#!/usr/bin/env python
# -*- coding: utf-8 -*-

__authors__  = (
	'Ricardo Garcia Gonzalez',
	'Danny Colligan',
	'Benjamin Johnson',
	'Vasyl\' Vavrychuk',
	'Witold Baryluk',
	'Paweł Paprota',
	'Gergely Imreh',
	'Rogério Brito',
	'Philipp Hagemeister',
	'Sören Schulze',
	'Kevin Ngo',
	'Ori Avtalion',
	'shizeeg',
	'Filippo Valsorda',
	)

__license__ = 'Public Domain'
__version__ = '2012.02.27'

UPDATE_URL = 'https://raw.github.com/rg3/youtube-dl/master/youtube-dl'


import cookielib
import datetime
import getpass
import gzip
import htmlentitydefs
import HTMLParser
import httplib
import locale
import math
import netrc
import optparse
import os
import os.path
import re
import shlex
import socket
import string
import subprocess
import sys
import time
import urllib
import urllib2
import warnings
import zlib

if os.name == 'nt':
	import ctypes

try:
	import email.utils
except ImportError: # Python 2.4
	import email.Utils
try:
	import cStringIO as StringIO
except ImportError:
	import StringIO

# parse_qs was moved from the cgi module to the urlparse module recently.
try:
	from urlparse import parse_qs
except ImportError:
	from cgi import parse_qs

try:
	import xml.etree.ElementTree
except ImportError: # Python<2.5: Not officially supported, but let it slip
	warnings.warn('xml.etree.ElementTree support is missing. Consider upgrading to Python >= 2.5 if you get related errors.')

std_headers = {
	'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:5.0.1) Gecko/20100101 Firefox/5.0.1',
	'Accept-Charset': 'ISO-8859-1,utf-8;q=0.7,*;q=0.7',
	'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
	'Accept-Encoding': 'gzip, deflate',
	'Accept-Language': 'en-us,en;q=0.5',
}

try:
	import json
except ImportError: # Python <2.6, use trivialjson (https://github.com/phihag/trivialjson):
	import re
	class json(object):
		@staticmethod
		def loads(s):
			s = s.decode('UTF-8')
			def raiseError(msg, i):
				raise ValueError(msg + ' at position ' + str(i) + ' of ' + repr(s) + ': ' + repr(s[i:]))
			def skipSpace(i, expectMore=True):
				while i < len(s) and s[i] in ' \t\r\n':
					i += 1
				if expectMore:
					if i >= len(s):
						raiseError('Premature end', i)
				return i
			def decodeEscape(match):
				esc = match.group(1)
				_STATIC = {
					'"': '"',
					'\\': '\\',
					'/': '/',
					'b': unichr(0x8),
					'f': unichr(0xc),
					'n': '\n',
					'r': '\r',
					't': '\t',
				}
				if esc in _STATIC:
					return _STATIC[esc]
				if esc[0] == 'u':
					if len(esc) == 1+4:
						return unichr(int(esc[1:5], 16))
					if len(esc) == 5+6 and esc[5:7] == '\\u':
						hi = int(esc[1:5], 16)
						low = int(esc[7:11], 16)
						return unichr((hi - 0xd800) * 0x400 + low - 0xdc00 + 0x10000)
				raise ValueError('Unknown escape ' + str(esc))
			def parseString(i):
				i += 1
				e = i
				while True:
					e = s.index('"', e)
					bslashes = 0
					while s[e-bslashes-1] == '\\':
						bslashes += 1
					if bslashes % 2 == 1:
						e += 1
						continue
					break
				rexp = re.compile(r'\\(u[dD][89aAbB][0-9a-fA-F]{2}\\u[0-9a-fA-F]{4}|u[0-9a-fA-F]{4}|.|$)')
				stri = rexp.sub(decodeEscape, s[i:e])
				return (e+1,stri)
			def parseObj(i):
				i += 1
				res = {}
				i = skipSpace(i)
				if s[i] == '}': # Empty dictionary
					return (i+1,res)
				while True:
					if s[i] != '"':
						raiseError('Expected a string object key', i)
					i,key = parseString(i)
					i = skipSpace(i)
					if i >= len(s) or s[i] != ':':
						raiseError('Expected a colon', i)
					i,val = parse(i+1)
					res[key] = val
					i = skipSpace(i)
					if s[i] == '}':
						return (i+1, res)
					if s[i] != ',':
						raiseError('Expected comma or closing curly brace', i)
					i = skipSpace(i+1)
			def parseArray(i):
				res = []
				i = skipSpace(i+1)
				if s[i] == ']': # Empty array
					return (i+1,res)
				while True:
					i,val = parse(i)
					res.append(val)
					i = skipSpace(i) # Raise exception if premature end
					if s[i] == ']':
						return (i+1, res)
					if s[i] != ',':
						raiseError('Expected a comma or closing bracket', i)
					i = skipSpace(i+1)
			def parseDiscrete(i):
				for k,v in {'true': True, 'false': False, 'null': None}.items():
					if s.startswith(k, i):
						return (i+len(k), v)
				raiseError('Not a boolean (or null)', i)
			def parseNumber(i):
				mobj = re.match('^(-?(0|[1-9][0-9]*)(\.[0-9]*)?([eE][+-]?[0-9]+)?)', s[i:])
				if mobj is None:
					raiseError('Not a number', i)
				nums = mobj.group(1)
				if '.' in nums or 'e' in nums or 'E' in nums:
					return (i+len(nums), float(nums))
				return (i+len(nums), int(nums))
			CHARMAP = {'{': parseObj, '[': parseArray, '"': parseString, 't': parseDiscrete, 'f': parseDiscrete, 'n': parseDiscrete}
			def parse(i):
				i = skipSpace(i)
				i,res = CHARMAP.get(s[i], parseNumber)(i)
				i = skipSpace(i, False)
				return (i,res)
			i,res = parse(0)
			if i < len(s):
				raise ValueError('Extra data at end of input (index ' + str(i) + ' of ' + repr(s) + ': ' + repr(s[i:]) + ')')
			return res


class IDParser(HTMLParser.HTMLParser):
	"""Modified HTMLParser that isolates a tag with the specified id"""
	def __init__(self, id):
		self.id = id
		self.result = None
		self.started = False
		self.depth = {}
		self.html = None
		self.watch_startpos = False
		HTMLParser.HTMLParser.__init__(self)

	def loads(self, html):
		self.html = html
		self.feed(html)
		self.close()

	def handle_starttag(self, tag, attrs):
		attrs = dict(attrs)
		if self.started:
			self.find_startpos(None)
		if 'id' in attrs and attrs['id'] == self.id:
			self.result = [tag]
			self.started = True
			self.watch_startpos = True
		if self.started:
			if not tag in self.depth: self.depth[tag] = 0
			self.depth[tag] += 1

	def handle_endtag(self, tag):
		if self.started:
			if tag in self.depth: self.depth[tag] -= 1
			if self.depth[self.result[0]] == 0:
				self.started = False
				self.result.append(self.getpos())

	def find_startpos(self, x):
		"""Needed to put the start position of the result (self.result[1])
		after the opening tag with the requested id"""
		if self.watch_startpos:
			self.watch_startpos = False
			self.result.append(self.getpos())
	handle_entityref = handle_charref = handle_data = handle_comment = \
	handle_decl = handle_pi = unknown_decl = find_startpos

	def get_result(self):
		if self.result == None: return None
		if len(self.result) != 3: return None
		lines = self.html.split('\n')
		lines = lines[self.result[1][0]-1:self.result[2][0]]
		lines[0] = lines[0][self.result[1][1]:]
		if len(lines) == 1:
			lines[-1] = lines[-1][:self.result[2][1]-self.result[1][1]]
		lines[-1] = lines[-1][:self.result[2][1]]
		return '\n'.join(lines).strip()

def get_element_by_id(id, html):
	"""Return the content of the tag with the specified id in the passed HTML document"""
	parser = IDParser(id)
	parser.loads(html)
	return parser.get_result()


def preferredencoding():
	"""Get preferred encoding.

