a

$ ls
00.jpg
01.jpg
02.jpg
03.jpg
04.jpg
05.jpg
06.jpg
07.jpg
08.jpg
09.jpg
$ ffmpeg -f image2 -r 5 -i %02d.jpg -s 640x480 output.mp4
$ ffmpeg -i output.mp4 2>>a
ffmpeg version N-35681-g16abd68, Copyright (c) 2000-2011 the FFmpeg developers
  built on Dec 11 2011 22:09:57 with gcc 4.6.2 20111125 (prerelease)
  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-gpl --enable-version3 --enable-runtime-cpudetect --disable-debug --disable-static
  libavutil    51. 32. 0 / 51. 32. 0
  libavcodec   53. 42. 0 / 53. 42. 0
  libavformat  53. 24. 0 / 53. 24. 0
  libavdevice  53.  4. 0 / 53.  4. 0
  libavfilter   2. 53. 0 /  2. 53. 0
  libswscale    2.  1. 0 /  2.  1. 0
  libpostproc  51.  2. 0 / 51.  2. 0
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'output.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    creation_time   : 1970-01-01 00:00:00
    encoder         : Lavf53.24.0
  Duration: 00:00:02.00, start: 0.000000, bitrate: 602 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuvj420p, 640x480, 598 kb/s, 5 fps, 5 tbr, 5 tbn, 10 tbc
    Metadata:
      creation_time   : 1970-01-01 00:00:00
      handler_name    : 
At least one output file must be specified