cpython/Lib/sunaudio.py

49 lines
1.3 KiB
Python

"""Interpret sun audio headers."""
MAGIC = b'.snd'
class error(Exception):
pass
def get_long_be(s):
"""Convert a 4-byte value to integer."""
return (s[0]<<24) | (s[1]<<16) | (s[2]<<8) | s[3]
def gethdr(fp):
"""Read a sound header from an open file."""
if fp.read(4) != MAGIC:
raise error, 'gethdr: bad magic word'
hdr_size = get_long_be(fp.read(4))
data_size = get_long_be(fp.read(4))
encoding = get_long_be(fp.read(4))
sample_rate = get_long_be(fp.read(4))
channels = get_long_be(fp.read(4))
excess = hdr_size - 24
if excess < 0:
raise error, 'gethdr: bad hdr_size'
if excess > 0:
info = fp.read(excess)
else:
info = b''
return (data_size, encoding, sample_rate, channels, info)
def printhdr(file):
"""Read and print the sound header of a named file."""
f = open(file, 'rb')
try:
hdr = gethdr(f)
finally:
f.close()
data_size, encoding, sample_rate, channels, info = hdr
while info.endswith(b'\0'):
info = info[:-1]
print('File name: ', file)
print('Data size: ', data_size)
print('Encoding: ', encoding)
print('Sample rate:', sample_rate)
print('Channels: ', channels)
print('Info: ', repr(info))