Week 4: Muddy

Audio File Formats

As someone more familiar with image and video file formats, I had difficulty understanding the appropriate use for each file type that was simply listed. Taking matters into my own hands, I researched and discovered the importance of becoming familiar with audio formats in the business world. Especially in my field of study, advertising, being comfortable with audio files is crucial in creating items like radio spots or as an interactive element for a client's Web site. The following formats are the ones discussed in the class lecture, and will be explained further based on my outside research in my attempt to understand audio files.

• WAV (Waveform Audio File Format): As one of the most common, WAV is a standard digital audio file format for storing waveform data. It allows audio recordings to be saved with different sampling rates and bitrates great for maintaining CD quality audio.

-Common on Windows-based systems

-Programs that open .wav files: iTunes, Roxio Toast, Windows Media Player

• AIFF (Audio Interchangeable File Format): With average popularity among file formats, it provides CD-quality audio stored in a non-compressed, lossless format similar to the .wav format.

-Typically used to burn audio CDs

-Programs that open .aiff files: Quicktime Player, Roxio Creator, Windows Media Player, iTunes

• WMA (Windows Media Audio): This very common file type is a proprietary format developed my Microsoft is similar to MP3 and can be converted into other formats.

-Commonly used to play music from the Web

-It's video counterpart, WMV is used to view Windows Media Video files

-Programs that open .wma files: Windows Media Player, Apple Quicktime, Web browsers, Nullsoft Winamp Media Player

• MP3 (MPEG-1 Audio Layer 3): Another very common audio file format, the MP3 uses "layer 3" audio compression, and the quality depends on the bitrate used for compression, the higher the better.

-Used to store music files and audiobooks on hard drives

-Supported by most portable music players like the iPod, Zune and Kindle

-Programs that open .mpeg files: iTunes, VideoLAN/VLC media player, WMP

• AAC (Advanced Audio Coding): This very common audio file is similar to MP3 but offers improvements like higher coding efficiency, an easier filterbank, and better handling of high frequencies.

-Maintains quality nearly indistinguishable from the original audio source

-Used as the default encoding used by Apple iTunes software

-Programs that use .aac file format: iTunes, MPlayer, WMP, KSP Sound Player

• Apple Lossless: a.k.a "ALE", is an audio codec developed by Apple for lossless data comprehension of digital music.

-An audio converter is needed to extract audio from ALE files

-Does not utilize any Digital Rights management scheme.

• FLAC: Free Losless Audio Codec is similar to the MP3 file format, but it is lossless, meaning the audio file is compressed without any loss of quality (very important!).

-Regurded as the fastest and most widely supported lossless audio codec, the only one that is non-proprietary (meaning it's independent and thus benefits by more freedom). [http://flac.sourceforge.net/]

Hopefully this description has helped you to understand the basics of each audio file format, if not:

Visit http://www.fileinfo.com/filetypes/audio for an even more detailed analysis.

And for a similar informational listing of video file formats, click here.

For image files, click here.