Files
SnootGame/game/python-packages/tinytag.py
2022-10-28 00:56:32 -03:00

1150 lines
54 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# tinytag - an audio meta info reader
# Copyright (c) 2014-2018 Tom Wallroth
#
# Sources on github:
# http://github.com/devsnd/tinytag/
# MIT License
# Copyright (c) 2014-2019 Tom Wallroth
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
from __future__ import print_function
import json
from collections import MutableMapping, OrderedDict
import codecs
from functools import reduce
import struct
import os
import io
import sys
from io import BytesIO
import re
DEBUG = os.environ.get('DEBUG', False) # some of the parsers can print debug info
class TinyTagException(LookupError): # inherit LookupError for backwards compat
pass
def _read(fh, nbytes): # helper function to check if we haven't reached EOF
b = fh.read(nbytes)
if len(b) < nbytes:
raise TinyTagException('Unexpected end of file')
return b
def stderr(*args):
sys.stderr.write('%s\n' % ' '.join(args))
sys.stderr.flush()
def _bytes_to_int_le(b):
fmt = {1: '<B', 2: '<H', 4: '<I', 8: '<Q'}.get(len(b))
return struct.unpack(fmt, b)[0] if fmt is not None else 0
def _bytes_to_int(b):
return reduce(lambda accu, elem: (accu << 8) + elem, b, 0)
class TinyTag(object):
def __init__(self, filehandler, filesize, ignore_errors=False):
if isinstance(filehandler, str):
raise Exception('Use `TinyTag.get(filepath)` instead of `TinyTag(filepath)`')
self._filehandler = filehandler
self.filesize = filesize
self.album = None
self.albumartist = None
self.artist = None
self.audio_offset = None
self.bitrate = None
self.channels = None
self.comment = None
self.composer = None
self.disc = None
self.disc_total = None
self.duration = None
self.genre = None
self.samplerate = None
self.title = None
self.track = None
self.track_total = None
self.year = None
self._load_image = False
self._image_data = None
self._ignore_errors = ignore_errors
def as_dict(self):
return {k: v for k, v in self.__dict__.items() if not k.startswith('_')}
@classmethod
def is_supported(cls, filename):
return cls._get_parser_for_filename(filename) is not None
def get_image(self):
return self._image_data
@classmethod
def _get_parser_for_filename(cls, filename):
mapping = {
(b'.mp3',): ID3,
(b'.oga', b'.ogg', b'.opus'): Ogg,
(b'.wav',): Wave,
(b'.flac',): Flac,
(b'.wma',): Wma,
(b'.m4b', b'.m4a', b'.mp4'): MP4,
}
if not isinstance(filename, bytes): # convert filename to binary
filename = filename.encode('ASCII', errors='ignore').lower()
for ext, tagclass in mapping.items():
if filename.endswith(ext):
return tagclass
@classmethod
def _get_parser_for_file_handle(cls, fh):
# https://en.wikipedia.org/wiki/List_of_file_signatures
magic_bytes_mapping = {
b'^ID3': ID3,
b'^\xff\xfb': ID3,
b'^OggS': Ogg,
b'^RIFF....WAVE': Wave,
b'^fLaC': Flac,
b'^\x30\x26\xB2\x75\x8E\x66\xCF\x11\xA6\xD9\x00\xAA\x00\x62\xCE\x6C': Wma,
b'....ftypM4A': MP4, # https://www.file-recovery.com/m4a-signature-format.htm
}
header = fh.peek(max(len(sig) for sig in magic_bytes_mapping))
for magic, parser in magic_bytes_mapping.items():
if re.match(magic, header):
return parser
@classmethod
def get_parser_class(cls, filename, filehandle):
if cls != TinyTag: # if `get` is invoked on TinyTag, find parser by ext
return cls # otherwise use the class on which `get` was invoked
parser_class = cls._get_parser_for_filename(filename)
if parser_class is not None:
return parser_class
# try determining the file type by magic byte header
parser_class = cls._get_parser_for_file_handle(filehandle)
if parser_class is not None:
return parser_class
raise TinyTagException('No tag reader found to support filetype! ')
@classmethod
def get(cls, filename, tags=True, duration=True, image=False, ignore_errors=False):
try: # cast pathlib.Path to str
import pathlib
if isinstance(filename, pathlib.Path):
filename = str(filename.absolute())
except ImportError:
pass
else:
filename = os.path.expanduser(filename)
size = os.path.getsize(filename)
if not size > 0:
return TinyTag(None, 0)
with io.open(filename, 'rb') as af:
parser_class = cls.get_parser_class(filename, af)
tag = parser_class(af, size, ignore_errors=ignore_errors)
tag.load(tags=tags, duration=duration, image=image)
return tag
def __str__(self):
return json.dumps(OrderedDict(sorted(self.as_dict().items())))
def __repr__(self):
return str(self)
def load(self, tags, duration, image=False):
self._load_image = image
if tags:
self._parse_tag(self._filehandler)
if duration:
if tags: # rewind file if the tags were already parsed
self._filehandler.seek(0)
self._determine_duration(self._filehandler)
def _set_field(self, fieldname, bytestring, transfunc=None):
"""convienience function to set fields of the tinytag by name.
