/usr/lib/python3/dist-packages/audiotools/accuraterip.py is in audiotools 3.1.1-1.1.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 | # Audio Tools, a module and set of tools for manipulating audio data
# Copyright (C) 2007-2015 Brian Langenberger
# 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
# MERCHANTABILITY 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
from audiotools import PY3
from audiotools._accuraterip import Checksum
class __Checksum__(object):
"""Python implementation of checksum calculator"""
def __init__(self, total_pcm_frames,
sample_rate=44100,
is_first=False,
is_last=False,
pcm_frame_range=1):
if total_pcm_frames <= 0:
raise ValueError("total PCM frames must be > 0")
if sample_rate <= 0:
raise ValueError("sample rate must be > 0")
if pcm_frame_range <= 0:
raise ValueError("PCM frame range must be > 0")
self.__total_pcm_frames__ = total_pcm_frames
self.__pcm_frame_range__ = pcm_frame_range
self.__values__ = []
if is_first:
self.__start_offset__ = ((sample_rate // 75) * 5)
else:
self.__start_offset__ = 1
if is_last:
self.__end_offset__ = (total_pcm_frames -
((sample_rate // 75) * 5))
else:
self.__end_offset__ = total_pcm_frames
def update(self, framelist):
from itertools import izip
from audiotools.pcm import FrameList
def value(l, r):
return (unsigned(r) << 16) | unsigned(l)
def unsigned(v):
return (v if (v >= 0) else ((1 << 16) - (-v)))
if not isinstance(framelist, FrameList):
raise TypeError("framelist must be instance of Framelist")
elif framelist.channels != 2:
raise ValueError("FrameList must have 2 channels")
elif framelist.bits_per_sample != 16:
raise ValueError("FrameList must have 16 bits-per-sample")
if ((len(self.__values__) +
framelist.frames) > (self.__total_pcm_frames__ +
self.__pcm_frame_range__ - 1)):
raise ValueError("too many samples for checksum")
self.__values__.extend(
[value(l, r) for (l, r) in izip(framelist.channel(0),
framelist.channel(1))])
def checksums_v1(self):
if (len(self.__values__) < (self.__total_pcm_frames__ +
self.__pcm_frame_range__ - 1)):
raise ValueError("insufficient samples for checksum")
return [sum([(v * i) if
((i >= self.__start_offset__) and
(i <= self.__end_offset__)) else 0
for (i, v) in
enumerate(self.__values__[r:
r + self.__total_pcm_frames__],
1)]) & 0xFFFFFFFF
for r in range(self.__pcm_frame_range__)]
def checksums_v2(self):
if (len(self.__values__) < (self.__total_pcm_frames__ +
self.__pcm_frame_range__ - 1)):
raise ValueError("insufficient samples for checksum")
def combine(x):
return (x >> 32) + (x & 0xFFFFFFFF)
return [sum([combine(v * i) if
((i >= self.__start_offset__) and
(i <= self.__end_offset__)) else 0
for (i, v) in
enumerate(self.__values__[r:
r + self.__total_pcm_frames__],
1)]) & 0xFFFFFFFF
for r in range(self.__pcm_frame_range__)]
def match_offset(ar_matches, checksums, initial_offset):
"""ar_matches is a list of (confidence, crc, crc2) tuples
checksums is a list of calculated AccurateRip crcs
initial_offset is the starting offset of the checksums
returns (checksum, confidence, offset) of the best match found
if no matches are found, confidence is None and offset is 0
"""
if len(checksums) == 0:
raise ValueError("at least 1 checksum is required")
# crc should be unique in the list
# but confidence may not be
matches = {crc: confidence for (confidence, crc, crc2) in
ar_matches}
offsets = {crc: offset for (offset, crc) in
enumerate(checksums, initial_offset)}
match_offsets = sorted(
[(crc, matches[crc], offsets[crc]) for crc in
set(matches.keys()) & set(offsets.keys())],
key=lambda triple: triple[1])
if len(match_offsets) > 0:
# choose the match with the highest confidence
return match_offsets[-1]
else:
# no match found
# return checksum at offset 0, or as close as possible
if initial_offset <= 0:
return (checksums[-initial_offset], None, 0)
else:
return (checksums[0], None, initial_offset)
class DiscID(object):
def __init__(self, track_numbers, track_offsets,
lead_out_offset, freedb_disc_id):
"""track_numbers is a list of track numbers, starting from 1
track_offsets is a list of offsets, in CD frames
