Magewell produces several professional grade A/V input cards under the ProCapture line. While these cards do unfortunately require binary-only drivers, RCS is unaware of any 4k 8CH LPCM SDI/HDMI professional level input cards that have open source drivers available at this time.
NOTE: THIS IS STILL WIP. CURRENT DRIVERS DO NOT HAVE PERFECTSYNC FEATURES FULLY IMPLEMENTED
Raptor has enhanced the existing Magewell drivers to provide perfect A/V sync for studio applications. This enhancement is POWER-exclusive; builds of the modified PerfectSync driver stack are not available for other architectures.
Unlike the ProCapture drivers available for other platforms, the PerfectSync drivers do not allow any A/V drift to occur over the life of a single SDI/HDMI transport stream. This makes them suitable for use with long-running broadcast applications; this feature has not been widely available until now. When paired with the slightly modified streaming variant of ffmpeg, you can run up to five 12G SDI 4k 8CH 48KHz live transports over HLS without any A/V sync drift, visible artifacts, or reliance on power hungry and limited GPU accelerators. Now that's POWER for you!
Note that if Magewell does decide to GPL their driver stack at any point in the future, we will gladly contribute our PerfectSync changes to the open driver stack. Until then, PerfectSync remains a Raptor exclusive feature.