chassis's system controller through a web interface or SNMP. Front-panel LEDs provide immediate status on signal presence and activity. By housing this functionality within a high-density frame, broadcast facilities can create centralized de-embedding nodes, efficiently managing audio extraction for numerous video feeds from a single, rack-mounted unit. The Evertz 7720AD4 is an essential tool for any modern broadcast facility that needs to reliably separate and manage high-quality audio from its embedded video transport streams.