and typically starting from 0
lead_out_offset is the offset of the lead-out track, in CD frames
freedb_disc_id is a string or freedb.DiscID object of the CD
"""
assert(len(track_numbers) == len(track_offsets))
self.__track_numbers__ = track_numbers
self.__track_offsets__ = track_offsets
self.__lead_out_offset__ = lead_out_offset
self.__freedb_disc_id__ = freedb_disc_id
@classmethod
def from_cddareader(cls, cddareader):
"""given a CDDAReader object, returns a DiscID for that object"""
from audiotools.freedb import DiscID as FDiscID
offsets = cddareader.track_offsets
return cls(track_numbers=list(sorted(offsets.keys())),
track_offsets=[(offsets[k] // 588) for k in
sorted(offsets.keys())],
lead_out_offset=cddareader.last_sector + 1,
freedb_disc_id=FDiscID.from_cddareader(cddareader))
@classmethod
def from_tracks(cls, tracks):
"""given a sorted list of AudioFile objects,
returns DiscID for those tracks as if they were a CD"""
from audiotools.freedb import DiscID as FDiscID
offsets = [0]
for track in tracks[0:-1]:
offsets.append(offsets[-1] + track.cd_frames())
return cls(track_numbers=range(1, len(tracks) + 1),
track_offsets=offsets,
lead_out_offset=sum([t.cd_frames() for t in tracks]),
freedb_disc_id=FDiscID.from_tracks(tracks))
@classmethod
def from_sheet(cls, sheet, total_pcm_frames, sample_rate):
"""given a Sheet object
length of the album in PCM frames
and sample rate of the disc,
returns a DiscID for that CD"""
from audiotools.freedb import DiscID as FDiscID
return cls(track_numbers=range(1, len(sheet) + 1),
track_offsets=[(int(t.index(1).offset() * 75))
for t in sheet],
lead_out_offset=total_pcm_frames * 75 // sample_rate,
freedb_disc_id=FDiscID.from_sheet(sheet,
total_pcm_frames,
sample_rate))
def track_numbers(self):
return self.__track_numbers__[:]
def id1(self):
return sum(self.__track_offsets__) + self.__lead_out_offset__
def id2(self):
return (sum([n * max(o, 1) for (n, o) in
zip(self.__track_numbers__, self.__track_offsets__)]) +
(max(self.__track_numbers__) + 1) * self.__lead_out_offset__)
def freedb_disc_id(self):
return int(self.__freedb_disc_id__)
if PY3:
def __str__(self):
return self.__unicode__()
else:
def __str__(self):
return self.__unicode__().encode('utf-8')
def __unicode__(self):
return u"dBAR-%(tracks)3.3d-%(id1)8.8x-%(id2)8.8x-%(freedb)8.8x.bin" % \
{"tracks": len(self.__track_numbers__),
"id1": self.id1(),
"id2": self.id2(),
"freedb": int(self.__freedb_disc_id__)}
def __repr__(self):
return "AccurateRipDiscID(%s)" % \
(", ".join(["%s=%s" % (key, repr(getattr(self, attr)))
for (key, attr) in
[("track_numbers", "__track_numbers__"),
("track_offsets", "__track_offsets__"),
("lead_out_offset", "__lead_out_offset__"),
("freedb_disc_id", "__freedb_disc_id__")]]))
def perform_lookup(disc_id,
accuraterip_server="www.accuraterip.com",
accuraterip_port=80):
"""performs web-based lookup using the given DiscID object
and returns a dict of
{track_number:[(confidence, crc, crc2), ...], ...}
where track_number starts from 1
may return a dict of empty lists if no AccurateRip entry is found
may raise urllib2.HTTPError if an error occurs querying the server
"""
from audiotools.bitstream import BitstreamReader
try:
from urllib.request import urlopen, URLError
except ImportError:
from urllib2 import urlopen, URLError
matches = {n: [] for n in disc_id.track_numbers()}
url = "http://%s:%s/accuraterip/%s/%s/%s/%s" % (accuraterip_server,
accuraterip_port,
str(disc_id)[16],
str(disc_id)[15],
str(disc_id)[14],
disc_id)
try:
response = BitstreamReader(urlopen(url), True)
except URLError:
# no CD found matching given parameters
return matches
try:
while True:
(track_count,
id1,
id2,
freedb_disc_id) = response.parse("8u 32u 32u 32u")
if (((id1 == disc_id.id1()) and
(id2 == disc_id.id2()) and
(freedb_disc_id == disc_id.freedb_disc_id()))):
for track_number in range(1, track_count + 1):
if track_number in matches:
matches[track_number].append(
tuple(response.parse("8u 32u 32u")))
except IOError:
# keep trying to parse values until the data runs out
response.close()
return matches
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