the payload (bytestring) can be changed using the transfunc"""
if getattr(self, fieldname): # do not overwrite existing data
return
value = bytestring if transfunc is None else transfunc(bytestring)
if DEBUG:
stderr('Setting field "%s" to "%s"' % (fieldname, value))
if fieldname == 'genre':
genre_id = 255
if value.isdigit(): # funky: id3v1 genre hidden in a id3v2 field
genre_id = int(value)
else: # funkier: the TCO may contain genres in parens, e.g. '(13)'
genre_in_parens = re.match('^\\((\\d+)\\)$', value)
if genre_in_parens:
genre_id = int(genre_in_parens.group(1))
if 0 <= genre_id < len(ID3.ID3V1_GENRES):
value = ID3.ID3V1_GENRES[genre_id]
if fieldname in ("track", "disc"):
if type(value).__name__ in ('str', 'unicode') and '/' in value:
current, total = value.split('/')[:2]
setattr(self, "%s_total" % fieldname, total)
else:
current = value
setattr(self, fieldname, current)
else:
setattr(self, fieldname, value)
def _determine_duration(self, fh):
raise NotImplementedError()
def _parse_tag(self, fh):
raise NotImplementedError()
def update(self, other):
# update the values of this tag with the values from another tag
for key in ['track', 'track_total', 'title', 'artist',
'album', 'albumartist', 'year', 'duration',
'genre', 'disc', 'disc_total', 'comment', 'composer']:
if not getattr(self, key) and getattr(other, key):
setattr(self, key, getattr(other, key))
@staticmethod
def _unpad(s):
# strings in mp3 and asf *may* be terminated with a zero byte at the end
return s.replace('\x00', '')
class MP4(TinyTag):
# see: https://developer.apple.com/library/mac/documentation/QuickTime/QTFF/Metadata/Metadata.html
# and: https://developer.apple.com/library/mac/documentation/QuickTime/QTFF/QTFFChap2/qtff2.html
class Parser:
# https://developer.apple.com/library/mac/documentation/QuickTime/QTFF/Metadata/Metadata.html#//apple_ref/doc/uid/TP40000939-CH1-SW34
ATOM_DECODER_BY_TYPE = {
0: lambda x: x, # 'reserved',
1: lambda x: codecs.decode(x, 'utf-8', 'replace'), # UTF-8
2: lambda x: codecs.decode(x, 'utf-16', 'replace'), # UTF-16
3: lambda x: codecs.decode(x, 's/jis', 'replace'), # S/JIS
# 16: duration in millis
13: lambda x: x, # JPEG
14: lambda x: x, # PNG
21: lambda x: struct.unpack('>b', x)[0], # BE Signed int
22: lambda x: struct.unpack('>B', x)[0], # BE Unsigned int
23: lambda x: struct.unpack('>f', x)[0], # BE Float32
24: lambda x: struct.unpack('>d', x)[0], # BE Float64
# 27: lambda x: x, # BMP
# 28: lambda x: x, # QuickTime Metadata atom
65: lambda x: struct.unpack('b', x)[0], # 8-bit Signed int
66: lambda x: struct.unpack('>h', x)[0], # BE 16-bit Signed int
67: lambda x: struct.unpack('>i', x)[0], # BE 32-bit Signed int
74: lambda x: struct.unpack('>q', x)[0], # BE 64-bit Signed int
75: lambda x: struct.unpack('B', x)[0], # 8-bit Unsigned int
76: lambda x: struct.unpack('>H', x)[0], # BE 16-bit Unsigned int
77: lambda x: struct.unpack('>I', x)[0], # BE 32-bit Unsigned int
78: lambda x: struct.unpack('>Q', x)[0], # BE 64-bit Unsigned int
}
@classmethod
def make_data_atom_parser(cls, fieldname):
def parse_data_atom(data_atom):
data_type = struct.unpack('>I', data_atom[:4])[0]
conversion = cls.ATOM_DECODER_BY_TYPE.get(data_type)
if conversion is None:
stderr('Cannot convert data type: %s' % data_type)
return {} # don't know how to convert data atom
# skip header & null-bytes, convert rest
return {fieldname: conversion(data_atom[8:])}
return parse_data_atom
@classmethod
def make_number_parser(cls, fieldname1, fieldname2):
def _(data_atom):
number_data = data_atom[8:14]
numbers = struct.unpack('>HHH', number_data)
# for some reason the first number is always irrelevant.
return {fieldname1: numbers[1], fieldname2: numbers[2]}
return _
@classmethod
def parse_id3v1_genre(cls, data_atom):
# dunno why the genre is offset by -1 but that's how mutagen does it
idx = struct.unpack('>H', data_atom[8:])[0] - 1
if idx < len(ID3.ID3V1_GENRES):
return {'genre': ID3.ID3V1_GENRES[idx]}
return {'genre': None}
@classmethod
def parse_audio_sample_entry(cls, data):
# this atom also contains the esds atom:
# https://ffmpeg.org/doxygen/0.6/mov_8c-source.html
# http://xhelmboyx.tripod.com/formats/mp4-layout.txt
datafh = BytesIO(data)
datafh.seek(16, os.SEEK_CUR) # jump over version and flags
channels = struct.unpack('>H', datafh.read(2))[0]
datafh.seek(2, os.SEEK_CUR) # jump over bit_depth
datafh.seek(2, os.SEEK_CUR) # jump over QT compr id & pkt size
sr = struct.unpack('>I', datafh.read(4))[0]
esds_atom_size = struct.unpack('>I', data[28:32])[0]
esds_atom = BytesIO(data[36:36 + esds_atom_size])
# http://sasperger.tistory.com/103
esds_atom.seek(22, os.SEEK_CUR) # jump over most data...
esds_atom.seek(4, os.SEEK_CUR) # jump over max bitrate
avg_br = struct.unpack('>I', esds_atom.read(4))[0] / 1000.0 # kbit/s
return {'channels': channels, 'samplerate': sr, 'bitrate': avg_br}
@classmethod
def parse_mvhd(cls, data):
# http://stackoverflow.com/a/3639993/1191373
walker = BytesIO(data)
version = struct.unpack('b', walker.read(1))[0]
walker.seek(3, os.SEEK_CUR) # jump over flags
if version == 0: # uses 32 bit integers for timestamps
walker.seek(8, os.SEEK_CUR) # jump over create & mod times
time_scale = struct.unpack('>I', walker.read(4))[0]
duration = struct.unpack('>I', walker.read(4))[0]
else: # version == 1: # uses 64 bit integers for timestamps
walker.seek(16, os.SEEK_CUR) # jump over create & mod times
time_scale = struct.unpack('>I', walker.read(4))[0]
duration = struct.unpack('>q', walker.read(8))[0]
return {'duration': float(duration) / time_scale}
@classmethod
def debug_atom(cls, data):
