youtube_dl/FileDownloader.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3
   4 import httplib
   5 import math
   6 import os
   7 import re
   8 import socket
   9 import subprocess
  10 import sys
  11 import time
  12 import urllib2
  13
  14 if os.name == 'nt':
  15         import ctypes
  16
  17 from Utils import *
  18
  19
  20 class FileDownloader(object):
  21         """File Downloader class.
  22
  23         File downloader objects are the ones responsible of downloading the
  24         actual video file and writing it to disk if the user has requested
  25         it, among some other tasks. In most cases there should be one per
  26         program. As, given a video URL, the downloader doesn't know how to
  27         extract all the needed information, task that InfoExtractors do, it
  28         has to pass the URL to one of them.
  29
  30         For this, file downloader objects have a method that allows
  31         InfoExtractors to be registered in a given order. When it is passed
  32         a URL, the file downloader handles it to the first InfoExtractor it
  33         finds that reports being able to handle it. The InfoExtractor extracts
  34         all the information about the video or videos the URL refers to, and
  35         asks the FileDownloader to process the video information, possibly
  36         downloading the video.
  37
  38         File downloaders accept a lot of parameters. In order not to saturate
  39         the object constructor with arguments, it receives a dictionary of
  40         options instead. These options are available through the params
  41         attribute for the InfoExtractors to use. The FileDownloader also
  42         registers itself as the downloader in charge for the InfoExtractors
  43         that are added to it, so this is a "mutual registration".
  44
  45         Available options:
  46
  47         username:         Username for authentication purposes.
  48         password:         Password for authentication purposes.
  49         usenetrc:         Use netrc for authentication instead.
  50         quiet:            Do not print messages to stdout.
  51         forceurl:         Force printing final URL.
  52         forcetitle:       Force printing title.
  53         forcethumbnail:   Force printing thumbnail URL.
  54         forcedescription: Force printing description.
  55         forcefilename:    Force printing final filename.
  56         simulate:         Do not download the video files.
  57         format:           Video format code.
  58         format_limit:     Highest quality format to try.
  59         outtmpl:          Template for output names.
  60         ignoreerrors:     Do not stop on download errors.
  61         ratelimit:        Download speed limit, in bytes/sec.
  62         nooverwrites:     Prevent overwriting files.
  63         retries:          Number of times to retry for HTTP error 5xx
  64         continuedl:       Try to continue downloads if possible.
  65         noprogress:       Do not print the progress bar.
  66         playliststart:    Playlist item to start at.
  67         playlistend:      Playlist item to end at.
  68         matchtitle:       Download only matching titles.
  69         rejecttitle:      Reject downloads for matching titles.
  70         logtostderr:      Log messages to stderr instead of stdout.
  71         consoletitle:     Display progress in console window's titlebar.
  72         nopart:           Do not use temporary .part files.
  73         updatetime:       Use the Last-modified header to set output file timestamps.
  74         writedescription: Write the video description to a .description file
  75         writeinfojson:    Write the video description to a .info.json file
  76         writesubtitles:   Write the video subtitles to a .srt file
  77         subtitleslang:    Language of the subtitles to download
  78         """
  79
  80         params = None
  81         _ies = []
  82         _pps = []
  83         _download_retcode = None
  84         _num_downloads = None
  85         _screen_file = None
  86
  87         def __init__(self, params):
  88                 """Create a FileDownloader object with the given options."""
  89                 self._ies = []
  90                 self._pps = []
  91                 self._download_retcode = 0
  92                 self._num_downloads = 0
  93                 self._screen_file = [sys.stdout, sys.stderr][params.get('logtostderr', False)]
  94                 self.params = params
  95
  96         @staticmethod
  97         def format_bytes(bytes):
  98                 if bytes is None:
  99                         return 'N/A'
 100                 if type(bytes) is str:
 101                         bytes = float(bytes)
 102                 if bytes == 0.0:
 103                         exponent = 0
 104                 else:
 105                         exponent = long(math.log(bytes, 1024.0))
 106                 suffix = 'bkMGTPEZY'[exponent]
 107                 converted = float(bytes) / float(1024 ** exponent)
 108                 return '%.2f%s' % (converted, suffix)
 109
 110         @staticmethod
 111         def calc_percent(byte_counter, data_len):
 112                 if data_len is None:
 113                         return '---.-%'
 114                 return '%6s' % ('%3.1f%%' % (float(byte_counter) / float(data_len) * 100.0))
 115
 116         @staticmethod
 117         def calc_eta(start, now, total, current):
 118                 if total is None:
 119                         return '--:--'
 120                 dif = now - start
 121                 if current == 0 or dif < 0.001: # One millisecond
 122                         return '--:--'
 123                 rate = float(current) / dif
 124                 eta = long((float(total) - float(current)) / rate)
 125                 (eta_mins, eta_secs) = divmod(eta, 60)
 126                 if eta_mins > 99:
 127                         return '--:--'
 128                 return '%02d:%02d' % (eta_mins, eta_secs)
 129
 130         @staticmethod
 131         def calc_speed(start, now, bytes):
 132                 dif = now - start
 133                 if bytes == 0 or dif < 0.001: # One millisecond
 134                         return '%10s' % '---b/s'
 135                 return '%10s' % ('%s/s' % FileDownloader.format_bytes(float(bytes) / dif))
 136
 137         @staticmethod
 138         def best_block_size(elapsed_time, bytes):
 139                 new_min = max(bytes / 2.0, 1.0)
 140                 new_max = min(max(bytes * 2.0, 1.0), 4194304) # Do not surpass 4 MB
 141                 if elapsed_time < 0.001:
 142                         return long(new_max)
 143                 rate = bytes / elapsed_time
 144                 if rate > new_max:
 145                         return long(new_max)
 146                 if rate < new_min:
 147                         return long(new_min)
 148                 return long(rate)
 149
 150         @staticmethod
 151         def parse_bytes(bytestr):
 152                 """Parse a string indicating a byte quantity into a long integer."""
 153                 matchobj = re.match(r'(?i)^(\d+(?:\.\d+)?)([kMGTPEZY]?)$', bytestr)
 154                 if matchobj is None:
 155                         return None
 156                 number = float(matchobj.group(1))
 157                 multiplier = 1024.0 ** 'bkmgtpezy'.index(matchobj.group(2).lower())
 158                 return long(round(number * multiplier))
 159
 160         def add_info_extractor(self, ie):
 161                 """Add an InfoExtractor object to the end of the list."""
 162                 self._ies.append(ie)
 163                 ie.set_downloader(self)
 164
 165         def add_post_processor(self, pp):
 166                 """Add a PostProcessor object to the end of the chain."""
 167                 self._pps.append(pp)
 168                 pp.set_downloader(self)
 169
 170         def to_screen(self, message, skip_eol=False):
 171                 """Print message to stdout if not in quiet mode."""
 172                 assert type(message) == type(u'')
 173                 if not self.params.get('quiet', False):
 174                         terminator = [u'\n', u''][skip_eol]
 175                         output = message + terminator
 176
 177                         if 'b' not in self._screen_file.mode or sys.version_info[0] < 3: # Python 2 lies about the mode of sys.stdout/sys.stderr
 178                                 output = output.encode(preferredencoding(), 'ignore')
 179                         self._screen_file.write(output)
 180                         self._screen_file.flush()
 181
 182         def to_stderr(self, message):
 183                 """Print message to stderr."""
 184                 print >>sys.stderr, message.encode(preferredencoding())
 185
 186         def to_cons_title(self, message):
 187                 """Set console/terminal window title to message."""
 188                 if not self.params.get('consoletitle', False):
 189                         return
 190                 if os.name == 'nt' and ctypes.windll.kernel32.GetConsoleWindow():
 191                         # c_wchar_p() might not be necessary if `message` is
 192                         # already of type unicode()
 193                         ctypes.windll.kernel32.SetConsoleTitleW(ctypes.c_wchar_p(message))
 194                 elif 'TERM' in os.environ:
 195                         sys.stderr.write('\033]0;%s\007' % message.encode(preferredencoding()))
 196
 197         def fixed_template(self):
 198                 """Checks if the output template is fixed."""
 199                 return (re.search(ur'(?u)%\(.+?\)s', self.params['outtmpl']) is None)
 200
 201         def trouble(self, message=None):
 202                 """Determine action to take when a download problem appears.
 203
 204                 Depending on if the downloader has been configured to ignore
 205                 download errors or not, this method may throw an exception or
 206                 not when errors are found, after printing the message.
 207                 """
 208                 if message is not None:
 209                         self.to_stderr(message)
 210                 if not self.params.get('ignoreerrors', False):
 211                         raise DownloadError(message)
 212                 self._download_retcode = 1
 213
 214         def slow_down(self, start_time, byte_counter):
 215                 """Sleep if the download speed is over the rate limit."""
 216                 rate_limit = self.params.get('ratelimit', None)
 217                 if rate_limit is None or byte_counter == 0:
 218                         return
 219                 now = time.time()
 220                 elapsed = now - start_time
 221                 if elapsed <= 0.0:
 222                         return
 223                 speed = float(byte_counter) / elapsed
 224                 if speed > rate_limit:
 225                         time.sleep((byte_counter - rate_limit * (now - start_time)) / rate_limit)
 226
 227         def temp_name(self, filename):
 228                 """Returns a temporary filename for the given filename."""
 229                 if self.params.get('nopart', False) or filename == u'-' or \
 230                                 (os.path.exists(encodeFilename(filename)) and not os.path.isfile(encodeFilename(filename))):
 231                         return filename
 232                 return filename + u'.part'
 233
 234         def undo_temp_name(self, filename):
 235                 if filename.endswith(u'.part'):
 236                         return filename[:-len(u'.part')]
 237                 return filename
 238
 239         def try_rename(self, old_filename, new_filename):
 240                 try:
 241                         if old_filename == new_filename:
 242                                 return
 243                         os.rename(encodeFilename(old_filename), encodeFilename(new_filename))
 244                 except (IOError, OSError), err:
 245                         self.trouble(u'ERROR: unable to rename file')
 246
 247         def try_utime(self, filename, last_modified_hdr):
 248                 """Try to set the last-modified time of the given file."""
 249                 if last_modified_hdr is None:
 250                         return
 251                 if not os.path.isfile(encodeFilename(filename)):
 252                         return
 253                 timestr = last_modified_hdr
 254                 if timestr is None:
 255                         return
 256                 filetime = timeconvert(timestr)
 257                 if filetime is None:
 258                         return filetime
 259                 try:
 260                         os.utime(filename, (time.time(), filetime))
 261                 except:
 262                         pass
 263                 return filetime
 264
 265         def report_writedescription(self, descfn):
 266                 """ Report that the description file is being written """
 267                 self.to_screen(u'[info] Writing video description to: ' + descfn)
 268
 269         def report_writesubtitles(self, srtfn):
 270                 """ Report that the subtitles file is being written """
 271                 self.to_screen(u'[info] Writing video subtitles to: ' + srtfn)
 272
 273         def report_writeinfojson(self, infofn):
 274                 """ Report that the metadata file has been written """
 275                 self.to_screen(u'[info] Video description metadata as JSON to: ' + infofn)
 276
 277         def report_destination(self, filename):
 278                 """Report destination filename."""
 279                 self.to_screen(u'[download] Destination: ' + filename)
 280
 281         def report_progress(self, percent_str, data_len_str, speed_str, eta_str):
 282                 """Report download progress."""
 283                 if self.params.get('noprogress', False):
 284                         return
 285                 self.to_screen(u'\r[download] %s of %s at %s ETA %s' %
 286                                 (percent_str, data_len_str, speed_str, eta_str), skip_eol=True)
 287                 self.to_cons_title(u'youtube-dl - %s of %s at %s ETA %s' %
 288                                 (percent_str.strip(), data_len_str.strip(), speed_str.strip(), eta_str.strip()))
 289
 290         def report_resuming_byte(self, resume_len):
 291                 """Report attempt to resume at given byte."""
 292                 self.to_screen(u'[download] Resuming download at byte %s' % resume_len)
 293
 294         def report_retry(self, count, retries):
 295                 """Report retry in case of HTTP error 5xx"""
 296                 self.to_screen(u'[download] Got server HTTP error. Retrying (attempt %d of %d)...' % (count, retries))
 297
 298         def report_file_already_downloaded(self, file_name):
 299                 """Report file has already been fully downloaded."""
 300                 try:
 301                         self.to_screen(u'[download] %s has already been downloaded' % file_name)
 302                 except (UnicodeEncodeError), err:
 303                         self.to_screen(u'[download] The file has already been downloaded')
 304
 305         def report_unable_to_resume(self):
 306                 """Report it was impossible to resume download."""
