How to control the music playing of music fountain?

Music performance fountain is based on the program-controlled fountain. The computer decodes and encodes the audio and MIDI signals, and finally outputs the signals to the control system, so as to keep the changes of the fountain’s shape and light synchronized with the music, so as to achieve the perfect combination of the changes of the fountain’s water type, light and color with the music mood, and make the fountain The performance is more vivid and full of connotation and reflects the art of water. Music fountain: it can vary according to the height of music. Users can write their favorite music programs in the editing interface. The playing system can realize the unity of music, water and light atmosphere, and play synchronously.

1. Tone and its extraction method

Volume, tone and timbre are three subjective quantities reflecting the characteristics of sound, which together reflect the human ear’s feeling of sound, and the tone reflects the human ear’s subjective feeling of the tone. Although pitch size is also related to other factors, such as sound pressure, it depends mainly on frequency. Therefore, the higher the frequency is, the higher the tone is. Otherwise, the lower the frequency is, the lower the tone is.

The frequency determines the tone, so the detection of tone is mainly the detection of fundamental frequency, that is, the study of tone period. The system adopts the traditional autocorrelation fundamental frequency detection algorithm, which is based on the time-domain analysis theory. It has the advantages of simple, small calculation, and can directly calculate the autocorrelation function of the time-domain signal sampling value.

2. Volume signal processing

Volume reflects the amplitude of sound signal, and the amplitude of sound wave determines the volume. The volume of different music signals is different, so when the volume is used as a signal to control the operation of the water pump, there will be ups and downs of the water column. However, if the volume signal is not processed, when the amplitude of the sound wave is large, the water column will change significantly; otherwise, when the amplitude of the sound wave is small, the water column will not change significantly.