如何使用pygame.midi发送“延音踏板” MIDI信号？

Question

Simple midi signals can be invoked by the note_on() or note_off() methods, but I couldn't find a way to send the 'sustain pedal' midi signal using pygame.midi . Is there any conventional way to do that?

Answer 1

Unfortunately, there is no implementation of the sustain pedal in pygame.midi (or most other commonly used Python-MIDI libraries), so doing it natively from the Pygame module is out of the question.

However, you may be able to work around this by re-structuring your code a little. If you can use a specific key (or an event) in place of what I assume to be a physical sustain pedal (after all, most MIDI sustain pedals are simple switches ), you can pull off something similar to a sustain. For example:

import pygame
from pygame.locals import *

# Midi init and setup, other code, etc...
# device_input = pygame.midi.Input(device_id)

sustain = False

# We will use the spacebar in place of a pedal in this case.

while 1:
    for event in pygame.event.get():
        # You can also use other events in place of KEYDOWN/KEYUP events.
        if event.type == KEYDOWN and event.key == K_SPACE:
            sustain = True
        elif event.type == KEYUP and event.key == K_SPACE:
            sustain = False
    # ...
    for i in device_input:
        if sustain:
            # Remove all MIDI key-up events here

    # Then play sounds or process midi input accordingly afterwards

Answer 2

The specification defines the sustain pedal as controller 64 , so you have to send a control change message.

pygame.midi does not have a special function for that, so you have to send the raw bytes:

write_short(0xb0 + channel, 64, 127 if pressed else 0);