	Returns the best encoding scheme for the system, based on
	locale.getpreferredencoding() and some further tweaks.
	"""
	def yield_preferredencoding():
		try:
			pref = locale.getpreferredencoding()
			u'TEST'.encode(pref)
		except:
			pref = 'UTF-8'
		while True:
			yield pref
	return yield_preferredencoding().next()


def htmlentity_transform(matchobj):
	"""Transforms an HTML entity to a Unicode character.

	This function receives a match object and is intended to be used with
	the re.sub() function.
	"""
	entity = matchobj.group(1)

	# Known non-numeric HTML entity
	if entity in htmlentitydefs.name2codepoint:
		return unichr(htmlentitydefs.name2codepoint[entity])

	# Unicode character
	mobj = re.match(ur'(?u)#(x?\d+)', entity)
	if mobj is not None:
		numstr = mobj.group(1)
		if numstr.startswith(u'x'):
			base = 16
			numstr = u'0%s' % numstr
		else:
			base = 10
		return unichr(long(numstr, base))

	# Unknown entity in name, return its literal representation
	return (u'&%s;' % entity)


def clean_html(html):
	"""Clean an HTML snippet into a readable string"""
	# Newline vs <br />
	html = html.replace('\n', ' ')
	html = re.sub('\s*<\s*br\s*/?\s*>\s*', '\n', html)
	# Strip html tags
	html = re.sub('<.*?>', '', html)
	# Replace html entities
	html = re.sub(ur'(?u)&(.+?);', htmlentity_transform, html)
	return html


def sanitize_title(utitle):
	"""Sanitizes a video title so it could be used as part of a filename."""
	utitle = re.sub(ur'(?u)&(.+?);', htmlentity_transform, utitle)
	return utitle.replace(unicode(os.sep), u'%')


def sanitize_open(filename, open_mode):
	"""Try to open the given filename, and slightly tweak it if this fails.

	Attempts to open the given filename. If this fails, it tries to change
	the filename slightly, step by step, until it's either able to open it
	or it fails and raises a final exception, like the standard open()
	function.

	It returns the tuple (stream, definitive_file_name).
	"""
	try:
		if filename == u'-':
			if sys.platform == 'win32':
				import msvcrt
				msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
			return (sys.stdout, filename)
		stream = open(_encodeFilename(filename), open_mode)
		return (stream, filename)
	except (IOError, OSError), err:
		# In case of error, try to remove win32 forbidden chars
		filename = re.sub(ur'[/<>:"\|\?\*]', u'#', filename)

		# An exception here should be caught in the caller
		stream = open(_encodeFilename(filename), open_mode)
		return (stream, filename)


def timeconvert(timestr):
	"""Convert RFC 2822 defined time string into system timestamp"""
	timestamp = None
	timetuple = email.utils.parsedate_tz(timestr)
	if timetuple is not None:
		timestamp = email.utils.mktime_tz(timetuple)
	return timestamp

def _simplify_title(title):
	expr = re.compile(ur'[^\w\d_\-]+', flags=re.UNICODE)
	return expr.sub(u'_', title).strip(u'_')

def _orderedSet(iterable):
	""" Remove all duplicates from the input iterable """
	res = []
	for el in iterable:
		if el not in res:
			res.append(el)
	return res

def _unescapeHTML(s):
	"""
	@param s a string (of type unicode)
	"""
	assert type(s) == type(u'')

	htmlParser = HTMLParser.HTMLParser()
	return htmlParser.unescape(s)

def _encodeFilename(s):
	"""
	@param s The name of the file (of type unicode)
	"""

	assert type(s) == type(u'')

	if sys.platform == 'win32' and sys.getwindowsversion().major >= 5:
		# Pass u'' directly to use Unicode APIs on Windows 2000 and up
		# (Detecting Windows NT 4 is tricky because 'major >= 4' would
		# match Windows 9x series as well. Besides, NT 4 is obsolete.)
		return s
	else:
		return s.encode(sys.getfilesystemencoding(), 'ignore')

class DownloadError(Exception):
	"""Download Error exception.

	This exception may be thrown by FileDownloader objects if they are not
	configured to continue on errors. They will contain the appropriate
	error message.
	"""
	pass


class SameFileError(Exception):
	"""Same File exception.

	This exception will be thrown by FileDownloader objects if they detect
	multiple files would have to be downloaded to the same file on disk.
	"""
	pass


class PostProcessingError(Exception):
	"""Post Processing exception.

	This exception may be raised by PostProcessor's .run() method to
	indicate an error in the postprocessing task.
	"""
	pass

class MaxDownloadsReached(Exception):
	""" --max-downloads limit has been reached. """
	pass


class UnavailableVideoError(Exception):
	"""Unavailable Format exception.

	This exception will be thrown when a video is requested
	in a format that is not available for that video.
	"""
	pass


class ContentTooShortError(Exception):
	"""Content Too Short exception.

	This exception may be raised by FileDownloader objects when a file they
	download is too small for what the server announced first, indicating
	the connection was probably interrupted.
	"""
	# Both in bytes
	downloaded = None
	expected = None

	def __init__(self, downloaded, expected):
		self.downloaded = downloaded
		self.expected = expected


class YoutubeDLHandler(urllib2.HTTPHandler):
	"""Handler for HTTP requests and responses.

	This class, when installed with an OpenerDirector, automatically adds
	the standard headers to every HTTP request and handles gzipped and
	deflated responses from web servers. If compression is to be avoided in
	a particular request, the original request in the program code only has
	to include the HTTP header "Youtubedl-No-Compression", which will be
	removed before making the real request.

	Part of this code was copied from:

	http://techknack.net/python-urllib2-handlers/

	Andrew Rowls, the author of that code, agreed to release it to the
	public domain.
	"""

	@staticmethod
	def deflate(data):
		try:
			return zlib.decompress(data, -zlib.MAX_WBITS)
		except zlib.error:
			return zlib.decompress(data)

	@staticmethod
	def addinfourl_wrapper(stream, headers, url, code):
		if hasattr(urllib2.addinfourl, 'getcode'):
			return urllib2.addinfourl(stream, headers, url, code)
		ret = urllib2.addinfourl(stream, headers, url)
		ret.code = code
		return ret

	def http_request(self, req):
		for h in std_headers:
			if h in req.headers:
				del req.headers[h]
			req.add_header(h, std_headers[h])
		if 'Youtubedl-no-compression' in req.headers:
			if 'Accept-encoding' in req.headers:
				del req.headers['Accept-encoding']
			del req.headers['Youtubedl-no-compression']
		return req

	def http_response(self, req, resp):
		old_resp = resp
		# gzip
		if resp.headers.get('Content-encoding', '') == 'gzip':
			gz = gzip.GzipFile(fileobj=StringIO.StringIO(resp.read()), mode='r')
			resp = self.addinfourl_wrapper(gz, old_resp.headers, old_resp.url, old_resp.code)
			resp.msg = old_resp.msg
		# deflate
		if resp.headers.get('Content-encoding', '') == 'deflate':
			gz = StringIO.StringIO(self.deflate(resp.read()))
			resp = self.addinfourl_wrapper(gz, old_resp.headers, old_resp.url, old_resp.code)
			resp.msg = old_resp.msg
		return resp


class FileDownloader(object):
	"""File Downloader class.

