Hello... I've been lurking on this list for awhile now and I've really started to
become interested in some of the more advanced aspects of lame such as the
experimental modes and stuff. Basically what I am trying to get out of lame is the
highest possible sound quality short of using 320kbps cbr. For me size isn't such a
big issue although the smaller the file the better.... I just figure if I'm going to
be using 320kbps I might as well just go lossless.. Anyway, over the last week or so
I have really started experimenting with all the different switches and have been
measuring their effects on sound quality via frequency analysis graphs, waveform
subtraction, and most importantly listening tests. When I first started encoding my
mp3s for archival purposes I was using the switches: -V1 -mj -b128 -q1 (thanks to
RoelVdB) and was fairly happy with the results. After performing the aforementioned
tests however, I have come up with what I consider significantly better setting!
s as far as sound quality is concerned. These new settings are: -V1 -mj -b128 -q2 -d
-p -k -F --nspsytune --athlower -35 -X3. The main reason I decided to switch to these
settings is because they seem to eliminate pretty much all of the artifacts from the
different test files I used it on, that the older settings were not able to. In
particular, the file where it seemed to make the biggest difference was in fatboy.wav.
With the original settings the file had very audible and harsh sounding pre echos...
The newer settings seem to almost completely eliminate this problem and the file
sounds nearly identical to the original wav. One thing that I am wondering about
these settings is whether or not they are the optimum way to acheive what I am trying
to do. Basically what I mean is, are some of those settings conflicting with
eachother in some way or another? I don't really know the internals of lame well
enough to figure out for myself... through my testing they seem to be !
pretty much the best I could get but I know for example that --nspsytune normally
enables -X1, but -X3 sounds quite a bit better although it is significantly slower...
which isn't too big of a deal to me. Also, I know that from earlier conversations
--athlower isn't perhaps the greatest way to control file size (which is what I am
using it for)... however without it the files average 270kbps or more usually which is
a bit too big... using --athlower they come down to around 230kbps average, although I
have had files which reached all the way up to 290kbps. It also seems that these
particular settings allow a larger bitrate range (ive seen from ~150 to ~290kbps),
while the older settings seemed limited to around ~170 to ~230kbps.. I plan on
posting some information about all of the tests and stuff that I have done on a
website soon.. I would like to hear some opinions on these settings and my findings.
Oh... and about that possible bug... when using these settings, ocassion!
aly (about 1 in 10 times or a bit less) while encoding lame will start giving an error
saying:
ERROR: MAX_HEADER_BUF too small in bitstream.c
It repeats this over and over until it crashes. It only seems to happen with these
particular settings though. Maybe someone can look into this and see if they find
something... it would be nice not to have it crash. Well thats about it for now... if
someone would like more information just email me.
Dibrom
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