stderr(data) # use this function to inspect atoms in an atom tree
return {}
# The parser tree: Each key is an atom name which is traversed if existing.
# Leaves of the parser tree are callables which receive the atom data.
# callables return {fieldname: value} which is updates the TinyTag.
META_DATA_TREE = {b'moov': {b'udta': {b'meta': {b'ilst': {
# see: http://atomicparsley.sourceforge.net/mpeg-4files.html
b'\xa9alb': {b'data': Parser.make_data_atom_parser('album')},
b'\xa9ART': {b'data': Parser.make_data_atom_parser('artist')},
b'aART': {b'data': Parser.make_data_atom_parser('albumartist')},
# b'cpil': {b'data': Parser.make_data_atom_parser('compilation')},
b'\xa9cmt': {b'data': Parser.make_data_atom_parser('comment')},
b'disk': {b'data': Parser.make_number_parser('disc', 'disc_total')},
b'\xa9wrt': {b'data': Parser.make_data_atom_parser('composer')},
b'\xa9day': {b'data': Parser.make_data_atom_parser('year')},
b'\xa9gen': {b'data': Parser.make_data_atom_parser('genre')},
b'gnre': {b'data': Parser.parse_id3v1_genre},
b'\xa9nam': {b'data': Parser.make_data_atom_parser('title')},
b'trkn': {b'data': Parser.make_number_parser('track', 'track_total')},
}}}}}
# see: https://developer.apple.com/library/mac/documentation/QuickTime/QTFF/QTFFChap3/qtff3.html
AUDIO_DATA_TREE = {
b'moov': {
b'mvhd': Parser.parse_mvhd,
b'trak': {b'mdia': {b"minf": {b"stbl": {b"stsd": {b'mp4a':
Parser.parse_audio_sample_entry
}}}}}
}
}
IMAGE_DATA_TREE = {b'moov': {b'udta': {b'meta': {b'ilst': {
b'covr': {b'data': Parser.make_data_atom_parser('_image_data')},
}}}}}
VERSIONED_ATOMS = {b'meta', b'stsd'} # those have an extra 4 byte header
FLAGGED_ATOMS = {b'stsd'} # these also have an extra 4 byte header
def _determine_duration(self, fh):
self._traverse_atoms(fh, path=self.AUDIO_DATA_TREE)
def _parse_tag(self, fh):
self._traverse_atoms(fh, path=self.META_DATA_TREE)
if self._load_image: # A bit inefficient, we rewind the file
self._filehandler.seek(0) # to parse it again for the image
self._traverse_atoms(fh, path=self.IMAGE_DATA_TREE)
def _traverse_atoms(self, fh, path, stop_pos=None, curr_path=None):
header_size = 8
atom_header = fh.read(header_size)
while len(atom_header) == header_size:
atom_size = struct.unpack('>I', atom_header[:4])[0] - header_size
atom_type = atom_header[4:]
if curr_path is None: # keep track how we traversed in the tree
curr_path = [atom_type]
if atom_size <= 0: # empty atom, jump to next one
atom_header = fh.read(header_size)
continue
if DEBUG:
stderr('%s pos: %d atom: %s len: %d' % (' ' * 4 * len(curr_path), fh.tell() - header_size, atom_type, atom_size + header_size))
if atom_type in self.VERSIONED_ATOMS: # jump atom version for now
fh.seek(4, os.SEEK_CUR)
if atom_type in self.FLAGGED_ATOMS: # jump atom flags for now
fh.seek(4, os.SEEK_CUR)
sub_path = path.get(atom_type, None)
# if the path leaf is a dict, traverse deeper into the tree:
if issubclass(type(sub_path), MutableMapping):
atom_end_pos = fh.tell() + atom_size
self._traverse_atoms(fh, path=sub_path, stop_pos=atom_end_pos,
curr_path=curr_path + [atom_type])
# if the path-leaf is a callable, call it on the atom data
elif callable(sub_path):
for fieldname, value in sub_path(fh.read(atom_size)).items():
if DEBUG:
stderr(' ' * 4 * len(curr_path), 'FIELD: ', fieldname)
if fieldname:
self._set_field(fieldname, value)
# if no action was specified using dict or callable, jump over atom
else:
fh.seek(atom_size, os.SEEK_CUR)
# check if we have reached the end of this branch:
if stop_pos and fh.tell() >= stop_pos:
return # return to parent (next parent node in tree)
atom_header = fh.read(header_size) # read next atom
class ID3(TinyTag):
FRAME_ID_TO_FIELD = { # Mapping from Frame ID to a field of the TinyTag
'COMM': 'comment', 'COM': 'comment',
'TRCK': 'track', 'TRK': 'track',
'TYER': 'year', 'TYE': 'year',
'TALB': 'album', 'TAL': 'album',
'TPE1': 'artist', 'TP1': 'artist',
'TIT2': 'title', 'TT2': 'title',
'TCON': 'genre', 'TCO': 'genre',
'TPOS': 'disc',
'TPE2': 'albumartist', 'TCOM': 'composer',
}
IMAGE_FRAME_IDS = {'APIC', 'PIC'}
PARSABLE_FRAME_IDS = set(FRAME_ID_TO_FIELD.keys()).union(IMAGE_FRAME_IDS)
_MAX_ESTIMATION_SEC = 30
_CBR_DETECTION_FRAME_COUNT = 5
_USE_XING_HEADER = True # much faster, but can be deactivated for testing
ID3V1_GENRES = [
'Blues', 'Classic Rock', 'Country', 'Dance', 'Disco',
'Funk', 'Grunge', 'Hip-Hop', 'Jazz', 'Metal', 'New Age', 'Oldies',
'Other', 'Pop', 'R&B', 'Rap', 'Reggae', 'Rock', 'Techno', 'Industrial',
'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', 'AlternRock', 'Bass', 'Soul', 'Punk',
'Space', 'Meditative', 'Instrumental Pop', 'Instrumental Rock',
'Ethnic', 'Gothic', 'Darkwave', 'Techno-Industrial', 'Electronic',
'Pop-Folk', 'Eurodance', 'Dream', 'Southern Rock', 'Comedy', 'Cult',
'Gangsta', 'Top 40', 'Christian Rap', 'Pop/Funk', 'Jungle',
'Native American', 'Cabaret', 'New Wave', 'Psychadelic', 'Rave',
'Showtunes', 'Trailer', 'Lo-Fi', 'Tribal', 'Acid Punk', 'Acid Jazz',
'Polka', 'Retro', 'Musical', 'Rock & Roll', 'Hard Rock',
# Wimamp Extended Genres
'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', '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',
'Duet', 'Punk Rock', 'Drum Solo', 'A capella', 'Euro-House',
'Dance Hall', 'Goa', 'Drum & Bass',
# according to https://de.wikipedia.org/wiki/Liste_der_ID3v1-Genres:
'Club-House', 'Hardcore Techno', 'Terror', 'Indie', 'BritPop',
'', # don't use ethnic slur ("Negerpunk", WTF!)