 307                 self.to_screen(u'[download] Unable to resume')
 308
 309         def report_finish(self):
 310                 """Report download finished."""
 311                 if self.params.get('noprogress', False):
 312                         self.to_screen(u'[download] Download completed')
 313                 else:
 314                         self.to_screen(u'')
 315
 316         def increment_downloads(self):
 317                 """Increment the ordinal that assigns a number to each file."""
 318                 self._num_downloads += 1
 319
 320         def prepare_filename(self, info_dict):
 321                 """Generate the output filename."""
 322                 try:
 323                         template_dict = dict(info_dict)
 324                         template_dict['epoch'] = unicode(long(time.time()))
 325                         template_dict['autonumber'] = unicode('%05d' % self._num_downloads)
 326                         filename = self.params['outtmpl'] % template_dict
 327                         return filename
 328                 except (ValueError, KeyError), err:
 329                         self.trouble(u'ERROR: invalid system charset or erroneous output template')
 330                         return None
 331
 332         def _match_entry(self, info_dict):
 333                 """ Returns None iff the file should be downloaded """
 334
 335                 title = info_dict['title']
 336                 matchtitle = self.params.get('matchtitle', False)
 337                 if matchtitle and not re.search(matchtitle, title, re.IGNORECASE):
 338                         return u'[download] "' + title + '" title did not match pattern "' + matchtitle + '"'
 339                 rejecttitle = self.params.get('rejecttitle', False)
 340                 if rejecttitle and re.search(rejecttitle, title, re.IGNORECASE):
 341                         return u'"' + title + '" title matched reject pattern "' + rejecttitle + '"'
 342                 return None
 343
 344         def process_info(self, info_dict):
 345                 """Process a single dictionary returned by an InfoExtractor."""
 346
 347                 reason = self._match_entry(info_dict)
 348                 if reason is not None:
 349                         self.to_screen(u'[download] ' + reason)
 350                         return
 351
 352                 max_downloads = self.params.get('max_downloads')
 353                 if max_downloads is not None:
 354                         if self._num_downloads > int(max_downloads):
 355                                 raise MaxDownloadsReached()
 356
 357                 filename = self.prepare_filename(info_dict)
 358
 359                 # Forced printings
 360                 if self.params.get('forcetitle', False):
 361                         print info_dict['title'].encode(preferredencoding(), 'xmlcharrefreplace')
 362                 if self.params.get('forceurl', False):
 363                         print info_dict['url'].encode(preferredencoding(), 'xmlcharrefreplace')
 364                 if self.params.get('forcethumbnail', False) and 'thumbnail' in info_dict:
 365                         print info_dict['thumbnail'].encode(preferredencoding(), 'xmlcharrefreplace')
 366                 if self.params.get('forcedescription', False) and 'description' in info_dict:
 367                         print info_dict['description'].encode(preferredencoding(), 'xmlcharrefreplace')
 368                 if self.params.get('forcefilename', False) and filename is not None:
 369                         print filename.encode(preferredencoding(), 'xmlcharrefreplace')
 370                 if self.params.get('forceformat', False):
 371                         print info_dict['format'].encode(preferredencoding(), 'xmlcharrefreplace')
 372
 373                 # Do nothing else if in simulate mode
 374                 if self.params.get('simulate', False):
 375                         return
 376
 377                 if filename is None:
 378                         return
 379
 380                 try:
 381                         dn = os.path.dirname(encodeFilename(filename))
 382                         if dn != '' and not os.path.exists(dn): # dn is already encoded
 383                                 os.makedirs(dn)
 384                 except (OSError, IOError), err:
 385                         self.trouble(u'ERROR: unable to create directory ' + unicode(err))
 386                         return
 387
 388                 if self.params.get('writedescription', False):
 389                         try:
 390                                 descfn = filename + u'.description'
 391                                 self.report_writedescription(descfn)
 392                                 descfile = open(encodeFilename(descfn), 'wb')
 393                                 try:
 394                                         descfile.write(info_dict['description'].encode('utf-8'))
 395                                 finally:
 396                                         descfile.close()
 397                         except (OSError, IOError):
 398                                 self.trouble(u'ERROR: Cannot write description file ' + descfn)
 399                                 return
 400
 401                 if self.params.get('writesubtitles', False) and 'subtitles' in info_dict and info_dict['subtitles']:
 402                         # subtitles download errors are already managed as troubles in relevant IE
 403                         # that way it will silently go on when used with unsupporting IE
 404                         try:
 405                                 srtfn = filename.rsplit('.', 1)[0] + u'.srt'
 406                                 self.report_writesubtitles(srtfn)
 407                                 srtfile = open(encodeFilename(srtfn), 'wb')
 408                                 try:
 409                                         srtfile.write(info_dict['subtitles'].encode('utf-8'))
 410                                 finally:
 411                                         srtfile.close()
 412                         except (OSError, IOError):
 413                                 self.trouble(u'ERROR: Cannot write subtitles file ' + descfn)
 414                                 return
 415
 416                 if self.params.get('writeinfojson', False):
 417                         infofn = filename + u'.info.json'
 418                         self.report_writeinfojson(infofn)
 419                         try:
 420                                 json.dump
 421                         except (NameError,AttributeError):
 422                                 self.trouble(u'ERROR: No JSON encoder found. Update to Python 2.6+, setup a json module, or leave out --write-info-json.')
