Posted Friday, July 01, 2005

The Worst iTunes Tip Ever, the Right Way to Convert to AAC, and Don't Miss This Weekend's Comet Show

Ah, it's the start of a three-day weekend here in the US of A. Before you go off and damage your hearing with fireworks, here are a few pixels worth reading.

Bum Tip
Like millions of Mac users, I've gotten some great tips from Rob Griffith's macosxhints site (now part of Mac Publishing, the company that publishes Macworld).

But there's one problem with user-submitted tip sites, and it's one that is by no means specific to macosxhints: some of the tips are, well, not so good.

A tip that appeared yesterday is a perfect example. The writer, who chose to remain anonymous (red flag!), wrote: For a long time now, I've wanted to convert my "old" and "outdated" MP3 files into AAC format -- mostly just to free up some space. I have put this off because manually doing this for every song seemed like such a massive undertaking that it didn't even seem worth it. Automator makes this task pretty simple.

The moment I read this, my neighbors heard a blood-curdling noooooooooo emanate from my studio. Converting from MP3 to AAC is the last thing you'd want to do if you care about the sound quality of your music.

Both formats are lossy: both discard audio information in the interest of making smaller files. An MP3 file has already been through the compression wringer; convert it into AAC, and you compound the sonic damage.

Now, if your favorite band is The Bleeding Eardrums and you've been listening to them for years with the volume turned up to 11, you may never notice the additional audio degradation.

But if you have a decent set of horns and you listen using good equipment, you certainly will. Cymbals and strings will take on a slightly swirly distortion. Classical musical will sound a lot less classical.

Just say no. Don't do it. Never convert one lossy format into another. It isn't worth any modest gains in disc space.

iTunes and the iPod family are quite happy with both MP3 and AAC formats. There's no need to standardize on one.

The Right Way to Convert
There is a way to make the transition from MP3 to AAC, and you'll find it in a sidebar on page 23 of my book. Here's the excerpt:

iTunes can convert existing MP3s to AAC, but you'll lose quality in the process. That's because both AAC and MP3 are lossy formats: each discards audio information in order to save disk space. Thus, when an MP3 file is compressed with AAC, the lossiness is compounded.

Bottom line: To take advantage of AAC’s space savings, re-rip your original CDs instead of recompressing existing MP3s.

This re-ripping requirement also applies if you want to take advantage of the Apple Lossless encoder introduced in iTunes 4.5. You can’t convert an MP3 (or an AAC) file into Apple Lossless and gain the quality benefits of the latter—the sonic damage has already been done.

iTunes has some smarts that make re-ripping less laborious: If you re-rip a CD that iTunes already has in its library, iTunes tells you that the songs have already been imported and asks if you want to import them again. Thus, you’re spared from having to rebuild your playlists, retype any song information, or manually delete your old MP3s.

Note: If you’ve edited a song's information—changed its name or that of the artist or album as described on page 26—iTunes won’t recognize that you’re importing it again, and you'll end up with two copies of the same song. To avoid this, make the same edits before you import the CD, or edit the song information of the existing MP3s to match that of the audio CD. Or just make a mental note to delete the old MP3 files after re-ripping.

Deep Impact Hits on Sunday
NASA's Deep Impact probe is expected to slam into comet Tempel 1 on Sunday night at about 10:52 pm Pacific time, and the word is that we Earthlings might see a little show at around 11 pm, skies permitting.

Today's San Francisco Chronicle has a good article on Deep Impact, and NASA TV has published a schedule of its comet impact coverage.

It all sounds great, and I'll have my beak pointed skyward, but I'll be thinking back to comet Hale-Bopp the entire time. We had a spectacular view of that comet back in the last millennium, and used to watch it set into the Pacific Ocean night after night. Now that was a show.

Have a good weekend, mah fellow 'maricans, and remember, if you value your hearing, avoid the fireworks.

And avoid converting MP3 into AAC.

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