Tuesday, July 28, 2009

Making opera portable

A tech blog that I follow occasionally ran an article today on audio file formats that I clicked through to with a thought to talking about the best way to convert your audio collection to digital and keep it sounding great (better than mp3 great,) without taking up a whole hard drive while doing so. Unfortunately the article was awful, mostly because it only covered a couple of options and not all of the good ones.

mp3 is a fine format. Everybody uses it. Every player plays it. It makes music small and portable. It just doesn't give very true sound (it strips away a lot of audio information,) which, for opera, is somewhat important. Fortunately there's other options and sometimes a good Wikipedia search is all you need. Here is a list explaining pretty much every audio codec in common use. Here is a list of the commonly accepted listening tests that have been run, grading them by quality. Here's a pretty good site that ran some tests using different music, including classical, to determine what works best for a lay person's ears.

Long story short, here are your best bets when getting audio off your CD (or digitally recording it from a record player using usb or line in.) :

-If you want to retain all of the sound from your CD when you digitize, use .PCM (usually saved as a .WAV file,) which can store huge amount of audio information. All of the data is there, it's just sizable, at between 10MB/minute. Slightly smaller would be FLAC or for those of you with iPods, "Apple Lossless," both of which compress audio into about half the size without any measurable loss of quality.

-If space is a serious issue, .ogg (OGG Vorbis) set at a low bit rate will do at under 1MB/minute. Just don't expect it to sound true to life.

-For a good balance of size and sound, try WMA9 or, if your player doesn't support it, (and it likely won't - this is Micorsoft's own codec,) mp3 at a variable bit sample. It will try to intelligently strip away the stuff you can't hear, and leave the stuff you want.

All told, this is a pretty basic run down of some pretty complex material. Heck, there are whole books and web sites dedicated to this. Hopefully though, this points you in the right direction if you're looking to digitize some music for the road. Just make sure that your music player can play the format before transferring the music or you'll have wasted an awful lot of time. Feel free to ask questions in the comments.