Question

尝试将以下内容转换为def，但做一些可能不允许的事情......我做错了什么，怎么能做得更好？

# Same for both
import alsaaudio
l_input = alsaaudio.PCM(alsaaudio.PCM_CAPTURE, alsaaudio.PCM_NONBLOCK, card='default')
r_input = alsaaudio.PCM(alsaaudio.PCM_CAPTURE, alsaaudio.PCM_NONBLOCK, card='default')
#

l, data = l_input.read()
if l > 0:
  # transform data to logarithmic scale
  lin_vu = (math.log(float(max(audioop.max(data, 2),1)))-log_lo)/(log_hi-log_lo)
  # Calculate value
  lin_vu = (min(max(int(lin_vu*15),0),15))
l, data = r_input.read()
if l > 0:
  # transform data to logarithmic scale
  rin_vu = (math.log(float(max(audioop.max(data, 2),1)))-log_lo)/(log_hi-log_lo)
  # Calculate value
  rin_vu = (min(max(int(rin_vu*15),0),15))

我希望能做到这样的事情，因为我需要阅读4个值，而不仅仅是列出的两个值：

def readvu( src ):
  l, data = src.read()
  if l > 0:
    # transform data to logarithmic scale
    l_vu = (math.log(float(max(audioop.max(data, 2),1)))-log_lo)/(log_hi-log_lo)
    # Calculate value
    l_vu = (min(max(int(l_vu*15),0),15))

lin_vu = readvu( 'l_input' );
rin_vu = readvu( 'r_input' );

但是这会产生上述错误......

Answer 1

解决方案很明显：如果您致电readvu('l_input')，则src变为'l_input'且.read()将失败。

电话应该像

lin_vu = readvu(l_input)
rin_vu = readvu(r_input)

传递实际变量，而不是字符串。

Answer 2

思想的转变让我想到了以下几点：

# Convert log scale, calculate value & max
def vu_log(data,vu_max,max_t):
  # transform data to logarithmic scale
  vu = (math.log(float(max(audioop.max(data, 2),1)))-log_lo)/(log_hi-log_lo)
  # Calculate value
  vu = (min(max(int(vu*15),0),15))
  if vu >= vu_max:
    max_t = (3 * vu_fps) # keep max for 3 seconds
    vu_max = vu
  else:
    max_t = max(0, max_t-1) # Reduce max timer by 1 until 0
  return (vu,vu_max,max_t);

# Fetch Left input VU from ALSA
l, data = l_input.read()
if l > 0:
  # Transform data to logarithmic scale and calculate value
  lin = vu_log(data,lin_max,lin_t)
  lin_vu = lin[0]  # Desired value
  lin_max = lin[1] # Maximum value (last 3 sec)
  lin_t = lin[2]   # Used for tracking age of lin_max

总是欢迎建设性的建议......：）

Python def（AttributeError：'str'对象没有属性'read'）

2 个答案: