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authorGuido van Rossum <guido@python.org>1993-06-01 13:21:04 (GMT)
committerGuido van Rossum <guido@python.org>1993-06-01 13:21:04 (GMT)
commit17ed1ae163f1ca6138dead19eb327f468f9995a7 (patch)
treef138c1f243560869356c3bd763b9bd05d7137f23 /Lib/whatsound.py
parentf3f753132a863e4b6f39e749e7e5e7ab4cd6d7a1 (diff)
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* toaiff.py: import whatsound instead of sndhdr
* sndhdr.py: renamed to whatsound.py; use new aifc module for AIFF/AIFC * ftplib.py: added close() (closes without sending QUIT command) * aifc.py: documented close()
Diffstat (limited to 'Lib/whatsound.py')
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+# This module contains several routines that help recognizing sound
+# files.
+#
+# Function whathdr() recognizes various types of sound file headers.
+# It understands almost all headers that SOX can decode.
+#
+# The return tuple contains the following items, in this order:
+# - file type (as SOX understands it)
+# - sampling rate (0 if unknown or hard to decode)
+# - number of channels (0 if unknown or hard to decode)
+# - number of frames in the file (-1 if unknown or hard to decode)
+# - number of bits/sample, or 'U' for U-LAW, or 'A' for A-LAW
+#
+# If the file doesn't have a recognizable type, it returns None.
+# If the file can't be opened, IOError is raised.
+#
+# To compute the total time, divide the number of frames by the
+# sampling rate (a frame contains a sample for each channel).
+#
+# Function whatraw() calls the "whatsound" program and interprets its
+# output. You'll have to guess the sampling rate by listening though!
+#
+# Function what() calls whathdr() and if it doesn't recognize the file
+# then calls whatraw().
+#
+# Finally, the function test() is a simple main program that calls
+# what() for all files mentioned on the argument list. For directory
+# arguments it calls what() for all files in that directory. Default
+# argument is "." (testing all files in the current directory). The
+# option -r tells it to recurse down directories found inside
+# explicitly given directories.
+#
+# The file structure is top-down except that the test program and its
+# subroutine come last.
+
+
+#------------------------------------------------------#
+# Guess the type of any sound file, raw or with header #
+#------------------------------------------------------#
+
+def what(filename):
+ res = whathdr(filename)
+ if not res:
+ res = whatraw(filename)
+ return res
+
+
+#-----------------------------#
+# Guess the type of raw sound #
+#-----------------------------#
+
+def whatraw(filename):
+ # Assume it's always 1 channel, byte-sized samples
+ # Don't assume anything about the rate
+ import os
+ from stat import ST_SIZE
+ # XXX "whatsound" should be part of the distribution somehow...
+ cmd = 'whatsound ' + filename + ' 2>/dev/null'
+ pipe = os.popen(cmd, 'r')
+ data = pipe.read()
+ sts = pipe.close()
+ if sts:
+ return None
+ if data[:13] == '-t raw -b -s ':
+ type = 'sb'
+ sample_size = 8
+ elif data[:13] == '-t raw -b -u ':
+ type = 'ub'
+ sample_size = 8
+ elif data[:13] == '-t raw -b -U ':
+ type = 'ul'
+ sample_size = 'U'
+ else:
+ return None
+ try:
+ frame_count = os.stat(filename)[ST_SIZE]
+ except IOError:
+ frame_count = -1
+ return type, 0, 1, frame_count, sample_size
+
+
+#-------------------------#
+# Recognize sound headers #
+#-------------------------#
+
+def whathdr(filename):
+ f = open(filename, 'r')
+ h = f.read(512)
+ for tf in tests:
+ res = tf(h, f)
+ if res:
+ return res
+ return None
+
+
+#-----------------------------------#
+# Subroutines per sound header type #
+#-----------------------------------#
+
+tests = []
+
+def test_aifc(h, f):
+ import aifc
+ if h[:4] <> 'FORM':
+ return None
+ if h[8:12] == 'AIFC':
+ fmt = 'aifc'
+ elif h[8:12] == 'AIFF':
+ fmt = 'aiff'
+ else:
+ return None
+ f.seek(0)
+ try:
+ a = aifc.openfp(f, 'r')
+ except (EOFError, aifc.Error):
+ return None
+ return (fmt, a.getframerate(), a.getnchannels(), \
+ a.getnframes(), 8*a.getsampwidth())
+
+tests.append(test_aifc)
+
+
+def test_au(h, f):
+ if h[:4] == '.snd':
+ f = get_long_be
+ elif h[:4] in ('\0ds.', 'dns.'):
+ f = get_long_le
+ else:
+ return None
+ type = 'au'
+ hdr_size = f(h[4:8])
+ data_size = f(h[8:12])
+ encoding = f(h[12:16])
+ rate = f(h[16:20])
+ nchannels = f(h[20:24])
+ sample_size = 1 # default
+ if encoding == 1:
+ sample_bits = 'U'
+ elif encoding == 2:
+ sample_bits = 8
+ elif encoding == 3:
+ sample_bits = 16
+ sample_size = 2
+ else:
+ sample_bits = '?'
