Huw Davies (@huw) commented about include/sapi.idl:
SPSF_NUM_FORMATS
} SPSTREAMFORMAT;
+cpp_quote("DEFINE_GUID(SPDFID_Text, 0x7ceef9f9, 0x3d13, 0x11d2, 0x9e, 0xe7, 0x00, 0xc0, 0x4f, 0x79, 0x73, 0x96);") +cpp_quote("DEFINE_GUID(SPDFID_WaveFormatEx, 0xc31adbae, 0x527f, 0x4ff5, 0xa2, 0x30, 0xf6, 0x2b, 0xb6, 0x1f, 0xf7, 0x0c);")
This isn't what I see in the native SDK.