https://github.com/Fraunhofer-IIS/mpeghdec
raunhofer provide an open source decoder on their github page – mpeghdec.
It could add support for decoding mpegh_3d_audio, which is already being used in Korean terrestrial TV (ATSC 3.0) and upcoming 4k TV standards in Europe.
The documentation for the sample program mpeghDecoder shows decoding options for the library, the most import one being -tl for the target layout.
I’m not sure the layouts in https://github.com/Fraunhofer-IIS/mpeghdec/wiki/MPEG-H-decoder-target-layouts can be mapped to those in libavutil/channel_layout.h 100%.