Converting video using php

We can convert video file to .flv format by ffmpeg-php extension but how can we convert .flv to other format, i searched but no solution find...

//ececute ffmpeg generate flv
  exec('ffmpeg -i '.$uploadfile.' -f flv -s 320x240 '.$new_flv.'');

// But can we this, convert it to mpeg..
  exec('ffmpeg -i '.$uploadfile.' -f mpg -s 320x240 '.$new_flv.'');

//execute ffmpeg and create thumb
  exec('ff开发者_如何学JAVAmpeg  -i '.$uploadfile.' -f mjpeg -vframes 1 -s 150x150 -an '.$new_image_path.'');

Or, is there any php api like (ffmpeg) to do this....???

the response is in the documentation but here are some command examples that i find quite useful

Good Luck