Initial Commit

lib/mutagen/optimfrog.py

@@ -0,0 +1,74 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (C) 2006  Lukas Lalinsky
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+
+"""OptimFROG audio streams with APEv2 tags.
+
+OptimFROG is a lossless audio compression program. Its main goal is to
+reduce at maximum the size of audio files, while permitting bit
+identical restoration for all input. It is similar with the ZIP
+compression, but it is highly specialized to compress audio data.
+
+Only versions 4.5 and higher are supported.
+
+For more information, see http://www.losslessaudio.org/
+"""
+
+__all__ = ["OptimFROG", "Open", "delete"]
+
+import struct
+
+from ._compat import endswith
+from mutagen import StreamInfo
+from mutagen.apev2 import APEv2File, error, delete
+
+
+class OptimFROGHeaderError(error):
+    pass
+
+
+class OptimFROGInfo(StreamInfo):
+    """OptimFROG stream information.
+
+    Attributes:
+
+    * channels - number of audio channels
+    * length - file length in seconds, as a float
+    * sample_rate - audio sampling rate in Hz
+    """
+
+    def __init__(self, fileobj):
+        header = fileobj.read(76)
+        if (len(header) != 76 or not header.startswith(b"OFR ") or
+                struct.unpack("<I", header[4:8])[0] not in [12, 15]):
+            raise OptimFROGHeaderError("not an OptimFROG file")
+        (total_samples, total_samples_high, sample_type, self.channels,
+         self.sample_rate) = struct.unpack("<IHBBI", header[8:20])
+        total_samples += total_samples_high << 32
+        self.channels += 1
+        if self.sample_rate:
+            self.length = float(total_samples) / (self.channels *
+                                                  self.sample_rate)
+        else:
+            self.length = 0.0
+
+    def pprint(self):
+        return "OptimFROG, %.2f seconds, %d Hz" % (self.length,
+                                                   self.sample_rate)
+
+
+class OptimFROG(APEv2File):
+    _Info = OptimFROGInfo
+
+    @staticmethod
+    def score(filename, fileobj, header):
+        filename = filename.lower()
+
+        return (header.startswith(b"OFR") + endswith(filename, b".ofr") +
+                endswith(filename, b".ofs"))
+
+Open = OptimFROG