The other day I was transcoding some needlessly high bitrate spoken podcasts (CBR 192kbps) from a not-so-slick podcaster that I just happen to like to a more normal VBR 64kbps. I didn't care so much about using LAME for this purpose. I just needed the podcasts to stop taking up 2.8GB.

So anyway, I was using the famously bad iTunes encoder and I noticed this new (to me??) dropbox in the VBR MP3 encoding options window in the 'Advanced' tab.

It's MP3 encoding quality -- it seems to only apply to VBR encoding, and the options are:

• Lowest
• Low
• Medium Low
• Medium
• Medium High
• High
• Highest

I think the default was 'Medium'.

Now, I don't *CARE* about this exactly, but I guess I find it interesting and wonder if, when we've tested MP3's here on the forums in all the tests we've done, what setting have we used, or did these even exist during the tests?

I'm dying to know if an iTunes VBR192kbps MP3 encoded in 'Highest' quality is competitive with LAME '--V2 fast'. Or at which point an audible difference begins to appear.

I'll probably do my own tests with Foobar tonight or tomorrow. But does anyone have any input on this?

I've downloaded the whole iTunes beast (just for testing the encoder), encoded a few (problem) samples, and after my ears were ruined I've promptly uninstalled it. (there was e.g. very noticeable pre-echo at 320k and the quality of VBR encodes was not even comparable to Lame). No, thanks.

J.M.

(edit- hope i'm not violating T.O.S - the difference was really obvious)

Well that's a common sentiment and it's backed by tests, but what I'm really asking is were the settings I mentioned present, and if so, were they used for our/your tests? It'd mean something entirely different if all the files were encoded at the default 'Medium' quality.

I'm wondering out loud if the iTunes MP3 encoder is just as terrible when the 'Highest' quality is used in conjunction with a decent bitrate.

The quality settings only determine the average bitrate bracket that the encoded files will belong to, and don't correspond to more advanced psymodels or anything. The number in the bitrate dropdown is the bitrate floor, so having a '192' kbps iTunes VBR MP3 compared to say preset standard will be very inefficient, as it will not use anything less that 192 kbps for easier passages. Think of the quality dropdown as the LAME '-Vx' equivalent, and the bitrate field as the LAME '-b' equivalent.

Edit: that's equivalent usage-wise, not quality-wise .
dpaint4: Yes, that's what we're talking about. The quality dropdown is separate from the bitrate dropdown. But both values are used in VBR- one as the overall bitrate and one as the minimum. Older threads have covered this.

No no no. You guys. You're not understanding me. There's a dropdown that is *other than* bitrate. It's called quality, and it has to do with the way in which iTunes encodes the VBR MP3 files. To see this particular dropdown, you have to open 'Preferences > Advanced > Importing > Custom... ' and select VBR. Then, the dropdown I'm talking about will be available to you. This dropdown is independant of bitrate, which must also be chosen.

I have no idea how important it is or whether or not this has been addressed a million times before, but I'd never noticed it before and I've been using iTunes since the first version for Mac, so... this might be relatively new.

The VBR dropdown menu has been there for as long as I can remember, and was used during at least one of Roberto's multi-format tests (I think he later said he shouldn't have used it).

I know it's common sentiment to say that the iTunes MP3 encoder is terrible but I sort of wish it could be tested at higher bitrates.

The Itunes mp3 vbr encoder was revamped within the last year or so. It's always had those options for vbr encoding (but at a different place in the menu structure), but after downloading a recent version I suddenly got very different results using the same settings I had used in the past when I upgraded. For one thing, the vbr encoder is now far more sensitive to the complexity of the music than it used to be. That is, using the vbr encoder, easy music will be encoded closer to the target rate and very complex music is encoded at a much higher rate than it would have been at with prior Itunes versions at the same setting.

If someone has a few old versions of iTunes around, can you please encode some identical content to MP3 using the same settings and "prove" the encoder and output is different. ABX results would be nice, too.

For the people that really want to how "how it competes" with LAME, just go ahead and test it yourself. 'nuff said.

Just pulling out a CD at random,

Steely Dan, Katy Lied

Itunes 4.9.0.17, 192 kbps mp3 vbr highest quality vs. Itunes 6.0.2.23, 192 kbps vbr highest quality

Black Friday 201 kpbs vs. 211 kbps
Bad Sneakers 202 kbps vs. 214 kbps
Rose Darling 201 kbps vs. 222 kbps
Daddy Don't Live in that NYC No More 203 kbps vs. 222 kbps
Dr. Wu 202 kbps vs. 216 kbps
Everyone's Gone to the Movies 205 kbps vs. 247 kbps
Your Gold Teeth II 200 kbps vs. 213 kbps
Chain Lightning 202 kbps vs. 217 kbps
Any World (That I'm Welcome To) 203 kbps vs. 214 kbps
Throw Back the Little Ones 200 kbps vs. 213 kbps

I find the high bitrate for Everyone's Gone to the Movies with Itunes 6 interesting. Both Itunes 4 and Itunes 6 seem to have found it the most complex song.

Having offered some sort of proof, I will tell you anecdotally that a relatively easy to encode song will go down to 192 or even 191 kbps with Itunes 6. Also Itunes purports to optimize vbr mp3 encoding for a given processor.

As for me trying to ABX this stuff, I have three small children. When I get some free time, I listen to music, not artifacts. Not gonna happen. ; )

It was actually " 'nuff said " before you posted.

To me iTunes does a decent job when reconverting Apple Lossless to VBR 192kbps with High selected but with CD Audio it's terrible

Thats's confusing - there should not be any difference between the two whatsoever.

I know, it doesn't make any senese. What encoder is iTunes using? Is it using Quicktime like it does for AAC files?

Dunno what encoder its using, don't really care sounds good enough to me. But it is not using quicktime. You can tell by right-clicking a song and clicking 'get info' i think its called, well the top selection. It will load up info about your song and it tells you if it can what program encoded the song or what type of format its in.

Eg. with itunes aac files it will say 'itunes 6.0.5.20, quicktime xxxx'.
If you encoded with itunes mp3 it will only say 'itunes xxxxx'

Ah ok, make sense.

I think the Quality options are strange, as regardless of what bitrate your doing surely you always at least set it to high