* morituri/image/table.py:

* morituri/test/test_image_table.py:
	  Implement MusicBrainz disc id.  Works for audio-only discs,
	  have to figure out why it fails for an Enhanced CD like the
	  Ladyhawke one.

ChangeLog

@@ -1,3 +1,11 @@
+2009-05-05  Thomas Vander Stichele  <thomas at apestaart dot org>
+
+	* morituri/image/table.py:
+	* morituri/test/test_image_table.py:
+	  Implement MusicBrainz disc id.  Works for audio-only discs,
+	  have to figure out why it fails for an Enhanced CD like the
+	  Ladyhawke one.
+
 2009-05-05  Thomas Vander Stichele  <thomas at apestaart dot org>
 
 	* morituri/image/table.py:

morituri/image/table.py

@@ -349,6 +349,55 @@ class IndexTable(object, log.Loggable):
         
         return "%08x" % value
 
+    def getMusicBrainzDiscId(self):
+        """
+        Calculate the MusicBrainz disc ID.
+
+        @rtype:   str
+        @returns: the 28-character base64-encoded disc ID
+        """
+        # MusicBrainz disc id does not take into account data tracks
+        import sha
+        import base64
+
+        sha1 = sha.new()
+
+        # number of first track
+        sha1.update("%02X" % 1)
+
+        # number of last track
+        sha1.update("%02X" % self.getAudioTracks())
+
+        # treat leadout offset as track 0 offset
+        sha1.update("%08X" % (150 + self.leadout))
+
+        # offsets of tracks
+        for i in range(1, 100):
+            try:
+                offset = self.tracks[i - 1].getIndex(1).absolute + 150
+            except IndexError:
+                #print 'track', i - 1, '0 offset'
+                offset = 0
+            sha1.update("%08X" % offset)
+
+        digest = sha1.digest()
+        assert len(digest) == 20, \
+            "digest should be 20 chars, not %d" % len(digest)
+
+        # The RFC822 spec uses +, /, and = characters, all of which are special
+        # HTTP/URL characters. To avoid the problems with dealing with that, I
+        # (Rob) used ., _, and -
+
+        # base64 altchars specify replacements for + and /
+        result = base64.b64encode(digest, '._')
+
+        # now replace =
+        result = "-".join(result.split("="))
+        assert len(result) == 28, \
+            "Result should be 28 characters, not %d" % len(result)
+
+        return result
+
     def getAccurateRipIds(self):
         """
         Calculate the two AccurateRip ID's.

morituri/test/test_image_table.py

@@ -39,6 +39,37 @@ class LadyhawkeTestCase(unittest.TestCase):
     def testCDDB(self):
         self.assertEquals(self.table.getCDDBDiscId(), "c60af50d")
 
+    def testMusicBrainz(self):
+        # FIXME: doesn't seem to be the correct id, so try the example on this
+        # track
+        #print self.table.getMusicBrainzDiscId()
+        pass
+
     def testAccurateRip(self):
         self.assertEquals(self.table.getAccurateRipIds(), (
             "0013bd5a", "00b8d489"))
+
+class MusicBrainzTestCase(unittest.TestCase):
+    # example taken from http://musicbrainz.org/doc/DiscIDCalculation
+    # disc is Ettella Diamant
+
+    def setUp(self):
+        self.table = table.IndexTable()
+
+        for i in range(6):
+            self.table.tracks.append(table.ITTrack(i + 1, audio=True))
+
+        offsets = [0, 15213, 32164, 46442, 63264, 80339]
+        t = self.table.tracks
+        for i, offset in enumerate(offsets):
+            t[i].index(1, absolute=offset)
+
+        self.failIf(self.table.hasTOC())
+
+        self.table.leadout = 95312
+
+        self.failUnless(self.table.hasTOC())
+
+    def testMusicBrainz(self):
+        self.assertEquals(self.table.getMusicBrainzDiscId(),
+            '49HHV7Eb8UKF3aQiNmu1GR8vKTY-')