	File downloader objects are the ones responsible of downloading the
	actual video file and writing it to disk if the user has requested
	it, among some other tasks. In most cases there should be one per
	program. As, given a video URL, the downloader doesn't know how to
	extract all the needed information, task that InfoExtractors do, it
	has to pass the URL to one of them.

	For this, file downloader objects have a method that allows
	InfoExtractors to be registered in a given order. When it is passed
	a URL, the file downloader handles it to the first InfoExtractor it
	finds that reports being able to handle it. The InfoExtractor extracts
	all the information about the video or videos the URL refers to, and
	asks the FileDownloader to process the video information, possibly
	downloading the video.

	File downloaders accept a lot of parameters. In order not to saturate
	the object constructor with arguments, it receives a dictionary of
	options instead. These options are available through the params
	attribute for the InfoExtractors to use. The FileDownloader also
	registers itself as the downloader in charge for the InfoExtractors
	that are added to it, so this is a "mutual registration".

	Available options:

	username:         Username for authentication purposes.
	password:         Password for authentication purposes.
	usenetrc:         Use netrc for authentication instead.
	quiet:            Do not print messages to stdout.
	forceurl:         Force printing final URL.
	forcetitle:       Force printing title.
	forcethumbnail:   Force printing thumbnail URL.
	forcedescription: Force printing description.
	forcefilename:    Force printing final filename.
	simulate:         Do not download the video files.
	format:           Video format code.
	format_limit:     Highest quality format to try.
	outtmpl:          Template for output names.
	ignoreerrors:     Do not stop on download errors.
	ratelimit:        Download speed limit, in bytes/sec.
	nooverwrites:     Prevent overwriting files.
	retries:          Number of times to retry for HTTP error 5xx
	continuedl:       Try to continue downloads if possible.
	noprogress:       Do not print the progress bar.
	playliststart:    Playlist item to start at.
	playlistend:      Playlist item to end at.
	matchtitle:       Download only matching titles.
	rejecttitle:      Reject downloads for matching titles.
	logtostderr:      Log messages to stderr instead of stdout.
	consoletitle:     Display progress in console window's titlebar.
	nopart:           Do not use temporary .part files.
	updatetime:       Use the Last-modified header to set output file timestamps.
	writedescription: Write the video description to a .description file
	writeinfojson:    Write the video description to a .info.json file
	writesubtitles:   Write the video subtitles to a .srt file
	subtitleslang:    Language of the subtitles to download
	"""

	params = None
	_ies = []
	_pps = []
	_download_retcode = None
	_num_downloads = None
	_screen_file = None

	def __init__(self, params):
		"""Create a FileDownloader object with the given options."""
		self._ies = []
		self._pps = []
		self._download_retcode = 0
		self._num_downloads = 0
		self._screen_file = [sys.stdout, sys.stderr][params.get('logtostderr', False)]
		self.params = params

	@staticmethod
	def format_bytes(bytes):
		if bytes is None:
			return 'N/A'
		if type(bytes) is str:
			bytes = float(bytes)
		if bytes == 0.0:
			exponent = 0
		else:
			exponent = long(math.log(bytes, 1024.0))
		suffix = 'bkMGTPEZY'[exponent]
		converted = float(bytes) / float(1024 ** exponent)
		return '%.2f%s' % (converted, suffix)

	@staticmethod
	def calc_percent(byte_counter, data_len):
		if data_len is None:
			return '---.-%'
		return '%6s' % ('%3.1f%%' % (float(byte_counter) / float(data_len) * 100.0))

	@staticmethod
	def calc_eta(start, now, total, current):
		if total is None:
			return '--:--'
		dif = now - start
		if current == 0 or dif < 0.001: # One millisecond
			return '--:--'
		rate = float(current) / dif
		eta = long((float(total) - float(current)) / rate)
		(eta_mins, eta_secs) = divmod(eta, 60)
		if eta_mins > 99:
			return '--:--'
		return '%02d:%02d' % (eta_mins, eta_secs)

	@staticmethod
	def calc_speed(start, now, bytes):
		dif = now - start
		if bytes == 0 or dif < 0.001: # One millisecond
			return '%10s' % '---b/s'
		return '%10s' % ('%s/s' % FileDownloader.format_bytes(float(bytes) / dif))

	@staticmethod
	def best_block_size(elapsed_time, bytes):
		new_min = max(bytes / 2.0, 1.0)
		new_max = min(max(bytes * 2.0, 1.0), 4194304) # Do not surpass 4 MB
		if elapsed_time < 0.001:
			return long(new_max)
		rate = bytes / elapsed_time
		if rate > new_max:
			return long(new_max)
		if rate < new_min:
			return long(new_min)
		return long(rate)

	@staticmethod
	def parse_bytes(bytestr):
		"""Parse a string indicating a byte quantity into a long integer."""
		matchobj = re.match(r'(?i)^(\d+(?:\.\d+)?)([kMGTPEZY]?)$', bytestr)
		if matchobj is None:
			return None
		number = float(matchobj.group(1))
		multiplier = 1024.0 ** 'bkmgtpezy'.index(matchobj.group(2).lower())
		return long(round(number * multiplier))

	def add_info_extractor(self, ie):
		"""Add an InfoExtractor object to the end of the list."""
		self._ies.append(ie)
		ie.set_downloader(self)

	def add_post_processor(self, pp):
		"""Add a PostProcessor object to the end of the chain."""
		self._pps.append(pp)
		pp.set_downloader(self)

	def to_screen(self, message, skip_eol=False):
		"""Print message to stdout if not in quiet mode."""
		assert type(message) == type(u'')
		if not self.params.get('quiet', False):
			terminator = [u'\n', u''][skip_eol]
			output = message + terminator

			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
				output = output.encode(preferredencoding(), 'ignore')
			self._screen_file.write(output)
			self._screen_file.flush()

	def to_stderr(self, message):
		"""Print message to stderr."""
		print >>sys.stderr, message.encode(preferredencoding())

	def to_cons_title(self, message):
		"""Set console/terminal window title to message."""
		if not self.params.get('consoletitle', False):
			return
		if os.name == 'nt' and ctypes.windll.kernel32.GetConsoleWindow():
			# c_wchar_p() might not be necessary if `message` is
			# already of type unicode()
			ctypes.windll.kernel32.SetConsoleTitleW(ctypes.c_wchar_p(message))
		elif 'TERM' in os.environ:
			sys.stderr.write('\033]0;%s\007' % message.encode(preferredencoding()))

	def fixed_template(self):
		"""Checks if the output template is fixed."""
		return (re.search(ur'(?u)%\(.+?\)s', self.params['outtmpl']) is None)

	def trouble(self, message=None):
		"""Determine action to take when a download problem appears.

