$ ffmpeg -v verbose -f video4linux2 -pix_fmt uyvy422 -i /dev/video0 -c:v libx264 -preset ultrafast cast.mkv
ffmpeg version 1.0 Copyright (c) 2000-2012 the FFmpeg developers
  built on Oct 23 2012 21:43:58 with gcc 4.7.2 (GCC)
  configuration: --prefix=/usr --enable-libmp3lame --enable-libvorbis --enable-libxvid --enable-libx264 --enable-libvpx --enable-libtheora --enable-libgsm --enable-libspeex --enable-postproc --enable-shared --enable-x11grab --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libschroedinger --enable-libopenjpeg --enable-librtmp --enable-libpulse --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libfdk-aac --enable-libaacplus --enable-libv4l2 --enable-gpl --enable-nonfree --enable-version3 --enable-runtime-cpudetect --disable-debug --disable-static
  libavutil      51. 73.101 / 51. 73.101
  libavcodec     54. 59.100 / 54. 59.100
  libavformat    54. 29.104 / 54. 29.104
  libavdevice    54.  2.101 / 54.  2.101
  libavfilter     3. 17.100 /  3. 17.100
  libswscale      2.  1.101 /  2.  1.101
  libswresample   0. 15.100 /  0. 15.100
  libpostproc    52.  0.100 / 52.  0.100
[video4linux2,v4l2 @ 0x1911340] [3]Capabilities: 5000001
[video4linux2,v4l2 @ 0x1911340] Querying the device for the current frame size
[video4linux2,v4l2 @ 0x1911340] Setting frame size to 720x487
[video4linux2,v4l2 @ 0x1911340] The v4l2 frame is 267840 bytes, but 701280 bytes are expected
[video4linux2,v4l2 @ 0x1911340] Estimating duration from bitrate, this may be inaccurate
Input #0, video4linux2,v4l2, from '/dev/video0':
  Duration: N/A, bitrate: 168139 kb/s
    Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 720x487, 168139 kb/s, 29.97 tbr, 1000k tbn, 29.97 tbc
File 'cast.mkv' already exists. Overwrite ? [y/N] y
w:720 h:487 pixfmt:uyvy422 tb:1/1000000 fr:30000/1001 sar:0/1 sws_param:flags=2
[format @ 0x1916dc0] auto-inserting filter 'auto-inserted scaler 0' between the filter 'Parsed_null_0' and the filter 'format'
[auto-inserted scaler 0 @ 0x19179c0] w:720 h:487 fmt:uyvy422 sar:0/1 -> w:720 h:487 fmt:yuv422p sar:0/1 flags:0x4
[libx264 @ 0x1912aa0] using cpu capabilities: MMX2 SSE2Slow SlowCTZ
[libx264 @ 0x1912aa0] profile High 4:2:2, level 3.1, 4:2:2 8-bit
[libx264 @ 0x1912aa0] 264 - core 124 - H.264/MPEG-4 AVC codec - Copyleft 2003-2012 - http://www.videolan.org/x264.html - options: cabac=0 ref=1 deblock=0:0:0 analyse=0:0 me=dia subme=0 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=3 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25 scenecut=0 intra_refresh=0 rc=crf mbtree=0 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=0
Output #0, matroska, to 'cast.mkv':
  Metadata:
    encoder         : Lavf54.29.104
    Stream #0:0: Video: h264, yuv422p, 720x487, q=-1--1, 1k tbn, 29.97 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo -> libx264)
Press [q] to stop, [?] for help
[video4linux2,v4l2 @ 0x1911340] The v4l2 frame is 426240 bytes, but 701280 bytes are expected
/dev/video0: Invalid data found when processing input
No more output streams to write to, finishing.