'Polsk Punk', 'Beat', 'Christian Gangsta Rap', 'Heavy Metal',
'Black Metal', 'Contemporary Christian', 'Christian Rock',
# WinAmp 1.91
'Merengue', 'Salsa', 'Thrash Metal', 'Anime', 'Jpop', 'Synthpop',
# WinAmp 5.6
'Abstract', 'Art Rock', 'Baroque', 'Bhangra', 'Big Beat', 'Breakbeat',
'Chillout', 'Downtempo', 'Dub', 'EBM', 'Eclectic', 'Electro',
'Electroclash', 'Emo', 'Experimental', 'Garage', 'Illbient',
'Industro-Goth', 'Jam Band', 'Krautrock', 'Leftfield', 'Lounge',
'Math Rock', 'New Romantic', 'Nu-Breakz', 'Post-Punk', 'Post-Rock',
'Psytrance', 'Shoegaze', 'Space Rock', 'Trop Rock', 'World Music',
'Neoclassical', 'Audiobook', 'Audio Theatre', 'Neue Deutsche Welle',
'Podcast', 'Indie Rock', 'G-Funk', 'Dubstep', 'Garage Rock', 'Psybient',
]
def __init__(self, filehandler, filesize, *args, **kwargs):
TinyTag.__init__(self, filehandler, filesize, *args, **kwargs)
# save position after the ID3 tag for duration mesurement speedup
self._bytepos_after_id3v2 = 0
@classmethod
def set_estimation_precision(cls, estimation_in_seconds):
cls._MAX_ESTIMATION_SEC = estimation_in_seconds
# see this page for the magic values used in mp3:
# http://www.mpgedit.org/mpgedit/mpeg_format/mpeghdr.htm
samplerates = [
[11025, 12000, 8000], # MPEG 2.5
[], # reserved
[22050, 24000, 16000], # MPEG 2
[44100, 48000, 32000], # MPEG 1
]
v1l1 = [0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, 0]
v1l2 = [0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 0]
v1l3 = [0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 0]
v2l1 = [0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0]
v2l2 = [0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0]
v2l3 = v2l2
bitrate_by_version_by_layer = [
[None, v2l3, v2l2, v2l1], # MPEG Version 2.5 # note that the layers go
None, # reserved # from 3 to 1 by design.
[None, v2l3, v2l2, v2l1], # MPEG Version 2 # the first layer id is
[None, v1l3, v1l2, v1l1], # MPEG Version 1 # reserved
]
samples_per_frame = 1152 # the default frame size for mp3
channels_per_channel_mode = [
2, # 00 Stereo
2, # 01 Joint stereo (Stereo)
2, # 10 Dual channel (2 mono channels)
1, # 11 Single channel (Mono)
]
@staticmethod
def _parse_xing_header(fh):
# see: http://www.mp3-tech.org/programmer/sources/vbrheadersdk.zip
fh.seek(4, os.SEEK_CUR) # read over Xing header
header_flags = struct.unpack('>i', fh.read(4))[0]
frames = byte_count = toc = vbr_scale = None
if header_flags & 1: # FRAMES FLAG
frames = struct.unpack('>i', fh.read(4))[0]
if header_flags & 2: # BYTES FLAG
byte_count = struct.unpack('>i', fh.read(4))[0]
if header_flags & 4: # TOC FLAG
toc = [struct.unpack('>i', fh.read(4))[0] for _ in range(100)]
if header_flags & 8: # VBR SCALE FLAG
vbr_scale = struct.unpack('>i', fh.read(4))[0]
return frames, byte_count, toc, vbr_scale
def _determine_duration(self, fh):
max_estimation_frames = (ID3._MAX_ESTIMATION_SEC * 44100) // ID3.samples_per_frame
frame_size_accu = 0
header_bytes = 4
frames = 0 # count frames for determining mp3 duration
bitrate_accu = 0 # add up bitrates to find average bitrate to detect
last_bitrates = [] # CBR mp3s (multiple frames with same bitrates)
# seek to first position after id3 tag (speedup for large header)
fh.seek(self._bytepos_after_id3v2)
while True:
# reading through garbage until 11 '1' sync-bits are found
b = fh.peek(4)
if len(b) < 4:
break # EOF
sync, conf, bitrate_freq, rest = struct.unpack('BBBB', b[0:4])
br_id = (bitrate_freq >> 4) & 0x0F # biterate id
sr_id = (bitrate_freq >> 2) & 0x03 # sample rate id
padding = 1 if bitrate_freq & 0x02 > 0 else 0
mpeg_id = (conf >> 3) & 0x03
layer_id = (conf >> 1) & 0x03
channel_mode = (rest >> 6) & 0x03
# check for eleven 1s, validate bitrate and sample rate
if not b[:2] > b'\xFF\xE0' or br_id > 14 or br_id == 0 or sr_id == 3 or layer_id == 0 or mpeg_id == 1:
idx = b.find(b'\xFF', 1) # invalid frame, find next sync header
if idx == -1:
idx = len(b) # not found: jump over the current peek buffer
fh.seek(max(idx, 1), os.SEEK_CUR)
continue
try:
self.channels = self.channels_per_channel_mode[channel_mode]
frame_bitrate = ID3.bitrate_by_version_by_layer[mpeg_id][layer_id][br_id]
self.samplerate = ID3.samplerates[mpeg_id][sr_id]
except (IndexError, TypeError):
raise TinyTagException('mp3 parsing failed')
# There might be a xing header in the first frame that contains
# all the info we need, otherwise parse multiple frames to find the
# accurate average bitrate
if frames == 0 and ID3._USE_XING_HEADER:
xing_header_offset = b.find(b'Xing')
if xing_header_offset != -1:
fh.seek(xing_header_offset, os.SEEK_CUR)
xframes, byte_count, toc, vbr_scale = ID3._parse_xing_header(fh)
if xframes and xframes != 0 and byte_count:
self.duration = xframes * ID3.samples_per_frame / float(self.samplerate)
self.bitrate = int(byte_count * 8 / self.duration / 1000)
self.audio_offset = fh.tell()
return
continue
