【发布时间】：2014-07-21 17:36:03
【问题描述】：
我有一个在按键上播放正弦波音符的程序。这个想法是模拟仪器。我添加了一些代码来调整音量，但是每次播放新音符时，音量的这个值似乎都会刷新。如何调整，以便在按键调整音量时，音量保持在此值，直到再次更改？
import pygame
from pygame.locals import *
import math
import numpy
pygame.init()
bits = 16
pygame.mixer.pre_init(44100, -bits, 2)
def generate_sound(freq):
volume = 0.5
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(volume)
for s in range(n_samples):
t = float(s)/sample_rate # time in seconds
buf[s][0] = int(round(max_sample*math.sin(2*math.pi*freq*t))) # left
buf[s][1] = int(round(max_sample*math.sin(2*math.pi*freq*t))) # right
return pygame.sndarray.make_sound(buf)
size = (1200, 720)
screen = pygame.display.set_mode(size, pygame.HWSURFACE | pygame.DOUBLEBUF)
duration = 2.0 # in seconds
sample_rate = 44100
n_samples = int(round(duration*sample_rate))
#lower
sound_130_81 = generate_sound(130.81) #C
_running = True
while _running:
for event in pygame.event.get():
if event.type == pygame.QUIT:
_running = False
if event.type == KEYDOWN:
#Volume control
if event.key == K_1:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.1)
elif event.key == K_2:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.2)
elif event.key == K_3:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.3)
elif event.key == K_4:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.4)
elif event.key == K_5:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.5)
elif event.key == K_6:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.6)
elif event.key == K_7:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.7)
elif event.key == K_8:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.8)
elif event.key == K_9:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.9)
elif event.key == K_0:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(1.0)
elif event.key == K_BACKSPACE:
for i in range(pygame.mixer.get_num_channels()):
c = pygame.mixer.Channel(i)
c.set_volume(0.0)
volume = c.get_volume()
if event.key == K_ESCAPE:
_running = False
#lower notes DOWN
elif event.key == K_z:
sound_130_81.play(-1)
if event.type == KEYUP:
#lower notes UP
if event.key == K_z:
sound_130_81.fadeout(350) #fade sound by .35 seconds
pygame.quit()
【问题讨论】：
-
删除所有无关代码并放弃一个精简的示例确实会有所帮助，足以证明问题。有关详细信息，请参阅MCVE。
-
我不确定有多少是相关的，因为相关部分都在整个代码中，而不仅仅是一个部分
-
请点击 MCVE 的链接，它比我在简短的评论中解释得更好。但是你可以把它分解成相关的部分，即使它们都在整个代码中，并且只需要足够的脚手架来连接它们。例如，显然您不需要对
generate_sound进行几十次调用、几十个关键处理程序等来演示问题。
标签： python audio numpy pygame volume