Initial Commit

lib/mutagen/monkeysaudio.py

@@ -0,0 +1,86 @@
+# -*- 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.
+
+"""Monkey's Audio streams with APEv2 tags.
+
+Monkey's Audio is a very efficient lossless audio compressor developed
+by Matt Ashland.
+
+For more information, see http://www.monkeysaudio.com/.
+"""
+
+__all__ = ["MonkeysAudio", "Open", "delete"]
+
+import struct
+
+from ._compat import endswith
+from mutagen import StreamInfo
+from mutagen.apev2 import APEv2File, error, delete
+from mutagen._util import cdata
+
+
+class MonkeysAudioHeaderError(error):
+    pass
+
+
+class MonkeysAudioInfo(StreamInfo):
+    """Monkey's Audio stream information.
+
+    Attributes:
+
+    * channels -- number of audio channels
+    * length -- file length in seconds, as a float
+    * sample_rate -- audio sampling rate in Hz
+    * bits_per_sample -- bits per sample
+    * version -- Monkey's Audio stream version, as a float (eg: 3.99)
+    """
+
+    def __init__(self, fileobj):
+        header = fileobj.read(76)
+        if len(header) != 76 or not header.startswith(b"MAC "):
+            raise MonkeysAudioHeaderError("not a Monkey's Audio file")
+        self.version = cdata.ushort_le(header[4:6])
+        if self.version >= 3980:
+            (blocks_per_frame, final_frame_blocks, total_frames,
+             self.bits_per_sample, self.channels,
+             self.sample_rate) = struct.unpack("<IIIHHI", header[56:76])
+        else:
+            compression_level = cdata.ushort_le(header[6:8])
+            self.channels, self.sample_rate = struct.unpack(
+                "<HI", header[10:16])
+            total_frames, final_frame_blocks = struct.unpack(
+                "<II", header[24:32])
+            if self.version >= 3950:
+                blocks_per_frame = 73728 * 4
+            elif self.version >= 3900 or (self.version >= 3800 and
+                                          compression_level == 4):
+                blocks_per_frame = 73728
+            else:
+                blocks_per_frame = 9216
+        self.version /= 1000.0
+        self.length = 0.0
+        if (self.sample_rate != 0) and (total_frames > 0):
+            total_blocks = ((total_frames - 1) * blocks_per_frame +
+                            final_frame_blocks)
+            self.length = float(total_blocks) / self.sample_rate
+
+    def pprint(self):
+        return "Monkey's Audio %.2f, %.2f seconds, %d Hz" % (
+            self.version, self.length, self.sample_rate)
+
+
+class MonkeysAudio(APEv2File):
+    _Info = MonkeysAudioInfo
+    _mimes = ["audio/ape", "audio/x-ape"]
+
+    @staticmethod
+    def score(filename, fileobj, header):
+        return header.startswith(b"MAC ") + endswith(filename.lower(), ".ape")
+
+
+Open = MonkeysAudio