/usr/lib/python2.7/dist-packages/mutagen/oggopus.py is in python-mutagen 1.36-1.
This file is owned by root:root, with mode 0o644.
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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 | # -*- coding: utf-8 -*-
# Copyright (C) 2012, 2013 Christoph Reiter
#
# 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.
"""Read and write Ogg Opus comments.
This module handles Opus files wrapped in an Ogg bitstream. The
first Opus stream found is used.
Based on http://tools.ietf.org/html/draft-terriberry-oggopus-01
"""
__all__ = ["OggOpus", "Open", "delete"]
import struct
from mutagen import StreamInfo
from mutagen._compat import BytesIO
from mutagen._util import get_size, loadfile, convert_error
from mutagen._tags import PaddingInfo
from mutagen._vorbis import VCommentDict
from mutagen.ogg import OggPage, OggFileType, error as OggError
class error(OggError):
pass
class OggOpusHeaderError(error):
pass
class OggOpusInfo(StreamInfo):
"""OggOpusInfo()
Ogg Opus stream information.
Attributes:
length (`float`): File length in seconds, as a float
channels (`int`): Number of channels
"""
length = 0
channels = 0
def __init__(self, fileobj):
page = OggPage(fileobj)
while not page.packets[0].startswith(b"OpusHead"):
page = OggPage(fileobj)
self.serial = page.serial
if not page.first:
raise OggOpusHeaderError(
"page has ID header, but doesn't start a stream")
(version, self.channels, pre_skip, orig_sample_rate, output_gain,
channel_map) = struct.unpack("<BBHIhB", page.packets[0][8:19])
self.__pre_skip = pre_skip
# only the higher 4 bits change on incombatible changes
major = version >> 4
if major != 0:
raise OggOpusHeaderError("version %r unsupported" % major)
def _post_tags(self, fileobj):
page = OggPage.find_last(fileobj, self.serial)
if page is None:
raise OggOpusHeaderError
self.length = (page.position - self.__pre_skip) / float(48000)
def pprint(self):
return u"Ogg Opus, %.2f seconds" % (self.length)
class OggOpusVComment(VCommentDict):
"""Opus comments embedded in an Ogg bitstream."""
def __get_comment_pages(self, fileobj, info):
# find the first tags page with the right serial
page = OggPage(fileobj)
while ((info.serial != page.serial) or
not page.packets[0].startswith(b"OpusTags")):
page = OggPage(fileobj)
# get all comment pages
pages = [page]
while not (pages[-1].complete or len(pages[-1].packets) > 1):
page = OggPage(fileobj)
if page.serial == pages[0].serial:
pages.append(page)
return pages
def __init__(self, fileobj, info):
pages = self.__get_comment_pages(fileobj, info)
data = OggPage.to_packets(pages)[0][8:] # Strip OpusTags
fileobj = BytesIO(data)
super(OggOpusVComment, self).__init__(fileobj, framing=False)
self._padding = len(data) - self._size
# in case the LSB of the first byte after v-comment is 1, preserve the
# following data
padding_flag = fileobj.read(1)
if padding_flag and ord(padding_flag) & 0x1:
self._pad_data = padding_flag + fileobj.read()
self._padding = 0 # we have to preserve, so no padding
else:
self._pad_data = b""
def _inject(self, fileobj, padding_func):
fileobj.seek(0)
info = OggOpusInfo(fileobj)
old_pages = self.__get_comment_pages(fileobj, info)
packets = OggPage.to_packets(old_pages)
vcomment_data = b"OpusTags" + self.write(framing=False)
if self._pad_data:
# if we have padding data to preserver we can't add more padding
# as long as we don't know the structure of what follows
packets[0] = vcomment_data + self._pad_data
else:
content_size = get_size(fileobj) - len(packets[0]) # approx
padding_left = len(packets[0]) - len(vcomment_data)
info = PaddingInfo(padding_left, content_size)
new_padding = info._get_padding(padding_func)
packets[0] = vcomment_data + b"\x00" * new_padding
new_pages = OggPage._from_packets_try_preserve(packets, old_pages)
OggPage.replace(fileobj, old_pages, new_pages)
class OggOpus(OggFileType):
"""OggOpus(filething)
An Ogg Opus file.
Arguments:
filething (filething)
Attributes:
info (`OggOpusInfo`)
tags (`mutagen._vorbis.VCommentDict`)
"""
_Info = OggOpusInfo
_Tags = OggOpusVComment
_Error = OggOpusHeaderError
_mimes = ["audio/ogg", "audio/ogg; codecs=opus"]
info = None
tags = None
@staticmethod
def score(filename, fileobj, header):
return (header.startswith(b"OggS") * (b"OpusHead" in header))
Open = OggOpus
@convert_error(IOError, error)
@loadfile(method=False, writable=True)
def delete(filething):
""" delete(filething)
Arguments:
filething (filething)
Raises:
mutagen.MutagenError
Remove tags from a file.
"""
t = OggOpus(filething)
filething.fileobj.seek(0)
t.delete(filething)
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