Tutorials/MIDI on Linux/it

Informazione

MIDI è un insieme di tecnologie correlate alla descrizione e alla trasmissione di dati musicali, ma non è un formato audio digitale. Per utilizzare la maggior parte dei programmi MIDI su Linux, così come su qualsiasi altro sistema operativo, è necessario un sintetizzatore MIDI.

Un sintetizzatore MIDI converte gli eventi MIDI in suoni. Il sintetizzatore può essere un dispositivo hardware esterno o integrato in una scheda audio. Può anch'essere un sintetizzatore software, cioè un programma.

Esistono file MIDI con estensione .MID contenenti musica in formato dati MIDI. Una spiegazione di questo può essere fatta in termini culinari. Ascoltare musica su un Compact Disc è simile a mangiare in un ristorante e l'MP3 potrebbe essere paragonato al fast food. Un file MIDI è come una ricetta: devi prendere gli ingredienti giusti ed utilizzare utensili da cucina. Invece di forno, pentole e padelle, utilizzerai i sintetizzatori MIDI. Come ogni buon esperto ed utente Linux vorrai cambiare la ricetta e gli ingredienti. Allora fallo! In KMid puoi aprire la finestra "canali" e sostituire il pianoforte con una chitarra o qualsiasi altro strumento tu voglia.

Sintetizzatori MIDI esterni

These are musical instruments that can be connected to the computer, or to other instruments through MIDI cables. To do this, your computer must have a MIDI interface. There are sound cards with MIDI interfaces, and also USB adapters supported by ALSA with the corresponding kernel module. There are even MIDI instruments that can be connected directly to your computer via USB. In any case, you should check that the MIDI interface model is supported by ALSA at the ALSA project site

In summary, this option will need:

• MIDI Interface
• ALSA Driver for the MIDI interface
• MIDI Cables

Hardware Synthesizer Sound Cards

Some sound cards, such as the ones manufactured by Creative Labs (SB AWE, Sound Blaster Live! and Audigy) have a MIDI synthesizer using wave-table sound samples as a synthesis method. These samples are being loaded into the sound card before using MIDI software, preferably at system boot. If you own one of these cards:

• In addition to ALSA, also install the software package awesfx which includes the sound samples loader, ALSA scripts and udev rules to automatically load on system boot.
• Install SoundFont files provided by the manufacturer or other alternative SF2 files in /usr/share/sounds/sf2.
• Edit the configuration file /etc/sysconfig/sound. On the value for the key SOUNDFONT_FILES, provide the name of one or several SF2 files that must be loaded on system startup. The file names and locations may vary from one distribution to another, these instructions apply to openSUSE.

SoundFont filescan also be loaded manually. Read the manual of asfxload for more information.

Software Synthesizers

The classic software synthesizer for Linux is TiMidity++, but the latest release is from 2004. It requires sound samples in GUS or SF2 format. It can be used independently as a player, but if you want to use it in conjunction with other ALSA sequencer compatible programs, you must provide the "-iA" option, for example:

timidity -iA

Another software synthesizer, with modern and modular design and active maintenance is FluidSynth. It uses sound samples in SF2 format, and has a friendly graphic interface called QSynth. You can also run it from the command line, for example:

fluidsynth -a alsa /usr/share/sound/sf2/soundfont.sf2

or:

fluidsynth -a pulseaudio /usr/share/sound/sf2/soundfont.sf2

The graphical configuration of QSynth is quite simple. See the following example screenshots.

SoundFont Files

These files represent the fish, meat and vegetables in your MIDI recipe. Here are some recommendations.

• SoundFonts Collections: http://www.hammersound.net
• General User GS, by S.Christian Collins.
  • Available at packman repositories for openSUSE.
• FluidR3. A big, high quality SoundFont.
  • Available for openSUSE packaged by Jan Engelhardt.
  • There is also a Debian package.