# Google is running rampant with bad examples that don't work and trac.ffmpeg.org is no exception
# from https://trac.ffmpeg.org/wiki/How to grab the desktop (screen) with FFmpeg
# https://trac.ffmpeg.org/wiki/How%20to%20grab%20the%20desktop%20%28screen%29%20with%20FFmpeg

# ./ffmpeg -video_size 1024x768 -framerate 25 -f x11grab -i :0.0+100,200 -f alsa -ac 2 -i pulse output.flv

# an older ffmpeg balked at the long option names and the order of options. Also, I obviously
# can set an offset on my whole screen and use full screen size. So my current rewrite is like so:

# ./ffmpeg -f x11grab -s 1024x768 -framerate 25 -i :0.0 -f alsa -ac 2 -i pulse output.flv

# command output:

./ffmpeg -f x11grab -s 1920x1080 -framerate 25 -i :0.0 -f alsa -ac 2 -i pulse output.flv
ffmpeg version git-2013-08-04-61af627 Copyright (c) 2000-2013 the FFmpeg developers
  built on Feb 19 2014 04:33:30 with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-4)
  configuration: --prefix=/mnt/video/ffmpeg/build --extra-cflags=-I/mnt/video/ffmpeg/build/include --extra-ldflags=-L/mnt/video/ffmpeg/build/lib --bindir=/mnt/video/ffmpeg/bin --extra-libs=-ldl --enable-gpl --enable-nonfree --enable-libfdk_aac --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libfreetype --enable-libspeex --enable-libtheora --enable-x11grab
  libavutil      52. 40.100 / 52. 40.100
  libavcodec     55. 20.100 / 55. 20.100
  libavformat    55. 13.101 / 55. 13.101
  libavdevice    55.  3.100 / 55.  3.100
  libavfilter     3. 82.100 /  3. 82.100
  libswscale      2.  4.100 /  2.  4.100
  libswresample   0. 17.103 /  0. 17.103
  libpostproc    52.  3.100 / 52.  3.100
[x11grab @ 0x3afc380] device: :0.0 -> display: :0.0 x: 0 y: 0 width: 1920 height: 1080
[x11grab @ 0x3afc380] shared memory extension found
Input #0, x11grab, from ':0.0':
  Duration: N/A, start: 1392827508.889571, bitrate: 1658880 kb/s
    Stream #0:0: Video: rawvideo (BGR[0] / 0x524742), bgr0, 1920x1080, 1658880 kb/s, 25 tbr, 1000k tbn, 25 tbc
Guessed Channel Layout for  Input Stream #1.0 : stereo
Input #1, alsa, from 'pulse':
  Duration: N/A, start: 1392827508.958655, bitrate: 1536 kb/s
    Stream #1:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
[swscaler @ 0x3ade040] deprecated pixel format used, make sure you did set range correctly
[flv @ 0x3b37a20] FLV does not support sample rate 48000, choose from (44100, 22050, 11025)
Output #0, flv, to 'output.flv':
  Metadata:
    encoder         : Lavf55.13.101
    Stream #0:0: Video: flv1 (flv) ([2][0][0][0] / 0x0002), yuv420p, 1920x1080, q=2-31, 200 kb/s, 1k tbn, 25 tbc
    Stream #0:1: Audio: mp3 (libmp3lame) ([2][0][0][0] / 0x0002), 48000 Hz, stereo, s16p
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo -> flv)
  Stream #1:0 -> #0:1 (pcm_s16le -> libmp3lame)
Could not write header for output file #0 (incorrect codec parameters ?): Invalid data found when processing input