		Depending on if the downloader has been configured to ignore
		download errors or not, this method may throw an exception or
		not when errors are found, after printing the message.
		"""
		if message is not None:
			self.to_stderr(message)
		if not self.params.get('ignoreerrors', False):
			raise DownloadError(message)
		self._download_retcode = 1

	def slow_down(self, start_time, byte_counter):
		"""Sleep if the download speed is over the rate limit."""
		rate_limit = self.params.get('ratelimit', None)
		if rate_limit is None or byte_counter == 0:
			return
		now = time.time()
		elapsed = now - start_time
		if elapsed <= 0.0:
			return
		speed = float(byte_counter) / elapsed
		if speed > rate_limit:
			time.sleep((byte_counter - rate_limit * (now - start_time)) / rate_limit)

	def temp_name(self, filename):
		"""Returns a temporary filename for the given filename."""
		if self.params.get('nopart', False) or filename == u'-' or \
				(os.path.exists(_encodeFilename(filename)) and not os.path.isfile(_encodeFilename(filename))):
			return filename
		return filename + u'.part'

	def undo_temp_name(self, filename):
		if filename.endswith(u'.part'):
			return filename[:-len(u'.part')]
		return filename

	def try_rename(self, old_filename, new_filename):
		try:
			if old_filename == new_filename:
				return
			os.rename(_encodeFilename(old_filename), _encodeFilename(new_filename))
		except (IOError, OSError), err:
			self.trouble(u'ERROR: unable to rename file')

	def try_utime(self, filename, last_modified_hdr):
		"""Try to set the last-modified time of the given file."""
		if last_modified_hdr is None:
			return
		if not os.path.isfile(_encodeFilename(filename)):
			return
		timestr = last_modified_hdr
		if timestr is None:
			return
		filetime = timeconvert(timestr)
		if filetime is None:
			return filetime
		try:
			os.utime(filename, (time.time(), filetime))
		except:
			pass
		return filetime

	def report_writedescription(self, descfn):
		""" Report that the description file is being written """
		self.to_screen(u'[info] Writing video description to: ' + descfn)

	def report_writesubtitles(self, srtfn):
		""" Report that the subtitles file is being written """
		self.to_screen(u'[info] Writing video subtitles to: ' + srtfn)

	def report_writeinfojson(self, infofn):
		""" Report that the metadata file has been written """
		self.to_screen(u'[info] Video description metadata as JSON to: ' + infofn)

	def report_destination(self, filename):
		"""Report destination filename."""
		self.to_screen(u'[download] Destination: ' + filename)

	def report_progress(self, percent_str, data_len_str, speed_str, eta_str):
		"""Report download progress."""
		if self.params.get('noprogress', False):
			return
		self.to_screen(u'\r[download] %s of %s at %s ETA %s' %
				(percent_str, data_len_str, speed_str, eta_str), skip_eol=True)
		self.to_cons_title(u'youtube-dl - %s of %s at %s ETA %s' %
				(percent_str.strip(), data_len_str.strip(), speed_str.strip(), eta_str.strip()))

	def report_resuming_byte(self, resume_len):
		"""Report attempt to resume at given byte."""
		self.to_screen(u'[download] Resuming download at byte %s' % resume_len)

	def report_retry(self, count, retries):
		"""Report retry in case of HTTP error 5xx"""
		self.to_screen(u'[download] Got server HTTP error. Retrying (attempt %d of %d)...' % (count, retries))

	def report_file_already_downloaded(self, file_name):
		"""Report file has already been fully downloaded."""
		try:
			self.to_screen(u'[download] %s has already been downloaded' % file_name)
		except (UnicodeEncodeError), err:
			self.to_screen(u'[download] The file has already been downloaded')

	def report_unable_to_resume(self):
		"""Report it was impossible to resume download."""
		self.to_screen(u'[download] Unable to resume')

	def report_finish(self):
		"""Report download finished."""
		if self.params.get('noprogress', False):
			self.to_screen(u'[download] Download completed')
		else:
			self.to_screen(u'')

	def increment_downloads(self):
		"""Increment the ordinal that assigns a number to each file."""
		self._num_downloads += 1

	def prepare_filename(self, info_dict):
		"""Generate the output filename."""
		try:
			template_dict = dict(info_dict)
			template_dict['epoch'] = unicode(long(time.time()))
			template_dict['autonumber'] = unicode('%05d' % self._num_downloads)
			filename = self.params['outtmpl'] % template_dict
			return filename
		except (ValueError, KeyError), err:
			self.trouble(u'ERROR: invalid system charset or erroneous output template')
			return None

	def _match_entry(self, info_dict):
		""" Returns None iff the file should be downloaded """

		title = info_dict['title']
		matchtitle = self.params.get('matchtitle', False)
		if matchtitle and not re.search(matchtitle, title, re.IGNORECASE):
			return u'[download] "' + title + '" title did not match pattern "' + matchtitle + '"'
		rejecttitle = self.params.get('rejecttitle', False)
		if rejecttitle and re.search(rejecttitle, title, re.IGNORECASE):
			return u'"' + title + '" title matched reject pattern "' + rejecttitle + '"'
		return None

	def process_info(self, info_dict):
		"""Process a single dictionary returned by an InfoExtractor."""

		reason = self._match_entry(info_dict)
		if reason is not None:
			self.to_screen(u'[download] ' + reason)
			return

		max_downloads = self.params.get('max_downloads')
		if max_downloads is not None:
			if self._num_downloads > int(max_downloads):
				raise MaxDownloadsReached()

		filename = self.prepare_filename(info_dict)
		
		# Forced printings
		if self.params.get('forcetitle', False):
			print info_dict['title'].encode(preferredencoding(), 'xmlcharrefreplace')
		if self.params.get('forceurl', False):
			print info_dict['url'].encode(preferredencoding(), 'xmlcharrefreplace')
		if self.params.get('forcethumbnail', False) and 'thumbnail' in info_dict:
			print info_dict['thumbnail'].encode(preferredencoding(), 'xmlcharrefreplace')
		if self.params.get('forcedescription', False) and 'description' in info_dict:
			print info_dict['description'].encode(preferredencoding(), 'xmlcharrefreplace')
		if self.params.get('forcefilename', False) and filename is not None:
			print filename.encode(preferredencoding(), 'xmlcharrefreplace')
		if self.params.get('forceformat', False):
			print info_dict['format'].encode(preferredencoding(), 'xmlcharrefreplace')

		# Do nothing else if in simulate mode
		if self.params.get('simulate', False):
			return

		if filename is None:
			return

		try:
			dn = os.path.dirname(_encodeFilename(filename))
			if dn != '' and not os.path.exists(dn): # dn is already encoded
				os.makedirs(dn)
		except (OSError, IOError), err:
			self.trouble(u'ERROR: unable to create directory ' + unicode(err))
			return

		if self.params.get('writedescription', False):
			try:
				descfn = filename + u'.description'
				self.report_writedescription(descfn)
				descfile = open(_encodeFilename(descfn), 'wb')
				try:
					descfile.write(info_dict['description'].encode('utf-8'))
				finally:
					descfile.close()
			except (OSError, IOError):
				self.trouble(u'ERROR: Cannot write description file ' + descfn)
				return
				
		if self.params.get('writesubtitles', False) and 'subtitles' in info_dict and info_dict['subtitles']:
			# subtitles download errors are already managed as troubles in relevant IE
			# that way it will silently go on when used with unsupporting IE 
			try:
				srtfn = filename.rsplit('.', 1)[0] + u'.srt'
				self.report_writesubtitles(srtfn)
				srtfile = open(_encodeFilename(srtfn), 'wb')
				try:
					srtfile.write(info_dict['subtitles'].encode('utf-8'))
				finally:
					srtfile.close()
			except (OSError, IOError):
				self.trouble(u'ERROR: Cannot write subtitles file ' + descfn)
				return

		if self.params.get('writeinfojson', False):
			infofn = filename + u'.info.json'
			self.report_writeinfojson(infofn)
			try:
				json.dump
			except (NameError,AttributeError):
				self.trouble(u'ERROR: No JSON encoder found. Update to Python 2.6+, setup a json module, or leave out --write-info-json.')
				return
			try:
				infof = open(_encodeFilename(infofn), 'wb')
				try:
					json_info_dict = dict((k,v) for k,v in info_dict.iteritems() if not k in ('urlhandle',))
					json.dump(json_info_dict, infof)
				finally:
					infof.close()
			except (OSError, IOError):
				self.trouble(u'ERROR: Cannot write metadata to JSON file ' + infofn)
				return

		if not self.params.get('skip_download', False):
			if self.params.get('nooverwrites', False) and os.path.exists(_encodeFilename(filename)):
				success = True
			else:
				try:
					success = self._do_download(filename, info_dict)
				except (OSError, IOError), err:
					raise UnavailableVideoError
				except (urllib2.URLError, httplib.HTTPException, socket.error), err:
					self.trouble(u'ERROR: unable to download video data: %s' % str(err))
					return
				except (ContentTooShortError, ), err:
					self.trouble(u'ERROR: content too short (expected %s bytes and served %s)' % (err.expected, err.downloaded))
					return
	
			if success:
				try:
					self.post_process(filename, info_dict)
				except (PostProcessingError), err:
					self.trouble(u'ERROR: postprocessing: %s' % str(err))
					return

	def download(self, url_list):
		"""Download a given list of URLs."""
		if len(url_list) > 1 and self.fixed_template():
			raise SameFileError(self.params['outtmpl'])

		for url in url_list:
			suitable_found = False
			for ie in self._ies:
				# Go to next InfoExtractor if not suitable
				if not ie.suitable(url):
					continue

