# works
dd if=/dev/video0 |tee >(mplayer tv:// -tv driver=v4l2:normid=4:width=720:height=576:outfmt=uyvy:input=1:fps=25 -vf yadif -aspect 4:3) > /dev/null

# doesn't work
dd if=/dev/video0   |tee >(avconv -f video4linux2 -aspect 1.3333 -s 720x576 -channel 1 -pix_fmt yuv420p -i pipe:0 -f alsa -ar 44100 -ac 2 -acodec pcm_s16le -i hw:0 -vcodec mpeg4 -vtag DX50 -b 1200k -r 25 -acodec libmp3lame -ar 44100 -ac 2 -ab 128k -y test_pipe.avi) > /dev/null

# Log:
ffmpeg version git-2012-03-06-0f13cc7 Copyright (c) 2000-2012 the FFmpeg developers
  built on Mar  6 2012 20:15:33 with gcc 4.6.1
  configuration: --enable-gpl --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libx264 --enable-nonfree --enable-version3 --enable-libxvid --enable-x11grab --enable-openssl --enable-librtmp
  libavutil      51. 41.100 / 51. 41.100
  libavcodec     54. 10.100 / 54. 10.100
  libavformat    54.  2.100 / 54.  2.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 63.100 /  2. 63.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  7.100 /  0.  7.100
  libpostproc    52.  0.100 / 52.  0.100
[video4linux2,v4l2 @ 0x2fa11c0] Cannot open video device pipe:0 : No such file or directory
pipe:0: No such file or directory