frames += 1 # it's most probably an mp3 frame
bitrate_accu += frame_bitrate
if frames == 1:
self.audio_offset = fh.tell()
if frames <= ID3._CBR_DETECTION_FRAME_COUNT:
last_bitrates.append(frame_bitrate)
fh.seek(4, os.SEEK_CUR) # jump over peeked bytes
frame_length = (144000 * frame_bitrate) // self.samplerate + padding
frame_size_accu += frame_length
# if bitrate does not change over time its probably CBR
is_cbr = (frames == ID3._CBR_DETECTION_FRAME_COUNT and
len(set(last_bitrates)) == 1)
if frames == max_estimation_frames or is_cbr:
# try to estimate duration
fh.seek(-128, 2) # jump to last byte (leaving out id3v1 tag)
audio_stream_size = fh.tell() - self.audio_offset
est_frame_count = audio_stream_size / (frame_size_accu / float(frames))
samples = est_frame_count * ID3.samples_per_frame
self.duration = samples / float(self.samplerate)
self.bitrate = int(bitrate_accu / frames)
return
if frame_length > 1: # jump over current frame body
fh.seek(frame_length - header_bytes, os.SEEK_CUR)
if self.samplerate:
self.duration = frames * ID3.samples_per_frame / float(self.samplerate)
def _parse_tag(self, fh):
self._parse_id3v2(fh)
attrs = ['track', 'track_total', 'title', 'artist', 'album', 'albumartist', 'year', 'genre']
has_all_tags = all(getattr(self, attr) for attr in attrs)
if not has_all_tags and self.filesize > 128:
fh.seek(-128, os.SEEK_END) # try parsing id3v1 in last 128 bytes
self._parse_id3v1(fh)
def _parse_id3v2(self, fh):
# for info on the specs, see: http://id3.org/Developer%20Information
header = struct.unpack('3sBBB4B', _read(fh, 10))
tag = codecs.decode(header[0], 'ISO-8859-1')
# check if there is an ID3v2 tag at the beginning of the file
if tag == 'ID3':
major, rev = header[1:3]
if DEBUG:
stderr('Found id3 v2.%s' % major)
# unsync = (header[3] & 0x80) > 0
extended = (header[3] & 0x40) > 0
# experimental = (header[3] & 0x20) > 0
# footer = (header[3] & 0x10) > 0
size = self._calc_size(header[4:8], 7)
self._bytepos_after_id3v2 = size
end_pos = fh.tell() + size
parsed_size = 0
if extended: # just read over the extended header.
size_bytes = struct.unpack('4B', _read(fh, 6)[0:4])
extd_size = self._calc_size(size_bytes, 7)
fh.seek(extd_size - 6, os.SEEK_CUR) # jump over extended_header
while parsed_size < size:
frame_size = self._parse_frame(fh, id3version=major)
if frame_size == 0:
break
parsed_size += frame_size
fh.seek(end_pos, os.SEEK_SET)
def _parse_id3v1(self, fh):
if fh.read(3) == b'TAG': # check if this is an ID3 v1 tag
def asciidecode(x):
return self._unpad(codecs.decode(x, 'latin1'))
fields = fh.read(30 + 30 + 30 + 4 + 30 + 1)
self._set_field('title', fields[:30], transfunc=asciidecode)
self._set_field('artist', fields[30:60], transfunc=asciidecode)
self._set_field('album', fields[60:90], transfunc=asciidecode)
self._set_field('year', fields[90:94], transfunc=asciidecode)
comment = fields[94:124]
if b'\x00\x00' < comment[-2:] < b'\x01\x00':
self._set_field('track', str(ord(comment[-1:])))
comment = comment[:-2]
self._set_field('comment', comment, transfunc=asciidecode)
genre_id = ord(fields[124:125])
if genre_id < len(ID3.ID3V1_GENRES):
self.genre = ID3.ID3V1_GENRES[genre_id]
def _parse_frame(self, fh, id3version=False):
# ID3v2.2 especially ugly. see: http://id3.org/id3v2-00
frame_header_size = 6 if id3version == 2 else 10
frame_size_bytes = 3 if id3version == 2 else 4
binformat = '3s3B' if id3version == 2 else '4s4B2B'
bits_per_byte = 7 if id3version == 4 else 8 # only id3v2.4 is synchsafe
frame_header_data = fh.read(frame_header_size)
if len(frame_header_data) != frame_header_size:
return 0
frame = struct.unpack(binformat, frame_header_data)
frame_id = self._decode_string(frame[0])
frame_size = self._calc_size(frame[1:1+frame_size_bytes], bits_per_byte)
if DEBUG:
stderr('Found id3 Frame %s at %d-%d of %d' % (frame_id, fh.tell(), fh.tell() + frame_size, self.filesize))
if frame_size > 0:
# flags = frame[1+frame_size_bytes:] # dont care about flags.
if frame_id not in ID3.PARSABLE_FRAME_IDS: # jump over unparsable frames
fh.seek(frame_size, os.SEEK_CUR)
return frame_size
content = fh.read(frame_size)
fieldname = ID3.FRAME_ID_TO_FIELD.get(frame_id)
if fieldname:
self._set_field(fieldname, content, self._decode_string)
elif frame_id in self.IMAGE_FRAME_IDS and self._load_image:
# See section 4.14: http://id3.org/id3v2.4.0-frames
if frame_id == 'PIC': # ID3 v2.2:
desc_end_pos = content.index(b'\x00', 1) + 1
else: # ID3 v2.3+
mimetype_end_pos = content.index(b'\x00', 1) + 1
desc_start_pos = mimetype_end_pos + 1 # jump over picture type
desc_end_pos = content.index(b'\x00', desc_start_pos) + 1
if content[desc_end_pos:desc_end_pos+1] == b'\x00':
desc_end_pos += 1 # the description ends with 1 or 2 null bytes
self._image_data = content[desc_end_pos:]
return frame_size
return 0
def _decode_string(self, bytestr):
try: # it's not my fault, this is the spec.