				# Suitable InfoExtractor found
				suitable_found = True

				# Extract information from URL and process it
				ie.extract(url)

				# Suitable InfoExtractor had been found; go to next URL
				break

			if not suitable_found:
				self.trouble(u'ERROR: no suitable InfoExtractor: %s' % url)

		return self._download_retcode

	def post_process(self, filename, ie_info):
		"""Run the postprocessing chain on the given file."""
		info = dict(ie_info)
		info['filepath'] = filename
		for pp in self._pps:
			info = pp.run(info)
			if info is None:
				break

	def _download_with_rtmpdump(self, filename, url, player_url):
		self.report_destination(filename)
		tmpfilename = self.temp_name(filename)

		# Check for rtmpdump first
		try:
			subprocess.call(['rtmpdump', '-h'], stdout=(file(os.path.devnull, 'w')), stderr=subprocess.STDOUT)
		except (OSError, IOError):
			self.trouble(u'ERROR: RTMP download detected but "rtmpdump" could not be run')
			return False

		# Download using rtmpdump. rtmpdump returns exit code 2 when
		# the connection was interrumpted and resuming appears to be
		# possible. This is part of rtmpdump's normal usage, AFAIK.
		basic_args = ['rtmpdump', '-q'] + [[], ['-W', player_url]][player_url is not None] + ['-r', url, '-o', tmpfilename]
		args = basic_args + [[], ['-e', '-k', '1']][self.params.get('continuedl', False)]
		if self.params.get('verbose', False):
			try:
				import pipes
				shell_quote = lambda args: ' '.join(map(pipes.quote, args))
			except ImportError:
				shell_quote = repr
			self.to_screen(u'[debug] rtmpdump command line: ' + shell_quote(args))
		retval = subprocess.call(args)
		while retval == 2 or retval == 1:
			prevsize = os.path.getsize(_encodeFilename(tmpfilename))
			self.to_screen(u'\r[rtmpdump] %s bytes' % prevsize, skip_eol=True)
			time.sleep(5.0) # This seems to be needed
			retval = subprocess.call(basic_args + ['-e'] + [[], ['-k', '1']][retval == 1])
			cursize = os.path.getsize(_encodeFilename(tmpfilename))
			if prevsize == cursize and retval == 1:
				break
			 # Some rtmp streams seem abort after ~ 99.8%. Don't complain for those
			if prevsize == cursize and retval == 2 and cursize > 1024:
				self.to_screen(u'\r[rtmpdump] Could not download the whole video. This can happen for some advertisements.')
				retval = 0
				break
		if retval == 0:
			self.to_screen(u'\r[rtmpdump] %s bytes' % os.path.getsize(_encodeFilename(tmpfilename)))
			self.try_rename(tmpfilename, filename)
			return True
		else:
			self.trouble(u'\nERROR: rtmpdump exited with code %d' % retval)
			return False

	def _do_download(self, filename, info_dict):
		url = info_dict['url']
		player_url = info_dict.get('player_url', None)

		# Check file already present
		if self.params.get('continuedl', False) and os.path.isfile(_encodeFilename(filename)) and not self.params.get('nopart', False):
			self.report_file_already_downloaded(filename)
			return True

		# Attempt to download using rtmpdump
		if url.startswith('rtmp'):
			return self._download_with_rtmpdump(filename, url, player_url)

		tmpfilename = self.temp_name(filename)
		stream = None

		# Do not include the Accept-Encoding header
		headers = {'Youtubedl-no-compression': 'True'}
		basic_request = urllib2.Request(url, None, headers)
		request = urllib2.Request(url, None, headers)

		# Establish possible resume length
		if os.path.isfile(_encodeFilename(tmpfilename)):
			resume_len = os.path.getsize(_encodeFilename(tmpfilename))
		else:
			resume_len = 0

		open_mode = 'wb'
		if resume_len != 0:
			if self.params.get('continuedl', False):
				self.report_resuming_byte(resume_len)
				request.add_header('Range','bytes=%d-' % resume_len)
				open_mode = 'ab'
			else:
				resume_len = 0

		count = 0
		retries = self.params.get('retries', 0)
		while count <= retries:
			# Establish connection
			try:
				if count == 0 and 'urlhandle' in info_dict:
					data = info_dict['urlhandle']
				data = urllib2.urlopen(request)
				break
			except (urllib2.HTTPError, ), err:
				if (err.code < 500 or err.code >= 600) and err.code != 416:
					# Unexpected HTTP error
					raise
				elif err.code == 416:
					# Unable to resume (requested range not satisfiable)
					try:
						# Open the connection again without the range header
						data = urllib2.urlopen(basic_request)
						content_length = data.info()['Content-Length']
					except (urllib2.HTTPError, ), err:
						if err.code < 500 or err.code >= 600:
							raise
					else:
						# Examine the reported length
						if (content_length is not None and
								(resume_len - 100 < long(content_length) < resume_len + 100)):
							# The file had already been fully downloaded.
							# Explanation to the above condition: in issue #175 it was revealed that
							# YouTube sometimes adds or removes a few bytes from the end of the file,
							# changing the file size slightly and causing problems for some users. So
							# I decided to implement a suggested change and consider the file
							# completely downloaded if the file size differs less than 100 bytes from
							# the one in the hard drive.
							self.report_file_already_downloaded(filename)
							self.try_rename(tmpfilename, filename)
							return True
						else:
							# The length does not match, we start the download over
							self.report_unable_to_resume()
							open_mode = 'wb'
							break
			# Retry
			count += 1
			if count <= retries:
				self.report_retry(count, retries)

		if count > retries:
			self.trouble(u'ERROR: giving up after %s retries' % retries)
			return False

		data_len = data.info().get('Content-length', None)
		if data_len is not None:
			data_len = long(data_len) + resume_len
		data_len_str = self.format_bytes(data_len)
		byte_counter = 0 + resume_len
		block_size = 1024
		start = time.time()
		while True:
			# Download and write
			before = time.time()
			data_block = data.read(block_size)
			after = time.time()
			if len(data_block) == 0:
				break
			byte_counter += len(data_block)

			# Open file just in time
			if stream is None:
				try:
					(stream, tmpfilename) = sanitize_open(tmpfilename, open_mode)
					assert stream is not None
					filename = self.undo_temp_name(tmpfilename)
					self.report_destination(filename)
				except (OSError, IOError), err:
					self.trouble(u'ERROR: unable to open for writing: %s' % str(err))
					return False
			try:
				stream.write(data_block)
			except (IOError, OSError), err:
				self.trouble(u'\nERROR: unable to write data: %s' % str(err))
				return False
			block_size = self.best_block_size(after - before, len(data_block))

