Merge lp:~eh/coverlovin/mutagen into lp:coverlovin

[Eetu Huisman]

Added support for other types besides mp3 by replacing id3reader with a dependency to Mutagen.

[James Stewart (amorphic)]

review: Approve

=== modified file 'coverlovin.py'
--- coverlovin.py	2012-02-06 14:08:17 +0000
+++ coverlovin.py	2012-04-21 08:59:19 +0000
@@ -10,7 +10,7 @@
 import os, sys
 import urllib, urllib2
 import simplejson
-import id3reader
+import mutagen
 import logging
 from optparse import OptionParser
 
@@ -147,16 +147,21 @@
         fileFullPath = os.path.join(thisDir, file)
         if os.path.getsize(fileFullPath) > 128:
 
-            # check file for id3 tag info
+            # check file for tag info
             try:
-                id3r = id3reader.Reader(fileFullPath)
+                fileInfo = mutagen.File(fileFullPath, easy=True)
             except:
                 log.info("Skipping " + file + " due to unicode error")
                 continue
 
-            artist = id3r.getValue('performer')
-            album = id3r.getValue('album')
+            try:
+                artist = fileInfo["artist"][0]
+                album = fileInfo["album"][0]
+            except:
+				log.debug("Artist or album of " + file + " not found, continuing")
+				continue
 
+            log.info("artist: " + artist + ", album: " + album)
             # sanitise None values
             if artist == None: artist = ''
             if album == None: album = ''

=== removed file 'id3reader.py'
--- id3reader.py	2011-02-06 03:46:54 +0000
+++ id3reader.py	1970-01-01 00:00:00 +0000
@@ -1,627 +0,0 @@
-""" Read ID3 tags from a file.
-    Ned Batchelder, http://nedbatchelder.com/code/modules/id3reader.html
-"""
-
-__version__ = '1.53.20070415'    # History at the end of the file.
-
-# ID3 specs: http://www.id3.org/develop.html
-
-import struct, sys, zlib
-
-# These are the text encodings, indexed by the first byte of a text value.
-_encodings = ['iso8859-1', 'utf-16', 'utf-16be', 'utf-8']
-
-# Simple pseudo-id's, mapped to their various representations.
-# Use these ids with getValue, and you don't need to know what
-# version of ID3 the file contains.
-_simpleDataMapping = {
-    'album':        ('TALB', 'TAL', 'v1album', 'TOAL'),
-    'performer':    ('TPE1', 'TP1', 'v1performer', 'TOPE'),
-    'title':        ('TIT2', 'TT2', 'v1title'),
-    'track':        ('TRCK', 'TRK', 'v1track'),
-    'year':         ('TYER', 'TYE', 'v1year'),
-    'genre':        ('TCON', 'TCO', 'v1genre'),
-    'comment':      ('COMM', 'COM', 'v1comment'),
-}
-
-# Provide booleans for older Pythons.
-try:
-    True, False
-except NameError:
-    True, False = 1==1, 1==0
-
-# Tracing
-_t = False
-def _trace(msg):
-    print msg
-
-# Coverage
-_c = False
-_features = {}
-def _coverage(feat):
-    #if _t: _trace('feature '+feat)
-    _features[feat] = _features.setdefault(feat, 0)+1
-
-def _safestr(s):
-    """ Get a good string for printing, that won't throw exceptions,
-        no matter what's in it.
-    """
-    try:
-        return unicode(s).encode(sys.getdefaultencoding())
-    except UnicodeError:
-        return '?: '+repr(s)
-
-# Can I just say that I think the whole concept of genres is bogus,
-# since they are so subjective?  And the idea of letting someone else pick
-# one of these things and then have it affect the categorization of my music
-# is extra bogus.  And the list itself is absurd. Polsk Punk?
