[FFmpeg-user] LATM demuxer

Sometime this year I thought I saw mention of ffmpeg and a LATM standalone demuxer. I may mis-recall/ may have misread, does anyone know anything about this? The reason I would need it is that currently feeding latm to decode with fdk seems impossible. Re-coding seems to lose the normal drc and the dvb (drc and mixdown) meta that fdk seems to have options to handle. In the absence of being able to do -c:a copy = the AAC re-coding case. Is there is a way not to loose meta data? TIA