I'm working on something where my choice of quality/bitrate is entirely dependent on the hardware I have.

I have some concerts that are 3CD sets. If I encode ABR192, they won't fit on my 256MB flash card. I could go all the way down to ABR160, but that is a little overkill.

I calculated that I could encode ABR176 (splitting the difference), and they would fit on the card. My question is, does choosing a bitrate like this throw off the tunings that have been done, or will it be fine?

Thanks,

Brett

--preset xxx will give you an ABR file with an average bitrate xxx, any bitrate can be set here. The encoder will choose frames smaller and larger than your target to achieve this.
However, what kind of music are you encoding? Some music styles will average around the requested 175 kbps with plain vanilla --preset standard and give better quality than any ABR mode.
If this gives too high bitrates still, you could experiment with --preset medium or --preset standard -Y
Another possibility still is to lower the lowpass setting (--preset standard uses 19 kHz as a default).
Adding --lowpass 18 to a command line will lower the average bitrate somewhat.
Do not forget to read the recommended settings thread as well.
Please notice that you can use --preset or --alt-preset in LAME 3.93.1 but it is still not the officially (whatever that may mean) recommended compile.

[edit: Default --APS lowpass freq was wrong]

A lot of the music is Metal or Progressive. With APS it generally runs in the +200kbs range. That's fine for my CDR stuff, but I really want to fit some of these 3CD sets together on a 256MB flash card. To do that I have to get the bitrates down around 180kbs.

I'll also try APS with the -Y switch and see how that goes.

If the -Y switch doesn't degrade the sound for you, but the total size (using --aps -Y) is still a bit too big, you can go back and encode some of the "less-critical" songs using --preset medium, too.

I'd go with --preset medium

Hmmmmm.......

Yes, I hadn't thought of that. I'll give it a try.

I suppose I was waiting to see some more discussion of that new preset before I jumped in with both feet.

Thanks.

Brett

Well, Ive started using medium. Seems like this is what I have been looking for. Only drawback is that it's sloooooooow....


Very slow. From my RazorLame log:

Encoded 25 files in 2:14:13

I'm using a P3800. Guess it's time for an upgrade.

Brett

@Gabriel

Do you think it would cause any problems if I added -b 112 or maybe even -b 128 to the preset medium, to keep the bitrate from dipping lower than what I really need.

I've had some older recordings dip down into the 64kbs range, and some that were consistently below 112kbs. That would be fine, except that I don't really need to save that much space, and those really low bitrates make me nervous.

Could I hear the difference? I have no idea. Probably not. Just wanted to see if adding -b 112 (or 128) would negatively impact the tunings you have made for that preset.

Thanks,

Brett

Edit: Actually, I don't even think I need to do this, unless you think there might be some benefit.

Recalling a lot of Dibrom's answers I think that changing lower bitrate down not affected preset tunes, but only a resulting average bitrate. So, my lame command line is:
--preset standard -Y -b32 (Yes, I have bad manners to use lame 3.93.1 with Dibrom's preset )
I observe a few number of 112, 96 and 80 kbps frames and - I trust the preset and Dibrom (and, of course, the VBR tecnology) - I believe that frames consists lite to encode sounds, I believe to encoder choise. (Naive )
Thus I have bitrates from 160 to 192, mostly 175 +/-5.
Of course, this method usable in purposes for portable mp3, for PC listening I use mpc.

After messing with this a bit, I decided to go back and really try using the -Y switch on preset standard. Suprisingly, that got the average bitrate on most of the stuff I was encoding down in the 180kbs range (even without adding the -b option).

The live shows that I was encoding (Dream Theater's Live Scenes from NY as an example) came out at about 246MB. My goal was to be able to fit shows like this on a 256MB flash card.

Looks like this will work, and still give me quality good enough for any CDR players I have.