-_genres = [
-    # 0-19
-    'Blues', 'Classic Rock', 'Country', 'Dance', 'Disco', 'Funk', 'Grunge', 'Hip - Hop', 'Jazz', 'Metal',
-    'New Age', 'Oldies', 'Other', 'Pop', 'R&B', 'Rap', 'Reggae', 'Rock', 'Techno', 'Industrial',
-    # 20-39
-    'Alternative', 'Ska', 'Death Metal', 'Pranks', 'Soundtrack', 'Euro - Techno', 'Ambient', 'Trip - Hop', 'Vocal', 'Jazz + Funk',
-    'Fusion', 'Trance', 'Classical', 'Instrumental', 'Acid', 'House', 'Game', 'Sound Clip', 'Gospel', 'Noise',
-    # 40-59
-    'Alt Rock', 'Bass', 'Soul', 'Punk', 'Space', 'Meditative', 'Instrumental Pop', 'Instrumental Rock', 'Ethnic', 'Gothic',
-    'Darkwave', 'Techno - Industrial', 'Electronic', 'Pop - Folk', 'Eurodance', 'Dream', 'Southern Rock', 'Comedy', 'Cult', 'Gangsta Rap',
-    # 60-79
-    'Top 40', 'Christian Rap', 'Pop / Funk', 'Jungle', 'Native American', 'Cabaret', 'New Wave', 'Psychedelic', 'Rave', 'Showtunes',
-    'Trailer', 'Lo - Fi', 'Tribal', 'Acid Punk', 'Acid Jazz', 'Polka', 'Retro', 'Musical', 'Rock & Roll', 'Hard Rock',
-    # 80-99
-    'Folk', 'Folk / Rock', 'National Folk', 'Swing', 'Fast - Fusion', 'Bebob', 'Latin', 'Revival', 'Celtic', 'Bluegrass',
-    'Avantgarde', 'Gothic Rock', 'Progressive Rock', 'Psychedelic Rock', 'Symphonic Rock', 'Slow Rock', 'Big Band', 'Chorus', 'Easy Listening', 'Acoustic',
-    # 100-119
-    'Humour', 'Speech', 'Chanson', 'Opera', 'Chamber Music', 'Sonata', 'Symphony', 'Booty Bass', 'Primus', 'Porn Groove',
-    'Satire', 'Slow Jam', 'Club', 'Tango', 'Samba', 'Folklore', 'Ballad', 'Power Ballad', 'Rhythmic Soul', 'Freestyle',
-    # 120-139
-    'Duet', 'Punk Rock', 'Drum Solo', 'A Cappella', 'Euro - House', 'Dance Hall', 'Goa', 'Drum & Bass', 'Club - House', 'Hardcore',
-    'Terror', 'Indie', 'BritPop', 'Negerpunk', 'Polsk Punk', 'Beat', 'Christian Gangsta Rap', 'Heavy Metal', 'Black Metal', 'Crossover',
-    # 140-147
-    'Contemporary Christian', 'Christian Rock', 'Merengue', 'Salsa', 'Thrash Metal', 'Anime', 'JPop', 'Synthpop'
-    ]
-
-class Id3Error(Exception):
-    """ An exception caused by id3reader properly handling a bad ID3 tag.
-    """
-    pass
-
-class _Header:
-    """ Represent the ID3 header in a tag.
-    """
-    def __init__(self):
-        self.majorVersion = 0
-        self.revision = 0
-        self.flags = 0
-        self.size = 0
-        self.bUnsynchronized = False
-        self.bExperimental = False
-        self.bFooter = False
-
-    def __str__(self):
-        return str(self.__dict__)
-
-class _Frame:
-    """ Represent an ID3 frame in a tag.
-    """
-    def __init__(self):
-        self.id = ''
-        self.size = 0
-        self.flags = 0
-        self.rawData = ''
-        self.bTagAlterPreserve = False
-        self.bFileAlterPreserve = False
-        self.bReadOnly = False
-        self.bCompressed = False
-        self.bEncrypted = False
-        self.bInGroup = False
-
-    def __str__(self):
-        return str(self.__dict__)
-
-    def __repr__(self):
-        return str(self.__dict__)
-
-    def _interpret(self):
-        """ Examine self.rawData and create a self.value from it.
-        """
-        if len(self.rawData) == 0:
-            # This is counter to the spec, but seems harmless enough.
-            #if _c: _coverage('zero data')
-            return
-
-        if self.bCompressed:
-            # Decompress the compressed data.
-            self.rawData = zlib.decompress(self.rawData)
-
-        if self.id[0] == 'T':
-            # Text fields start with T
-            encoding = ord(self.rawData[0])
-            if 0 <= encoding < len(_encodings):
-                #if _c: _coverage('encoding%d' % encoding)
-                value = self.rawData[1:].decode(_encodings[encoding])
-            else:
-                #if _c: _coverage('bad encoding')
-                value = self.rawData[1:]
-            # Don't let trailing zero bytes fool you.
-            if value:
-                value = value.strip('\0')
-            # The value can actually be a list.
