I encode all my digital music at 128k AAC with iTunes 4.1. I want to know if the AAC encoder with iTunes 4.6 is any better than 4.1? If so, would it be worth it to reimport all my music cds with the iTunes 4.6 AAC encoder?

Not at all. Actually, some quality issues were spotted at iTunes 4.6 that weren't present at 4.1. It's very likely that 4.1 has better audio quality than 4.6

And even if quality improved with 4.6, it should make no difference. If you are happy with 4.1 quality, why go through all the job of reencoding?

Regards;

Roberto.

The funny thing is that the quality in iTunes 4.1 & 4.6 is exactly the same.

QT 6.5 & 6.5.1 though..

Damn, dude, you are still having a hard time understanding what's going on with iTunes, I see!

iTunes 4.5 and 4.6 have same quality. iTunes 4.2 is the version I tested, because 4.5, that came later, had those quality issues (that you keep trying to portray as insignificant, but never offered any listening test results)

iTunes 4.1 came much before 4.2. So yes, quality is surely different compared to 4.6.

Umm.. iTunes relies on QT for its AAC encoding. If you have, say, iTunes 4.0 and QT 6.5, you will get the *same* file as if you use iTunes 4.6 & QT 6.5

when you diss, diss properly

I'm just saying people might have jumped the gun on the "dont use itunes for aac since it gives ringing" that gets repeated here. I'm not saying it might not be true, but no one outside this board has commented on it so..

Well, duh, of course. If you want to install an older version of iTunes, you should first uninstall both iTunes and QuickTime. And, for good measure, delete the \QuickTime folder in your windows\system folder.



I did diss you properly. But, not surprisingly, you didn't seem to understand what I said and preferred to nitpick.



Bullshit. You clearly said "the overall quality in QT 6.5.1 is better than the previous versions" without offering any proof. I'm not surprised that you never replied to my post in that thread demanding proof.

Well, you only made mention of iTunes 4.1 vs 4.2 etc.

Besides, on the mac at least, QT and iTunes are completely separate products so QT isn't installed with iTunes and vice versa.

So be it. The thread starter asked for comparision between iTunes versions, I wouldn't deliberately make things more complicated for him without reason.

And I'm still waiting for you to justify your claim that QuickTime 6.5.1 offers better quality than previous versions.

For the record, iTunes 4.6 has problems decoding AAC files, as I've shown in another thread. The same files decoded with QT come out completely different, as I've also shown, which means that iTunes may be using its own (flawed) library to decode the files. Thus, I'd stay away from 4.6 until a newer version comes out. The encoding end (QT 6.5.1) and decoder in iTunes are both flawed, unfortunately.

An older version of iTunes, like 4.5, coupled with QT 6.4 or lower would be ideal.

So do 4.1 and 4.2 use the same encoding backend (Quicktime 6.5), or is there a difference? Should the original poster upgrade to 4.2 at least?

This is another aspect of the confusion I'm feeling, as described in the "mp4 to m4a (whether and how)" thread. I've assumed that each new version of QT is improved, so 6.5 is better than 6.4, and so on, so I'm using 6.5 now. Is this wrong? And is the quality of QT-6.5 different for Windows and Mac?

Usually I make AAC files (from AIFF files) directly in QT-6.5 for Mac, rather than opening them up first in iTunes 4.6. Since iTunes uses QT (whatever version is installed, I assume), how do files made using iTunes as a "front end" differ from files made directly in QT? (in quality, and also in the "creator" and compatibility,... questions in my "whether and how" thread)

For example, is the "better" setting used in iTunes? I've heard that for 16-bit recording "better" and "best" give the same quality, that "best" is only improved over "better" for 24-bit sound. I did a simple experiment about a year ago (with whatever version of QT was available then) by checking the encoding times, and the times were different (much shorter, as I recall) when using iTunes than for the "better" setting of QT (and I think even less than with "good" setting), so it seemed that iTunes was doing something totally different (since the times didn't match for either good, better, or best) than anything in the QT settings. I'm confused.

Is there anywhere that explains exactly (yet in simple language) what iTunes is doing, and how this relates to the settings within QT?

Mike

iTunes uses the "better" setting. The only other option is bitrate, which gets passed directly to Quicktime.

AFAIK, the only difference in the files that are created in iTunes and those in Quicktime is the tagging information and the filename extension.

QT 6.5.2 was released today anyway, with claimed improvements to AAC and Lossless Encoding...

The decoding issue seems to have improved in iTunes 4.7. My VBR AAC files finally play back without skipping frames and crackling! Furthermore, a Miles Davis recording that used to have a very nasty ringing artifact on high-pitched trumpet attacks doesn't have obvious errors, either.

Lossless ratio are apparently the same than previously (tested on 6 album: four have exactly the same filesize, and two other were very, very slightly bigger than previously). I can't compare yet encoding and decoding speed.

I can confirm this as well.

I totally agree 6.5.1 had issues (I can easily ABX 6.5.1 vs 6.5.2 because of it), but as I've said, I think the overall quality was a little better than earlier versions. I don't think many people could even hear the bug as it seems to be a 16khz++ only issue..

Now that 6.5.2 is out, we're all happy though