mencoder in.wav -o out.wav -of lavf -oac lavc -lavcopts acodec=pcm_u8 -v
MEncoder 1.2.1 (Debian), built with gcc-5.3.1 (C) 2000-2016 MPlayer Team
get_path('codecs.conf') -> '/home/anon/.mplayer/codecs.conf'
Reading optional codecs config file /home/anon/.mplayer/codecs.conf: No such file or directory
Reading optional codecs config file /etc/mplayer/codecs.conf: No such file or directory
Using built-in default codecs.conf.
init_freetype
Using MMX (with tiny bit MMX2) Optimized OnScreenDisplay
get_path('fonts') -> '/home/anon/.mplayer/fonts'
Configuration: --prefix=/usr --confdir=/etc/mplayer --enable-debug --enable-xvmc --enable-menu --disable-arts --language=all --disable-libmpeg2-internal --disable-ffmpeg_a --extra-cflags=-g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 --extra-ldflags=-Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,--as-needed --enable-runtime-cpudetection --enable-joystick --enable-radio --enable-radio-capture --disable-gui
[file] File size is 7043 bytes
STREAM: [file] in.wav
STREAM: Description: File
STREAM: Author: Albeu
STREAM: Comment: based on the code from ??? (probably Arpi)
success: format: 0  data: 0x0 - 0x1b83
libavformat version 56.40.101 (external)
Configuration: --prefix=/usr --extra-version=0ubuntu0.16.04.1 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 --enable-libopencv
LAVF_check: WAV / WAVE (Waveform Audio)
Checking for YUV4MPEG2
ASF_check: not ASF guid!
Checking for REAL
Checking for SMJPEG
Searching demuxer type for filename in.wav ext: .wav
Trying demuxer 17 based on filename extension
==> Found audio stream: 0
======= WAVE Format =======
Format Tag: 1 (0x1)
Channels: 1
Samplerate: 11025
avg byte/sec: 11025
Block align: 1
bits/sample: 8
cbSize: 0
==========================================================================
demux_audio: audio data 0x2C - 0x1B83
Audio only file format detected.
Video stream is mandatory!

Exiting...