-            if '\0' in value:
-                value = value.split('\0')
-                #if _c: _coverage('textlist')
-            self.value = value
-        elif self.id[0] == 'W':
-            # URL fields start with W
-            self.value = self.rawData.strip('\0')
-            if self.id == 'WXXX':
-                self.value = self.value.split('\0')
-        elif self.id == 'CDM':
-            # ID3v2.2.1 Compressed Data Metaframe
-            if self.rawData[0] == 'z':
-                self.rawData = zlib.decompress(self.rawData[5:])
-            else:
-                #if _c: _coverage('badcdm!')
-                raise Id3Error, 'Unknown CDM compression: %02x' % self.rawData[0]
-            #@TODO: re-interpret the decompressed frame.
-
-        elif self.id in _simpleDataMapping['comment']:
-            # comment field
-
-            # In limited testing a typical comment looks like
-            # '\x00XXXID3v1 Comment\x00comment test' so in this
-            # case we need to find the second \x00 to know where
-            # where we start for a comment.  In case we only find
-            # one \x00, lets just start at the beginning for the
-            # value
-            s = str(self.rawData)
-
-            pos = 0
-            count = 0
-            while pos < len(s) and count < 2:
-                if ord(s[pos]) == 0:
-                    count = count + 1
-                pos = pos + 1
-            if count < 2:
-                pos = 1
-
-            if pos > 0 and pos < len(s):
-                s = s[pos:]
-                if ord(s[-1]) == 0:
-                    s = s[:-1]
-
-            self.value = s
-
-class Reader:
-    """ An ID3 reader.
-        Create one on a file object, and then use getValue('TIT2') (for example)
-        to pull values.
-    """
-    def __init__(self, file):
-        """ Create a reader from a file or filename. """
-        self.file = file
-        self.header = None
-        self.frames = {}
-        self.allFrames = []
-        self.bytesLeft = 0
-        self.padbytes = ''
-
-        bCloseFile = False
-        # If self.file is a string of some sort, then open it to get a file.
-        if isinstance(self.file, (type(''), type(u''))):
-            self.file = open(self.file, 'rb')
-            bCloseFile = True
-
-        self._readId3()
-
-        if bCloseFile:
-            self.file.close()
-
-    def _readBytes(self, num, desc=''):
-        """ Read some bytes from the file.
-            This method implements the "unsynchronization" scheme,
-            where 0xFF bytes may have had 0x00 bytes stuffed after
-            them.  These zero bytes have to be removed transparently.
-        """
-        #if _t: _trace("ask %d (%s)" % (num,desc))
-        if num > self.bytesLeft:
-            #if _c: _coverage('long!')
-            raise Id3Error, 'Long read (%s): (%d > %d)' % (desc, num, self.bytesLeft)
-        bytes = self.file.read(num)
-        self.bytesLeft -= num
-
-        if len(bytes) < num:
-            #if _t: _trace("short read with %d left, %d total" % (self.bytesLeft, self.header.size))
-            #if _c: _coverage('short!')
-            raise Id3Error, 'Short read (%s): (%d < %d)' % (desc, len(bytes), num)
-
-        if self.header.bUnsynchronized:
-            nUnsync = 0
-            i = 0
-            while True:
-                i = bytes.find('\xFF\x00', i)
-                if i == -1:
-                    break
-                #if _t: _trace("unsync at %d" % (i+1))
-                #if _c: _coverage('unsyncbyte')
-                nUnsync += 1
-                # This is a stuffed byte to remove
-                bytes = bytes[:i+1] + bytes[i+2:]
-                # Have to read one more byte from the file to adjust
-                bytes += self.file.read(1)
-                self.bytesLeft -= 1
-                i += 1
-            #if _t: _trace("unsync'ed %d" % (nUnsync))
-
-        return bytes
-
-    def _unreadBytes(self, num):
-        self.file.seek(-num, 1)
-        self.bytesLeft += num
-
-    def _getSyncSafeInt(self, bytes):
-        assert len(bytes) == 4
-        if type(bytes) == type(''):
-            bytes = [ ord(c) for c in bytes ]
-        return (bytes[0] << 21) + (bytes[1] << 14) + (bytes[2] << 7) + bytes[3]
-
-    def _getInteger(self, bytes):
-        i = 0;
-        if type(bytes) == type(''):
-            bytes = [ ord(c) for c in bytes ]
-        for b in bytes:
-            i = i*256+b
-        return i
-
-    def _addV1Frame(self, id, rawData):
-        if id == 'v1genre':
-            assert len(rawData) == 1
-            nGenre = ord(rawData)
-            try:
-                value = _genres[nGenre]
-            except IndexError:
-                value = "(%d)" % nGenre
-        else:
-            value = rawData.strip(' \t\r\n').split('\0')[0]
-        if value:
-            frame = _Frame()
-            frame.id = id
-            frame.rawData = rawData
-            frame.value = value
-            self.frames[id] = frame
-            self.allFrames.append(frame)
-
-    def _pass(self):
-        """ Do nothing, for when we need to plug in a no-op function.