+ frame_size = sample_size * nchannels
+ return type, rate, nchannels, data_size/frame_size, sample_bits
+
+tests.append(test_au)
+
+
+def test_hcom(h, f):
+ if h[65:69] <> 'FSSD' or h[128:132] <> 'HCOM':
+ return None
+ divisor = get_long_be(h[128+16:128+20])
+ return 'hcom', 22050/divisor, 1, -1, 8
+
+tests.append(test_hcom)
+
+
+def test_voc(h, f):
+ if h[:20] <> 'Creative Voice File\032':
+ return None
+ sbseek = get_short_le(h[20:22])
+ rate = 0
+ if 0 <= sbseek < 500 and h[sbseek] == '\1':
+ ratecode = ord(h[sbseek+4])
+ rate = int(1000000.0 / (256 - ratecode))
+ return 'voc', rate, 1, -1, 8
+
+tests.append(test_voc)
+
+
+def test_wav(h, f):
+ # 'RIFF' <len> 'WAVE' 'fmt ' <len>
+ if h[:4] <> 'RIFF' or h[8:12] <> 'WAVE' or h[12:16] <> 'fmt ':
+ return None
+ style = get_short_le(h[20:22])
+ nchannels = get_short_le(h[22:24])
+ rate = get_long_le(h[24:28])
+ sample_bits = get_short_le(h[34:36])
+ return 'wav', rate, nchannels, -1, sample_bits
+
+tests.append(test_wav)
+
+
+def test_8svx(h, f):
+ if h[:4] <> 'FORM' or h[8:12] <> '8SVX':
+ return None
+ # Should decode it to get #channels -- assume always 1
+ return '8svx', 0, 1, 0, 8
+
+tests.append(test_8svx)
+
+
+def test_sndt(h, f):
+ if h[:5] == 'SOUND':
+ nsamples = get_long_le(h[8:12])
+ rate = get_short_le(h[20:22])
+ return 'sndt', rate, 1, nsamples, 8
+
+tests.append(test_sndt)
+
+
+def test_sndr(h, f):
+ if h[:2] == '\0\0':
+ rate = get_short_le(h[2:4])
+ if 4000 <= rate <= 25000:
+ return 'sndr', rate, 1, -1, 8
+
+tests.append(test_sndr)
+
+
+#---------------------------------------------#
+# Subroutines to extract numbers from strings #
+#---------------------------------------------#
+
+def get_long_be(s):
+ return (ord(s[0])<<24) | (ord(s[1])<<16) | (ord(s[2])<<8) | ord(s[3])
+
+def get_long_le(s):
+ return (ord(s[3])<<24) | (ord(s[2])<<16) | (ord(s[1])<<8) | ord(s[0])
+
+def get_short_be(s):
+ return (ord(s[0])<<8) | ord(s[1])
+
+def get_short_le(s):
+ return (ord(s[1])<<8) | ord(s[0])
+
+
+#--------------------#
+# Small test program #
+#--------------------#
+
+def test():
+ import sys
+ recursive = 0
+ if sys.argv[1:] and sys.argv[1] == '-r':
+ del sys.argv[1:2]
+ recursive = 1
+ try:
+ if sys.argv[1:]:
+ testall(sys.argv[1:], recursive, 1)
+ else:
+ testall(['.'], recursive, 1)
+ except KeyboardInterrupt:
+ sys.stderr.write('\n[Interrupted]\n')
+ sys.exit(1)
+
+def testall(list, recursive, toplevel):
+ import sys
+ import os
+ for filename in list:
+ if os.path.isdir(filename):
+ print filename + '/:',
+ if recursive or toplevel:
+ print 'recursing down:'
+ import glob
+ names = glob.glob(os.path.join(filename, '*'))
+ testall(names, recursive, 0)
+ else:
+ print '*** directory (use -r) ***'
+ else:
+ print filename + ':',
+ sys.stdout.flush()
+ try:
+ print what(filename)
+ except IOError:
+ print '*** not found ***'