SuperLow Bitrate audio encoding

[smokeslikeapoet]

I'm encoding my dvds to watch on my pocket pc. Currently i've tried joint stereo at 56 ABR and mono ABR 56. I think the mono sounds better. I was wondering if a mono mp3 is the same quality as a joint stereo MP3 at twice the bitrate? My hearing isn't that good due to my service in the Marine Corps. The louder it is the better it sounds to me. I was also wondering if you guys could suggest any other perameters for recording at low bitrates. below are some of the switches I've tried. It's very important that I get the files size as small as possible since I only have a 128 MB CF card.

Azid: -z1 -b1 -c normal -L -3db

Lame:
-m j --abr 56 --resample 48

This was one that turned out pretty good with Legally Blonde. I took a few suggestions from different websites and merged them.

-m m --abr 56 -h --nspsytune --athtype 2 --lowpass 16 --ns-bass -8 --scale 0.93 --resample 48

[tangent]

-m m --abr 56 -h --nspsytune --athtype 2 --lowpass 16 --ns-bass -8 --scale 0.93 --resample 48

Obviously, you copied and pasted from ff123's ABR128 line amd changed -mj to -mm and --abr 134 to --abr 56

It's not going to work becaues ff123's ABR128 line was tuned for 128kbps. Even considering that you are working in mono, 56kbps is still less than half of 128kbps. You can take from the --alt-preset 112 line, but mono is not exactly half of stereo with joint stereo used.

So you should take a pick from either the --alt-preset 80 or --alt-preset 96 lines:

-mm --abr 56 -h --nsysptune --athtype 2 --lowpass 13.5 --ns-bass -3 --scale 0.85

or

-mm --abr 56 -h --nsysptune --athtype 2 --lowpass 15.3 --ns-bass -4 --scale 0.85


BTW, I recommend either resampling to 44.1 or leaving it to the default resampling. Forcing 48kHz isn't a good idea.

[MxxCon]

indeed, 48khz w/ such low bitrate is a waste.

you might want to set lower lowpass.
or consider using other formats. some of them handle lower bitrates better than mp3
realaudio comes to mind.
ogg and mp3pro are pretty good also.

[smokeslikeapoet]

I resample to 48 per the help tab in gordian knot. I get bad sync problems when I use lame default. I've never used anything but MP3 audio for my encoding. Can you point me to some other howto's?

Again the point of encoding at such a low bitrate is to get this 2 hour movie onto a 128 MB CF card for my PocketPC, so I'm less concerned with quaility, but I would still like to hear the voices clearly. I've encoded a couple of movies today and I'm leaning to think that Mono is the way to go for a ABR of 56 kbps/