Hello,


I was wondering if this is the highest quality mp3 one can get when converting from a FLAC?

I used winLAME ( http://winlame.sourceforge.net/ ) for the conversion.





Correct?

320kbps is the highest you get out of MP3 no matter what, it is the maximum bitrate.

What about the LAME version and joint stereo? They do nothing in improving audio quality once at 320 bitrate?

At a bitrate of 320kbps (which is way overkill), you will be hard pressed to hear a difference between Lame and even the iTunes built-in mp3 encoder. Lame 3.97 is the current stable version though Lame 3.98b3 has been released. Either way, that bitrate is so high that it doesn't matter. Joint stereo is fine, don't pay attention to some of the common myths about joint stereo. It doesn't decrease the sound quality of a file.

At very high bitrate there is no improvement on normal music, there might be a theoretical improvement on less common problem samples and even then there is probably no solution. The whole mp3 psymodel and format would need overhauling to overcome those. Joint stereo improves coding noise at all bitrates. Any recent LAME version is not an issue with those settings ; 3.90 ~ 3.98.

Damn!!!

So this song:


If it where LAME3.97 and joint stereo, it would make no difference because the bitrate is already 320?

It's not a waste, FLAC is intended for other purposes than MP3.

If your exclusive goal is transparency on 99.99% of samples, MP3@320kbps is fine (generally considered overkill, you should use LAME -V2) and FLAC is a waste of bits.

If your exclusive goal is bit perfect archiving, FLAC is ok and MP3 @ any bitrate is useless. Same thing if you want to be 100% sure there will be no artifacts, no matter the sample.

Quality aside, this is wrong; from the LAME switch document:

* --freeformat free format bitstream

Produces a free format bitstream. With this option, you can use -b with any bitrate higher than 8 kbps. However, even if an mp3 decoder is required to support free bitrates at least up to 320 kbps, many players are unable to deal with it. Tests have shown that the following decoders support free format:

FreeAmp up to 440 kbps
in_mpg123 up to 560 kbps
l3dec up to 310 kbps
LAME up to 560 kbps
MAD up to 640 kbps

Can I convert my 320 bitrate MP3s to V0 or V2 MP3s?

Would it be the same quality if I were to convert to V0 or V2 from FLAC? Will anything be loss during conversion from stereo to joint stereo or LAME3.92 to LAME3.97 ?

Overkill for your portable, overkill for others portables, overkill as email attachments and only leads to mp3 > mp3 transcoding (OP's question).

But is this type of transcoding the bad kind?

Its not going to be the same as coding from flac. Lossy transcoding is in general inferior to lossless, mp3 >> mp3 transcoding is proven to be suboptimal at best.. but: you may get different results so test and see if you really need to do it. Regarding joint stereo, I say again: It will reduce coding noise so going from stereo > joint stereo is better than stereo > stereo.

Take a look at mp3 repacker. Note that 320 CBR is also known as "preset insane".

You should never convert between lossy compressions. And transcoding from MP3 to MP3 is probably the worst situation. Because the same compression artifacts will be multiplied.

Wait, are you sure about that, shadowking? I don't know about 3.90...but with LAME 3.92 which I use, when you encode in Joint Stereo the "normal" gpsycho way (without using --nspsytune or --alt-presets) you don't get safe Joint Stereo. You can check by applying --nssafejoint and there's no difference in output. Also the amount of M/S frames is large even at 320 kbps, which means its stuck WITHOUT --nssafejoint on.

I haven't tested myself but I think old gpsycho LAME without --nssafejoint (note that old gpsycho LAME uses Forced Stereo by default at higher bitrates, it's different from current nspsytune LAME) has always been known to introduce hearable issues.

spiricom, that doesn't matter for you though because you use LAME 3.97...all LAME versions from 3.94 and later use nspsytune psychoacoustics ("new" LAME vs "old" LAME) and various implementations of --nssafejoint by default. The specifics are a little quirky, though. But anyways, at 320 kbps Joint-Stereo and regular forced Stereo are essentially the same file with "new" LAME...you can check the text report output and for most typical music there are 100% L/R frames or very close to it.

To answer the OP's question: No, it is not the highest quality mp3.

Theoretically, freeformat mp3 at the highest bitrate should be the highest quality mp3, but not practically efficient for any purpose nowadays. Personally, I would say that "the highest quality mp3 should be at the lowest bitrate that the target audience should find transparent." Whether it would be -V5 or -V2, it's up to your ears.

Again, just answering your question.