			# Progress message
			speed_str = self.calc_speed(start, time.time(), byte_counter - resume_len)
			if data_len is None:
				self.report_progress('Unknown %', data_len_str, speed_str, 'Unknown ETA')
			else:
				percent_str = self.calc_percent(byte_counter, data_len)
				eta_str = self.calc_eta(start, time.time(), data_len - resume_len, byte_counter - resume_len)
				self.report_progress(percent_str, data_len_str, speed_str, eta_str)

			# Apply rate limit
			self.slow_down(start, byte_counter - resume_len)

		if stream is None:
			self.trouble(u'\nERROR: Did not get any data blocks')
			return False
		stream.close()
		self.report_finish()
		if data_len is not None and byte_counter != data_len:
			raise ContentTooShortError(byte_counter, long(data_len))
		self.try_rename(tmpfilename, filename)

		# Update file modification time
		if self.params.get('updatetime', True):
			info_dict['filetime'] = self.try_utime(filename, data.info().get('last-modified', None))

		return True


class InfoExtractor(object):
	"""Information Extractor class.

	Information extractors are the classes that, given a URL, extract
	information from the video (or videos) the URL refers to. This
	information includes the real video URL, the video title and simplified
	title, author and others. The information is stored in a dictionary
	which is then passed to the FileDownloader. The FileDownloader
	processes this information possibly downloading the video to the file
	system, among other possible outcomes. The dictionaries must include
	the following fields:

	id:		Video identifier.
	url:		Final video URL.
	uploader:	Nickname of the video uploader.
	title:		Literal title.
	stitle:		Simplified title.
	ext:		Video filename extension.
	format:		Video format.
	player_url:	SWF Player URL (may be None).

	The following fields are optional. Their primary purpose is to allow
	youtube-dl to serve as the backend for a video search function, such
	as the one in youtube2mp3.  They are only used when their respective
	forced printing functions are called:

	thumbnail:	Full URL to a video thumbnail image.
	description:	One-line video description.

	Subclasses of this one should re-define the _real_initialize() and
	_real_extract() methods and define a _VALID_URL regexp.
	Probably, they should also be added to the list of extractors.
	"""

	_ready = False
	_downloader = None

	def __init__(self, downloader=None):
		"""Constructor. Receives an optional downloader."""
		self._ready = False
		self.set_downloader(downloader)

	def suitable(self, url):
		"""Receives a URL and returns True if suitable for this IE."""
		return re.match(self._VALID_URL, url) is not None

	def initialize(self):
		"""Initializes an instance (authentication, etc)."""
		if not self._ready:
			self._real_initialize()
			self._ready = True

	def extract(self, url):
		"""Extracts URL information and returns it in list of dicts."""
		self.initialize()
		return self._real_extract(url)

	def set_downloader(self, downloader):
		"""Sets the downloader for this IE."""
		self._downloader = downloader

	def _real_initialize(self):
		"""Real initialization process. Redefine in subclasses."""
		pass

	def _real_extract(self, url):
		"""Real extraction process. Redefine in subclasses."""
		pass


class YoutubeIE(InfoExtractor):
	"""Information extractor for youtube.com."""

	_VALID_URL = r'^((?:https?://)?(?:youtu\.be/|(?:\w+\.)?youtube(?:-nocookie)?\.com/)(?!view_play_list|my_playlists|artist|playlist)(?:(?:(?:v|embed|e)/)|(?:(?:watch(?:_popup)?(?:\.php)?)?(?:\?|#!?)(?:.+&)?v=))?)?([0-9A-Za-z_-]+)(?(1).+)?$'
	_LANG_URL = r'http://www.youtube.com/?hl=en&persist_hl=1&gl=US&persist_gl=1&opt_out_ackd=1'
	_LOGIN_URL = 'https://www.youtube.com/signup?next=/&gl=US&hl=en'
	_AGE_URL = 'http://www.youtube.com/verify_age?next_url=/&gl=US&hl=en'
	_NETRC_MACHINE = 'youtube'
	# Listed in order of quality
	_available_formats = ['38', '37', '22', '45', '35', '44', '34', '18', '43', '6', '5', '17', '13']
	_available_formats_prefer_free = ['38', '37', '45', '22', '44', '35', '43', '34', '18', '6', '5', '17', '13']
	_video_extensions = {
		'13': '3gp',
		'17': 'mp4',
		'18': 'mp4',
		'22': 'mp4',
		'37': 'mp4',
		'38': 'video', # You actually don't know if this will be MOV, AVI or whatever
		'43': 'webm',
		'44': 'webm',
		'45': 'webm',
	}
	_video_dimensions = {
		'5': '240x400',
		'6': '???',
		'13': '???',
		'17': '144x176',
		'18': '360x640',
		'22': '720x1280',
		'34': '360x640',
		'35': '480x854',
		'37': '1080x1920',
		'38': '3072x4096',
		'43': '360x640',
		'44': '480x854',
		'45': '720x1280',
	}	
	IE_NAME = u'youtube'

	def report_lang(self):
		"""Report attempt to set language."""
		self._downloader.to_screen(u'[youtube] Setting language')

	def report_login(self):
		"""Report attempt to log in."""
		self._downloader.to_screen(u'[youtube] Logging in')

	def report_age_confirmation(self):
		"""Report attempt to confirm age."""
		self._downloader.to_screen(u'[youtube] Confirming age')

	def report_video_webpage_download(self, video_id):
		"""Report attempt to download video webpage."""
		self._downloader.to_screen(u'[youtube] %s: Downloading video webpage' % video_id)

	def report_video_info_webpage_download(self, video_id):
		"""Report attempt to download video info webpage."""
		self._downloader.to_screen(u'[youtube] %s: Downloading video info webpage' % video_id)

	def report_video_subtitles_download(self, video_id):
		"""Report attempt to download video info webpage."""
		self._downloader.to_screen(u'[youtube] %s: Downloading video subtitles' % video_id)

	def report_information_extraction(self, video_id):
		"""Report attempt to extract video information."""
		self._downloader.to_screen(u'[youtube] %s: Extracting video information' % video_id)

	def report_unavailable_format(self, video_id, format):
		"""Report extracted video URL."""
		self._downloader.to_screen(u'[youtube] %s: Format %s not available' % (video_id, format))

	def report_rtmp_download(self):
		"""Indicate the download will use the RTMP protocol."""
		self._downloader.to_screen(u'[youtube] RTMP download detected')

	def _closed_captions_xml_to_srt(self, xml_string):
		srt = ''
		texts = re.findall(r'<text start="([\d\.]+)"( dur="([\d\.]+)")?>([^<]+)</text>', xml_string, re.MULTILINE)
		# TODO parse xml instead of regex
		for n, (start, dur_tag, dur, caption) in enumerate(texts):
			if not dur: dur = '4'
			start = float(start)
			end = start + float(dur)
			start = "%02i:%02i:%02i,%03i" %(start/(60*60), start/60%60, start%60, start%1*1000)
			end = "%02i:%02i:%02i,%03i" %(end/(60*60), end/60%60, end%60, end%1*1000)
			caption = re.sub(ur'(?u)&(.+?);', htmlentity_transform, caption)
			caption = re.sub(ur'(?u)&(.+?);', htmlentity_transform, caption) # double cycle, inentional
			srt += str(n) + '\n'
			srt += start + ' --> ' + end + '\n'
			srt += caption + '\n\n'
		return srt

	def _print_formats(self, formats):
		print 'Available formats:'
		for x in formats:
			print '%s\t:\t%s\t[%s]' %(x, self._video_extensions.get(x, 'flv'), self._video_dimensions.get(x, '???'))

