oggenc do not suport some wav.pcm files what flac actually support
oggenc fails with: ERROR: Wav file is unsupported subformat (must be 8,16, or 24 bit PCM or floating point PCM ERROR: Input file "example.wav" is not a supported format
with files it actually should support: AUDIO: 22050 Hz, 1 ch, s16le, 352.8 kbit
i do not have any problems with other aplications like flac --encode or mplayer.