 423                                 return
 424                         try:
 425                                 infof = open(encodeFilename(infofn), 'wb')
 426                                 try:
 427                                         json_info_dict = dict((k,v) for k,v in info_dict.iteritems() if not k in ('urlhandle',))
 428                                         json.dump(json_info_dict, infof)
 429                                 finally:
 430                                         infof.close()
 431                         except (OSError, IOError):
 432                                 self.trouble(u'ERROR: Cannot write metadata to JSON file ' + infofn)
 433                                 return
 434
 435                 if not self.params.get('skip_download', False):
 436                         if self.params.get('nooverwrites', False) and os.path.exists(encodeFilename(filename)):
 437                                 success = True
 438                         else:
 439                                 try:
 440                                         success = self._do_download(filename, info_dict)
 441                                 except (OSError, IOError), err:
 442                                         raise UnavailableVideoError
 443                                 except (urllib2.URLError, httplib.HTTPException, socket.error), err:
 444                                         self.trouble(u'ERROR: unable to download video data: %s' % str(err))
 445                                         return
 446                                 except (ContentTooShortError, ), err:
 447                                         self.trouble(u'ERROR: content too short (expected %s bytes and served %s)' % (err.expected, err.downloaded))
 448                                         return
 449
 450                         if success:
 451                                 try:
 452                                         self.post_process(filename, info_dict)
 453                                 except (PostProcessingError), err:
 454                                         self.trouble(u'ERROR: postprocessing: %s' % str(err))
 455                                         return
 456
 457         def download(self, url_list):
 458                 """Download a given list of URLs."""
 459                 if len(url_list) > 1 and self.fixed_template():
 460                         raise SameFileError(self.params['outtmpl'])
 461
 462                 for url in url_list:
 463                         suitable_found = False
 464                         for ie in self._ies:
 465                                 # Go to next InfoExtractor if not suitable
 466                                 if not ie.suitable(url):
 467                                         continue
 468
 469                                 # Suitable InfoExtractor found
 470                                 suitable_found = True
 471
 472                                 # Extract information from URL and process it
 473                                 videos = ie.extract(url)
 474                                 for video in videos or []:
 475                                         try:
 476                                                 self.increment_downloads()
 477                                                 self.process_info(video)
 478                                         except UnavailableVideoError:
 479                                                 self.trouble(u'\nERROR: unable to download video')
 480
 481                                 # Suitable InfoExtractor had been found; go to next URL
 482                                 break
 483
 484                         if not suitable_found:
 485                                 self.trouble(u'ERROR: no suitable InfoExtractor: %s' % url)
 486
 487                 return self._download_retcode
 488
 489         def post_process(self, filename, ie_info):
 490                 """Run the postprocessing chain on the given file."""
