<p>if i convert a video to an mp3 audio file and it terms of size let's say i choose 5MB instead of 10 MB does it mean that I lose some of the quality by compressing it more? i guess basically, does size correlate with quality?...does size matter? (haha)</p>
<p>Yes to all of your questions(ignoring your immaturity). That said the loss in quality might not be perceptible. Also be clear about what you are doing, you are converting the audio in a movie, not the movie itself.</p>