/usr/share/pyshared/kaa/metadata/audio/m4a.py is in python-kaa-metadata 0.7.7+svn4596-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 | # -*- coding: iso-8859-1 -*-
# -----------------------------------------------------------------------------
# m4a.py - m4a file parser
# -----------------------------------------------------------------------------
# $Id: m4a.py 4375 2010-09-03 21:08:29Z tack $
#
# -----------------------------------------------------------------------------
# kaa-Metadata - Media Metadata for Python
# Copyright (C) 2003-2006 Thomas Schueppel, Dirk Meyer
#
# First Edition: Aubin Paul <aubin@outlyer.org>
# Maintainer: Dirk Meyer <dischi@freevo.org>
#
# Please see the file AUTHORS for a complete list of authors.
#
# Based on a sample implementation posted to daap-dev mailing list by
# Bob Ippolito <bob@redivi.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MER-
# CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
# Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# -----------------------------------------------------------------------------
__all__ = ['Parser']
# python imports
import logging
# import kaa.metadata.audio core
import core
# get logging object
log = logging.getLogger('metadata')
import struct
FLAGS= CONTAINER, SKIPPER, TAGITEM, IGNORE= [2**_ for _ in xrange(4)]
# CONTAINER: datum contains other boxes
# SKIPPER: ignore first 4 bytes of datum
# TAGITEM: "official" tag item
CALLBACK= TAGITEM
FLAGS.append(CALLBACK)
TAGTYPES= (
('ftyp', TAGITEM),
('mvhd', 0),
('moov', CONTAINER),
('mdat', 0),
('udta', CONTAINER),
('meta', CONTAINER|SKIPPER),
('ilst', CONTAINER),
('\xa9ART', TAGITEM),
('\xa9nam', TAGITEM),
('\xa9too', TAGITEM),
('\xa9alb', TAGITEM),
('\xa9day', TAGITEM),
('\xa9gen', TAGITEM),
('\xa9wrt', TAGITEM),
('\xa9cmt', TAGITEM),
('trkn', TAGITEM),
('trak', CONTAINER),
('mdia', CONTAINER),
('mdhd', TAGITEM),
('minf', CONTAINER),
('dinf', CONTAINER),
('stbl', CONTAINER),
)
flagged= {}
for flag in FLAGS:
flagged[flag]= frozenset(_[0] for _ in TAGTYPES if _[1] & flag)
def _analyse(fp, offset0, offset1):
"Walk the atom tree in a mp4 file"
offset= offset0
while offset < offset1:
fp.seek(offset)
atomsize= struct.unpack("!i", fp.read(4))[0]
atomtype= fp.read(4)
if atomsize < 9:
# This logic is not likely correct, but at least avoids
# an exception from fp.read() below.
break
if atomtype in flagged[CONTAINER]:
data= ''
for reply in _analyse(fp, offset+(atomtype in flagged[SKIPPER] and 12 or 8),
offset+atomsize):
yield reply
else:
fp.seek(offset+8)
if atomtype in flagged[TAGITEM]:
data=fp.read(atomsize-8)
else:
data= fp.read(min(atomsize-8, 32))
#print `atomtype`, `data`
if not atomtype in flagged[IGNORE]: yield atomtype, atomsize, data
offset+= atomsize
def mp4_atoms(fp):
fp.seek(0,2)
size=fp.tell()
for atom in _analyse(fp, 0, size):
yield atom
class M4ATags(dict):
"An class reading .m4a tags"
convtag= {
'ftyp': 'FileType',
'trkn': 'Track',
'length': 'Length',
'samplerate': 'SampleRate',
'\xa9ART': 'Artist',
'\xa9nam': 'Title',
'\xa9alb': 'Album',
'\xa9day': 'Year',
'\xa9gen': 'Genre',
'\xa9cmt': 'Comment',
'\xa9wrt': 'Writer',
'\xa9too': 'Tool',
}
def __init__(self, fp):
super(dict, self).__init__()
self['FileType'] = 'unknown'
fp.seek(0,0)
try:
size= struct.unpack("!i", fp.read(4))[0]
except struct.error:
# EOF.
return
type= fp.read(4)
#check for ftyp identification
if type == 'ftyp':
for atomtype, atomsize, atomdata in mp4_atoms(fp):
self.atom2tag(atomtype, atomdata)
def atom2tag(self, atomtype, atomdata):
"Insert items using descriptive key instead of atomtype"
if atomtype.find('\xa9',0,4) != -1:
key= self.convtag[atomtype]
self[key]= atomdata[16:].decode("utf-8")
elif atomtype == 'mdhd':
if ord(atomdata[0]) == 1:
#if version is 1 then date and duration values are 8 bytes in length
timescale= struct.unpack("!Q",atomdata[20:24])[0]
duration= struct.unpack("!Q",atomdata[24:30])[0]
else:
timescale= struct.unpack("!i",atomdata[12:16])[0]
duration= struct.unpack("!i",atomdata[16:20])[0]
self[self.convtag['length']]= duration/timescale
self[self.convtag['samplerate']]= timescale
elif atomtype == 'trkn':
self[self.convtag[atomtype]]= struct.unpack("!i",atomdata[16:20])[0]
elif atomtype == 'ftyp':
self[self.convtag[atomtype]]= atomdata[8:12].decode("utf-8")
class Mpeg4Audio(core.Music):
def __init__(self, file):
core.Music.__init__(self)
tags = M4ATags(file)
if tags.get('FileType') != 'M4A ':
raise core.ParseError()
self.valid = True
self.mime = 'audio/mp4'
self.filename = getattr(file, 'name', None)
# Initialize core attributes from available tag values.
self.title = tags.get('Title')
self.artist = tags.get('Artist')
self.album = tags.get('Album')
self.trackno = tags.get('Track')
self.year = tags.get('Year')
self.encoder = tags.get('Tool')
self.length = tags.get('Length')
self.samplerate = tags.get('SampleRate')
Parser = Mpeg4Audio
|