xx@(none) ~ $ ffmpeg -y -f alsa -i hw:3,0 -f video4linux2 -r 20 -s 1280x720 -i /dev/video0 -acodec libfaac -ab 128k -vcodec libx264 /tmp/web.avi
ffmpeg version 0.10.3 Copyright (c) 2000-2012 the FFmpeg developers
  built on Oct 28 2012 21:47:51 with gcc 4.5.4
  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' --extra-cflags='-march=native -O2 -pipe' --extra-cxxflags='-march=native -O2 -pipe' --disable-static --enable-gpl --enable-version3 --enable-postproc --enable-avfilter --disable-stripping --disable-debug --disable-doc --disable-vaapi --disable-vdpau --enable-runtime-cpudetect --enable-openssl --enable-nonfree --enable-libmp3lame --enable-libvo-aacenc --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --enable-libfaac --enable-nonfree --enable-openal --disable-indev=v4l --disable-indev=oss --enable-x11grab --disable-outdev=oss --enable-libfreetype --enable-pthreads --enable-libgsm --enable-librtmp --enable-libspeex --enable-libopenjpeg --disable-amd3dnow --disable-amd3dnowext --disable-altivec --disable-avx --disable-vis --disable-neon --cpu=host --enable-  libavutil      51. 35.100 / 51. 35.100
  libavcodec     53. 61.100 / 53. 61.100
  libavformat    53. 32.100 / 53. 32.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 61.100 /  2. 61.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  6.100 /  0.  6.100
  libpostproc    52.  0.100 / 52.  0.100
[alsa @ 0x1c6fbf0] Estimating duration from bitrate, this may be inaccurate
Input #0, alsa, from 'hw:3,0':
  Duration: N/A, start: 1351487850.525225, bitrate: N/A
    Stream #0:0: Audio: pcm_s16le, 32000 Hz, 2 channels, s16, 1024 kb/s
[video4linux2,v4l2 @ 0x1c703d0] The driver changed the time per frame from 1/20 to 1/10
[video4linux2,v4l2 @ 0x1c703d0] Estimating duration from bitrate, this may be inaccurate
Input #1, video4linux2,v4l2, from '/dev/video0':
  Duration: N/A, start: 45223.081171, bitrate: 147456 kb/s
    Stream #1:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 1280x720, 147456 kb/s, 10 tbr, 1000k tbn, 10 tbc
Incompatible pixel format 'yuyv422' for codec 'libx264', auto-selecting format 'yuv422p'
[buffer @ 0x1c76b40] w:1280 h:720 pixfmt:yuyv422 tb:1/1000000 sar:0/1 sws_param:
[buffersink @ 0x1c717f0] auto-inserting filter 'auto-inserted scale 0' between the filter 'src' and the filter 'out'
[scale @ 0x1c72e00] w:1280 h:720 fmt:yuyv422 -> w:1280 h:720 fmt:yuv422p flags:0x4
[libx264 @ 0x1c71330] using cpu capabilities: MMX2 SSE2Fast SSSE3 FastShuffle SSE4.2 AVX
[libx264 @ 0x1c71330] profile High 4:2:2, level 3.1, 4:2:2 8-bit
Output #0, avi, to '/tmp/web.avi':
  Metadata:
    ISFT            : Lavf53.32.100
    Stream #0:0: Video: h264 (H264 / 0x34363248), yuv422p, 1280x720, q=-1--1, 10 tbn, 10 tbc
    Stream #0:1: Audio: aac ([255][0][0][0] / 0x00FF), 32000 Hz, 2 channels, s16, 128 kb/s
Stream mapping:
  Stream #1:0 -> #0:0 (rawvideo -> libx264)
  Stream #0:0 -> #0:1 (pcm_s16le -> libfaac)
Press [q] to stop, [?] for help
frame=   25 fps=  8 q=-1.0 Lsize=     658kB time=00:00:02.30 bitrate=2345.1kbits/s
video:606kB audio:40kB global headers:0kB muxing overhead 1.931709%
[libx264 @ 0x1c71330] frame I:2     Avg QP:19.56  size: 34850
[libx264 @ 0x1c71330] frame P:23    Avg QP:19.76  size: 23968
[libx264 @ 0x1c71330] mb I  I16..4: 24.8% 63.9% 11.4%
[libx264 @ 0x1c71330] mb P  I16..4:  1.2%  4.6%  0.3%  P16..4: 36.4% 13.9% 13.5%  0.0%  0.0%    skip:30.1%
[libx264 @ 0x1c71330] 8x8 transform intra:68.5% inter:59.6%
[libx264 @ 0x1c71330] coded y,uvDC,uvAC intra: 60.0% 73.8% 53.4% inter: 26.7% 42.9% 4.5%
[libx264 @ 0x1c71330] i16 v,h,dc,p: 68% 16% 11%  4%
[libx264 @ 0x1c71330] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 19%  9% 43%  6%  5%  6%  4%  6%  3%
[libx264 @ 0x1c71330] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 34% 13% 30%  6%  5%  4%  3%  3%  2%
[libx264 @ 0x1c71330] i8c dc,h,v,p: 65% 12% 18%  5%
[libx264 @ 0x1c71330] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0x1c71330] ref P L0: 42.1%  4.8% 32.1% 21.0%
[libx264 @ 0x1c71330] kb/s:1987.12