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convert 14

All about......
Converting between sound formats



So you want to learn about converting?

Not really, no, I'm a Buddhist, and I'm happy with that. No, I mean converting between sound formats.

Oh, well, yeah, I guess, is it hard? No, it's quite simple

Here we go yet again. No really, it is.

Okay, go ahead. Thanks.

First let's start off with why you might want to do so. There are two main reasons

1) You want to upload your song to the web, or perhaps email it

The AIFF files that GB exports are uncompressed, high quality, and huge, running about 10MB/minute! Far too large to be emailed or posted on the web, so you'd typically convert the AIFF to an Mp3 or AAC file

Okay, that makes sense, go on.

2) You have a sound file which you would like to import into GB, but either GB won't accept it or the pitch and tempo are off after it is imported

This happens because GB expects every sound file to be a specific "Sample Rate" and "Bit Rate"

You said this was going to be easy! What the heck are Sample Things and Bits and Pieces?! Don't Panic

Easy for you to say. Yeah, it is, isn't it B-)>

Seriously, don't worry, we'll go over the terms a little, but you truly don't need to know what they mean, just that they can cause problems if the values are incorrect.

Okay, I'm not panicking, I'm not panicking. Why are you repeating yourself? Because I'm panicking. Okay, we'll let's get the big words out of the way.

The sample rate is the number of times each second that a measurement is taken of the sound. The measurement is the exact frequency that was recorded at that moment in time. According to the Nyquist Theorem the sample rate has to be at least twice as high as the highest frequency being digitized (turned into something that a computer can store and use), thus to accurately digitize frequencies up to 22Kc (22,000 cycles per second) the sample rate has to be at least 44K (44,000 samples per second)

The number of bits that are used (Bit Rate) determines how many levels of volume can be stored.  2 bits gives you 4 levels, 4 bits gives 16 levels, 6 bits gives 64, and so on.  So 16 bit digital sound has more resolution and accuracy than 8 bit and 24 bit has even better resolution.

In our case, using GarageBand, we are restricted to a 44.1K sample rate and a bit rate of 16.

Boom! What was that? My head exploding. Look the only two things you have to remember are 44.1K and 16-Bit, that's it.

You're a poet. Funny.

So anyway, now we know the magic numbers, 44100 and 16

Wait, you said 44.1 not 44100. That's not exactly what I said, I said 44.1K and since "K" generally means thousand, 44.1K is 44100 What do you mean "Generally". Maybe we'll tackle that in another article, for our purposes here K means 1,000. Okay.

Now that we have all the background out of the way, let's get this party started...

We'll start off with a file that won't import. Since a GB export is already listed in iTunes this step is unnecessary, but for a file just randomly sitting on your HD we have to get it into iTunes. Drag the file into iTunes' window so that it can be loaded into iTunes:

convert


Once it's imported into iTunes, you need to find it. I have iTunes set up to list by "Date Added". This works out best for me because the latest song is always at the top, so just scrolling up to the very top always finds it. To set yourself up this way, make sure the "Date Added" column is visible. Pick View Options from the Edit menu:

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and you'll see this dialogue Box:

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Simply add a checkmark to the Date Added box as I have. Next, back in the iTunes window click on the column labeled, well, "Date Added" (You may have to scroll to the right some to see it if you have many columns, like I do):

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(Note: If you click the Date Added title a second time it reverses the order, so if you have newest at the top and click again newest will be at the bottom and vice versa)

Now your Library is displayed in the order in which you add tunes, so the song you dropped in is at the very top, simply scroll up to find it.

If you've exported from GB, your song is already in iTunes, and it's already at the top, so we're ready to get to the nitty gritty.

If you didn't follow the above steps, it's not too important, you're just on your own for finding the song in the list (iTunes' search is good for that). Find your song and select it:

convert


Now Open iTunes' preferences, click "Advanced" and then click "Importing":

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At this point, what you do depends on what you want. If you have a troublesome file that you want to import into GB (perhaps one that won't import at all, or that plays at the wrong Pitch and Tempo), select AIFF in the Import Using PopUp menu, and then Automatic in the Setting Menu:

convert


If you're trying to make a GB export smaller, select "Mp3" in the Import Using PopUp menu, and then select the quality you desire in the setting menu:

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What you choose here is really a personal preference. The lower the quality, the smaller the file, the higher the quality, the larger the file (custom offers more options, but the above rule still applies, it's always a trade off, the better you want the sound, the larger the file will be, you have to decide which is more important)

Once you've chosen the encoder and quality setting, it's time to make the new file.

iTunes uses the term "Convert", but in truth iTunes does not convert anything, it creates a brand new file in the requested format. This is important to understand because if you have a lot of songs in your collection you may not realize this and you'll think that the "Convert" function didn't work.

For my example I've set my encoder to a Higher Quality Mp3 and I'm going to convert the song "Words and Words". I've already selected it, so now I use the convert function from under the "Advanced" Menu. This menuItem changes depending on which encoder you choose. In other words, it you set iTunes' preferences to AIFF it will say Convert To AIFF, if you set it to AAC it will say Convert To AAC. Since I chose Mp3 the menu looks like this:

convert


I select it, wait a few moments, and when the conversion is done my itunes window looks like this:

convert


Ummm, it kind of looks the same as before, bud. That's because when you have a lot of music, it's difficult to detect small changes like adding a single file. If you happen to be insane like me and have 24,493 songs in iTunes you can't see any change in the scroll bar. Scroll up once by using the scroll bar's arrow:

convert


and the list looks like this:

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With Date Added as my display method, the top song is an Mp3. If you had selected another encoder it would be whatever format you had selected

Now whatever you plan to do with the file (upload, email, drop into GB) the next step is to find the actual file. iTunes makes this easy, make sure your new song is selected in the list and then simply select the Show Song File MenuItem from iTunes' File menu:

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And your song file will be displayed, and selected, in Finder so that you can do what you wish with it.

Now, if you want to be extra cool, you can use Mac OS X Services.

What are they? They are probably one of the least used and most glossed over features in OS X. With the new Song selected in iTunes (the Mp3), click on the Application Menu (The one named "iTunes") and look at the Services MenuItem:

convert


Neat huh? I Guess so. What do they do? If you choose "Send File", the song you have selected in iTunes will be placed in a new Mail Message ready to be emailed to anyone. If you choose Send Selection then all the textual info for that song will be sent, for example:

Words and Words 02    3:06    hangtime    hangtime's Album   2:28 PM  3   2:43 AM   hangtime

So there you go, everything you ever wanted to know about Converting.

Thanks, and all, but I'm still going to stay Buddhist. {sigh}



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