-        """
-        pass
-
-    def _readId3(self):
-        header = self.file.read(10)
-        if len(header) < 10:
-            return
-        hstuff = struct.unpack('!3sBBBBBBB', header)
-        if hstuff[0] != "ID3":
-            # Doesn't look like an ID3v2 tag,
-            # Try reading an ID3v1 tag.
-            self._readId3v1()
-            return
-
-        self.header = _Header()
-        self.header.majorVersion = hstuff[1]
-        self.header.revision = hstuff[2]
-        self.header.flags = hstuff[3]
-        self.header.size = self._getSyncSafeInt(hstuff[4:8])
-
-        self.bytesLeft = self.header.size
-
-        self._readExtHeader = self._pass
-
-        if self.header.majorVersion == 2:
-            #if _c: _coverage('id3v2.2.%d' % self.header.revision)
-            self._readFrame = self._readFrame_rev2
-        elif self.header.majorVersion == 3:
-            #if _c: _coverage('id3v2.3.%d' % self.header.revision)
-            self._readFrame = self._readFrame_rev3
-        elif self.header.majorVersion == 4:
-            #if _c: _coverage('id3v2.4.%d' % self.header.revision)
-            self._readFrame = self._readFrame_rev4
-        else:
-            #if _c: _coverage('badmajor!')
-            raise Id3Error, "Unsupported major version: %d" % self.header.majorVersion
-
-        # Interpret the flags
-        self._interpretFlags()
-
-        # Read any extended header
-        self._readExtHeader()
-
-        # Read the frames
-        while self.bytesLeft > 0:
-            frame = self._readFrame()
-            if frame:
-                frame._interpret()
-                self.frames[frame.id] = frame
-                self.allFrames.append(frame)
-            else:
-                #if _c: _coverage('padding')
-                break
-
-    def _interpretFlags(self):
-        """ Interpret ID3v2.x flags.
-        """
-        if self.header.flags & 0x80:
-            self.header.bUnsynchronized = True
-            #if _c: _coverage('unsynctag')
-
-        if self.header.majorVersion == 2:
-            if self.header.flags & 0x40:
-                #if _c: _coverage('compressed')
-                # "Since no compression scheme has been decided yet,
-                # the ID3 decoder (for now) should just ignore the entire
-                # tag if the compression bit is set."
-                self.header.bCompressed = True
-
-        if self.header.majorVersion >= 3:
-            if self.header.flags & 0x40:
-                #if _c: _coverage('extheader')
-                if self.header.majorVersion == 3:
-                    self._readExtHeader = self._readExtHeader_rev3
-                else:
-                    self._readExtHeader = self._readExtHeader_rev4
-            if self.header.flags & 0x20:
-                #if _c: _coverage('experimental')
-                self.header.bExperimental = True
-
-        if self.header.majorVersion >= 4:
-            if self.header.flags & 0x10:
-                #if _c: _coverage('footer')
-                self.header.bFooter = True
-
-    def _readExtHeader_rev3(self):
-        """ Read the ID3v2.3 extended header.
-        """
-        # We don't interpret this yet, just eat the bytes.
-        size = self._getInteger(self._readBytes(4, 'rev3ehlen'))
-        self._readBytes(size, 'rev3ehdata')
-
-    def _readExtHeader_rev4(self):
-        """ Read the ID3v2.4 extended header.
-        """
-        # We don't interpret this yet, just eat the bytes.
-        size = self._getSyncSafeInt(self._readBytes(4, 'rev4ehlen'))
-        self._readBytes(size-4, 'rev4ehdata')
-
-    def _readId3v1(self):
-        """ Read the ID3v1 tag.
