I have converted the flv files into mp4 using the mencoder by using the following command
mencoder input.flv -o outout.mp4 -of lavf -oac mp3lame -lameopts abr:br=56 -ovc lavc -lavcopts vbitrate=800:mbd=2:mv0:trell:v4mv:cbp:last_pred=3 -srate 22050 -ofps 24 -vf harddup
It is converting the videos. But if i am using these videos in the html5 video tags. It is not playing. Please give me the suggestions.