cast.sh
ffmpeg version 1.2.1 Copyright (c) 2000-2013 the FFmpeg developers
  built on Jul 26 2013 10:23:32 with gcc 4.8.1 (Gentoo 4.8.1 p1.0, pie-0.5.6)
  configuration: --prefix=/usr --libdir=/usr/lib64 --shlibdir=/usr/lib64 --mandir=/usr/share/man --enable-shared --cc=x86_64-pc-linux-gnu-gcc --cxx=x86_64-pc-linux-gnu-g++ --ar=x86_64-pc-linux-gnu-ar --optflags='-march=native -O2 -pipe -m64' --extra-cflags='-march=native -O2 -pipe -m64' --extra-cxxflags='-march=native -O2 -pipe -m64' --disable-static --enable-gpl --enable-postproc --enable-avfilter --enable-avresample --disable-stripping --enable-nonfree --enable-version3 --enable-nonfree --disable-indev=v4l2 --disable-indev=oss --disable-indev=jack --disable-outdev=oss --enable-version3 --enable-bzlib --enable-runtime-cpudetect --disable-debug --disable-doc --disable-gnutls --enable-hardcoded-tables --enable-iconv --enable-network --enable-openssl --enable-ffplay --enable-vaapi --enable-vdpau --enable-zlib --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libmp3lame --disable-libfdk-aac --enable-libaacplus --enable-libfaac --enable-libtheora --disable-libtwolame --enable-libx264 --enable-libxvid --enab  libavutil      52. 18.100 / 52. 18.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[x11grab @ 0x6b0ec0] device: :0.0+24,52 -> display: :0.0 x: 24 y: 52 width: 1440 height: 960
[x11grab @ 0x6b0ec0] shared memory extension found
[x11grab @ 0x6b0ec0] Estimating duration from bitrate, this may be inaccurate
Input #0, x11grab, from ':0.0+24,52':
  Duration: N/A, start: 1374848963.368025, bitrate: 1105920 kb/s
    Stream #0:0: Video: rawvideo (BGR[0] / 0x524742), bgr0, 1440x960, 1105920 kb/s, 25 tbr, 1000k tbn, 25 tbc
[alsa @ 0x6cf220] Estimating duration from bitrate, this may be inaccurate
Guessed Channel Layout for  Input Stream #1.0 : mono
Input #1, alsa, from 'pulse':
  Duration: N/A, start: 1374848963.393263, bitrate: 768 kb/s
    Stream #1:0: Audio: pcm_s16le, 48000 Hz, mono, s16, 768 kb/s
File 'output.webm' already exists. Overwrite ? [y/N] y
sws: filterSize 1440 is too large, try less extreem scaling or increase MAX_FILTER_SIZE and recompile
sws: initFilter failed
sws: filterSize 1440 is too large, try less extreem scaling or increase MAX_FILTER_SIZE and recompile
sws: initFilter failed
sws: filterSize 1440 is too large, try less extreem scaling or increase MAX_FILTER_SIZE and recompile
sws: initFilter failed
[Parsed_scale_0 @ 0x6a92c0] Failed to configure output pad on Parsed_scale_0
Error opening filters!