I have an MP3 player that only supports MPEG-1 and only at 44.1 KHz. The memory is also limited so I'm going for 64 Kbps. Does it make sense to use the following LAME options: "--alt-preset cbr 64 --resample 44.1"? If not, what is recommended?

By the way, I'm limited to CBR.

I guess so, but jesus that's going to sound bad.

If you use '--alt-preset cbr 64 --resample 44.1' the lowpass will remain of 11Khz (it's the default for this preset, which use a sampling rate of 22Khz).

I suggest you to use mono and set the lowpass to 16,5 (--alt-preset cbr 64 -m m --resample 44.1 --lowpass 16.5), you could also use a sampling rate of 32 or a lower the lowpass to decrease artifacts.

You might also want to try a FhG encoder at this bitrate, as FhG uses intensity stereo, which LAME does not (yet) have as an option. This may increase quality a little bit, but at 64kbps, I'm not sure it will be all that noticeable. If you can get your hands on an encoder, something like -br 64000 -esr 44100 -bw 12000 might work fine, though the sound will suck at this bitrate no matter what encoder you use. If you can comprimise a little, 80kbps will sound noticeably better and take up only a little more space.

Are you sure it only plays 44.1 KHz? My mp3-player only plays MPEG-1 Layer 3, but at least it supports 32 KHz sampling rate.

If you can live with mono, then I'd suggest someting like [--alt-preset cbr 64 -m m --resample 44.1 --lowpass 15]. --lowpass 16.5 is way to high if you're going for 64 kbps.

Yes, it only plays 44.1 KHz. It's actually a PDA - a Sony Clie N760C with a 32MB Memory Stick.

So, here are the complete parameters:

- MPEG-1 Layer 3
- 44.1 KHz
- I do want to keep it stereo
- A whole CD needs to fit on the 32MB Memory Stick
- So, I can use 80 Kbps for shorter CDs
- But, I need to use 64 Kbps for longer CDs
- A fairly cheap ($25) pair of headphones are being used
- Since the frequency response is not too good, a higher --lowpass parameter should be OK
- The CDs being encoded are primarily Alternative, Progressive Rock, Vocal, and Light Rock.
- It's primarily for my wife but I might use it sometimes so I want it to be as decent as possible at 64 Kbps
- Encoding time is not an issue - I don't care if it takes all day for one CD

In this context then, what would everyone recommend? Is using --alt-preset still OK or is it a bad starting point because it's tuned for 22.05 KHz at 64 Kbps? So far, I think I'm leaning toward [--alt-preset cbr 64 --resample 44.1 --lowpass 15] although I'm not too sure about the lowpass parameter. If the frequency response of the headphones is, say, 20 - 20,000 Hz, should the --lowpass parameter be set to 20?

Thanks for all the replies so far.

Since you are dealing with 64kbps, I would strongly discourage you from raising the lowpass higher than about 12Khz. Because you are using 44.1Khz, it will sound worse to begin with (at 64kbps and below, MPEG-2 Layer 3 does a better job, but is only for 24Khz rates and lower, so you can't use it). A 15Khz or (God forbid) 20Khz cutoff would be absolutely unlistenable, especially with rock. MP3 is just not designed to produce good sound at that bitrate (and with a 20Khz lowpass, will only produce robotic noise, not music). Are you sure that you cannot run alternative music software on the Clie? What OS does it use? I know that on my PDA (a Pocket PC 2002 Toshiba w/206Mhz ARM) there are plenty of alternatives to MP3, including Vorbis, which sounds way better than MP3 at 64kbps. You might even see if Sony hasn't come up with software that uses it's own ATRAC3 compression format, which still sounds a little more palatable at 66kbps than MP3 does at 64kbps.

It runs Palm OS 4.1. I'll have to check into alternatives, but the program would have to be fairly small, since it would have to run from main memory (which I think is only 8MB). As far as ATRAC3 goes, the stock player supports it, but only when using MagicGate (white) Memory Sticks (which support digital rights management). I only have the non-MagicGate (purple) Memory Sticks.

I think I got confused on what the --lowpass parameter did. It cuts off all frequencies ABOVE the specified parameter and the parameter is in KHz, right? (I initially thought it cut off all frequencies BELOW the specified parameter and was in Hz.)

Yes, it cuts all the frequencies above the given parameter.
The parameter can be in Khz (--lowpass 12) and in Hz (--lowpass 12000).

If this means WinCE as the OS, there's a MPEG-4 freeware player from Philips which is supposed to play standard-compliant AAC audio files in a MP4 container. So you could also try to encode something with PsyTEL or Nero AAC at -radio -resample 32000 and test it:

http://www.digitalnetworks.philips.com/Inf...nelId=N764A2175

There had been reports about incompatibilities with the predecessor of the platform4 player, but as far as I know no one has really tested this new version. If you are using PsyTEL, you should also mux it with a mp4creator version that can already change the MPEG-2 flag in the header to MPEG-4.

If you just want to test the general interoperability of this combination, you can also try out FAAC v1.16 with -q 75 -m 4 -n which results in a ~80 kbps file with a cutoff at 11 kHz. The sound is worse than the one from PsyTEL AACEnc (no resampling, no joint stereo etc.), but not as bad as I expected it to be.

This is good news....I had searched in vain for an AAC/MP4 player, and this one worked fine on my Pocket PC using an mp4 encoded with Nero's "normal" preset. It's very basic, and lacks an EQ, etc. , but it does the job. I've been interested in playing some of my PsyTel AAC encodings on my PDA without having to transcode to Vorbis or whatnot, so thanks for the link!

And thank you for testing...

Roberto, did you hear this? Philips rox, knew it all the time...

I stand corrected.

Use a 64Mb stick. You'll only get crappy results if you are forced to using 64-80kbps. MP3 at this bitrate can sound worse than even a cheap tape recording.