[FFmpeg-user] ffmpeg Could not open X display

[motty cruz]

Hello, I'm trying to screen capture video with ffmpeg. I get the follwoing
command:

ffmpeg -f x11grab -s wuxga -vf crop=1024:768 -r 25 -i :0.0  /tmp/cdb.mpg


it:~ admin$ ffmpeg -f x11grab -r 24 -i :0.0 out.mpg
ffmpeg version N-49669-gd11ac64 Copyright (c) 2000-2013 the FFmpeg
developers
 built on Feb  7 2013 09:43:01 with Apple LLVM version 4.2 (clang-425.0.24)
(based on LLVM 3.2svn)
  configuration: --prefix=/opt/local --enable-swscale --enable-avfilter
--enable-libmp3lame --enable-libvorbis --enable-libopus --enable-libtheora
--enable-libschroedinger --enable-libopenjpeg --enable-libmodplug
--enable-libvpx --enable-libspeex --enable-libfreetype
--mandir=/opt/local/share/man --enable-shared --enable-pthreads
--cc=/usr/bin/clang --arch=x86_64 --enable-yasm
--extra-cflags=-I/opt/X11/include --extra-ldflags=-L/opt/X11/lib
--enable-gpl --enable-x11grab --enable-postproc --enable-libx264
--enable-libxvid

  libavutil      52. 17.101 / 52. 17.101

  libavcodec     54. 91.101 / 54. 91.101

  libavformat    54. 61.104 / 54. 61.104

  libavdevice    54.  3.103 / 54.  3.103

  libavfilter     3. 35.101 /  3. 35.101

  libswscale      2.  2.100 /  2.  2.100

  libswresample   0. 17.102 /  0. 17.102

  libpostproc    52.  2.100 / 52.  2.100

[x11grab @ 0x7fd238838800] device: :0.0 -> display: :0.0 x: 0 y: 0 width:
640 height: 480

[x11grab @ 0x7fd238838800] Could not open X display.

:0.0: Input/output error

it:~ admin$
any help is appreciate!
Thanks in advance.