oggenc from vorbis-tools (trunk version) has following permutation row for 6.1 channel setup: 0 2 1 4 5 6 3 But: 1) according to vorbis specs, the order should be: FL, FC, FR, SL, SR, BC, LFE 2) according to wave extensible, 0x70F expects: FL, FR, FC, LFE, BC, SL, SR So the proper permutation matrix should likely be: 0 2 1 5 6 4 3 If I adjust the matrix and recompile, I get proper channel order from e.g. libavcodec.