| 4710c53d |
1 | """Routines to help recognizing sound files.\r |
| 2 | \r |
| 3 | Function whathdr() recognizes various types of sound file headers.\r |
| 4 | It understands almost all headers that SOX can decode.\r |
| 5 | \r |
| 6 | The return tuple contains the following items, in this order:\r |
| 7 | - file type (as SOX understands it)\r |
| 8 | - sampling rate (0 if unknown or hard to decode)\r |
| 9 | - number of channels (0 if unknown or hard to decode)\r |
| 10 | - number of frames in the file (-1 if unknown or hard to decode)\r |
| 11 | - number of bits/sample, or 'U' for U-LAW, or 'A' for A-LAW\r |
| 12 | \r |
| 13 | If the file doesn't have a recognizable type, it returns None.\r |
| 14 | If the file can't be opened, IOError is raised.\r |
| 15 | \r |
| 16 | To compute the total time, divide the number of frames by the\r |
| 17 | sampling rate (a frame contains a sample for each channel).\r |
| 18 | \r |
| 19 | Function what() calls whathdr(). (It used to also use some\r |
| 20 | heuristics for raw data, but this doesn't work very well.)\r |
| 21 | \r |
| 22 | Finally, the function test() is a simple main program that calls\r |
| 23 | what() for all files mentioned on the argument list. For directory\r |
| 24 | arguments it calls what() for all files in that directory. Default\r |
| 25 | argument is "." (testing all files in the current directory). The\r |
| 26 | option -r tells it to recurse down directories found inside\r |
| 27 | explicitly given directories.\r |
| 28 | """\r |
| 29 | \r |
| 30 | # The file structure is top-down except that the test program and its\r |
| 31 | # subroutine come last.\r |
| 32 | \r |
| 33 | __all__ = ["what","whathdr"]\r |
| 34 | \r |
| 35 | def what(filename):\r |
| 36 | """Guess the type of a sound file"""\r |
| 37 | res = whathdr(filename)\r |
| 38 | return res\r |
| 39 | \r |
| 40 | \r |
| 41 | def whathdr(filename):\r |
| 42 | """Recognize sound headers"""\r |
| 43 | f = open(filename, 'rb')\r |
| 44 | h = f.read(512)\r |
| 45 | for tf in tests:\r |
| 46 | res = tf(h, f)\r |
| 47 | if res:\r |
| 48 | return res\r |
| 49 | return None\r |
| 50 | \r |
| 51 | \r |
| 52 | #-----------------------------------#\r |
| 53 | # Subroutines per sound header type #\r |
| 54 | #-----------------------------------#\r |
| 55 | \r |
| 56 | tests = []\r |
| 57 | \r |
| 58 | def test_aifc(h, f):\r |
| 59 | import aifc\r |
| 60 | if h[:4] != 'FORM':\r |
| 61 | return None\r |
| 62 | if h[8:12] == 'AIFC':\r |
| 63 | fmt = 'aifc'\r |
| 64 | elif h[8:12] == 'AIFF':\r |
| 65 | fmt = 'aiff'\r |
| 66 | else:\r |
| 67 | return None\r |
| 68 | f.seek(0)\r |
| 69 | try:\r |
| 70 | a = aifc.openfp(f, 'r')\r |
| 71 | except (EOFError, aifc.Error):\r |
| 72 | return None\r |
| 73 | return (fmt, a.getframerate(), a.getnchannels(), \\r |
| 74 | a.getnframes(), 8*a.getsampwidth())\r |
| 75 | \r |
| 76 | tests.append(test_aifc)\r |
| 77 | \r |
| 78 | \r |
| 79 | def test_au(h, f):\r |
| 80 | if h[:4] == '.snd':\r |
| 81 | f = get_long_be\r |
| 82 | elif h[:4] in ('\0ds.', 'dns.'):\r |
| 83 | f = get_long_le\r |
| 84 | else:\r |
| 85 | return None\r |
| 86 | type = 'au'\r |
| 87 | hdr_size = f(h[4:8])\r |
| 88 | data_size = f(h[8:12])\r |
| 89 | encoding = f(h[12:16])\r |
| 90 | rate = f(h[16:20])\r |
| 91 | nchannels = f(h[20:24])\r |
| 92 | sample_size = 1 # default\r |
| 93 | if encoding == 1:\r |
| 94 | sample_bits = 'U'\r |
| 95 | elif encoding == 2:\r |
| 96 | sample_bits = 8\r |
| 97 | elif encoding == 3:\r |
| 98 | sample_bits = 16\r |
| 99 | sample_size = 2\r |
| 100 | else:\r |
| 101 | sample_bits = '?'\r |
| 102 | frame_size = sample_size * nchannels\r |
| 103 | return type, rate, nchannels, data_size//frame_size, sample_bits\r |
| 104 | \r |
| 105 | tests.append(test_au)\r |
| 106 | \r |
| 107 | \r |
| 108 | def test_hcom(h, f):\r |
| 109 | if h[65:69] != 'FSSD' or h[128:132] != 'HCOM':\r |
| 110 | return None\r |
