MP3

MP3 stands for MPEG layer 3 and this is the sound/audio component of the DVD system. It basically works by compressing the data component of the typical sound (say Cd audio) withour harming the quality.

CD audio stores data by sampling music at 44100 times in 1 second and the samples are 2 bytes (16 bits)long (one from the right and one from the left speakers) this gives us a storage requirement of 44100 * 2 * 16 bits of data per second, this is equal to roougly 1.4 million bits per second or 176KB per sec. So for a 4 minute jam one expects about 4 * 176 * 60KB (~43MB) for one jam alone. A typical CD disc can hold a total of 650MB of data and when you divide it by 40MB you get around 15 jams (4 minutes each).

However by cleverly manipulating the same data, the MP3 system can reduce the same jam by as much as 1/10 - 1/14 of its size which implies either a capacity of 10*15 (150) or 14*15 (170) jams of the same 4 minutes each. This is achieved by utilizing a technique called perceptual noise shaping - the deal is that we humans has a certain sound range which we simply cannot hear, there are others which we can hear very well and if two jams play simultanously our hearing is biased towards the louder jam. When you now cleverly manipulate these facts by dumping some jams which our ear cannot hear in any case and highlighting the others which we can, then applying data compression techniques much as one compresses a JPG or a GIF graphic file then we are left with only 1/10 of the starting size. The good news being that the jam is not battered in the process.

Hi!

Well Mp3 is a kind of compression. It can compress your .cda files(Cd Audio Files) or .wav files (wave files) into size up 3-4 times smaller than their original size. The most remarkable thing here is you do not have to compromise on quality.You get near Cd digital Stereo when you compress your CD Files to Mp3 format.

Secondly Cd can hold only 15-17 songs where as the same CD can hold 100's of Mp3 songs because 1 single Cd song file is upto 30-40 b (approx) whereas the same song whenconverted to Mp3 is just 3-4 Mb. So if you want to fill up 650 Mb of Cd Disk space with Cd Audio you get few songs whereas you fill the same CD with Mp3's you can store 100's of songs.

I hope this is helpful for you.

Cheers!~
Dhaval Desai