Anyway to make Audacity 2.1.0 read THD+AC3?

Installing the ffmpeg 2.2.2 plugin enables Audacity to read AC3 and probably other formats, but not THD+AC3. Is there any plugin which can give it this capability? TIA

I think you would need to remux/"copy" it as just .thd and not .thd+ac3 extension. TrueHD doesn't have core. The +ac3 is only for compatibility where software/hardware can pick one. Or convert to something like FLAC. If the WAV can come in under 4GB, it should be easily readible in Audacity if you use FFMPEG to convert.

Yep, like Sparktank say only the .thd is supported. To edit the track you don't need at all the lossy AC3 embebed. BTW the ffmpeg 2.2.2 plugin still don't support TrueHD Atmos and, I supose, the -libdcadec to decode DTS-HD. Then to edit Atmos or DTS-HD you need before convert to FLAC or W64 with a new ffmpeg or eac3to.