Popular Audio File Formats

There are three major groups of audio file formats:

• Uncompressed audio formats, such as WAV
• Formats with lossless compression, such as FLAC, lossless Windows Media Audio (WMA)
• Formats with lossy compression, such as MP3, Vorbis, lossy Windows Media Audio (WMA) and AAC.

Zamzar is a free online file conversion service that let's you convert files from one format to other. The audio formats they support can be considered the most popular.

We're keen to be a verb in the Oxford English dictionary: Want to convert a file? Just "Zamzar" it.
Co-founders Chris and Mike Whyley still run Zamzar on a part-time basis without external funding (Picture courtesy: Guardian)

I was curious to know more about formats other than MP3 & WMA and my search took me to Wikipedia. Here is some paraphrased info on popular audio file formats -

• aac – the Advanced Audio Coding format is based on the MPEG2 and MPEG4 standards. aac files are usually ADTS or ADIF containers. AAC's best known use is as the default audio format of Apple's iPhone, iPod, iTunes, and the format used for all iTunes Store audio (with extensions for proprietary digital rights management). AAC is also the standard audio format for Sony’s PlayStation 3 and is supported by Sony's Playstation Portable, latest generation of Sony Walkman, Walkman Phones from Sony Ericsson, Nintendo's Wii, the Nintendo DSi, and the MPEG-4 video standard. AAC has better sound quality and smaller file size than .mp3.
• ac3 - lossy audio compression format developed by Dolby.
• flac – a lossless compression codec. This format is a lossless compression as like zip but for audio. If you compress a PCM file to flac and then restore it again it will be a perfect copy of the original. The cost of this losslessness is that the compression ratio is not good. Flac is recommended for archiving PCM files where quality is important (e.g. broadcast or music use).
• mp4/m4a – MPEG-4 audio most often AAC but sometimes MP2/MP3.
• mmf - a Samsung audio format that is used in ringtones.
• mp3 – the MPEG Layer-3 format is the most popular format for downloading and storing music. By eliminating portions of the audio file that are essentially inaudible, mp3 files are compressed to roughly one-tenth the size of an equivalent PCM file while maintaining good audio quality.
• ogg – a free, open source container format supporting a variety of codecs, the most popular of which is the audio codec Vorbis. Vorbis offers compression similar to MP3 but is less popular.
• ra – a Real Audio format designed for streaming audio over the Internet. The .ra format allows files to be stored in a self-contained fashion on a computer, with all of the audio data contained inside the file itself.
• ram – a text file that contains a link to the Internet address where the Real Audio file is stored. The .ram file contains no audio data itself.
• wav - a Microsoft and IBM audio file format standard for storing an audio bitstream on PCs. It is an application of the RIFF bitstream format method for storing data in "chunks" unlike the usual bitstream encoding is the Pulse Code Modulation (PCM) format. It is the main format used on Windows systems for raw and typically uncompressed audio.
  
• wma – the popular Windows Media Audio format owned by Microsoft. Designed with Digital Rights Management (DRM) abilities for copy protection.

BTW, VidtoMP3.com let's you convert video or music video files into mp3s.