How to play a sound on a computer

My goal is to simulate a variety of musical instruments on the computer and use the speaker to play the sound of the Instrument in a realistic manner. Everything starts hard. The first step is to let the computer play a simple syllable, which is the same as helloworld when learning C language.

(1) first download the rtmidi library, which is an open source audio and audio library. Rtmidi is
A set of C ++ classes (rtmidiin, rtmidiout and
API-specific classes) that provides a common API (Application Programming Interface) for realtime MIDI input/output audio SS Linux (ALSA & Jack), Macintosh OS X (coremidi & Jack ), and windows (Multimedia Library & kernel streaming) operating systems. rtmidi significantly
Simplifies the process of interacting with computer MIDI hardware and software. it was designed with the following goals: rtmidi is an open-source Real-Time MIDI Player Library written in C ++. It can run on MacOSX, Linux, and windows.

: Http://www.music.mcgill.ca /~ Gary/rtmidi/release/rtmidi-2.0.1.tar.gz; the latest version is 2.0.1.

(2) Open the downloaded file, decompress it to a folder, open the test folder, and use vs to open the *. sln file in it. Then click "run". A sound is played in the audio.

(3) However, the example provided by the database itself is too complex to be suitable for beginners. So I wrote a new helloworld (you can also find the following source code on the official website). The program is as follows:

(4) If you are not familiar with the terms, read several other blog posts. Especially: http://blog.csdn.net/jia_zhengshen/article/details/8777071

# Include <iostream> # include <cstdlib> # include "rtmidi. H "int main () {rtmidiout * midiout = new rtmidiout (); STD: vector <unsigned char> message; // check available ports. unsigned int nports = midiout-> getportcount (); If (nports = 0) {// you can check the number of available MIDI interfaces. What does 0 mean? Not explained. STD: cout <"no ports available! \ N "; goto cleanup; // although the GOTO statement is rarely used, there is so little code here, You can always score the two or three bad noodles} // open first available port. midiout-> openport (0); // open the first MIDI port. // Send out a series of MIDI messages. // program change: 192, 5 message. push_back (192); // 192 = 0xc0, what does this mean? Let's look at the http://blog.csdn.net/jia_zhengshen/article/details/8777071. Here we use an article to explain the message. push_back (5); midiout-> sendmessage (& message); // control change: 176, 7,100 (volume) Message [0] = 176; // adjust the volume. // 176 = b0; view the preceding URL description. It is too complicated. Although the code is simple, it is not easy to explain it clearly. Message [1] = 7; message. push_back (100); // push_back. Message [2] may cause memory overflow. Midiout-> sendmessage (& message); // note on: 144, 64, 90 message [0] = 144; // start playing message [1] = 64; // The message of the 64-bit PLAYING code [2] = 90; // The speed is 90, and the highest position is 7fh midiout-> sendmessage (& message); sleep (500 ); // platform-dependent... see example in tests directory. // note off: 128, 64, 40 message [0] = 128; // stop playing message [1] = 64; // stop the 64-bit note message [2] = 40; // The speed is 40 midiout-> sendmessage (& message); // clean up cleanup: delete midiout; getchar (); return 0 ;}

These codes are relatively simple. Suitable for beginners. Comment out all the code in the sysextest. cpp file in the test project and copy it into the code. A note will be output through audio.

The explanation is complete. This article is based on http://my.csdn.net/jia_zhengshensource.