Copyright Michael Karbo, Denmark, Europe.


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    Chapter 9. More about mp3

    Sonyís compression algorithms work really well but they can only be used for one kind of sound device, which is the MiniDisc. The mp3 format is quite different, and is gradually being used everywhere Ė in stereo systems, in transportable players, in certain cameras, in computers, etc. The format is very flexible.

    Let us look a little closer at some of the options an mp3 gives.

    Figure 47. A Mp3 player with 20 GB hard disk.

    German compression

    Mp3 stands for MPEG Audio Layer 3, and the German research institute Fraun≠hofer originally developed the format. Several companies have tried to take out a patent for mp3 but it hasnít been respected. So, in practice, mp3 is used everywhere.

    The mp3 standard describes what a sound file should look like, but not how it is produced!! Which is why, in principle, anyone can produce an algorithm, which compresses sound into mp3.

    Where CD music fills up circa 1,4 mega≠≠bits per second (2 X 44100 X 16 bit/second), mp3 compresses the amount of bits between 5 and 20 times, dependent, however, on the selected bit rate (see Figure 48).

    Compression is, as described earlier, of a psycho-acoustical nature. The sound signals that the human ear cannot hear anyway are simply removed. Another compression principle consists of simplifying the sound quality from stereo to mono in the low ranges, where the human ear cannot register the direction of the sound. Up to 30 different compression mechanisms can be a part of the mp3 system, which can come in completely different designs depending on the manufacturer.

    But regardless of which method is used to produce the mp3 file (which is called ripping), it can be played on any sort of mp3 compatible player.

    What is smart is that you can burn hundreds of mp3 files on a completely ordinary CD. In this way 10 or even more music CDS can be squeezed onto a burnt disk.

    Figure 48.Select a quality before the CD is ripped

    It is very easy to make mp3 files. You pick up a ripper on the net. Which can be, for example, the program Musicmatch, which has its own particular look (which can, incidentally, be altered with different skins), but you will soon get used to this.

    Figure 49. Musicmatch, which is brilliant for ripping.

    You put a CD-ROM in the computerís drive and open the ripper software. The program will then read a code on the CD, which is used to identify the CD with the artistís name, the albums title and the titles of the individual tracks. This information can be fetched from the Internet and it is done quite automatically, as long as the computer is online.

    Figure 50. List of tracks, which are ready to be ripped.

    Then you ask the program to rip the CDís single tracks. This is done relatively quickly Ė dependent on the speed of the CD drive; it might take up to 10 minutes to rip a whole CD. The individual tracks are stored on the hard disk in a folder, which is given a name according to the albumís title and artist. Easy and elegant!

    Figure 51.If your computer is connected to the Internet, then the ripper can automatically download information about the album.

    Illegal copying

    Mp3 is a controversial technology. In some countries, ripping CDs has been forbidden and in others it is allowed. Laws are often changed. You yourself will have to take a position on what is allowed.

    The mp3 format has been in focus in big lawsuits involving the music branch and different websites. The online service Napster was at one time talked about a lot. Napster was a big network for users interested in music with Internet connections. Every one of the users could make their mp3 files available for each other. The copying took place from hard disk to hard disk. Napster itself only contained information about which melodies could be found on the individual userís hard disks. It was a brilliant concept, which was closed at the request of the music branch.

    Figure 52. Napster had millions of users when it was at its highest in the year 2000.

    The Internet is still full of pirate recordings in mp3. You can find any CD at all, if you can be bothered to look for it. There are also, however, legal websites (like www.mp3.com), which are full of lawful mp3 music.

    De-ripping and playlists

    If you want to burn a copy of a CD with the help of mp3 files, it is very easy. I have used Adaptec Easy CD Creator, which works without reproach. In this way it is easy to use mp3 files as back up for CDs.

    If you need a copy for the carís stereo system then you can burn it from the mp3s. You have to, of course, be aware of the fact that, the mp3s are compressed, so the sound quality will not be quite as good as on the original CD. But very few will notice much difference.

    Another smart facility is the so-called play≠lists. These are small text files with the surname M3U, which contain the file names (maybe with path information) of a number of mp3 files. Most players can play all the melodies on the list one after the other continuously. Many people use this for parties, where the music plays all evening. All in all the mp3 format is immensely practical. The sound quality is, of course, not satisfactory, if you want the best of the best. But for daily use, it really is very smart. With a litte mp3 compatible Ēghetto≠blasterĒ (as in Figure 18 on page 3) and a couple of active loudspeakers of good quality, you will have a complete, compact and flexible stereo system for relatively little money.

    Another possibility is a stereo system, which is designed to play Internet radio and mp3 files directly from the hard disk. The system is just connected to the computerís network and if you have a permanent Internet connection (in the form of ADSL, for example), then you can alternate between the hundreds of radio channels found on the Internet.

    Figure 53. Philips Streamium system, which is directly connected to a computer and the Internet.


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