	def _real_initialize(self):
		if self._downloader is None:
			return

		username = None
		password = None
		downloader_params = self._downloader.params

		# Attempt to use provided username and password or .netrc data
		if downloader_params.get('username', None) is not None:
			username = downloader_params['username']
			password = downloader_params['password']
		elif downloader_params.get('usenetrc', False):
			try:
				info = netrc.netrc().authenticators(self._NETRC_MACHINE)
				if info is not None:
					username = info[0]
					password = info[2]
				else:
					raise netrc.NetrcParseError('No authenticators for %s' % self._NETRC_MACHINE)
			except (IOError, netrc.NetrcParseError), err:
				self._downloader.to_stderr(u'WARNING: parsing .netrc: %s' % str(err))
				return

		# Set language
		request = urllib2.Request(self._LANG_URL)
		try:
			self.report_lang()
			urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.to_stderr(u'WARNING: unable to set language: %s' % str(err))
			return

		# No authentication to be performed
		if username is None:
			return

		# Log in
		login_form = {
				'current_form': 'loginForm',
				'next':		'/',
				'action_login':	'Log In',
				'username':	username,
				'password':	password,
				}
		request = urllib2.Request(self._LOGIN_URL, urllib.urlencode(login_form))
		try:
			self.report_login()
			login_results = urllib2.urlopen(request).read()
			if re.search(r'(?i)<form[^>]* name="loginForm"', login_results) is not None:
				self._downloader.to_stderr(u'WARNING: unable to log in: bad username or password')
				return
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.to_stderr(u'WARNING: unable to log in: %s' % str(err))
			return

		# Confirm age
		age_form = {
				'next_url':		'/',
				'action_confirm':	'Confirm',
				}
		request = urllib2.Request(self._AGE_URL, urllib.urlencode(age_form))
		try:
			self.report_age_confirmation()
			age_results = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to confirm age: %s' % str(err))
			return

	def _real_extract(self, url):
		# Extract video id from URL
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid URL: %s' % url)
			return
		video_id = mobj.group(2)

		# Get video webpage
		self.report_video_webpage_download(video_id)
		request = urllib2.Request('http://www.youtube.com/watch?v=%s&gl=US&hl=en&has_verified=1' % video_id)
		try:
			video_webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to download video webpage: %s' % str(err))
			return

		# Attempt to extract SWF player URL
		mobj = re.search(r'swfConfig.*?"(http:\\/\\/.*?watch.*?-.*?\.swf)"', video_webpage)
		if mobj is not None:
			player_url = re.sub(r'\\(.)', r'\1', mobj.group(1))
		else:
			player_url = None

		# Get video info
		self.report_video_info_webpage_download(video_id)
		for el_type in ['&el=embedded', '&el=detailpage', '&el=vevo', '']:
			video_info_url = ('http://www.youtube.com/get_video_info?&video_id=%s%s&ps=default&eurl=&gl=US&hl=en'
					% (video_id, el_type))
			request = urllib2.Request(video_info_url)
			try:
				video_info_webpage = urllib2.urlopen(request).read()
				video_info = parse_qs(video_info_webpage)
				if 'token' in video_info:
					break
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				self._downloader.trouble(u'ERROR: unable to download video info webpage: %s' % str(err))
				return
		if 'token' not in video_info:
			if 'reason' in video_info:
				self._downloader.trouble(u'ERROR: YouTube said: %s' % video_info['reason'][0].decode('utf-8'))
			else:
				self._downloader.trouble(u'ERROR: "token" parameter not in video info for unknown reason')
			return

		# Start extracting information
		self.report_information_extraction(video_id)

		# uploader
		if 'author' not in video_info:
			self._downloader.trouble(u'ERROR: unable to extract uploader nickname')
			return
		video_uploader = urllib.unquote_plus(video_info['author'][0])

		# title
		if 'title' not in video_info:
			self._downloader.trouble(u'ERROR: unable to extract video title')
			return
		video_title = urllib.unquote_plus(video_info['title'][0])
		video_title = video_title.decode('utf-8')
		video_title = sanitize_title(video_title)

		# simplified title
		simple_title = _simplify_title(video_title)

		# thumbnail image
		if 'thumbnail_url' not in video_info:
			self._downloader.trouble(u'WARNING: unable to extract video thumbnail')
			video_thumbnail = ''
		else:	# don't panic if we can't find it
			video_thumbnail = urllib.unquote_plus(video_info['thumbnail_url'][0])

		# upload date
		upload_date = u'NA'
		mobj = re.search(r'id="eow-date.*?>(.*?)</span>', video_webpage, re.DOTALL)
		if mobj is not None:
			upload_date = ' '.join(re.sub(r'[/,-]', r' ', mobj.group(1)).split())
			format_expressions = ['%d %B %Y', '%B %d %Y', '%b %d %Y']
			for expression in format_expressions:
				try:
					upload_date = datetime.datetime.strptime(upload_date, expression).strftime('%Y%m%d')
				except:
					pass

		# description
		video_description = get_element_by_id("eow-description", video_webpage)
		if video_description: video_description = clean_html(video_description.decode('utf8'))
		else: video_description = ''
			
		# closed captions
		video_subtitles = None
		if self._downloader.params.get('writesubtitles', False):
			self.report_video_subtitles_download(video_id)
			request = urllib2.Request('http://video.google.com/timedtext?hl=en&type=list&v=%s' % video_id)
			try:
				srt_list = urllib2.urlopen(request).read()
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				self._downloader.trouble(u'WARNING: unable to download video subtitles: %s' % str(err))
			else:
				srt_lang_list = re.findall(r'lang_code="([\w\-]+)"', srt_list)
				if srt_lang_list:
					if self._downloader.params.get('subtitleslang', False):
						srt_lang = self._downloader.params.get('subtitleslang')
					elif 'en' in srt_lang_list:
						srt_lang = 'en'
					else:
						srt_lang = srt_lang_list[0]
					if not srt_lang in srt_lang_list:
						self._downloader.trouble(u'WARNING: no closed captions found in the specified language')
					else:
						request = urllib2.Request('http://video.google.com/timedtext?hl=en&lang=%s&v=%s' % (srt_lang, video_id))
						try:
							srt_xml = urllib2.urlopen(request).read()
						except (urllib2.URLError, httplib.HTTPException, socket.error), err:
							self._downloader.trouble(u'WARNING: unable to download video subtitles: %s' % str(err))
						else:
							video_subtitles = self._closed_captions_xml_to_srt(srt_xml.decode('utf-8'))
				else:
					self._downloader.trouble(u'WARNING: video has no closed captions')

