Mystery Behind MP3s – Understanding its concept
This very Post is to make people of my locality (& others) understand the Mystery behind the most popular Music Format, MP3. Here students of my college think that full forms of MP3 are Music Player 3, Media Player 3, Multi Player 3 & so on! Here I’m explaining what actually this MP3 means & how it reduces the size of Audio Files. I hope people will welcome my sincere effort! At least those who don’t know about the MP3!
Actually MP3 means: MPeg-1 audio layer 3. Yes this is the full form of MP3. MPEG means Motion Picture Experts Group. Interesting No! MP3 technology has been designed to reduce the file size of Audio files. So how does MP3 shrink the mammoth Audio CD’s Songs to small MP3 Music files?
An Audio CD you purchase holds about 12-13 Songs (About an Hour worth of Music). These songs are stored in a format called WAV which provides high quality sound but at the price of Hard Drive space. You can’t store these songs on your disk in Digital form. They will also store a large amount of Disk space.
Here comes MP3 to rescue. Actually conversion of Audio CD Tracks to MP3 format involves 2 steps: Ripping & Encoding. Ripping means obtaining the Track from CD & preparing that for conversion. Encoding converts the Track to MP3 or any other Music format. During Encoding an Encoder like MP3 converts the WAVE File to a highly compressed form known as “bit stream“. This is done by exploiting a limitation of human Ear. This is based on phenomena called “Psycho-Acoustic Model“. As we all know that Human Audible Range is 20Hz-20KHz i.e. Human Ears can perceive the Sounds which have frequencies between 20 to 20,000 Hz. MP3 or other Encoders eliminate all the frequencies which are Inaudible to human ears. Thus a compressed form of Original Track is obtained which offers an excellent Sound Quality at much lesser Size. The degree of Compression (Bit-rate) determines the size of output MP3 file. This degree is measured in Bits per Second (also KiloBPS or KBPS). Higher the KBPS, lesser the compression, better the Sound Quality but more the File size. Normally most of the songs are encoded at 128 KBPS which reduces the original Track to 1/11th of its size! Obviously songs encoded at 160, 256 or 320 KBPS have better quality but more size. My choice for Bit-rate is 160 KBPS.
Since some data is lost from the original Track, the MP3 encoding is called Lossy. But this loss can’t be sensed by human ears at 128 or Higher Bit-rates! (Normally). But if encoding is done at lower Bit-rates, then quality does get reduced. Go on & try different Bit-rates for your favourite Track Using Winamp, iTunes or any other Media Player. Check my previous Posts for more help.
I hope you now understand what MP3 means actually. Stop calling it Music Player-3 Now!
One more thing, MP3 is a patented Algorithm & hence it can’t be used in free Audio Editors like Audacity. They use a different Encoder called LAME (Lame Ain’t Mp3 Encoder) which is Free & Open Source for exporting Projects as MP3 files. Other Free Encoders apart from LAME are Ogg Vorbis & FLAC (Free Lossless Audio Coder).
Currently a more Powerful Music Encoder is Available, AAC (Advanced Audio Coding) from Coding Technologies. Its files ripped at 128 KBPS sound better than the file ripped using MP3 at 160 KBPS! Means less size & better Sound Quality.
But MP3 still remains the favourite encoder for many people.