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- = Facts about MP3 = -
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| !_PeTrUs_! |
What is MP3?
MP3 is a compression form (like .zip). The name MP3 stands for Mpeg 1 Audio Layer 3 and its compression algorithm is based on a complicated psycho-acoustic model. This model is based on the fact that the human ear cannot hear all the audio frequencies. The human hearing range is between 20Hz to 20Khz and it is most sensitive between 2 to 4 KHz.
This MP3 model among other techniques tries to eliminate the frequencies which the human ear is unable to hear keeping all the hearing frequencies leaving intact the hearing experience. As a result the MP3 compression form is destructive. That means that the compression algorithm causes the file to lose some information so that it cannot be restored to its original content.
When compressing an audio file (encoding) using the MP3 algorithm you can set the desired encoding level and have any compression level you want. The larger the compressed file the better the audio quality of the result. The majority of the files available on the internet are encoded in 128 kbits stereo 44khz which results to a high quality file that is 12 times smaller than the original!! This of course has many interesting consequences.
How do I play an MP3 file?
You just need an MP3 player. like Winamp, Nad MP3 Player, Unreal Player Max for other players (unix, mac, beos enz.) you can check here. Download the songs that you want to hear.
What hardware do I need for playing MP3 files?
The minimum requirement for acceptable quality is a Pentium 75.
The technology now gives as solutions to all the above tasks and problems.
Why to compress audio?
There is a simple reason to compress digital audio. High quality uncompressed digital audio takes a lot of space. Just 1 minute of CD quality uncompressed audio takes around 10Mb and needs around 50 min to be transmitted over a 28.8 modem!
Digital audio coding tries to compress digital audio so as to take less space. Modern perceptual audio coding techniques like MP3 (MPEG Layer 3), use the human ear perception of sound to achieve compression factors of 12 with no perceptible loss of quality.
The two parts of audio compression
Audio compression consists of two parts.
1. The Encoding which transforms digital audio data into a highly compressed form called bitstream (or coded audio data). (like MP3)
2. The Decoding which reconstructs digital audio data from the bitstream. This is absolutely necessary if you want to play the bitstream on your soundcard. (like WAV)
Audio Quality
Please note that what you end up with after encoding and decoding is not the same sound file anymore. Redundant and irrelevant (for the human auditory system) parts of the sound signal. The reconstructed audio file differs from the original, but it will sound the same - more or less, depending on how much compression had been performed on it. |
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| rawkus rowan |
interesting!
thanks a lot petrus :)
RR |
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| Paul Griffiths 1 |
Yeah, what brought all that on! :D :)
Also go to www.r3mix.net for the truth about ripping & encoding too :) |
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| !_PeTrUs_! |
| quote: | Originally posted by Paul Griffiths 1
Yeah, what brought all that on! :D :)
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Well, I thought it was some interesting stuff. You don't think about that when your listening bto MP3... |
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| DjTS-NeXiLe |
| quote: | Originally posted by !_PeTrUs_!
What is MP3?
MP3 is a compression form
The name MP3 stands for Mpeg 1 Audio Layer 3 How do I play an MP3 file?
You just need an MP3 player. like Winamp, Nad MP3 Player, Unreal Player Max for other players (unix, mac, beos enz.) you can check here. Download the songs that you want to hear.
What hardware do I need for playing MP3 files?
The minimum requirement for acceptable quality is a Pentium 75.
Why to compress audio?
There is a simple reason to compress digital audio. High quality uncompressed digital audio takes a lot of space. Just 1 minute of CD quality uncompressed audio takes around 10Mb and needs around 50 min to be transmitted over a 28.8 modem!
The two parts of audio compression
Audio compression consists of two parts.
Audio Quality
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Oh my god.... all this time i didnt know how to play all these bloody .mp3 files i was downloading. I just deleted them because notpad couldnt open them ! Thanx A BUNCH Petrul !!! :p |
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| !_PeTrUs_! |
| quote: | Originally posted by DjTS-NeXiLe
Oh my god.... all this time i didnt know how to play all these bloody .mp3 files i was downloading. I just deleted them because notpad couldnt open them ! Thanx A BUNCH Petrul !!! :p |
Jaja, LOL :) :) |
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| Paul Griffiths 1 |
| quote: | Originally posted by !_PeTrUs_!
Well, I thought it was some interesting stuff. You don't think about that when your listening bto MP3... |
Well I used to, when I first started using MP3's 6-7 years ago :D
| quote: | Originally posted by DjTS-NeXiLe
Oh my god.... all this time i didnt know how to play all these bloody .mp3 files i was downloading. I just deleted them because notpad couldnt open them ! Thanx A BUNCH Petrul !!! :p |
That's a bit harsh! Ease up!...lol :)
At least !_PeTrUs_! took it the right way! |
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| rockster77 |
i've always wondered one thing about mp3's. conversion programs will allow you to convert from .wav to .mp3 and vice versa. some programs will also allow you to convert from .mp3 to .mp3 of a different bitrate. the program i use (musicmatch) allows you to convert from a lower bitrate to a higher one. i didn't think that this could be possible.
for example: you convert a .wav file to an .mp3 of 128 kbps. in doing so, information is lost. then (using musicmatch) you convert from the 128 kbps to, say, 160 kbps. as a result, the file is larger due to the added audio information.
how is this possible? how can you ragain the lost information? |
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| !_PeTrUs_! |
| It's like a garbagebag. The harder you press the stuff together, the more will fit in the bag... |
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| Paul Griffiths 1 |
| quote: | Originally posted by rockster77
for example: you convert a .wav file to an .mp3 of 128 kbps. in doing so, information is lost. then (using musicmatch) you convert from the 128 kbps to, say, 160 kbps. as a result, the file is larger due to the added audio information.
how is this possible? how can you ragain the lost information?
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Good point, but obviously quality is lost...You can do the same with a picture in a graphics program...You can resize the smaller picture to a bigger one by increasing width and height which makes the file bigger, but the version before would still be the better quality, and the larger one pixelated.
Does that put it in perspective? |
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| rockster77 |
| quote: | Originally posted by Paul Griffiths 1
Good point, but obviously quality is lost...You can do the same with a picture in a graphics program...You can resize the smaller picture to a bigger one by increasing width and height which makes the file bigger, but the version before would still be the better quality, and the larger one pixelated.
Does that put it in perspective? |
kind of...i can see why someone would want to enlarge a picture...but why would anyone want to simply enlarge an mp3 if, by doing so, the quality is diminished? |
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| DjTS-NeXiLe |
| quote: | Originally posted by !_PeTrUs_!
It's like a garbagebag. The harder you press the stuff together, the more will fit in the bag... |
Yeh Something Like that. |
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