first_byte = bytestr[:1]
if first_byte == b'\x00': # ISO-8859-1
bytestr = bytestr[1:]
encoding = 'ISO-8859-1'
elif first_byte == b'\x01': # UTF-16 with BOM
bytestr = bytestr[1:]
if bytestr[:5] == b'eng\xff\xfe':
bytestr = bytestr[3:] # remove language (but leave BOM)
if bytestr[:5] == b'eng\xfe\xff':
bytestr = bytestr[3:] # remove language (but leave BOM)
if bytestr[:4] == b'eng\x00':
bytestr = bytestr[4:] # remove language
if bytestr[:1] == b'\x00':
bytestr = bytestr[1:] # strip optional additional null byte
# read byte order mark to determine endianess
encoding = 'UTF-16be' if bytestr[0:2] == b'\xfe\xff' else 'UTF-16le'
# strip the bom and optional null bytes
bytestr = bytestr[2:] if len(bytestr) % 2 == 0 else bytestr[2:-1]
# remove ADDITIONAL EXTRA BOM :facepalm:
if bytestr[:4] == b'\x00\x00\xff\xfe':
bytestr = bytestr[4:]
elif first_byte == b'\x02': # UTF-16LE
# strip optional null byte, if byte count uneven
bytestr = bytestr[1:-1] if len(bytestr) % 2 == 0 else bytestr[1:]
encoding = 'UTF-16le'
elif first_byte == b'\x03': # UTF-8
bytestr = bytestr[1:]
encoding = 'UTF-8'
else:
bytestr = bytestr
encoding = 'ISO-8859-1' # wild guess
if bytestr[:4] == b'eng\x00':
bytestr = bytestr[4:] # remove language
errors = 'ignore' if self._ignore_errors else 'strict'
return self._unpad(codecs.decode(bytestr, encoding, errors))
except UnicodeDecodeError:
raise TinyTagException('Error decoding ID3 Tag!')
def _calc_size(self, bytestr, bits_per_byte):
# length of some mp3 header fields is described by 7 or 8-bit-bytes
return reduce(lambda accu, elem: (accu << bits_per_byte) + elem, bytestr, 0)
class Ogg(TinyTag):
def __init__(self, filehandler, filesize, *args, **kwargs):
TinyTag.__init__(self, filehandler, filesize, *args, **kwargs)
self._tags_parsed = False
self._max_samplenum = 0 # maximum sample position ever read
def _determine_duration(self, fh):
max_page_size = 65536 # https://xiph.org/ogg/doc/libogg/ogg_page.html
if not self._tags_parsed:
self._parse_tag(fh) # determine sample rate
fh.seek(0) # and rewind to start
if self.filesize > max_page_size:
fh.seek(-max_page_size, 2) # go to last possible page position
while True:
b = fh.peek(4)
if len(b) == 0:
return # EOF
if b[:4] == b'OggS': # look for an ogg header
for _ in self._parse_pages(fh):
pass # parse all remaining pages
self.duration = self._max_samplenum / float(self.samplerate)
else:
idx = b.find(b'OggS') # try to find header in peeked data
seekpos = idx if idx != -1 else len(b) - 3
fh.seek(max(seekpos, 1), os.SEEK_CUR)
def _parse_tag(self, fh):
page_start_pos = fh.tell() # set audio_offest later if its audio data
for packet in self._parse_pages(fh):
walker = BytesIO(packet)
if packet[0:7] == b"\x01vorbis":
(channels, self.samplerate, max_bitrate, bitrate,
min_bitrate) = struct.unpack("<B4i", packet[11:28])
if not self.audio_offset:
self.bitrate = bitrate / 1024.0
self.audio_offset = page_start_pos
elif packet[0:7] == b"\x03vorbis":
walker.seek(7, os.SEEK_CUR) # jump over header name
self._parse_vorbis_comment(walker)
elif packet[0:8] == b'OpusHead': # parse opus header
# https://www.videolan.org/developers/vlc/modules/codec/opus_header.c
# https://mf4.xiph.org/jenkins/view/opus/job/opusfile-unix/ws/doc/html/structOpusHead.html
walker.seek(8, os.SEEK_CUR) # jump over header name
(version, ch, _, sr, _, _) = struct.unpack("<BBHIHB", walker.read(11))
if (version & 0xF0) == 0: # only major version 0 supported
self.channels = ch
self.samplerate = 48000 # internally opus always uses 48khz
elif packet[0:8] == b'OpusTags': # parse opus metadata:
walker.seek(8, os.SEEK_CUR) # jump over header name
self._parse_vorbis_comment(walker)
else:
break
page_start_pos = fh.tell()
def _parse_vorbis_comment(self, fh):
# for the spec, see: http://xiph.org/vorbis/doc/v-comment.html
# discnumber tag based on: https://en.wikipedia.org/wiki/Vorbis_comment
# https://sno.phy.queensu.ca/~phil/exiftool/TagNames/Vorbis.html
comment_type_to_attr_mapping = {
'album': 'album',
'albumartist': 'albumartist',
'title': 'title',
'artist': 'artist',
'date': 'year',
'tracknumber': 'track',
'discnumber': 'disc',
'genre': 'genre',
'description': 'comment',
'composer': 'composer',
}
vendor_length = struct.unpack('I', fh.read(4))[0]
fh.seek(vendor_length, os.SEEK_CUR) # jump over vendor
elements = struct.unpack('I', fh.read(4))[0]
for i in range(elements):
length = struct.unpack('I', fh.read(4))[0]
try:
keyvalpair = codecs.decode(fh.read(length), 'UTF-8')
except UnicodeDecodeError:
continue
if '=' in keyvalpair:
key, value = keyvalpair.split('=', 1)
fieldname = comment_type_to_attr_mapping.get(key.lower())
if fieldname:
self._set_field(fieldname, value)
def _parse_pages(self, fh):
# for the spec, see: https://wiki.xiph.org/Ogg
previous_page = b'' # contains data from previous (continuing) pages
header_data = fh.read(27) # read ogg page header
while len(header_data) != 0:
header = struct.unpack('<4sBBqIIiB', header_data)
oggs, version, flags, pos, serial, pageseq, crc, segments = header
self._max_samplenum = max(self._max_samplenum, pos)
if oggs != b'OggS' or version != 0:
raise TinyTagException('Not a valid ogg file!')
segsizes = struct.unpack('B'*segments, fh.read(segments))
total = 0
for segsize in segsizes: # read all segments
total += segsize
if total < 255: # less than 255 bytes means end of page
yield previous_page + fh.read(total)
previous_page = b''
total = 0
if total != 0:
if total % 255 == 0:
previous_page += fh.read(total)
else:
yield previous_page + fh.read(total)
previous_page = b''
header_data = fh.read(27)
class Wave(TinyTag):
# https://sno.phy.queensu.ca/~phil/exiftool/TagNames/RIFF.html
riff_mapping = {
b'INAM': 'title',
b'TITL': 'title',
b'IART': 'artist',
b'ICMT': 'comment',
b'ICRD': 'year',
b'IGNR': 'genre',
b'TRCK': 'track',
b'PRT1': 'track',
b'PRT2': 'track_number',
b'YEAR': 'year',
# riff format is lacking the composer field.
}
def __init__(self, filehandler, filesize, *args, **kwargs):
TinyTag.__init__(self, filehandler, filesize, *args, **kwargs)
self._duration_parsed = False
def _determine_duration(self, fh):
# see: https://ccrma.stanford.edu/courses/422/projects/WaveFormat/
# and: https://en.wikipedia.org/wiki/WAV
riff, size, fformat = struct.unpack('4sI4s', fh.read(12))
if riff != b'RIFF' or fformat != b'WAVE':
raise TinyTagException('not a wave file!')
