What is the function of MIDI in mobile phones?

1. It has all the functions of an ordinary mobile phone and can make normal calls, send text messages and other mobile applications.

2. Have the ability to wirelessly access the Internet, that is, it needs to support GPRS under the GSM network or CDMA 1X or 3G network under the CDMA network. ?

3. Equipped with PDA functions, including PIM (Personal Information Management), calendar notes, task arrangements, multimedia applications, and web browsing.

4. Have an open operating system.

Extended information

Main functions

One of the advantages of MIDI technology is that the amount of data it sends and stores in the computer is quite small, one contains one minute. A stereo digital audio file requires about 10 megabytes (equivalent to the capacity of 7 floppy disks) of storage space.

However, a one-minute MIDI music file is only 2KB. This also means that the data transfer between the instrument and the computer is very low, meaning that even the most expensive computers can run and record MIDI files.

By using MIDI sequencers, the cost of composition and orchestration can be greatly reduced, and there is no need for a huge band to perform. The music director can compose the music and match it with instruments at home. There is no need for a big band to record part by part in the studio.

You only need to use the computer or keyboard in the recording studio to input all the information of each part of the MIDI sequencer stored in the keyboard into the recorder.

The design goal of the MIDI program is to convert the music or music pieces to be played into MIDI control language according to its rhythm, speed, technical measures and other requirements, so that it can be controlled by these MIDI instructions. Under this method, various sound sources can play the required sound at the appropriate time point with specified timbre, duration, intensity, etc.

In the recording system, these sounds must also be controlled and recorded. The scope that MIDI is applicable to is only electroacoustic music or music that simulates other musical instruments.

The emergence and application of MIDI technology has greatly reduced the cost of music creation, saved a lot of band players' expenses, shortened the working time in the recording studio, and improved work efficiency. The composition, orchestration, and recording of an entire TV show require only one music director and one sound engineer to complete the composition (arrangement), orchestration, performance, and recording of the instrumental music.

Technical Principle

MIDI is the abbreviation of Musical Instrument Digital Interface. The direct translation means musical instrument digital interface. MIDI can be understood as a protocol, a standard, or It is a technology, but it does not just refer to a certain hardware device.

MIDI is just a communication standard. It was established by electronic musical instrument manufacturers to determine the method for computer music programs, synthesizers and other electronic audio equipment to exchange information and control signals with each other. The cable used to connect various MIDI devices is a 5-core cable, which is usually also called a MIDI cable.

The MIDI system is actually a composition, orchestration, and electronic simulation performance system. The data transferred from one MIDI device to another MIDI device is MIDI information. MIDI data is not a digital audio waveform, but a music code or electronic score.

MIDI is a unified communication protocol between electronic musical instruments and between electronic musical instruments and computers. Many popular games and entertainment software have many MIDI format music files with MID and RMI extensions.

MIDI file is a descriptive "music language" that describes the music information to be played in bytes. For example, at a certain moment, what instrument is used, what note it starts with, what tone it ends with, what accompaniment is added, etc. The MIDI file itself does not contain waveform data, so the MIDI file is very small.

In order for MIDI to form computer music, it must be synthesized. Early ISA sound cards commonly used FM synthesis, that is, "frequency modulation". It uses the principle of sound oscillation to synthesize MIDI. Due to the limitations of the technology itself, the effect is difficult to satisfy.

Most sound cards use wavetable synthesis, which first samples all the sounds that can be produced by various real musical instruments (including various ranges and tones) and stores them as a wavetable file.

Reference material: Baidu Encyclopedia-MIDI