hello...
first of all let me state that I'm new to this forum and new to encoding mp3s... that is I used to encode mp3s with lame in the past, but I've never really cared much for the lame versions and mostly used presets...

lately I've experimented a bit with mp3 encoding with using my own parameters... I have found that when encoding certain songs the bitrates of songs encoded with lame 3.97 were considerably lower than bitrates of songs encoded with either 3.96.1 or 3.98a10...

for all of these versions I have used the following parameters:

-V2 --vbr-new -b128

here are the bitrates I got on 2 songs that I used for testing (lameversion: bitrate-song1, bitrate-song2):

3.97: 145, 165
3.96.1: 156, 179
3.98: 161, 180

the bitrates resulted from using lame 3.97 are the lowest... when I looked at the bitrate distribution (with encspot) I've noticed that songs encoded with lame 3.97 have a higher percentage of 128kbits than songs encoded with the other lame version...

for example, song1 has a bitrate of 145 when encoded with lame 3.97 and a bitrate of 156 when encoded with lame 3.96.1 (look above)... the bitrate distrubiution is as follows (lame version: 128, 160, 192, 224)

3.97: 61, 25, 10, 2, ...
3.96.1: 41, 33, 18, 6, ...
3.98: 41, 36, 14, 5, ...

so the song encoded with lame 3.97 has 61% of it encoded as a 128kbit stream, whereas 3.96.1 version is only 41%... 3.98a10 follows closely to 3.96.1...


I have seen this happen (lower bitrates with lame 3.97) with several songs that I've encoded... now I realize I may be wrong with many things up there, but as I said I'm quite *new* to all this...

is this OK for 3.97 to encode with such noticeably lower bitrates (and higher 128kbit percentages) ? Is this a *fault* of the encoder that it encodes most of a song as a 128kbit stream, or is it actually a plus (a better algorithm is used that can result with same quality *but* using lower bitrate) ?


I'm really confused.... help me put this all in a perspective of some sort



ps. and I'm terribly sorry for the length of this post, but this being my first post I had a lot of questions on my mind... next time I'll keep it shorter and to-the-point

How do the files sound? Can you hear any difference?

I see your point.... no, I can't really hear any difference so I might just as well keep them the way they are... still I'm rather curious where does this bitrate drop come from and if this is 'by design' or by fault of some sort...

I think that the goal with each new version of LAME is to produce better sounding (or at least equal sounding) files, while also reducing the file size with respect to previous LAME versions. This would explain the lower bitrate, assuming the files sound just as good (or better) than previous versions.