bitdepth = 16 # assume 16bit depth (CD quality)
chunk_header = fh.read(8)
while len(chunk_header) == 8:
subchunkid, subchunksize = struct.unpack('4sI', chunk_header)
if subchunkid == b'fmt ':
_, self.channels, self.samplerate = struct.unpack('HHI', fh.read(8))
_, _, bitdepth = struct.unpack('<IHH', fh.read(8))
self.bitrate = self.samplerate * self.channels * bitdepth / 1024.0
elif subchunkid == b'data':
self.duration = float(subchunksize)/self.channels/self.samplerate/(bitdepth/8)
self.audio_offest = fh.tell() - 8 # rewind to data header
fh.seek(subchunksize, 1)
elif subchunkid == b'LIST':
is_info = fh.read(4) # check INFO header
if is_info != b'INFO': # jump over non-INFO sections
fh.seek(subchunksize - 4, os.SEEK_CUR)
else:
sub_fh = BytesIO(fh.read(subchunksize - 4))
field = sub_fh.read(4)
while len(field) == 4:
data_length = struct.unpack('I', sub_fh.read(4))[0]
data = sub_fh.read(data_length).split(b'\x00', 1)[0] # strip zero-byte
data = codecs.decode(data, 'utf-8')
fieldname = self.riff_mapping.get(field)
if fieldname:
self._set_field(fieldname, data)
field = sub_fh.read(4)
elif subchunkid == b'id3 ' or subchunkid == b'ID3 ':
id3 = ID3(fh, 0)
id3._parse_id3v2(fh)
self.update(id3)
else: # some other chunk, just skip the data
fh.seek(subchunksize, 1)
chunk_header = fh.read(8)
self._duration_parsed = True
def _parse_tag(self, fh):
if not self._duration_parsed:
self._determine_duration(fh) # parse whole file to determine tags:(
class Flac(TinyTag):
METADATA_STREAMINFO = 0
METADATA_VORBIS_COMMENT = 4
def load(self, tags, duration, image=False):
header = self._filehandler.peek(4)
if header[:3] == b'ID3': # parse ID3 header if it exists
id3 = ID3(self._filehandler, 0)
id3._parse_id3v2(self._filehandler)
self.update(id3)
header = self._filehandler.peek(4) # after ID3 should be fLaC
if header[:4] != b'fLaC':
raise TinyTagException('Invalid flac header')
self._filehandler.seek(4, os.SEEK_CUR)
self._determine_duration(self._filehandler, skip_tags=not tags)
def _determine_duration(self, fh, skip_tags=False):
# for spec, see https://xiph.org/flac/ogg_mapping.html
header_data = fh.read(4)
while len(header_data):
meta_header = struct.unpack('B3B', header_data)
block_type = meta_header[0] & 0x7f
is_last_block = meta_header[0] & 0x80
size = _bytes_to_int(meta_header[1:4])
# http://xiph.org/flac/format.html#metadata_block_streaminfo
if block_type == Flac.METADATA_STREAMINFO:
stream_info_header = fh.read(size)
if len(stream_info_header) < 34: # invalid streaminfo
return
header = struct.unpack('HH3s3s8B16s', stream_info_header)
# From the ciph documentation:
# py | <bits>
# ----------------------------------------------
# H | <16> The minimum block size (in samples)
# H | <16> The maximum block size (in samples)
# 3s | <24> The minimum frame size (in bytes)
# 3s | <24> The maximum frame size (in bytes)
# 8B | <20> Sample rate in Hz.
# | <3> (number of channels)-1.
# | <5> (bits per sample)-1.
# | <36> Total samples in stream.
# 16s| <128> MD5 signature
# min_blk, max_blk, min_frm, max_frm = header[0:4]
# min_frm = _bytes_to_int(struct.unpack('3B', min_frm))
# max_frm = _bytes_to_int(struct.unpack('3B', max_frm))
# channels--. bits total samples
# |----- samplerate -----| |-||----| |---------~ ~----|
# 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
# #---4---# #---5---# #---6---# #---7---# #--8-~ ~-12-#
self.samplerate = _bytes_to_int(header[4:7]) >> 4
self.channels = ((header[6] >> 1) & 0x07) + 1
# bit_depth = ((header[6] & 1) << 4) + ((header[7] & 0xF0) >> 4)
# bit_depth = (bit_depth + 1)
total_sample_bytes = [(header[7] & 0x0F)] + list(header[8:12])
total_samples = _bytes_to_int(total_sample_bytes)
self.duration = float(total_samples) / self.samplerate
if self.duration > 0:
self.bitrate = self.filesize / self.duration * 8 / 1024
elif block_type == Flac.METADATA_VORBIS_COMMENT and not skip_tags:
oggtag = Ogg(fh, 0)
oggtag._parse_vorbis_comment(fh)
self.update(oggtag)
elif block_type >= 127:
return # invalid block type
else:
fh.seek(size, 1) # seek over this block
if is_last_block:
return
header_data = fh.read(4)
class Wma(TinyTag):
ASF_CONTENT_DESCRIPTION_OBJECT = b'3&\xb2u\x8ef\xcf\x11\xa6\xd9\x00\xaa\x00b\xcel'
ASF_EXTENDED_CONTENT_DESCRIPTION_OBJECT = b'@\xa4\xd0\xd2\x07\xe3\xd2\x11\x97\xf0\x00\xa0\xc9^\xa8P'
STREAM_BITRATE_PROPERTIES_OBJECT = b'\xceu\xf8{\x8dF\xd1\x11\x8d\x82\x00`\x97\xc9\xa2\xb2'
ASF_FILE_PROPERTY_OBJECT = b'\xa1\xdc\xab\x8cG\xa9\xcf\x11\x8e\xe4\x00\xc0\x0c Se'
ASF_STREAM_PROPERTIES_OBJECT = b'\x91\x07\xdc\xb7\xb7\xa9\xcf\x11\x8e\xe6\x00\xc0\x0c Se'
STREAM_TYPE_ASF_AUDIO_MEDIA = b'@\x9ei\xf8M[\xcf\x11\xa8\xfd\x00\x80_\\D+'
# see:
# http://web.archive.org/web/20131203084402/http://msdn.microsoft.com/en-us/library/bb643323.aspx
# and (japanese, but none the less helpful)
# http://uguisu.skr.jp/Windows/format_asf.html
def __init__(self, filehandler, filesize, *args, **kwargs):
TinyTag.__init__(self, filehandler, filesize, *args, **kwargs)
self.__tag_parsed = False
def _determine_duration(self, fh):
if not self.__tag_parsed:
self._parse_tag(fh)
def read_blocks(self, fh, blocks):
