Will a conversion from WAV to AIFF within Itunes cause any degradation

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Will a conversion from WAV to AIFF within Itunes cause any degradation

Here is my problem:

I use iTunes to manage my collection of lossless music. I am an "Audiofile". It is understood in the audiofile community that using a software other than iTunes that is build for lossless conversion is better (and often neccessary for formats like FLAC).

Mistake: I collected and purchased thousands of songs in WAV format. On purchase, the WAV's came with no metadata, with an unclear filename such as "1023854901208358912.WAV". I then proceeded to painstakingly tag each and every song within iTunes with Title, Artist, Album, and Genre.

Now I stand on a precipice in which I want to migrate my songs to other computers and libraries, and I do not want to manually rename all of these songs over again. The issue I'm sure you can see I'm driving at is that iTunes stores metadata for WAV files in a list that is only accessible by iTunes.

I don't mean to expose the negative qualities of iTunes, but this is obviously a disadvantage to choosing it as an organizational tool for my music property. I would appreciate it if a staffmember from the iTunes department at Apple could contact me personally to let me know what changes my files would experience as a result of converting them from .WAV to .AIFF using iTunes. I would probably be willing to sign an NDA if I could know, since (as a professional audio engineer) I consider my lossless music a vested interest.

The reason this is so important to me is that I will go through the trouble of renaming all of the files if there is a single change in the audio, however minute (audible to the human ear, visible on a waveform, or distinguishable on advanced audio inspection tools.)

It has been difficult to obtain a trustworthy answer from external forums, so I am asking here to see if there are any audio experts that either built or understand the mechanics of the itunes conversion process specifically in terms of converting one completely lossless format to another completely lossless format (.wav to .aiff)

Thank You!

MacBook Air, OS X Mavericks (10.9.4)

Posted on Apr 1, 2015 8:22 PM

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Answer 1

Limnos

Level 10

411,253 points

Apr 1, 2015 9:22 PM in response to Plasmon

Audiophile? 😉

If you want Apple technical support you will have to call them (and probably pay for it) as this forum is a user-user interface. Even then I doubt you will get one of the iTunes programmers to tell you all the details of the underlying conversion software of the application. I also don't recall any regular hangers-on of this forum being techy audiophiles who can answer those detailed questions. Usually when I want to know that kind of stuff I browse the web. Maybe research can reveal if all a WAV to AIFF conversion involves is a simple relabeling of the audio data without any real conversion.

You know the way to do this? Get a friend. Convert 10 files. You put on headphones. Have friend play back 10 originals and 10 duplicates in pairs but random order first/second and see if you can really tell the difference.

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Answer 2

Plasmon Author

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Apr 1, 2015 9:37 PM in response to Limnos

The problem is that I'm an audio engineer and not only do I listen to audio, I stretch it, slow it down, edit it, and store it at many different sampling rates. When you stretch (digitally change the length of audio while maintaining pitch) you begin to hear distortions the more you stretch. With higher sampling rate and bit rate, this distortion becomes less and less. I'm also a DJ, and the software I use to mix music digitally stretches the audio.

I will definitely take your suggestion and research what the conversion does, and if by some luck it is only a text change.

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Answer 3

Limnos

Level 10

411,253 points

Apr 1, 2015 10:08 PM in response to Plasmon

Not so much a text change but a simple restructuring of existing data vs. having to do an interpretation.

https://www.gearslutz.com/board/music-computers/109944-aiff-vs-wav.html

One thing to which you may need to pay attention is how iTunes handles 24 bit files if that is what you have. iTunes is likely targeted at consumer level use and I don't know how it handles things if you start throwing really exotic formats at it such as 24bit 96kHz etc. It is getting better about playing such things but I don't know how if it does conversion at that level.

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Answer 4

ed2345

Level 9

62,498 points

Apr 2, 2015 3:49 PM in response to Plasmon

WAV and AIFF use identical PCM audio encoding, so it is theoretically possible to do the conversion with zero degradation. But, having seen iTunes do unexpected things with files that are other than 44/16, I share Limnos's concern that you should verify before committing.

However, you don't really have a choice. Using iTunes to convert WAV to AIFF will give you properly tagged AIFFs that can then be used in other applications. I am not sure there is any other way to achieve that.

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Answer 5

Limnos

Level 10

411,253 points

Apr 2, 2015 4:31 PM in response to ed2345

I am not sure there is any other way to achieve that.

There is but it isn't fun. 🙂 Re-code the WAVs using some other trusted tool. Import the unlabeled AIFFs into iTunes with the existing WAVs then use the Dougscript which lets you transfer tag data from one file to another. It can handle large number of files in one go as long as you are scrupulous in your ordering of them.

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Answer 6

Plasmon Author

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Apr 3, 2015 9:35 AM in response to Limnos

Thank U Limnos! that is a big step in the right direction. After sleeping on it I have a new plan that I will experiment with today. I still have a few details to work out.

1. Use doug's M3Unify to copy the files with an m3u file organized by date added added I guess.

2. convert the m3u to a cue file using m3u2cue

3. "Open the folder as a CD" with all the tracks with XLD by opening the cue file

4. Import the tracks (hopefully with names from the cue!) one by one in XLD because it exports smaller songs faster and the order would get messed up in date added. (import tracks with options "copy converted songs to itunes if possible" and "use original directory as destination")

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Answer 7

Plasmon Author

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Apr 3, 2015 1:46 PM in response to Plasmon

I could not get m3u2cue to convert the m3u to a cue file properly (so far). I'm looking for an alternative to this.

The requirements are:

- can import m3u files

- supports wave+cue files

- can use relative references (cue is able to "look for" referenced files in a designated directory)

- can be read by XLD

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Answer 8

Limnos

Level 10

411,253 points

Apr 3, 2015 3:22 PM in response to Plasmon

?? Me, I would simply add the WAVs to XLD. Convert to AIFF but keeping the same file names (will have different extensions). Import the AIFFs to a playlist. Sort by name. Have another playlist sorted by name with the WAVs. Use Dougscript "Copy Tag Info Tracks To Tracks" to copy desired information from the labeled WAV files to the unlabeled AIFFs sorted in exactly the same order. This will copy almost all the tags you might need unless your existence is based upon Date Added or something which won't copy. If you use some exotic tag that's not in teh script you can open it up with AppleScript the way I did and edit it in after a bit of reverse engineering.

It is just possible both sets of tracks may have to be in the same playlist. I always use it with all in the same playlist but one batch at the top and the other at the bottom and I haven't tested it in two playlists -- think it should still work.

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Answer 9

Plasmon Author

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Apr 3, 2015 4:02 PM in response to Limnos

That would work for most of my collection, but for the tracks that i purchased from beatport, the filename is a random number, and for others it is "track 01" or other.

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