frame=   10 fps=0.0 q=32766.0 Lsize=     202kB time=375436:09:34.58 bitrate=   0.0kbits/s
video:201kB audio:0kB subtitle:0 global headers:0kB muxing overhead 0.323549%
[libx264 @ 0x1912aa0] frame I:1     Avg QP:20.00  size: 37667
[libx264 @ 0x1912aa0] frame P:9     Avg QP:24.22  size: 18654
[libx264 @ 0x1912aa0] mb I  I16..4: 100.0%  0.0%  0.0%
[libx264 @ 0x1912aa0] mb P  I16..4: 21.1%  0.0%  0.0%  P16..4: 25.6%  0.0%  0.0%  0.0%  0.0%    skip:53.3%
[libx264 @ 0x1912aa0] coded y,uvDC,uvAC intra: 51.3% 75.1% 54.7% inter: 17.2% 28.4% 12.9%
[libx264 @ 0x1912aa0] i16 v,h,dc,p: 35% 47% 11%  8%
[libx264 @ 0x1912aa0] i8c dc,h,v,p: 31% 43% 19%  7%
[libx264 @ 0x1912aa0] kb/s:242.77





$ ffmpeg -v verbose -f video4linux2 -pix_fmt uyvy422 -i /dev/video0 -c:v libx264 -preset ultrafast cast.mkv
ffmpeg version 1.0 Copyright (c) 2000-2012 the FFmpeg developers
  built on Oct 23 2012 21:43:58 with gcc 4.7.2 (GCC)
  configuration: --prefix=/usr --enable-libmp3lame --enable-libvorbis --enable-libxvid --enable-libx264 --enable-libvpx --enable-libtheora --enable-libgsm --enable-libspeex --enable-postproc --enable-shared --enable-x11grab --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libschroedinger --enable-libopenjpeg --enable-librtmp --enable-libpulse --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libfdk-aac --enable-libaacplus --enable-libv4l2 --enable-gpl --enable-nonfree --enable-version3 --enable-runtime-cpudetect --disable-debug --disable-static
  libavutil      51. 73.101 / 51. 73.101
  libavcodec     54. 59.100 / 54. 59.100
  libavformat    54. 29.104 / 54. 29.104
  libavdevice    54.  2.101 / 54.  2.101
  libavfilter     3. 17.100 /  3. 17.100
  libswscale      2.  1.101 /  2.  1.101
  libswresample   0. 15.100 /  0. 15.100
  libpostproc    52.  0.100 / 52.  0.100
[video4linux2,v4l2 @ 0x1841340] [3]Capabilities: 5000001
[video4linux2,v4l2 @ 0x1841340] Querying the device for the current frame size
[video4linux2,v4l2 @ 0x1841340] Setting frame size to 720x487
[video4linux2,v4l2 @ 0x1841340] The v4l2 frame is 702720 bytes, but 701280 bytes are expected
[video4linux2,v4l2 @ 0x1841340] Estimating duration from bitrate, this may be inaccurate
Input #0, video4linux2,v4l2, from '/dev/video0':
  Duration: N/A, bitrate: 168139 kb/s
    Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 720x487, 168139 kb/s, 29.97 tbr, 1000k tbn, 29.97 tbc
File 'cast.mkv' already exists. Overwrite ? [y/N] y
w:720 h:487 pixfmt:uyvy422 tb:1/1000000 fr:30000/1001 sar:0/1 sws_param:flags=2
[format @ 0x1846dc0] auto-inserting filter 'auto-inserted scaler 0' between the filter 'Parsed_null_0' and the filter 'format'
[auto-inserted scaler 0 @ 0x18479c0] w:720 h:487 fmt:uyvy422 sar:0/1 -> w:720 h:487 fmt:yuv422p sar:0/1 flags:0x4
[libx264 @ 0x1842aa0] using cpu capabilities: MMX2 SSE2Slow SlowCTZ
[libx264 @ 0x1842aa0] profile High 4:2:2, level 3.1, 4:2:2 8-bit
[libx264 @ 0x1842aa0] 264 - core 124 - H.264/MPEG-4 AVC codec - Copyleft 2003-2012 - http://www.videolan.org/x264.html - options: cabac=0 ref=1 deblock=0:0:0 analyse=0:0 me=dia subme=0 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=3 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25 scenecut=0 intra_refresh=0 rc=crf mbtree=0 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=0
Output #0, matroska, to 'cast.mkv':
  Metadata:
    encoder         : Lavf54.29.104
    Stream #0:0: Video: h264, yuv422p, 720x487, q=-1--1, 1k tbn, 29.97 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo -> libx264)
Press [q] to stop, [?] for help
[video4linux2,v4l2 @ 0x1841340] The v4l2 frame is 129600 bytes, but 701280 bytes are expected
/dev/video0: Invalid data found when processing input
No more output streams to write to, finishing.
frame=    3 fps=0.0 q=32766.0 Lsize=      42kB time=375436:10:55.13 bitrate=   0.0kbits/s
video:42kB audio:0kB subtitle:0 global headers:0kB muxing overhead 1.386781%
[libx264 @ 0x1842aa0] frame I:1     Avg QP:20.00  size: 36287
[libx264 @ 0x1842aa0] frame P:2     Avg QP:23.00  size:  2973
[libx264 @ 0x1842aa0] mb I  I16..4: 100.0%  0.0%  0.0%
[libx264 @ 0x1842aa0] mb P  I16..4:  8.1%  0.0%  0.0%  P16..4:  5.4%  0.0%  0.0%  0.0%  0.0%    skip:86.5%
[libx264 @ 0x1842aa0] coded y,uvDC,uvAC intra: 48.4% 78.3% 46.3% inter: 0.7% 5.6% 0.7%
[libx264 @ 0x1842aa0] i16 v,h,dc,p: 47% 30% 11% 11%
[libx264 @ 0x1842aa0] i8c dc,h,v,p: 35% 31% 25% 10%
[libx264 @ 0x1842aa0] kb/s:3375.26