Convert iTunes Library to AAC

H

heathpitts

Registered
Don't know if this has been posted yet but I noticed last night in the iTunes menu that there is a selection for convert selection to aac. I used it to convert some of my 160 mp3s to 96 aac files. I could not hear any quality loss by converting them to the aac format directly from the mp3 format and they were all quite a bit smaller. This should free up some space on my 10 gb ipod if i convert my whole library. It also leaves the original file in case you want to revert back to it or compare the two.


Anyone else tried this?
 
In the "advanced" pulldown. It becomes bold when you select a song to be converted. It took quite a while for me to convert an entire album, but the sound quality is excellent.
 
It took me nearly 5 hours to convert 210+ 192 MP3 to 128 AAC. Since it duplicates the song listing in the iTunes Library, I moved my music files to another location, set that as the library, relaunched iTunes, and then changed the Library setting back to where I had it. That way, iTunes placed the new AAC files into the directory I want and don't have to sort through.

I can post a real HOWTO later :D.

BTW: I find that 192 MP3 to 128 AAC is fine, and I can be strict on how my music sounds :D. Your milage may varry, so don't get rid of the mP3 untill you are sure you like the AAC quality.
 
Ah, found it. I had to change my prefs first to see that option. Hmmm, it did save a 5.2 mb mp3 as a 4.2 mb and the sound seems about the same. But it's gonna take a heckuva long time to convert more than a thousand songs.
I haven't hooked up my iPod to try it myself, but can you switch formats for stuff on the Pod? Or do you have to move it back to the hard drive first? I only keep about 25% of what's on my iPod on my hard drive.
 
Im not sure, but i think somewhere i read that converting from MP3-AAC is not recommended because both are "lossy" codecs, and you will actually lose more quality by going from mp3-aac.
 
I have read the "lossy" codec thing as well but it seems to sound fine to me. Certainly it is no better but it sounds the same to me just at a lower bit rate and smaller file size.
 
So rhale1 what was the size before and after the convert? I'm trying to see if it's worth the time to convert all these songs. I have lots of MP3 discs I made, and ripping those CDs was far from fun.
 
I'm currently converting 1300 songs (5.8 gigs) from mp3 to AAC...the audio quality, so far as my soundsticks, ipod (albeit with crappy earbuds) and ears are concerned, is the same, and the files are 20-50% smaller. FIFTY PERCENT SMALLER. I was running out of room on my 10 gb pod, and was thinking of upgrading. I'm gonna be able to hold almost 6k songs on this 10 gigger, @ this rate:)
 
ok this is exactly the hint i was looking for but how do you make itunes REPLACE all your mp3's with aac's? I don't wanna convert my 8 gig library by re-burning it, and I also don't want to have duplicate songs. does anyone know how to do this? thanks alot btw - great discovery
 
What I did was this....I went to my library, and put my songs in order by bitrate. I selected all the songs that were over 128 (it wont make a difference in size to convert a 128 MP3 to a 128 AAC) I highlighted all my 128+ bitrate songs, and clicked convert to AAC (in the advanced menu. So far, it's done about 415 of them, in 5 hours or so. When they're all done, I'll put my library in order of file type, so all my AAC's are grouped together, and then simply delete all the MP3's with a bitrate of greater than 128, as those are the ones I converted. The MP3's with a bitrate of under 128 weren't converted, so I have to leave those as is.
 
I said screw it and have re-ripped most of my CDs to AAC , still have about 25 or so left to rip. Maybe on my iMac at home I'll just convert. I'll just start with a few to make sure, though.

Before I started I had around 1450 songs at just over 8GB. I now have 1666 songs at 7.6GB. Keep in mind that I still have those 25ish left to rip.
 
I've done testing, and my hearing is good though not the best, and I've found that the raw aiff is still the best (since that's the source that's not surprising) and that I find my 160kbps mp3's to be the worst (though not by far)

Here's the surprising part. I have not been able to tell the difference between 160, 128, and 96 k mp4's (or as iTunes labels them m4a's.)

So if you're going from mp3 to mp4, you're missing the boat. You want the originals to go to mp4 if possible, mp4 keeps more sound intact than mp3.

I'm re-ripping everything I have on CD to 96k m4a. The stuff I pulled from analog sources will likely remain mp3 as it's a total pain to re-do those from source, and I don't want to add mp4 artifacting to the mp3 artifacting on top of the analog media artifacting.
 
Originally posted by blastic
i use 192 mp3s, what would be the equivilent in aac bit?
Click to expand...

Something like 148 kbit/s. AAC is approx. 30 % more effective than MP3, so the difference is pretty noticeable when your music library is a couple of GBs.

But converting directly from MP3 to AAC is a crime :confused:
AAC uses different algorithms, and as toast said you'd lose quality both from the MP3 and the AAC encoding - and the file size would be the same as if converting from AIFF (CD). It's not worth it ;)
 
whelp, i need the hard drive spave desparatly, i now have to convert my 6100+ songs to aac, it will take days
 
i have just converted a few 192's to 160 aac and the difference is noticable, but sooo slight it will not matter to me, good luck everyone with this new format!
 
Originally posted by blastic
i have just converted a few 192's to 160 aac and the difference is noticable, but sooo slight it will not matter to me, good luck everyone with this new format!
Click to expand...

Arrrgh, pleease! Stop, you're torturing me! ;)
 
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