Convert MP3s to AAC?

lucaluca
Posted:
in iPod + iTunes + AppleTV edited January 2014
Well, now I can convert my MP3 files to AAC. I'm actually doing that right now, but I'm keeping all my old MP3 files... you know, just in case. Anyway, I was discussing the issue of converting a lossy format to another lossy format in a chat, and although I said that I couldn't hear any difference, quite a few others said that it's a really bad idea and it'll degrade the quality of my music. So that's why I'm keeping my MP3s around for now. I'm planning to re-rip my music in AAC as well, but like a lot of people I don't have the CDs for all my music.



Anyway, is it a good idea? Bad idea? Doesn't matter? This will save me quite a bit of space so I'm definitely interested.

Comments

  • Reply 1 of 12
    dhagan4755dhagan4755 Posts: 2,152member
    So you're recompressing the compressed files? Does that make sense? I read converting from MP3 to AAC was not recommended.
  • Reply 2 of 12
    dviantdviant Posts: 483member
    lossy to lossy is a bad idea... quality is degraded. But hey if you can't tell the difference then more power to ya...
  • Reply 3 of 12
    kneelbeforezodkneelbeforezod Posts: 1,120member
    Quote:

    Originally posted by Luca Rescigno



    Anyway, is it a good idea? Bad idea? Doesn't matter? This will save me quite a bit of space so I'm definitely interested.



    There was a thing on MacRumors about this a few days back...



    Here tis
  • Reply 4 of 12
    lucaluca Posts: 3,833member
    Well, see, that's why I'm keeping the old ones around. I'll have very little drive space afterwards, but I am getting an external hard drive tomorrow or the next day so I'll just toss all my MP3s onto there. I suppose I just don't have a trained ear... I'm not much of an audiophile. I like my music, sure, but I don't usually notice minor changes in quality. Major ones, yes.



    EDIT: I am aware that converting a 128 kilobit MP3 to a 128 kilobit AAC will show me no benefit, and in fact it'll probably cause me to lose quality... what about a 192 kilobit or higher MP3 to 128 kilobit AAC? Will that give me equal quality with less space taken up? Because that's all I'm interested in - I never thought that converting all my music to AAC would have increased the quality. And I will certainly re-rip all my CDs.
  • Reply 5 of 12
    ghost_user_nameghost_user_name Posts: 22,667member
    Quote:

    Originally posted by Luca Rescigno

    Well, see, that's why I'm keeping the old ones around. I'll have very little drive space afterwards, but I am getting an external hard drive tomorrow or the next day so I'll just toss all my MP3s onto there. I suppose I just don't have a trained ear... I'm not much of an audiophile. I like my music, sure, but I don't usually notice minor changes in quality. Major ones, yes.



    EDIT: I am aware that converting a 128 kilobit MP3 to a 128 kilobit AAC will show me no benefit, and in fact it'll probably cause me to lose quality... what about a 192 kilobit or higher MP3 to 128 kilobit AAC? Will that give me equal quality with less space taken up? Because that's all I'm interested in - I never thought that converting all my music to AAC would have increased the quality. And I will certainly re-rip all my CDs.



    Don´t even consider such a thing.
  • Reply 6 of 12
    dviantdviant Posts: 483member
    Quote:

    Originally posted by Luca Rescigno

    EDIT: I am aware that converting a 128 kilobit MP3 to a 128 kilobit AAC will show me no benefit, and in fact it'll probably cause me to lose quality... what about a 192 kilobit or higher MP3 to 128 kilobit AAC? Will that give me equal quality with less space taken up? Because that's all I'm interested in - I never thought that converting all my music to AAC would have increased the quality. And I will certainly re-rip all my CDs.



    To my ears, so far 128kbps .m4a sounds just as good as my usual rips at 192kbps .mp3 (on a direct rip from a CD that is).



    Um.. if you're doing this to conserve space I don't see why you're bothering to save the .mp3s
  • Reply 7 of 12
    lucaluca Posts: 3,833member
    Ok, so I've decided to stick with my current MP3 collection and just rerip my CDs to AAC. Since I'm getting that external drive, I'll be able to take a load off my main drive, and I won't need to save space.
  • Reply 8 of 12
    alexisalexis Posts: 82member
    Quote:

    Originally posted by Anders the White

    Don´t even consider such a thing.



    Why? I've converted several songs to AAC from whatever quality they were at (192 using VBR, so they range from 192kbps to 230 or so...) and they sound exactly the same to me. What's the problem?



    --Alexis
  • Reply 9 of 12
    lucaluca Posts: 3,833member
    Oh, it's just what the other people were telling me... I told them I put them both on my desktop, and alternated between the two in QuickTime (they were playing synchronized, and only the audio in the front player was going). When I told them that, they said, "What? That's all you're doing to see if they're the same? You should run it through an equalizer thingamabobber, and check the highs and the lows and the middles, and look at all the mix preset doohickys... and meanwhile, you shouldn't just listen to your headphones through your computer, you have to get a USB digital audio output along with an analog-to-digital amp converter for your headphones..."



    So I told them I'm not made of money, and they didn't seem to understand the concept, at which point they talked about how it was "so worth it to get all that stuff."



    I think these guys were WAY too into it...
  • Reply 10 of 12
    buonrottobuonrotto Posts: 6,368member
    FYI, I doubt this works in bulk, and of course there is the compression:compression problem, but under iTunes 4's Advanced menu, there is a menu item to "Convert Selection to AAC."
  • Reply 11 of 12
    overhopeoverhope Posts: 1,123member
    Keg of beer for the first poster to select their entire library and click "Convert to AAC".
  • Reply 12 of 12
    stupider...likeafoxstupider...likeafox Posts: 1,618member
    Quote:

    Originally posted by Luca Rescigno

    I think these guys were WAY too into it...



    Audio geeks are just like other geeks, i.e. mostly full of bullshit.



    On the other hand, while average pop songs will sound fine under mp3/aac style compression and the changes from the original won't be grating or unpleasant, certain types of music suffer badly.



    For example unnatural, completely computer generated music (especially square waves) can give it trouble, as can thrash metal while classical, acoustic music and vocals do well. Generally, the less 'musical' the music the more trouble mp3/aac has. Applause and crowd noise on live recordings freak out the encoder, for example, but then who cares how they sound.



    So the point to take away is, do you want an unpredictable x% of your music collection to sound a bit-off? Or more worrying x% of every song?



    How many times per song/album/playlist does a needle or CD laser have to skip to annoy you? What about hiss or other vaguer losses of 'quality'?



    So, the sensible approach, when choosing a constant bitrate is to aim for quite a bit more than most of your music will need in order to catch the difficult songs (or parts of songs) which are unpredictable unless you know a fair bit about of encoder theory.



    To relate this to recoding: recoding gives you all the errors of both formats, it's like faxing a photocopy.



    And finally, because some people seem to miss this fundemental point: a 128 bitrate mp3 will be the *exact* same size as a 128 bitrate aac. The bitrate is measured in kbps = kilobytes per second.



    (OT: this is why the LAME and Ogg Vorbis encoders specify quality levels rather than bitrates, you can only guarantee one by varying the other.)
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