datamosh.rb

#!/usr/bin/env ruby
# remove key frame information from AVI file(codec: xvid)

# a name of AVI file
filename = ARGV.shift

f = open(filename)
data = f.read
f.close

main, index = data.split('idx1')
frames = main.split('00dc')
header = frames.shift

new_frames = []
frames.each_with_index do |frame, i|
  unless frame.index("\x00\x01\xb0\x03")
    new_frames << frame
  end
end

print [([header] + new_frames).join('00dc'), index].join('idx1')

encodetoxvid.pl

use strict;
use Carp;
use FFmpeg::Command;

my $ffmpeg = FFmpeg::Command->new('/Users/youpy/Desktop/ffmpeg');
my $output_file = 'out.avi';

$ffmpeg->input_options({
		file => shift,
});

$ffmpeg->timeout(300);
$ffmpeg->output_options({
		file                => $output_file,
		video_codec         => 'libxvid',
 		format              => 'avi',
    });

# disable audio
#push @{ $ffmpeg->options }, '-an';

push @{ $ffmpeg->options }, qw/-sameq -aspect 4:3/;
#push @{ $ffmpeg->options }, qw/-sameq/;

my $result = $ffmpeg->exec();
croak $ffmpeg->errstr unless $result;