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View Full Version : Archiving in AAC vs. MP3?


Yudha
Oct 18, 2003, 07:36 AM
I just downloaded iTunes Windows the other day as soon as it came out, and promptly began ripping all my CDs into AAC and converting my existing MP3s. But now I am left w/ something of a dilemma. I will be getting an iPod soon, but I'd like to keep an archive of music on my computer rather than put everything on the iPod. As it stands, I have an MP3 and and AAC version of most of my music. I already know I'll load only AACs onto the iPod. Now, does it make more sense to stick with MP3 for the songs on my computer, or would AAC be better? Is there any way to convert AAC to MP3 in case I need to send a song to someone who doesn't use iTunes? I am somewhat hesitant to delete all my MP3s and leave only AACs on my HD. Any advice would be most appreciated.

crazzyeddie
Oct 18, 2003, 08:20 AM
When iTunes came out with AAC support I promptly converted my entire library to AAC. Then I realized what you did... how will i send these to my PC friends?

Its actually a very simple solution though!

In the preferences for iTunes, under importing, you can set the format. If you change the format to MP3, and then select a song in your library, you can "import" that song back into your library as MP3 using the Convert Selection to MP3 function in the "advanced" menu.

After its done, you can right click, find its location in the finder, and send it to your friend. THe original copy is still there (in AAC) so you can delete the MP3 copy when youre done.

Hope the helps.

Yudha
Oct 18, 2003, 08:28 AM
That was a simply fantastic explanation. Phew, now I can halve the disk space currently occupied by my music. Thanks a million.

CubeHacker
Oct 18, 2003, 08:44 AM
I hope your realize that everytime you convert an MP3 to AAC or vice versa, you are actually degrading the quality of the music significantly, because you are just recompressing the compressed.

The best option would be to convert to MP3 or AAC from the source - the original CD.

FattyMembrane
Oct 18, 2003, 09:36 AM
DOACleric is right. for the best sound quality, you'll want to rip directly from the cd at an AAC encoding of about 160-192. you can play AAC's with any program that supports the MPEG4 standard (quicktime, VLC, Nero, 3ivx codec, etc). your ipod can play mp3s and if you convert an mp3 to an AAC, it's similar to making a copy of a copy, so you're better off just re-ripping what you have on cd to AAC and just leave whatever mp3s are left.

WinterMute
Oct 18, 2003, 09:46 AM
There's a Windoze AAC player here:

http://www.mpeg.org/MPEG/aac.html#faqs

Get your PC friends to join the sonic beauty of the AAC universe:D ;)

Yudha
Oct 18, 2003, 10:08 AM
Ah well... too late for that. Well, my AACs sound perfectly fine, with negligible degradation to my untrained ears. As it happens, I wanted to make the most out of my iPod space, so AAC was a must in my mind. That said, I didn't exactly have the CDs for all the MP3s I had... so re-ripping wasn't an option.

Yudha
Oct 18, 2003, 10:16 AM
Although I can't hear the difference, I am curious: How significant is the alleged degradation when converting from MP3 to AAC?

WinterMute
Oct 18, 2003, 10:27 AM
It's not significant at all if you start with a decently encoded MP3 at a good rate, a 128 MP3 will sound grotty anyway, AAC'ing it won't help.

I reencoded a batch if 256Kbps MP3's to 160 AAC last week, some student work, and the results were fine, in fact the AAC files sounded a tad better to me.

You do need to be careful with amplitude, if you have a loud MP3, re-encoding can cause some slight distortion, but not always it seems.

ColoJohnBoy
Oct 18, 2003, 12:01 PM
I converted my whole library of 192kbps MP3 library to 160kbps AAC (Except for the Lord of the Rings soundtracks - those are always at the highest quality - reripped from the CDs into 320kbps AAC :D:D:D) - It freed up about 2 GB of space on my hard drive. Plus, when I play them through my Altec-Lansing speakers, there is quite a difference. It's a cleaner sound, not as much "air". Yay for AAC!

slowtreme
Oct 18, 2003, 01:32 PM
Originally posted by ColoJohnBoy
I converted my whole library of 192kbps MP3 library to 160kbps AAC [...] there is quite a difference. It's a cleaner sound, not as much "air". Yay for AAC! That's impossible, you can't get back LOST sound. I'm not going to argue mp3 vs AAC, but if the original encoding to mp3 caused any degradation to the music, that same thing will exist in a re-encoded file. You can't get bits back. It's simple math.

ColoJohnBoy
Oct 18, 2003, 02:36 PM
Sorry, I should clarify. I re-ripped nearly everything from the original CDs. Stuff I had pirated I just left as it was. Pardon the mistake. :)

absurdio
Jan 28, 2004, 07:46 PM
Is everyone using 160 kbps or above for aac instead of apple's default "High Quality (128kbps)" setting?

I've been using 128kbps and haven't really noticed anything amiss... how huge is the difference in quality? what about the difference in size?

and if you converted an mp3 into a 160 or 192kbps aac would it sound better than if you converted it into a 128kbps aac?

thanks, all.

oldschool
Jan 28, 2004, 09:25 PM
I use 128 aac as I don't want to run out of room on my ipod just for a little extra quality.

absurdio
Jan 28, 2004, 10:42 PM
i've been using 128, too. And for the same reason. I'm not sure how noticible the quality difference is, but, as I've got a Powerbook, an ipod, and eight tons of music, I'm pretty space concious.

Rincewind42
Jan 28, 2004, 10:58 PM
Originally posted by absurdio
Is everyone using 160 kbps or above for aac instead of apple's default "High Quality (128kbps)" setting?

I agree with the 128kbps AAC encode. As long as I can't hear any artifacts I'm not gonna go searching for them :D .

I've been using 128kbps and haven't really noticed anything amiss... how huge is the difference in quality? what about the difference in size?

128/160 = 4/5 so a 128kbps file will be 20% smaller than a 160kbps file :) . The compression rate is just that, so for two songs of the same length you just divide to determine your savings/gain for using a different rate.

and if you converted an mp3 into a 160 or 192kbps aac would it sound better than if you converted it into a 128kbps aac?

Maybe, maybe not. Since your transcoding you'll get different kinds of artifacts. Some of them may be more pleasing, some of them less. The only way to know really is to do the encode and compare - if the song sounds like crap to you, encode it higher or leave it as it is. Remember - your not saving any space using a 192 AAC vs a 192 MP3, and if your AAC ends up at a higher bit rate than the MP3 your wasting more space for less quality!