newer seems to default to x264

newer ffmpeg

$ ffmpeg -y -f dshow -i video=screen-capture-recorder  -r 5 -t 1 "yo3.mp4"
ffmpeg version N-32138-g312645e, Copyright (c) 2000-2011 the FFmpeg developers
  built on Aug 28 2011 21:12:09 with gcc 4.6.1
  configuration: --enable-gpl --enable-version3 --enable-memalign-hack --enable-runtime-cpudetect --enable-avisynth --enable-bzlib --enable-frei0r --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-libopenjpeg --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
  libavutil    51. 14. 0 / 51. 14. 0
  libavcodec   53. 12. 0 / 53. 12. 0
  libavformat  53. 10. 0 / 53. 10. 0
  libavdevice  53.  3. 0 / 53.  3. 0
  libavfilter   2. 35. 0 /  2. 35. 0
  libswscale    2.  0. 0 /  2.  0. 0
  libpostproc  51.  2. 0 / 51.  2. 0
[dshow @ 0197A400] Estimating duration from bitrate, this may be inaccurate
Input #0, dshow, from 'video=screen-capture-recorder':
  Duration: N/A, start: 65578.947000, bitrate: N/A
    Stream #0.0: Video: rawvideo, bgra, 500x500, 10000k tbr, 10000k tbn, 10000k tbc
Incompatible pixel format 'bgra' for codec 'libx264', auto-selecting format 'yuv420p'
[buffer @ 03CE5680] w:500 h:500 pixfmt:bgra tb:1/1000000 sar:0/1 sws_param:
[buffersink @ 03CE5920] auto-inserting filter 'auto-inserted scaler 0' between the filter 'src' and the filter 'out'
[scale @ 03CE6F20] w:500 h:500 fmt:bgra -> w:500 h:500 fmt:yuv420p flags:0x4
[libx264 @ 03CE90E0] using cpu capabilities: MMX2 SSE2Slow SlowCTZ
[dshow @ 0197A400] real-time buffer 65% full! frame dropped!
[libx264 @ 03CE90E0] profile High, level 2.2
[dshow @ 0197A400] real-time buffer 98% full! frame dropped!
[libx264 @ 03CE90E0] 264 - core 116 r2044 392e762 - H.264/MPEG-4 AVC codec - Copyleft 2003-2011 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2
b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=5 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'yo3.mp4':
  Metadata:
    encoder         : Lavf53.10.0
    Stream #0.0: Video: h264 (![0][0][0] / 0x0021), yuv420p, 500x500, q=2-31, 5 tbn, 5 tbc
Stream mapping:
  Stream #0.0 -> #0.0: rawvideo -> libx264
Press [q] to stop, [?] for help
[dshow @ 0197A400] real-time buffer 131% full! frame dropped!
    Last message repeated 3 times     0kB time=00:00:00.00 bitrate=   0.0kbits/s dup=0 drop=49
[dshow @ 0197A400] real-time buffer 65% full! frame dropped!
[dshow @ 0197A400] real-time buffer 98% full! frame dropped!
[dshow @ 0197A400] real-time buffer 131% full! frame dropped!
    Last message repeated 43 times
frame=    7 fps=  5 q=23.0 Lsize=     199kB time=00:00:01.00 bitrate=1626.6kbits/s dup=0 drop=83
video:198kB audio:0kB global headers:0kB muxing overhead 0.434201%
frame I:1     Avg QP:21.35  size: 72495
[libx264 @ 03CE90E0] frame P:4     Avg QP:25.67  size: 32169
[libx264 @ 03CE90E0] frame B:2     Avg QP:13.10  size:   282
[libx264 @ 03CE90E0] consecutive B-frames: 57.1%  0.0% 42.9%  0.0%
[libx264 @ 03CE90E0] mb I  I16..4: 26.1%  0.3% 73.6%
[libx264 @ 03CE90E0] mb P  I16..4:  8.0%  0.1% 24.6%  P16..4: 23.0%  3.8%  3.4%  0.0%  0.0%    skip:37.0%
[libx264 @ 03CE90E0] mb B  I16..4:  2.1%  0.0%  0.0%  B16..8: 22.3%  0.3%  0.0%  direct: 0.1%  skip:75.1%  L0:19.5% L1:78.8% BI: 1.7%
[libx264 @ 03CE90E0] 8x8 transform intra:0.2% inter:1.7%
[libx264 @ 03CE90E0] coded y,uvDC,uvAC intra: 65.4% 75.0% 72.5% inter: 13.8% 8.5% 8.2%
[libx264 @ 03CE90E0] i16 v,h,dc,p: 43% 54%  3%  0%
[dshow @ 0197A400] real-time buffer 131% full! frame dropped!
[libx264 @ 03CE90E0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 42%  4% 50%  0%  0%  0%  0%  0%  4%
[libx264 @ 03CE90E0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 25% 31% 17%  2%  2%  4%  7%  2% 10%
[libx264 @ 03CE90E0] i8c dc,h,v,p: 46% 25% 23%  6%
[libx264 @ 03CE90E0] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 03CE90E0] ref P L0: 78.8%  7.6% 11.3%  2.4%
[libx264 @ 03CE90E0] ref B L0: 51.1% 30.9% 18.0%
[libx264 @ 03CE90E0] ref B L1: 90.7%  9.3%
[libx264 @ 03CE90E0] kb/s:1152.76
[dshow @ 0197A400] real-time buffer 131% full! frame dropped!
    Last message repeated 1 times

