Apple Lossless 24 bit

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Level 1

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Apple Lossless 24 bit

Hello,

I successfully imported a 24 bit / 192 kHz WAV into iTunes 9.0 and converted it to Apple Lossless format. Now I would like to convert my file back to its original format, however the WAV converter seems to be limited to 16 bit / 48 kHz formats. Any suggestions ? Thanks.

Windows XP

Posted on Oct 7, 2009 7:51 AM

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Answer 1

ed2345

Level 9

62,462 points

Oct 7, 2009 2:34 PM in response to prefab

Use a conversion program such as Switch. It has far more conversion options than iTunes, including the ability to create 24-bit WAV files at various sample rates.

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Answer 2

prefab Author

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Oct 7, 2009 11:38 PM in response to prefab

Hi ed2345,

thank you for your suggestion. I was hoping there would be a parameter in iTunes or QuickTime. It would be disappointing if an extra program is required to restore a lossless file created by iTunes. Actually the reason I moved to iTunes in the first place was to avoid the collection of tools needed to manage my music. Sigh...

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Answer 3

ed2345

Level 9

62,462 points

Oct 8, 2009 4:08 AM in response to prefab

prefab wrote:
Hi ed2345,

Actually the reason I moved to iTunes in the first place was to avoid the collection of tools needed to manage my music.

iTunes is a "consumer grade" product. Beyond the basics, you will need to use more specialized programs. Your case with 24 bit WAV files is a good example.

Go find an appropriate 3rd party program to do what you want. Think of it as an "app store."

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Answer 4

prefab Author

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Oct 8, 2009 6:43 AM in response to ed2345

Classifying iTunes as a "consumer grade" product is a perfectly valid personal opinion but misses the point of the post.

A Lossless codec is simply a way of storing music without modifying it in a compressed format (think ZIP).
iTunes allows you to read and compress (zip) 24 bit / 192 kHz PCM files but there is no way to retrieve the original file (unzip).

This would be a specification error if Apple was not planning to supply the unzip function (how many products do you know that only give you a zip capability). I do not think this is the case and it is probably an implementation oversight (When the lossless codec got updated to support 24 bit the WAV interface for choosing sample rate / size was forgotten - their defaults being auto). Actually if you read the help file under WAV custom import settings it says "In general, the best choice is Auto, which uses the *same rate* as the original music".

IMHO iTunes should be corrected to take a WAV file and losslessly encode/decode it or give a warning before starting if it cannot deal with it.

And since the code to deal with high resolution files is already there (take a look at QuickTime / Preferences / Audio, and depending on your hardware you can set high resolution audio out) I am still looking for a way around what appears to be a GUI limitation.

cheers

Message was edited by: prefab

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Answer 5

ed2345

Level 9

62,462 points

Oct 8, 2009 4:04 PM in response to prefab

I hope you will not be disappointed to know that I in fact did get your point.

Yes, if one imagines one is dealing with a full-fledged conversion program, it would be surprisining if it could convert from A to B but not B to A.

But if one realizes that the program has very limited conversion capabilities that are there for the convenience of people who use the program for its main purposes, then one might not be so surprised.

You may provide your feedback to Apple via the feedback page.

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Answer 6

prefab Author

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Oct 9, 2009 2:57 AM in response to prefab

spent some time playing with import settings, here is what I found:

= iTunes can import and play (limited by your hardware) WAV files up to 24 bit / 352.8 kHz ⚠

= iTunes can convert these files to Apple Lossless without any transcoding up to 24 bit / 352.8 kHz.

= iTunes can convert Apple Lossless files back to WAV without any loss up to *16 bit* / 352.8 kHz. In "import settings" choose "automatic" or "custom and auto for sample size / rate". So the only problem left is transcoding 24 bit content to 16 bit (without any warning).

= when converting to WAV, in "import settings" you can finely select the sample rate up to 48 kHz: 8, 11.025, 12, 16, 22.050, 24, 32, 44.1 and 48 (actually this gives the wrong impression that 48 kHz is the maximum rate). Since it supports rates at least up to 352.8 kHz it should include the following options too: 88.2, 96, 176.4, 192, 352.8 and probably 384.

@ed2345
thanks for your suggestion I will send this as feedback to Apple.

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