The MP3 Format - what is an mp3?
'MP3 format' is a term that refers to a compression system for music. Actually, it refers to the 'algorithm' used to compress music (an algorithm is another name for a computer program or function). The data on a music CD uses an uncompressed, high-resolution format.
Lets look at a track on a CD first:
- Music is sampled 44,100 times per second. The samples are 2 bytes (16 bits) long.
- Separate samples are taken for the left and right speakers in a stereo system.
Therefore, a music CD stores :
If an average song is three minutes long, then the average song on a CD consumes about 32 million bytes or approximately 30.5 gigabytes (GB) of space.
So how does MP3 compression help?
The MP3 algorithm helps reduce the number of bytes in a song without hurting the quality of the song's sound. The aim of the MP3 format is to compress a CD-quality song by a factor of 10 without noticably affecting the CD-quality sound. It does this by removing frequencies that are normally ourside or on the verge of a human's audible range. In other words, it removes extemely low and extremely high information from the music file. This, in turn, reduces the amount of information per second and thereby the overall file size.
Is there a loss in quality?
Yes - by removing information from the audio file, you are degrading the overall sound quality. So, mp3 compression is a trade off between size and quality. Now that mp3 players have virtually unlimited disk space, file size is no longer of such paramount importance when compression rates are concerned. An mp3 file compression rate of 256kps is more than suitable to satisfy all but the fussiest audiophile and is certainly of infinitely higher quality than listening to old tapes.
Other formats
MP3 is certainly not the only compression format available. The problem is that not all MP3 Players play all formats and some will only play their own. Other common audio formats are:
- Media Audio (WMA) - a digital audio file format created by Microsoft. It was initially intended to be a competitor to MP3 format, though in terms of popularity of WMA files versus mp3 files, this never happened. With the introduction of Apple's iTunes Music Store, WMA has positioned itself as a competitor to the Advanced Audio Coding (AAC) format used by Apple and is part of Microsoft's Windows Media framework.
- Advanced Audio Coding (AAC) - a digital audio file format created by Apple. It was initially promoted as the successor to MP3 for audio coding at medium to high bitrates. It is mainly used in iTunes as the default codec behind the media player which powers the Apple iPod.
- OGG Vorbis (OGG) - Ogg Vorbis is a new audio compression format. It is roughly comparable to other formats used to store and play digital music, such as MP3, VQF, AAC, and other digital audio formats. It is different from these other formats because it is completely free, open, and unpatented..
How do I create MP3s?
You will need an mp3 converter - there are a number of free ones on the internet but our favourite is Apple's iTunes available for free download from the Apple iTunes site.
Linked Pages:
» End results for MP3 Format