Ffmpeg poor quality on conversion

Hi guys,
Not sure if this is the right area or even if anyone knows how to use ffmpeg on here but here goes anyway.

I am having a problem with ffmpeg converting my quicktime movies to flv.
The movie converts fine but the quality is really poor.
What can i do to make sure that the quality is that of the input movie?


toexec = "D:\ffmpeg\bin\ffmpeg.exe -i D:\wwwroot\media\mentorMedia\	emp_".$upID."\\".$movieName." -r 15 -ar 22050 D:\wwwroot\media\mentorMedia\	emp_".$upID."\\".$newMovie;
        $doWhat = "Convert ".$movieName." to ".$newMovie;

I read in the docs that ffmpeg should ouput to as close a quality to the input file but that dosnt seem to be the case with my converted video file.

Can anyone advise?

Thanks
Paul