 491                 info = dict(ie_info)
 492                 info['filepath'] = filename
 493                 for pp in self._pps:
 494                         info = pp.run(info)
 495                         if info is None:
 496                                 break
 497
 498         def _download_with_rtmpdump(self, filename, url, player_url):
 499                 self.report_destination(filename)
 500                 tmpfilename = self.temp_name(filename)
 501
 502                 # Check for rtmpdump first
 503                 try:
 504                         subprocess.call(['rtmpdump', '-h'], stdout=(file(os.path.devnull, 'w')), stderr=subprocess.STDOUT)
 505                 except (OSError, IOError):
 506                         self.trouble(u'ERROR: RTMP download detected but "rtmpdump" could not be run')
 507                         return False
 508
 509                 # Download using rtmpdump. rtmpdump returns exit code 2 when
 510                 # the connection was interrumpted and resuming appears to be
 511                 # possible. This is part of rtmpdump's normal usage, AFAIK.
 512                 basic_args = ['rtmpdump', '-q'] + [[], ['-W', player_url]][player_url is not None] + ['-r', url, '-o', tmpfilename]
 513                 args = basic_args + [[], ['-e', '-k', '1']][self.params.get('continuedl', False)]
 514                 if self.params.get('verbose', False):
 515                         try:
 516                                 import pipes
 517                                 shell_quote = lambda args: ' '.join(map(pipes.quote, args))
 518                         except ImportError:
 519                                 shell_quote = repr
 520                         self.to_screen(u'[debug] rtmpdump command line: ' + shell_quote(args))
 521                 retval = subprocess.call(args)
 522                 while retval == 2 or retval == 1:
 523                         prevsize = os.path.getsize(encodeFilename(tmpfilename))
 524                         self.to_screen(u'\r[rtmpdump] %s bytes' % prevsize, skip_eol=True)
 525                         time.sleep(5.0) # This seems to be needed
 526                         retval = subprocess.call(basic_args + ['-e'] + [[], ['-k', '1']][retval == 1])
 527                         cursize = os.path.getsize(encodeFilename(tmpfilename))
 528                         if prevsize == cursize and retval == 1:
 529                                 break
 530                          # Some rtmp streams seem abort after ~ 99.8%. Don't complain for those
 531                         if prevsize == cursize and retval == 2 and cursize > 1024:
 532                                 self.to_screen(u'\r[rtmpdump] Could not download the whole video. This can happen for some advertisements.')
 533                                 retval = 0
 534                                 break
 535                 if retval == 0:
 536                         self.to_screen(u'\r[rtmpdump] %s bytes' % os.path.getsize(encodeFilename(tmpfilename)))
 537                         self.try_rename(tmpfilename, filename)
 538                         return True
 539                 else:
 540                         self.trouble(u'\nERROR: rtmpdump exited with code %d' % retval)
 541                         return False
 542
 543         def _do_download(self, filename, info_dict):
 544                 url = info_dict['url']
 545                 player_url = info_dict.get('player_url', None)
 546
 547                 # Check file already present
 548                 if self.params.get('continuedl', False) and os.path.isfile(encodeFilename(filename)) and not self.params.get('nopart', False):
 549                         self.report_file_already_downloaded(filename)
 550                         return True
 551
 552                 # Attempt to download using rtmpdump
 553                 if url.startswith('rtmp'):
 554                         return self._download_with_rtmpdump(filename, url, player_url)
 555
 556                 tmpfilename = self.temp_name(filename)
 557                 stream = None
 558
 559                 # Do not include the Accept-Encoding header
 560                 headers = {'Youtubedl-no-compression': 'True'}
 561                 basic_request = urllib2.Request(url, None, headers)
 562                 request = urllib2.Request(url, None, headers)
 563
 564                 # Establish possible resume length
 565                 if os.path.isfile(encodeFilename(tmpfilename)):
 566                         resume_len = os.path.getsize(encodeFilename(tmpfilename))
 567                 else:
 568                         resume_len = 0
 569
 570                 open_mode = 'wb'
 571                 if resume_len != 0:
 572                         if self.params.get('continuedl', False):
 573                                 self.report_resuming_byte(resume_len)
 574                                 request.add_header('Range','bytes=%d-' % resume_len)
 575                                 open_mode = 'ab'
 576                         else:
 577                                 resume_len = 0
 578
 579                 count = 0
 580                 retries = self.params.get('retries', 0)
 581                 while count <= retries:
 582                         # Establish connection
 583                         try:
 584                                 if count == 0 and 'urlhandle' in info_dict:
 585                                         data = info_dict['urlhandle']
 586                                 data = urllib2.urlopen(request)
 587                                 break
 588                         except (urllib2.HTTPError, ), err:
 589                                 if (err.code < 500 or err.code >= 600) and err.code != 416:
 590                                         # Unexpected HTTP error
 591                                         raise
 592                                 elif err.code == 416:
 593                                         # Unable to resume (requested range not satisfiable)
 594                                         try:
 595                                                 # Open the connection again without the range header
 596                                                 data = urllib2.urlopen(basic_request)
 597                                                 content_length = data.info()['Content-Length']
 598                                         except (urllib2.HTTPError, ), err:
 599                                                 if err.code < 500 or err.code >= 600:
 600                                                         raise
 601                                         else:
 602                                                 # Examine the reported length
 603                                                 if (content_length is not None and
 604                                                                 (resume_len - 100 < long(content_length) < resume_len + 100)):
 605                                                         # The file had already been fully downloaded.
