symbian-qemu-0.9.1-12/python-win32-2.6.1/lib/sndhdr.py
changeset 1 2fb8b9db1c86
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-win32-2.6.1/lib/sndhdr.py	Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,228 @@
+"""Routines to 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 what() calls whathdr().  (It used to also use some
+heuristics for raw data, but this doesn't work very well.)
+
+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.
+
+__all__ = ["what","whathdr"]
+
+def what(filename):
+    """Guess the type of a sound file"""
+    res = whathdr(filename)
+    return res
+
+
+def whathdr(filename):
+    """Recognize sound headers"""
+    f = open(filename, 'rb')
+    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 ***'
+
+if __name__ == '__main__':
+    test()