ref: b579acef97171a057fb8f4c6fd2493690b5cf3c7
dir: /sys/lib/python/sunaudio.py/
"""Interpret sun audio headers."""
MAGIC = '.snd'
class error(Exception):
pass
def get_long_be(s):
"""Convert a 4-char value to integer."""
return (ord(s[0])<<24) | (ord(s[1])<<16) | (ord(s[2])<<8) | ord(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 = ''
return (data_size, encoding, sample_rate, channels, info)
def printhdr(file):
"""Read and print the sound header of a named file."""
hdr = gethdr(open(file, 'r'))
data_size, encoding, sample_rate, channels, info = hdr
while info[-1:] == '\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)