 606                                                         # Explanation to the above condition: in issue #175 it was revealed that
 607                                                         # YouTube sometimes adds or removes a few bytes from the end of the file,
 608                                                         # changing the file size slightly and causing problems for some users. So
 609                                                         # I decided to implement a suggested change and consider the file
 610                                                         # completely downloaded if the file size differs less than 100 bytes from
 611                                                         # the one in the hard drive.
 612                                                         self.report_file_already_downloaded(filename)
 613                                                         self.try_rename(tmpfilename, filename)
 614                                                         return True
 615                                                 else:
 616                                                         # The length does not match, we start the download over
 617                                                         self.report_unable_to_resume()
 618                                                         open_mode = 'wb'
 619                                                         break
 620                         # Retry
 621                         count += 1
 622                         if count <= retries:
 623                                 self.report_retry(count, retries)
 624
 625                 if count > retries:
 626                         self.trouble(u'ERROR: giving up after %s retries' % retries)
 627                         return False
 628
 629                 data_len = data.info().get('Content-length', None)
 630                 if data_len is not None:
 631                         data_len = long(data_len) + resume_len
 632                 data_len_str = self.format_bytes(data_len)
 633                 byte_counter = 0 + resume_len
 634                 block_size = 1024
 635                 start = time.time()
 636                 while True:
 637                         # Download and write
 638                         before = time.time()
 639                         data_block = data.read(block_size)
 640                         after = time.time()
 641                         if len(data_block) == 0:
 642                                 break
 643                         byte_counter += len(data_block)
 644
 645                         # Open file just in time
 646                         if stream is None:
 647                                 try:
 648                                         (stream, tmpfilename) = sanitize_open(tmpfilename, open_mode)
 649                                         assert stream is not None
 650                                         filename = self.undo_temp_name(tmpfilename)
 651                                         self.report_destination(filename)
 652                                 except (OSError, IOError), err:
 653                                         self.trouble(u'ERROR: unable to open for writing: %s' % str(err))
 654                                         return False
 655                         try:
 656                                 stream.write(data_block)
 657                         except (IOError, OSError), err:
 658                                 self.trouble(u'\nERROR: unable to write data: %s' % str(err))
 659                                 return False
 660                         block_size = self.best_block_size(after - before, len(data_block))
 661
 662                         # Progress message
 663                         speed_str = self.calc_speed(start, time.time(), byte_counter - resume_len)
 664                         if data_len is None:
 665                                 self.report_progress('Unknown %', data_len_str, speed_str, 'Unknown ETA')
 666                         else:
 667                                 percent_str = self.calc_percent(byte_counter, data_len)
 668                                 eta_str = self.calc_eta(start, time.time(), data_len - resume_len, byte_counter - resume_len)
 669                                 self.report_progress(percent_str, data_len_str, speed_str, eta_str)
 670
 671                         # Apply rate limit
 672                         self.slow_down(start, byte_counter - resume_len)
 673
 674                 if stream is None:
 675                         self.trouble(u'\nERROR: Did not get any data blocks')
 676                         return False
 677                 stream.close()
 678                 self.report_finish()
 679                 if data_len is not None and byte_counter != data_len:
 680                         raise ContentTooShortError(byte_counter, long(data_len))
 681                 self.try_rename(tmpfilename, filename)
 682
 683                 # Update file modification time
 684                 if self.params.get('updatetime', True):
 685                         info_dict['filetime'] = self.try_utime(filename, data.info().get('last-modified', None))
 686
 687                 return True