oggenc can't process 22050 Hz, 1 ch, s16le .wav file

I'm trying to process .wav file:

$ oggenc audiodump.wav
ERROR: Wav file is unsupported subformat (must be 8,16, or 24 bit PCM or floating point PCM
ERROR: Input file "audiodump.wav" is not a supported format

But e.g. mplayer says following about audiodump.wav:

$ mplayer audiodump.wav
...
Playing audiodump.wav.
Audio file detected.
...
Opening audio decoder: [pcm] Uncompressed PCM audio decoder
AUDIO: 22050 Hz, 1 ch, s16le, 352.8 kbit/100.00% (ratio: 44100->44100)
Selected audio codec: [pcm] afm:pcm (Uncompressed PCM)
...

As for oggenc version,

$ oggenc --version
OggEnc v1.0.1 (libvorbis 1.0.1)

I'd be very grateful for any solution of this mystery. It is probably just my ignorance.