AUDIO FILE GUIDE - getting the most from your music

**Jared Moya** · March 15th, 2006, 11:42 AM

This guide is both for those of you out there who want to learn more about the different types of audio files one encounters when downloading, as well as for those of you looking to learn what variables are involved in making them. From turning audio files into the type of your choosing, to simply making better audio CDs, we’ll cover all the audio basics.

To start, we’ll go over the basic audio files one usually encounters when downloading. We’ll cover the variety of types and forms and what they mean in terms of quality, size, and meaning.

.wav
WAV (or WAVE), short for WAVE form audio format, is a Microsoft and IBM audio file format standard for storing audio on PCs. WAV files store music in exactly the same format as on a CD. They're the highest quality sound files, but by far the largest in size. To note, Audio CDs do not use WAV as their storage format. WAV is a data file format for computer use only.

.aif/.aiff
Audio Interchange File Format (AIFF) files are the same as WAV files, but are read as such by the Macintosh OSX. Thus, for it’s profile and characteristics please see the WAV description above.

.flac
Free Lossless Audio Codec (FLAC) is similar to MP3, but lossless, meaning that audio is compressed in FLAC without any loss in quality. Unlike lossy codecs such as MP3 and AAC, it does not remove any information from the audio stream. Simply put, FLAC files are identical in quality to those of the WAV file format, but are smaller in size from their compression.

.ape
Monkey’s Audio (APE) is a lossless audio compression codec. Unlike lossy formats, such as MP3, Monkey’s Audio does not permanently discard data during compression. A file compressed with Monkey's Audio sounds the same as the original file, no matter how many times it is uncompressed and reencoded. Monkey's Audio achieves compression rates of around 40–50% without loss of data. So like FLAC , APE files are identical to those of the WAV file format, but are smaller in size from their compression.

.wma
Windows Media Audio (WMA) is a proprietary format developed by Microsoft. It can be either lossy or lossless. Though not as popular as MP3, some say that lossy WMA tends to outperform MP3 in the area of sound quality, particularly with files encoded at lower bitrates like 64 or 96 Kbps. This performance advantage makes it handy for applications like portable digital audio players, where total play time is limited by a finite amount of internal memory. The Windows Media Audio format features built-in copy protection abilities, unlike MP3, so one is faced with challenges if the file is copy protected. Currently there is no known software that exists which will allow non-licensed users the ability to “crack” the Microsoft DRM (Digital Rights Management) technology other than by using real-time recording to “convert” the file to another of your choosing.

.ogg
OGG refers to the audio file format Ogg Vorbis, that is, Vorbis-encoded audio in an Ogg container. It is a patent and royalty-free, lossy audio compression technology from the Xiph.Org Foundation (www.xiph.org), which is dedicated to open source multimedia standards for the Internet. Ogg Vorbis is considered comparable to AAC and better than MP3 in sound quality as well as providing lower bit rates and smaller file sizes.

.aac
Advanced Audio Coding (AAC), also known as MPEG-2 Part 7, is a digital audio encoding and lossy compression format. It was popularized by Apple computer through its iPod and iTunes Music Store. AAC offers the listener a better and more stable quality than MP3 at equivalent or slightly lower bitrates. AAC files encoded at lower bitrates (like 96 Kbps) sound as good or better than MP3s encoded at higher bitrates (like 128 Kbps) despite their notably smaller size. Thus, one can have smaller file sizes with comparable sound quality to that of MP3.

.mp3
MP3 (MPEG Audio Layer 3) is an audio compression technology that is part of the MPEG-1 and MPEG-2 specifications. MP3 compresses CD-quality sound by a factor of roughly 10, while retaining most of the original fidelity. For example, a 30MB CD track is turned into a 3MB MP3 file. Like other lossy files, MP3 files are much smaller than the recordings they're made from. That's because some less-audible information is discarded when the file is made. The encoding bit rate, measured in kilobits per second (kbps), is important to the quality of the sound. In general, the higher the bitrate the better the sound quality.

So now that you know a little more about the audio files you’ve downloaded, the question arises, “Which format do I want my audio files to be in?”

All things considered, more often than not, the MP3 audio file format is the one that you will want to use. From simply conserving storage space on your computer, to ease of transfer to a portable music player, it’s the format of choice. As such, the process of turning different audio files into the MP3 format will be our next task.

Our first step is to determine the desired quality and size of our MP3, as better the quality means bigger the size. This means we must decide at what bit rate, or the number of bits that are conveyed or processed per unit of time, we will reencode the audio file. We will discuss the 112 to 256 kbit/s range, which represents an 8%(1:12) to 18.2%(1:5) compression size of a CD-quality, or WAV, audio file.

Now the minimum bitrate acceptable for upload to popular music file-sharing sites like OINK is 192 kbit/s.

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