I see what you mean now. However, doesn't this mean all codecs/players that output channels in non-FFmpeg order are horribly broken, even if they report the actual order to AE?

At least Ogg Vorbis (paplayer/OGGcodec.cpp) uses a channel order that differs from FFmpeg (it has FC before FR, and SL/SR before BL/BR.

Seems like something in AE should check that m_channelLayout is in FFmpeg order, and if not, do something about it. Or is that not feasible or otherwise not wanted?