# blocks are a list(tuple('fieldname', byte_count, cast_int), ...)
decoded = {}
for block in blocks:
val = fh.read(block[1])
if block[2]:
val = _bytes_to_int_le(val)
decoded[block[0]] = val
return decoded
def __bytes_to_guid(self, obj_id_bytes):
return '-'.join([
hex(_bytes_to_int_le(obj_id_bytes[:-12]))[2:].zfill(6),
hex(_bytes_to_int_le(obj_id_bytes[-12:-10]))[2:].zfill(4),
hex(_bytes_to_int_le(obj_id_bytes[-10:-8]))[2:].zfill(4),
hex(_bytes_to_int(obj_id_bytes[-8:-6]))[2:].zfill(4),
hex(_bytes_to_int(obj_id_bytes[-6:]))[2:].zfill(12),
])
def __decode_string(self, bytestring):
return self._unpad(codecs.decode(bytestring, 'utf-16'))
def __decode_ext_desc(self, value_type, value):
""" decode ASF_EXTENDED_CONTENT_DESCRIPTION_OBJECT values"""
if value_type == 0: # Unicode string
return self.__decode_string(value)
elif value_type == 1: # BYTE array
return value
elif 1 < value_type < 6: # DWORD / QWORD / WORD
return _bytes_to_int_le(value)
def _parse_tag(self, fh):
self.__tag_parsed = True
guid = fh.read(16) # 128 bit GUID
if guid != b'0&\xb2u\x8ef\xcf\x11\xa6\xd9\x00\xaa\x00b\xcel':
return # not a valid ASF container! see: http://www.garykessler.net/library/file_sigs.html
struct.unpack('Q', fh.read(8))[0] # size
struct.unpack('I', fh.read(4))[0] # obj_count
if fh.read(2) != b'\x01\x02':
# http://web.archive.org/web/20131203084402/http://msdn.microsoft.com/en-us/library/bb643323.aspx#_Toc521913958
return # not a valid asf header!
while True:
object_id = fh.read(16)
object_size = _bytes_to_int_le(fh.read(8))
if object_size == 0 or object_size > self.filesize:
break # invalid object, stop parsing.
if object_id == Wma.ASF_CONTENT_DESCRIPTION_OBJECT:
len_blocks = self.read_blocks(fh, [
('title_length', 2, True),
('author_length', 2, True),
('copyright_length', 2, True),
('description_length', 2, True),
('rating_length', 2, True),
])
data_blocks = self.read_blocks(fh, [
('title', len_blocks['title_length'], False),
('artist', len_blocks['author_length'], False),
('', len_blocks['copyright_length'], True),
('comment', len_blocks['description_length'], False),
('', len_blocks['rating_length'], True),
])
for field_name, bytestring in data_blocks.items():
if field_name:
self._set_field(field_name, bytestring, self.__decode_string)
elif object_id == Wma.ASF_EXTENDED_CONTENT_DESCRIPTION_OBJECT:
mapping = {
'WM/TrackNumber': 'track',
'WM/PartOfSet': 'disc',
'WM/Year': 'year',
'WM/AlbumArtist': 'albumartist',
'WM/Genre': 'genre',
'WM/AlbumTitle': 'album',
'WM/Composer': 'composer',
}
# see: http://web.archive.org/web/20131203084402/http://msdn.microsoft.com/en-us/library/bb643323.aspx#_Toc509555195
descriptor_count = _bytes_to_int_le(fh.read(2))
for _ in range(descriptor_count):
name_len = _bytes_to_int_le(fh.read(2))
name = self.__decode_string(fh.read(name_len))
value_type = _bytes_to_int_le(fh.read(2))
value_len = _bytes_to_int_le(fh.read(2))
value = fh.read(value_len)
field_name = mapping.get(name)
if field_name:
field_value = self.__decode_ext_desc(value_type, value)
self._set_field(field_name, field_value)
elif object_id == Wma.ASF_FILE_PROPERTY_OBJECT:
blocks = self.read_blocks(fh, [
('file_id', 16, False),
('file_size', 8, False),
('creation_date', 8, True),
('data_packets_count', 8, True),
('play_duration', 8, True),
('send_duration', 8, True),
('preroll', 8, True),
('flags', 4, False),
('minimum_data_packet_size', 4, True),
('maximum_data_packet_size', 4, True),
('maximum_bitrate', 4, False),
])
self.duration = blocks.get('play_duration') / float(10000000)
elif object_id == Wma.ASF_STREAM_PROPERTIES_OBJECT:
blocks = self.read_blocks(fh, [
('stream_type', 16, False),
('error_correction_type', 16, False),
('time_offset', 8, True),
('type_specific_data_length', 4, True),
('error_correction_data_length', 4, True),
('flags', 2, True),
('reserved', 4, False)
])
already_read = 0
if blocks['stream_type'] == Wma.STREAM_TYPE_ASF_AUDIO_MEDIA:
stream_info = self.read_blocks(fh, [
('codec_id_format_tag', 2, True),
('number_of_channels', 2, True),
('samples_per_second', 4, True),
('avg_bytes_per_second', 4, True),
('block_alignment', 2, True),
('bits_per_sample', 2, True),
])
self.samplerate = stream_info['samples_per_second']
self.bitrate = stream_info['avg_bytes_per_second'] * 8 / float(1000)
already_read = 16
fh.seek(blocks['type_specific_data_length'] - already_read, os.SEEK_CUR)
fh.seek(blocks['error_correction_data_length'], os.SEEK_CUR)
else:
fh.seek(object_size - 24, os.SEEK_CUR) # read over onknown object ids