However, AC-4 is complex. It uses a hybrid backward-compatible coding structure, employing both Advanced Joint Coding and Enhanced Low Delay AAC. To verify that an AC-4 encoder is working correctly, or to troubleshoot why a TV fails to trigger "immersive mode," you need a reference decoder.
The Reference Player handles both, but v3.1.0 specifically upgrades the AC-4 pipeline. dolby reference player with dolby ac-4 v3.1.0