The libavcodec MP2 is far from being as good as the other two libraries
Well, it does explain it indeed, if you are familiar with video encoding: quality respectively quality-size ratio is not as good.
OK, that tells me what MP2(Twolame) is, but does NOTHING to explain the difference between that and MP2(lav).
Yes, we all know you are able to format a word in upper case, bold and underlined all together. Using only one formating would be more appropriate and convenient.