I'm in the process of ripping my audio cd collection using EAC to FLAC. Unfortunately my car receiver only accepts .MP3 and .WMA, but not raw .WAV. So I am converting everything to .MP3 and .WMA. Space is not an issue since I'm using an external 250 gig USB enclosed HD. I'm not convinced that there will be much difference between .MP3 and .WMA at the maximum bit rates my Pioneer supports (320). I am using LAME with options -b 320 -m s -k -q 0. It is my understanding that the .MP3 spec has a hard upper limit of 320 kbps so 320 CBR should yield the best possible results. It does appear from reading the Windows Media Encoder using the standard WMA 9.2 codec you can exceed 320 kbps by using VBR encoding although my test files have averaged out right at 320 in VBR mode. Is there any advantage to use VBR encoding in WME over 320 CBR?

Use your ears and then tell us!

Chances are more likely than not that, with the exception of a few problem samples, everything will sound exactly the same at these bitrates.

-------

Space is always an issue. There's never a point to using it up unnecessarily.

You really should do some ABX tests with LAME starting from -V5 (--vbr-new), up to -V0 if necessary.

I think it's basically meaningless to go over 320kbps with any lossy codec. If you encode lossy 400 or 500kbps lossy you could go lossless (on classical music you probably can achieve the same compression with lossless anyway ) and forget all worries about quality.
As for lame settings, personally I've never done any ABX tests but I had a 'something is wrong' feeling when I listened -V4 encodes on my PMP, but with -V2 everything was all right both on portable and home stereo (I still use lossless on my home PC if I can, not just because of the probablility of finding some music that 'outwits' lame -V2 but to have my music backed up and futureproof).

Hmm. Better to sort out these 'wrong' feelings rather than use some setting that gives a warm fuzzy. On audiophile forums its ok. Can you really tell differences before spreading needless fears here ?

Considering the less than ideal acoustical environment in a car, would you even be able to discern a difference with your ears with anything higher than 160 kbps or 192 kbps VBR?

Could someone enlighten me? I would have expected that a high bitrate MP3Pro would have abandoned the added sbr and simply encoded as an ordinary mp3, albeit not as well tuned as lame. As such a 320 kbps MP3Pro should be competitive with a 160 kbps lame, not so?

Then the file would not be "pro", but an ordinary FhG MP3. I don't think Mp3Pro allows 320 kBit. Nero encoder maxed out at 96 or 112 kBit.

Right you are. mp3PRO, which is analogous to He-AAC in the AAC world, adds additional encoding techniques when the bitrate is low enough. This can effectively make low bitrate files sound much more transparent. When these techniques are applied to higher bitrate files, however, there is no transparency increase, so by default they are turned off. It is also important to note that mp3PRO as well as He-AAC are not fully backwards compatible with MP3 and AAC respectively, and if played back on a decoder that does not support them, the files will not be able to play to the full of their potential.

Thanks for the responses.

If I could I would just load the USB hard drive up with my FLAC files from my PC that I use for my home stereo, but unfortunately my head unit won't even accept a WAV file through the USB interface. Even if I ripped my whole collection without lossless compression I could fit it on a 250 gig hard drive. So converting it to high bitrate MP3 or WMA isn't going to pose a space concern for me. 2.5" drives are already up to 320 gig and they will just get larger and cheaper.

I may not be able to tell the difference between 192k and 320k in the car, but I want to convert my collection once and be able to use it as the need arises anywhere I can't use lossless. I realize bitrate isn't everything too, but the high bitrate does remove/minimize one variable in the equation.

Thanks again for the responses.

Nah. You'll probably won't be able to tell the diference between lame v5, even on high end equipment.

The q98 VBR setting for WMA encodes at over 320kbps.

And note if you're encoding for WMA, you have access to the 2-pass encoding methods as well. So if you want to save some space, you could encode at 192 ABR 320 PBR or something like that, if you'd like more predictable file sizes.

WMA Pro: 24-bit stereo can be encoded up to 440kbps as CBR and (after couple tests) VBR gives little lower bit-rate when encoded using Q98/24-bit. I don't know if your car stereo supports WMA Pro decoding.

Lame: There's an option for free bit-rate (--freeformat -b <bit-rate>). By the documentation, 640 is the max bit-rate.

IIRC, if playback device supports bit-rates up to 320kbps, all above that will be either played as 320kbps (BTW, how is it converted from higher rate to 320?) or silent/distortioned.


Juha

They don't.

Very few players support freeformat, and I doubt that this includes any portable players. Those that do not support it will simply refuse to play it at all. There is no requirement in the standard to support freeformat.

That's why it's extremely unwise to even suggest that someone break a standard in the first place as the files are likely to not even play back at all. 320Kbps is the highest MP3 bitrate natively supported by all hardware players. Anything higher is, strictly speaking, no longer MP3.

With LAME MP3 encodings in VBR reaching perceptual transparency for the vast majority of people at -V3 (~175Kbps), it seems ridiculous to even suggest a bitrate of over 320Kbps, even if it was the OP who mentioned it in the first place.

I've noticed that Juha has seemed intent on reinventing the wheel with regards LAME and lossy audio codecs in general ever since his arrival. May I respectfully suggest that he read the following...

Hydrogenaudio LAME WIKI

Cheers, Slipstreem.

I just followed the message subject ... and assumed the OP didn't know what the limits are ... looked like no one answered that ....so I did. Looks like it was wrong (again), though, Slipstreem, I noticed already that this is maybe a bit 'hostile' forum if someone tries to argue w/ you 'specialists' so, I must keep my keyboard locked to not confuse you fellow more w/ my thoughts/questions/suggestions.
Anyway, I don't use lame and as far as I know I have not written anything against it or any other lossy codecs nor trying to reinvent anything so, I guess you took cause for the "abuse" from the "spitstream" running in your head.


Juha

You seem to take any form of correction, even when supported by well documented and researched information as being a personal insult. Chill, Juha.

Just because an OP makes a ridiculous suggestion that goes against everything that anybody who's even glanced through the widely available information on the subject would find bizarre, that doesn't make it wise to go along with it.

I provided the link to the WIKI entry as a form of help to yourself as well as anybody else who clicks on it. Please read it and calm down.

Cheers, Slipstreem.

There is no requirement in the standard to support freeformat higher than 320kbps. Freeformat <= 320kbps must be supported, according to the standard.
However in real life it's rarely supported, so from a practical point of view, you could consider freeformat a "no go".



Nitpicking: stricly speaking, freeformat higher than 320kbps is still a perfectly compliant mp3 stream, but decoders are not required to support this. (read: no hardware player support this)

Just FYI,

my portable CD/MP3 Player EXP 511 and my home DVD/DIVX Player Cyberhome 462, both play back MP3 with 640kbit/s just fine ...

But coming back to the original poster's question, I encode my own MP3s for car stereo use with LAME VBR preset V5, simply because I cannot distinguish any higher bitrate as soon as the motor's running, let alone the tires or airstream start making noise when driving.

Cheers,
Maggi

If you consider any form of pointing out errors in someones statements "hostility", then you are perhaps indeed on a forum, which doesn't match your prefered conversation-style. Some people see meaningful and valid criticism as one way to improve oneself - other people though, consider it as an attack on ones own self.

---

On-Topic:
At 320kbit or more, mp3 and wma practically always sound the same, so i wouldn't make the choice dependent on soundquality, but other criteria.