| 111 | divisor = get_long_be(h[128+16:128+20])\r |
| 112 | return 'hcom', 22050//divisor, 1, -1, 8\r |
| 113 | \r |
| 114 | tests.append(test_hcom)\r |
| 115 | \r |
| 116 | \r |
| 117 | def test_voc(h, f):\r |
| 118 | if h[:20] != 'Creative Voice File\032':\r |
| 119 | return None\r |
| 120 | sbseek = get_short_le(h[20:22])\r |
| 121 | rate = 0\r |
| 122 | if 0 <= sbseek < 500 and h[sbseek] == '\1':\r |
| 123 | ratecode = ord(h[sbseek+4])\r |
| 124 | rate = int(1000000.0 / (256 - ratecode))\r |
| 125 | return 'voc', rate, 1, -1, 8\r |
| 126 | \r |
| 127 | tests.append(test_voc)\r |
| 128 | \r |
| 129 | \r |
| 130 | def test_wav(h, f):\r |
| 131 | # 'RIFF' <len> 'WAVE' 'fmt ' <len>\r |
| 132 | if h[:4] != 'RIFF' or h[8:12] != 'WAVE' or h[12:16] != 'fmt ':\r |
| 133 | return None\r |
| 134 | style = get_short_le(h[20:22])\r |
| 135 | nchannels = get_short_le(h[22:24])\r |
| 136 | rate = get_long_le(h[24:28])\r |
| 137 | sample_bits = get_short_le(h[34:36])\r |
| 138 | return 'wav', rate, nchannels, -1, sample_bits\r |
| 139 | \r |
| 140 | tests.append(test_wav)\r |
| 141 | \r |
| 142 | \r |
| 143 | def test_8svx(h, f):\r |
| 144 | if h[:4] != 'FORM' or h[8:12] != '8SVX':\r |
| 145 | return None\r |
| 146 | # Should decode it to get #channels -- assume always 1\r |
| 147 | return '8svx', 0, 1, 0, 8\r |
| 148 | \r |
| 149 | tests.append(test_8svx)\r |
| 150 | \r |
| 151 | \r |
| 152 | def test_sndt(h, f):\r |
| 153 | if h[:5] == 'SOUND':\r |
| 154 | nsamples = get_long_le(h[8:12])\r |
| 155 | rate = get_short_le(h[20:22])\r |
| 156 | return 'sndt', rate, 1, nsamples, 8\r |
| 157 | \r |
| 158 | tests.append(test_sndt)\r |
| 159 | \r |
| 160 | \r |
| 161 | def test_sndr(h, f):\r |
| 162 | if h[:2] == '\0\0':\r |
| 163 | rate = get_short_le(h[2:4])\r |
| 164 | if 4000 <= rate <= 25000:\r |
| 165 | return 'sndr', rate, 1, -1, 8\r |
| 166 | \r |
| 167 | tests.append(test_sndr)\r |
| 168 | \r |
| 169 | \r |
| 170 | #---------------------------------------------#\r |
| 171 | # Subroutines to extract numbers from strings #\r |
| 172 | #---------------------------------------------#\r |
| 173 | \r |
| 174 | def get_long_be(s):\r |
| 175 | return (ord(s[0])<<24) | (ord(s[1])<<16) | (ord(s[2])<<8) | ord(s[3])\r |
| 176 | \r |
| 177 | def get_long_le(s):\r |
| 178 | return (ord(s[3])<<24) | (ord(s[2])<<16) | (ord(s[1])<<8) | ord(s[0])\r |
| 179 | \r |
| 180 | def get_short_be(s):\r |
| 181 | return (ord(s[0])<<8) | ord(s[1])\r |
| 182 | \r |
| 183 | def get_short_le(s):\r |
| 184 | return (ord(s[1])<<8) | ord(s[0])\r |
| 185 | \r |
| 186 | \r |
| 187 | #--------------------#\r |
| 188 | # Small test program #\r |
| 189 | #--------------------#\r |
| 190 | \r |
| 191 | def test():\r |
| 192 | import sys\r |
| 193 | recursive = 0\r |
| 194 | if sys.argv[1:] and sys.argv[1] == '-r':\r |
| 195 | del sys.argv[1:2]\r |
| 196 | recursive = 1\r |
| 197 | try:\r |
| 198 | if sys.argv[1:]:\r |
| 199 | testall(sys.argv[1:], recursive, 1)\r |
| 200 | else:\r |
| 201 | testall(['.'], recursive, 1)\r |
| 202 | except KeyboardInterrupt:\r |
| 203 | sys.stderr.write('\n[Interrupted]\n')\r |
| 204 | sys.exit(1)\r |
| 205 | \r |
| 206 | def testall(list, recursive, toplevel):\r |
| 207 | import sys\r |
| 208 | import os\r |
| 209 | for filename in list:\r |
| 210 | if os.path.isdir(filename):\r |
| 211 | print filename + '/:',\r |
| 212 | if recursive or toplevel:\r |
| 213 | print 'recursing down:'\r |
| 214 | import glob\r |
| 215 | names = glob.glob(os.path.join(filename, '*'))\r |
| 216 | testall(names, recursive, 0)\r |
| 217 | else:\r |
| 218 | print '*** directory (use -r) ***'\r |
| 219 | else:\r |
| 220 | print filename + ':',\r |
| 221 | sys.stdout.flush()\r |
| 222 | try:\r |
| 223 | print what(filename)\r |
| 224 | except IOError:\r |
| 225 | print '*** not found ***'\r |
| 226 | \r |
| 227 | if __name__ == '__main__':\r |
| 228 | test()\r |
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