-            spec: http://www.id3.org/id3v1.html
-        """
-        self.file.seek(-128, 2)
-        tag = self.file.read(128)
-        if len(tag) != 128:
-            return
-        if tag[0:3] != 'TAG':
-            return
-        self.header = _Header()
-        self.header.majorVersion = 1
-        self.header.revision = 0
-
-        self._addV1Frame('v1title', tag[3:33])
-        self._addV1Frame('v1performer', tag[33:63])
-        self._addV1Frame('v1album', tag[63:93])
-        self._addV1Frame('v1year', tag[93:97])
-        self._addV1Frame('v1comment', tag[97:127])
-        self._addV1Frame('v1genre', tag[127])
-        if tag[125] == '\0' and tag[126] != '\0':
-            #if _c: _coverage('id3v1.1')
-            self.header.revision = 1
-            self._addV1Frame('v1track', str(ord(tag[126])))
-        else:
-            #if _c: _coverage('id3v1.0')
-            pass
-        return
-
-    _validIdChars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
-
-    def _isValidId(self, id):
-        """ Determine if the id bytes make a valid ID3 id.
-        """
-        for c in id:
-            if not c in self._validIdChars:
-                #if _c: _coverage('bad id')
-                return False
-        #if _c: _coverage('id '+id)
-        return True
-
-    def _readFrame_rev2(self):
-        """ Read a frame for ID3v2.2: three-byte ids and lengths.
-            spec: http://www.id3.org/id3v2-00.txt
-        """
-        if self.bytesLeft < 6:
-            return None
-        id = self._readBytes(3, 'rev2id')
-        if len(id) < 3 or not self._isValidId(id):
-            self._unreadBytes(len(id))
-            return None
-        hstuff = struct.unpack('!BBB', self._readBytes(3, 'rev2len'))
-        frame = _Frame()
-        frame.id = id
-        frame.size = self._getInteger(hstuff[0:3])
-        frame.rawData = self._readBytes(frame.size, 'rev2data')
-        return frame
-
-    def _readFrame_rev3(self):
-        """ Read a frame for ID3v2.3: four-byte ids and lengths.
-        """
-        if self.bytesLeft < 10:
-            return None
-        id = self._readBytes(4,'rev3id')
-        if len(id) < 4 or not self._isValidId(id):
-            self._unreadBytes(len(id))
-            return None
-        hstuff = struct.unpack('!BBBBh', self._readBytes(6,'rev3head'))
-        frame = _Frame()
-        frame.id = id
-        frame.size = self._getInteger(hstuff[0:4])
-        cbData = frame.size
-        frame.flags = hstuff[4]
-        #if _t: _trace('flags = %x' % frame.flags)
-        frame.bTagAlterPreserve = (frame.flags & 0x8000 != 0)
-        frame.bFileAlterPreserve = (frame.flags & 0x4000 != 0)
-        frame.bReadOnly = (frame.flags & 0x2000 != 0)
-        frame.bCompressed = (frame.flags & 0x0080 != 0)
-        if frame.bCompressed:
-            frame.decompressedSize = self._getInteger(self._readBytes(4, 'decompsize'))
-            cbData -= 4
-            #if _c: _coverage('compress')
-        frame.bEncrypted = (frame.flags & 0x0040 != 0)
-        if frame.bEncrypted:
-            frame.encryptionMethod = self._readBytes(1, 'encrmethod')
-            cbData -= 1
-            #if _c: _coverage('encrypt')
-        frame.bInGroup = (frame.flags & 0x0020 != 0)
-        if frame.bInGroup:
-            frame.groupid = self._readBytes(1, 'groupid')
-            cbData -= 1
-            #if _c: _coverage('groupid')
-
-        frame.rawData = self._readBytes(cbData, 'rev3data')
-        return frame
-
-    def _readFrame_rev4(self):
-        """ Read a frame for ID3v2.4: four-byte ids and lengths.