older ffmpeg

ffmpeg -f dshow -i video=screen-capture-recorder  -r 5 -t 1 -y "yo3.mp4"
ffmpeg version N-31706-g335bbe4, Copyright (c) 2000-2011 the FFmpeg developers
  built on Jul 31 2011 18:52:06 with gcc 4.6.1
  configuration: --enable-gpl --enable-version3 --enable-memalign-hack --enable-runtime-cpudetect --enable-avisynth --enable-bzlib --enable-frei0r --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-libopenjpeg --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
  libavutil    51. 11. 1 / 51. 11. 1
  libavcodec   53.  9. 0 / 53.  9. 0
  libavformat  53.  6. 0 / 53.  6. 0
  libavdevice  53.  2. 0 / 53.  2. 0
  libavfilter   2. 27. 5 /  2. 27. 5
  libswscale    2.  0. 0 /  2.  0. 0
  libpostproc  51.  2. 0 / 51.  2. 0
[dshow @ 0037A4C0] Estimating duration from bitrate, this may be inaccurate
Input #0, dshow, from 'video=screen-capture-recorder':
  Duration: N/A, start: 65506.384000, bitrate: N/A
    Stream #0.0: Video: rawvideo, bgra, 500x500, 10000k tbr, 10000k tbn, 10000k tbc
Incompatible pixel format 'bgra' for codec 'mpeg4', auto-selecting format 'yuv420p'
[buffer @ 03BA60A0] w:500 h:500 pixfmt:bgra tb:1/1000000 sar:0/1 sws_param:
[buffersink @ 03BA6320] auto-inserting filter 'auto-inserted scaler 0' between the filter 'src' and the filter 'out'
[scale @ 00378D00] w:500 h:500 fmt:bgra -> w:500 h:500 fmt:yuv420p flags:0x4
Output #0, mp4, to 'yo3.mp4':
  Metadata:
    encoder         : Lavf53.6.0
    Stream #0.0: Video: mpeg4, yuv420p, 500x500, q=2-31, 200 kb/s, 5 tbn, 5 tbc
Stream mapping:
  Stream #0.0 -> #0.0
Press [q] to stop, [?] for help
[dshow @ 0037A4C0] real-time buffer 65% full! frame dropped!
[dshow @ 0037A4C0] real-time buffer 98% full! frame dropped!
[dshow @ 0037A4C0] real-time buffer 65% full! frame dropped!itrate=4203.1kbits/s dup=0 drop=49
frame=    7 fps=  0 q=9.6 Lsize=     445kB time=00:00:01.40 bitrate=2605.4kbits/s dup=0 drop=88
video:444kB audio:0kB global headers:0kB muxing overhead 0.181713%