iTunes - Apple Lossless Encoder question

Discussion in 'Audio Hardware' started by Chris R, Oct 20, 2009.

  1. I recently started ripping CDs to my new Classic 120GB iPod thru iTunes 8 using the Apple Lossless file format. Have never used it before.

    When you rip a CD to iTunes using the Apple Lossless file format, why does it use a variable bit rate? Shouldn't lossless files be a fixed bit rate?

    If I chose 320 kbps, iTunes rips all the songs at 320, not at a variable rate.

    You can see the results in the following screen shot.

    [​IMG]
     
  2. Vidiot

    Vidiot Death to Film Terrorists!

    Location:
    Hollywood, USA
    Apple chose to use VBR for Lossless, because it's a more efficient codec (i.e., takes up less space).

    Even with lossless Zip encoding, there's several different ways to do it. Each has compromises in the amount of time for encoding and file sizes. As long as the result decodes and is 100% bit-for-bit identical to the original file, there's no problem.

    There are alternatives to iTunes for Apple Lossless encoding where you can choose bitrates, or at least VBR minimums, number of channels, and things like that. dBPowerAmp is one of them, using Nero's ALAC plug-in.
     
  3. Shakey

    Shakey New Member

    Location:
    Chicago, Illinois
    No, ALAC or Apple Lossless, is VBR.
    WAV is 1411 kbps, cbr (constant bit rate) and the lossy ones are whatever they are.
     
  4. Galley

    Galley Forum Resident

    Since it uses VBR, ALAC bitrates can be well under 300Kbps.
     
  5. GreenDrazi

    GreenDrazi Well-Known Member

    Location:
    Atlanta, GA
    It's a variable bit rate because the compression is based on the amount of information contained in the original file. For example, take any track, make a copy of it and then boost the level on one of them by 3dB's. Then compress both with a lossless codec and you will find that the original track (now, in lossless format) to be smaller in size.
     
  6. floweringtoilet

    floweringtoilet Forum Resident

    If ALAC didn't use VBR there would be no compression and the resulting files would be just as big as the uncompressed files on the CD. Choosing a fixed bit rate like 320 kps would introduce lossy compression. Even if you chose a very high bit rate, like say 1,300 kps (very close to CD), there would still be at least the possibility of losing some audio data.

    Possible, but not likely. I have hundreds of ALAC files on my computer, and I don't recall seeing any under the 500 kps range.
     
  7. attym

    attym Well-Known Member

    Location:
    US
    I'm very tempted to take my library of flac files and convert to apple lossless if fornothing else, the ability to really use itunes (without a weird plugin) and have art work.
     
  8. Duggeh

    Duggeh Active Member

    Location:
    Scotland
    High lossless bitrates (1000+) are indicative of a loud song. I have an ALAC file thats got a bitrate of 2kpbs, thats two, because its a 32 second track of almost entire silence. (Rob Dougan - Pause, from Furious Angels). Indeed 320kbps MP3 is a worse choice than -0VBR because very low information tracks end up being padded up and taking up far more space than they might with VBR.

    Don't worry about the bitrate is my advice.
     
  9. DaveN

    DaveN Music Glutton

    Location:
    Apex, NC
    :righton:

    I've been using iTunes for years without issue. I generally do not use it as a direct player but rather as a ripper. iTunes is the conduit to my ipod. The rest of the music server duties fall to Squeezecenter.

    People always complain about iTunes, but that is the kneejerk reaction to the proprietary nature of the program. My rips have been very high quality and frequently sound better (?!?) than the original cd. EAC might do a better job, but I doubt that I'll ever hear it.
     
  10. attym

    attym Well-Known Member

    Location:
    US
    I should say that I've been using itunes from the very begining with MP3 and AAC, but I don't use it for my flac. Apple lossless would allow me to use it with all of my lossless as well as what I have already in there.
     
  11. DaveN

    DaveN Music Glutton

    Location:
    Apex, NC
    Yep. Having it all in one place is a nice advantage.
     
  12. Galley

    Galley Forum Resident

    I've got 575 lossless tracks @ 500Kbps or less; 134 of them are The Beatles.
     
  13. Vidiot

    Vidiot Death to Film Terrorists!

    Location:
    Hollywood, USA
    That's a common misconception. The file size really depends on the efficiency of the codec and the nature of the material being compressed. And there are some variables, particularly if you use a different compression engine (i.e., non-Apple). The reality is that a lossless compressed file is generally about 50-60% the size of the uncompressed file, assuming a normal WAV or AIFF file.

    There's something like 20 different lossless file format out there -- some of them very obscure -- and each of them yield different file sizes. With FLAC, if you encode in mono, the file size is somewhat smaller than it is with a stereo file, regardless of the fact that the material is identical in each channel. And you can create mono ALAC files with 3rd party programs like dBPowerAmp, using Nero's ALAC plug-in.

    You can get more on this by reading the Lossless Comparison page over on the Hydrogen Audio website. They also regularly test and debate different lossless codecs, but the differences generally boil down to a) compatibility, b) compression speed, and c) file size.

    Other than that, in theory, lossless is lossless. By the same token, if I use an old version of Zip compression for a raw photo file, and then use a new version of Zip (or another compressor), I'll probably get a smaller file. And yet when decompressed, they're bit-for-bit identical.
     
  14. attym

    attym Well-Known Member

    Location:
    US
    I just did a test using XLD to convert a folder of flac files to apple lossless. It was a fast process and the file size seems about the same (just slightly smaller for apple lossless). It is very nice to be able to combine those files with the huge MP3 library and have artwork... I think I'm going to try and batch them all (keeping the flac still for the time being)
     
  15. What's the big deal? FLAC files are variable bitrates too, but decode to bit-perfect copies of their wav counterparts too...
     
  16. bootray

    bootray Member

    Location:
    D.M. Iowa
    Do flac file decode during playback in foobar as lossless or play as VBR?
     

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