Error while converting AVI file using FFMPEG

I am trying to convert a avi file to mp4 format using ffmpeg, however it's giving me an error. Any help in this regard would be helpful.

 ffmpeg -y -i /var/www/crittermedia/data/tmp/fe0246a73843ee4dab856e7af517fcdd.avi -r 20 -g 40 -acodec libfaac -ar 44100 -ab 96k -vcodec libx264 -sameq -vpre medium /var/www/crittermedia/data/videos/fe0246a73843ee4dab856e7af517fcdd.mp4

It works fine for other format like flv, mov files however not for avi. The error given by ffmpeg is below:

    FFmpeg version 0.6.1, Copyright (c) 2000-2010 the FFmpeg developers
  built on Feb 19 2011 19:03:56 with gcc 4.4.5
  configuration: --enable-gpl --enable-version3 --enable-nonfree --enable-postproc --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-x11grab
  libavutil     50.15. 1 / 50.15. 1
  libavcodec    52.72. 2 / 52.72. 2
  libavformat   52.64. 2 / 52.64. 2
  libavdevice   52. 2. 0 / 52. 2. 0
  libswscale     0.11. 0 /  0.11. 0
  libpostproc   51. 2. 0 / 51. 2. 0
[avi @ 0x1c56460]max_analyze_duration reached
Input 开发者_如何学Python#0, avi, from '/var/www/crittermedia/data/tmp/fe0246a73843ee4dab856e7af517fcdd':
  Duration: 00:00:06.25, start: 0.000000, bitrate: 1071 kb/s
    Stream #0.0: Video: IV41 / 0x31345649, 256x240, 40 fps, 40 tbr, 40 tbn, 40 tbc
swScaler: Unknown format is not supported as input pixel format
Cannot get resampling context

Has somebody faced a similar issue?

According to this post:

This means that a codec is missing, here IV41(Intel Indeo 4). Intel Indeo versions 2 and 3 have decoders in FFmpeg. Indeo version 4 and 5 are not supported by any open source decoders. So we cannot trans-code this file.