First of all, here are the most oft-found formats:
- WAV/AIFF - WAVs and AIFFs are basic audio files. They are uncompressed and generally take up a lot of disk space, but can have exceptional sound quality, as they are not limited by bitrates as other formats are and contain the audio data in its rawest form. WAVs are generally used on Windows PCs, while AIFFs are more likely to be found on a Macintosh. They are usually supported on either platform, however.
- MP3 - A compressed file format that can have varying quality, based on its bitrate. The higher the bitrate, the better quality and larger size. Your probably won't notice any difference past 160kbps, but I have seen MP3s go to rates as high as 540kbps. Unfortunately MP3s tend to cut off some pitches from the extreme high and low ranges. This is a really popular format for some reason even though there are more efficient formats out there, such as OGG (below.)
- WMA - A proprietary audio format created by Microsoft for fast delivery and streaming (and an attempt to create another monopoly.) In short, it's very low quality and very compressed. WMA files are generally a medium size. They also have variable bitrates, but a 128kbps WMA has lower sound quality than a 128kbps MP3. Sometimes they can be protected, making them difficult to copy - and currently, protected WMA files are not playable on a Mac.
- OGG - A less-widely-used format, but can be as compressed as an MP3 file and have higher sound quality at a lower bitrate. It's gradually becoming more popular. Some audio tools (such as the open-source app Audacity) can encode OGG files.
- MID/MIDI/RMI - MIDI is an old technology, but MIDI files are still used widely. They contain notes as instructions for a software synthesizer, such as the Roland wavetable. A wavetable is the bank of sounds the computer uses to output the instructions as notes. Different computers have different wavetables sometimes, so not all MIDIs will sound the same for everyone. Since they contain no actual audio data, they are very small files.
- MOD, XM, IT - Sometimes referred to as "Tracker" files, these are very similar to MIDI files, except that the file contains its own wavetable, created by the author of the file, but contains no other audio data. Because of this distinction, they are generally larger than MIDIs, and depending on the size and quality of the samples in its wavetable, the tracker file can have a broad range of file sizes.
- AAC/M4A - These are in the Apple Lossless format. If downloaded from the iTunes store (or sometimes elsewhere), you won't be able to convert these easily (though there are ways to do so.) They can be copy-protected, and may not be burned to CDs sometimes, or shared with others without a password. In the case of iTunes Plus, you get an AAC at a higher bitrate, but it's still tagged as purchased from the store - you can only burn it 7 times, and these unique files also can't be converted to a non-tagged state. So once you burn it 7 times, you're done.
- There are certainly other audio file types, but these are the most likely you'll be to find.
The formats that Zelda Classic can use are MIDIs and tracker files. You can also use mp3s in the recent betas.
Converting between certain file types is impossible or extremely difficult. You can convert any file consisting of mainly audio to any other all-audio format (WMA to MP3, MP3 to WMA, WAV to MP3, AIFF to WMA, WAV to OGG, etc) easily using ACID, Audacity, Winamp, or other popular audio applications. In the case of protected files (AAC, WMA) you are going to have to figure out how to convert them on your own (illegally.) 'Cause I'm not gonna tell you.
You can convert MIDIs to MP3s, WMAs, AACs, or pretty much anything else. Doing so will not change how the song sounds, however. It will just make a larger file that sounds exactly the same as the MIDI already did.
You can't convert an MP3/WAV/whatever to a MIDI unless you feel like resequencing the whole song yourself. No software is available that can do it for you - there are some that claim they can, but they can't. It's not possible - yet. Audio recognition technology is still a long way off from reconstructing audio as instructions.
Some commonly asked questions about non-format-related things:
I want to separate the vocals from a track, so I can sing it myself/learn the backing/blah blah blah.
You can't do it. Don't try. If you really, really want the backing, contact the artist and see if they have it available for you to purchase. You might be able to make the vocals softer in a song using an equalizer, but it will also have an adverse effect on the rest of the song, and the vocals will still partially be there.
I'm running Windows, and I'd like to convert a file to WMA. How do I do that?
Luckily for Windows users, you have some free options. I'd suggest getting something like ACID Express that lets you do it for free. Unfortunately ACID express limits you to 48kbps WMAs, so it won't be high-quality (though it is WMA after all.) You can Google around if you like for other options, but this is the only safe, spyware-free option I could find. You can also use Windows Media Encoder, from Microsoft, but it only lets you save as WMVs, a WMA with video. If you save it that way, you'll have your audio track, but an empty video track along with it. On occasion you can simply change the file extension to .wma, but it doesn't always work.
I'd like to save a file as a WMA, and I'm running Mac OS X, and I can't find any way to do it.
There's no free option for Mac users, since Microsoft has not licensed the technology to any Apple or NeXT platforms.
The best option for a Mac user right now: buy Flip4Mac's encoder and save WMAs and WMVs from QuickTime Pro, iMovie HD (version 6 as of this writing, the new iMovie in iLife '08 doesn't support iMovie HD plugins), Logic, or Final Cut. It's a bit clunky, but it works. Another alternative, if you have an Intel Mac, is boot into Windows and use one of those free apps.
If any other audio questions come up, I or possibly someone else could add them. I hope this thread is useful.
Edited by Bagel, 10 November 2011 - 10:20 PM.