-        """
-        if self.bytesLeft < 10:
-            return None
-        id = self._readBytes(4,'rev4id')
-        if len(id) < 4 or not self._isValidId(id):
-            self._unreadBytes(len(id))
-            return None
-        hstuff = struct.unpack('!BBBBh', self._readBytes(6,'rev4head'))
-        frame = _Frame()
-        frame.id = id
-        frame.size = self._getSyncSafeInt(hstuff[0:4])
-        cbData = frame.size
-        frame.flags = hstuff[4]
-        frame.bTagAlterPreserve = (frame.flags & 0x4000 != 0)
-        frame.bFileAlterPreserve = (frame.flags & 0x2000 != 0)
-        frame.bReadOnly = (frame.flags & 0x1000 != 0)
-        frame.bInGroup = (frame.flags & 0x0040 != 0)
-        if frame.bInGroup:
-            frame.groupid = self._readBytes(1, 'groupid')
-            cbData -= 1
-            #if _c: _coverage('groupid')
-
-        frame.bCompressed = (frame.flags & 0x0008 != 0)
-        if frame.bCompressed:
-            #if _c: _coverage('compress')
-            pass
-        frame.bEncrypted = (frame.flags & 0x0004 != 0)
-        if frame.bEncrypted:
-            frame.encryptionMethod = self._readBytes(1, 'encrmethod')
-            cbData -= 1
-            #if _c: _coverage('encrypt')
-        frame.bUnsynchronized = (frame.flags & 0x0002 != 0)
-        if frame.bUnsynchronized:
-            #if _c: _coverage('unsyncframe')
-            pass
-        if frame.flags & 0x0001:
-            frame.datalen = self._getSyncSafeInt(self._readBytes(4, 'datalen'))
-            cbData -= 4
-            #if _c: _coverage('datalenindic')
-
-        frame.rawData = self._readBytes(cbData, 'rev3data')
-
-        return frame
-
-    def getValue(self, id):
-        """ Return the value for an ID3 tag id, or for a
-            convenience label ('title', 'performer', ...),
-            or return None if there is no such value.
-        """
-        if self.frames.has_key(id):
-            if hasattr(self.frames[id], 'value'):
-                return self.frames[id].value
-        if _simpleDataMapping.has_key(id):
-            for id2 in _simpleDataMapping[id]:
-                v = self.getValue(id2)
-                if v:
-                    return v
-        return None
-
-    def getRawData(self, id):
-        if self.frames.has_key(id):
-            return self.frames[id].rawData
-        return None
-
-    def dump(self):
-        import pprint
-        print "Header:"
-        print self.header
-        print "Frames:"
-        for fr in self.allFrames:
-            if len(fr.rawData) > 30:
-                fr.rawData = fr.rawData[:30]
-        pprint.pprint(self.allFrames)
-        for fr in self.allFrames:
-            if hasattr(fr, 'value'):
-                print '%s: %s' % (fr.id, _safestr(fr.value))
-            else:
-                print '%s= %s' % (fr.id, _safestr(fr.rawData))
-        for label in _simpleDataMapping.keys():
-            v = self.getValue(label)
-            if v:
-                print 'Label %s: %s' % (label, _safestr(v))
-
-    def dumpCoverage(self):
-        feats = _features.keys()
-        feats.sort()
-        for feat in feats:
-            print "Feature %-12s: %d" % (feat, _features[feat])
-
-if __name__ == '__main__':
-    if len(sys.argv) < 2 or '-?' in sys.argv:
-        print "Give me a filename"
-    else:
-        id3 = Reader(sys.argv[1])
-        id3.dump()
-        #if _c: id3.dumpCoverage()
-
-# History:
-# 20040104: Created.
-# 20040105: Two bugs: didn't read v1 properly, and didn't like empty strings in values.
-#
-# 20040109: Properly reads v2.3 properly (4-byte lens, but not synchsafe)
-#           Handles unsynchronized tags properly.
-#
-# 20040110: Total length was wrong for unsynchronized tags.
-#           Treat input filename better so path module can be used.
-#           Frame ids are more closely scrutinized for validity.
-#           Errors are now thrown as our own exception.
-#           Pad bytes aren't retained any more.
-#           Frame.value is not set if there is no interpretation performed.
-#
-# 20040111: Tracing and code coverage more formalized.
-#           Exceptions are now all Id3Error.
-#           Zero-length data in frames is handled pleasantly.
-#           Compressed frames are decompressed.
-#           Extended headers are read (but uninterpreted).
-#           Non-zero pad bytes are handled.
-#           Frame flags are read and interpreted.
-#           W*** frames are interpreted.
-#           Multi-string frames set .value to a list of strings.
-#
-# 20040113: Strip all trailing zero bytes from text strings.
-#           If we opened the file, we should close the file.
-#
-# 20040205: Do a better job printing strings without throwing.
-#           Support genre information, even if it is stupid.
-#
-# 20040913: When dumping strings, be more robust when trying to print
-#               non-character data. Thanks to Duane Harkness for the fix.
-#
-# 20061230: Fix ommission of self. in a few places.
-#
-# 20070415: Extended headers in ID3v2.4 weren't skipped properly, throwing
-#               everything out of whack.
-#           Be more generous about finding album and performer names in the tag.