		# token
		video_token = urllib.unquote_plus(video_info['token'][0])

		# Decide which formats to download
		req_format = self._downloader.params.get('format', None)

		if 'conn' in video_info and video_info['conn'][0].startswith('rtmp'):
			self.report_rtmp_download()
			video_url_list = [(None, video_info['conn'][0])]
		elif 'url_encoded_fmt_stream_map' in video_info and len(video_info['url_encoded_fmt_stream_map']) >= 1:
			url_data_strs = video_info['url_encoded_fmt_stream_map'][0].split(',')
			url_data = [parse_qs(uds) for uds in url_data_strs]
			url_data = filter(lambda ud: 'itag' in ud and 'url' in ud, url_data)
			url_map = dict((ud['itag'][0], ud['url'][0]) for ud in url_data)

			format_limit = self._downloader.params.get('format_limit', None)
			available_formats = self._available_formats_prefer_free if self._downloader.params.get('prefer_free_formats', False) else self._available_formats
			if format_limit is not None and format_limit in available_formats:
				format_list = available_formats[available_formats.index(format_limit):]
			else:
				format_list = available_formats
			existing_formats = [x for x in format_list if x in url_map]
			if len(existing_formats) == 0:
				self._downloader.trouble(u'ERROR: no known formats available for video')
				return
			if self._downloader.params.get('listformats', None):
				self._print_formats(existing_formats)
				return
			if req_format is None or req_format == 'best':
				video_url_list = [(existing_formats[0], url_map[existing_formats[0]])] # Best quality
			elif req_format == 'worst':
				video_url_list = [(existing_formats[len(existing_formats)-1], url_map[existing_formats[len(existing_formats)-1]])] # worst quality
			elif req_format in ('-1', 'all'):
				video_url_list = [(f, url_map[f]) for f in existing_formats] # All formats
			else:
				# Specific formats. We pick the first in a slash-delimeted sequence.
				# For example, if '1/2/3/4' is requested and '2' and '4' are available, we pick '2'.
				req_formats = req_format.split('/')
				video_url_list = None
				for rf in req_formats:
					if rf in url_map:
						video_url_list = [(rf, url_map[rf])]
						break
				if video_url_list is None:
					self._downloader.trouble(u'ERROR: requested format not available')
					return
		else:
			self._downloader.trouble(u'ERROR: no conn or url_encoded_fmt_stream_map information found in video info')
			return

		for format_param, video_real_url in video_url_list:
			# At this point we have a new video
			self._downloader.increment_downloads()

			# Extension
			video_extension = self._video_extensions.get(format_param, 'flv')

			try:
				# Process video information
				self._downloader.process_info({
					'id':		video_id.decode('utf-8'),
					'url':		video_real_url.decode('utf-8'),
					'uploader':	video_uploader.decode('utf-8'),
					'upload_date':	upload_date,
					'title':	video_title,
					'stitle':	simple_title,
					'ext':		video_extension.decode('utf-8'),
					'format':	(format_param is None and u'NA' or format_param.decode('utf-8')),
					'thumbnail':	video_thumbnail.decode('utf-8'),
					'description':	video_description,
					'player_url':	player_url,
					'subtitles':	video_subtitles
				})
			except UnavailableVideoError, err:
				self._downloader.trouble(u'\nERROR: unable to download video')


class MetacafeIE(InfoExtractor):
	"""Information Extractor for metacafe.com."""

	_VALID_URL = r'(?:http://)?(?:www\.)?metacafe\.com/watch/([^/]+)/([^/]+)/.*'
	_DISCLAIMER = 'http://www.metacafe.com/family_filter/'
	_FILTER_POST = 'http://www.metacafe.com/f/index.php?inputType=filter&controllerGroup=user'
	_youtube_ie = None
	IE_NAME = u'metacafe'

	def __init__(self, youtube_ie, downloader=None):
		InfoExtractor.__init__(self, downloader)
		self._youtube_ie = youtube_ie

	def report_disclaimer(self):
		"""Report disclaimer retrieval."""
		self._downloader.to_screen(u'[metacafe] Retrieving disclaimer')

	def report_age_confirmation(self):
		"""Report attempt to confirm age."""
		self._downloader.to_screen(u'[metacafe] Confirming age')

	def report_download_webpage(self, video_id):
		"""Report webpage download."""
		self._downloader.to_screen(u'[metacafe] %s: Downloading webpage' % video_id)

	def report_extraction(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[metacafe] %s: Extracting information' % video_id)

	def _real_initialize(self):
		# Retrieve disclaimer
		request = urllib2.Request(self._DISCLAIMER)
		try:
			self.report_disclaimer()
			disclaimer = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to retrieve disclaimer: %s' % str(err))
			return

		# Confirm age
		disclaimer_form = {
			'filters': '0',
			'submit': "Continue - I'm over 18",
			}
		request = urllib2.Request(self._FILTER_POST, urllib.urlencode(disclaimer_form))
		try:
			self.report_age_confirmation()
			disclaimer = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to confirm age: %s' % str(err))
			return

	def _real_extract(self, url):
		# Extract id and simplified title from URL
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid URL: %s' % url)
			return

		video_id = mobj.group(1)

		# Check if video comes from YouTube
		mobj2 = re.match(r'^yt-(.*)$', video_id)
		if mobj2 is not None:
			self._youtube_ie.extract('http://www.youtube.com/watch?v=%s' % mobj2.group(1))
			return

		# At this point we have a new video
		self._downloader.increment_downloads()

		simple_title = mobj.group(2).decode('utf-8')

		# Retrieve video webpage to extract further information
		request = urllib2.Request('http://www.metacafe.com/watch/%s/' % video_id)
		try:
			self.report_download_webpage(video_id)
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable retrieve video webpage: %s' % str(err))
			return

		# Extract URL, uploader and title from webpage
		self.report_extraction(video_id)
		mobj = re.search(r'(?m)&mediaURL=([^&]+)', webpage)
		if mobj is not None:
			mediaURL = urllib.unquote(mobj.group(1))
			video_extension = mediaURL[-3:]

			# Extract gdaKey if available
			mobj = re.search(r'(?m)&gdaKey=(.*?)&', webpage)
			if mobj is None:
				video_url = mediaURL
			else:
				gdaKey = mobj.group(1)
				video_url = '%s?__gda__=%s' % (mediaURL, gdaKey)
		else:
			mobj = re.search(r' name="flashvars" value="(.*?)"', webpage)
			if mobj is None:
				self._downloader.trouble(u'ERROR: unable to extract media URL')
				return
			vardict = parse_qs(mobj.group(1))
			if 'mediaData' not in vardict:
				self._downloader.trouble(u'ERROR: unable to extract media URL')
				return
			mobj = re.search(r'"mediaURL":"(http.*?)","key":"(.*?)"', vardict['mediaData'][0])
			if mobj is None:
				self._downloader.trouble(u'ERROR: unable to extract media URL')
				return
			mediaURL = mobj.group(1).replace('\\/', '/')
			video_extension = mediaURL[-3:]
			video_url = '%s?__gda__=%s' % (mediaURL, mobj.group(2))

		mobj = re.search(r'(?im)<title>(.*) - Video</title>', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract title')
			return
		video_title = mobj.group(1).decode('utf-8')
		video_title = sanitize_title(video_title)

		mobj = re.search(r'(?ms)By:\s*<a .*?>(.+?)<', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract uploader nickname')
			return
		video_uploader = mobj.group(1)

		try:
			# Process video information
			self._downloader.process_info({
				'id':		video_id.decode('utf-8'),
				'url':		video_url.decode('utf-8'),
				'uploader':	video_uploader.decode('utf-8'),
				'upload_date':	u'NA',
				'title':	video_title,
				'stitle':	simple_title,
				'ext':		video_extension.decode('utf-8'),
				'format':	u'NA',
				'player_url':	None,
			})
		except UnavailableVideoError:
			self._downloader.trouble(u'\nERROR: unable to download video')


class DailymotionIE(InfoExtractor):
	"""Information Extractor for Dailymotion"""

	_VALID_URL = r'(?i)(?:https?://)?(?:www\.)?dailymotion\.[a-z]{2,3}/video/([^_/]+)_([^/]+)'
	IE_NAME = u'dailymotion'

	def __init__(self, downloader=None):
		InfoExtractor.__init__(self, downloader)

	def report_download_webpage(self, video_id):
		"""Report webpage download."""
		self._downloader.to_screen(u'[dailymotion] %s: Downloading webpage' % video_id)

	def report_extraction(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[dailymotion] %s: Extracting information' % video_id)

	def _real_extract(self, url):
		# Extract id and simplified title from URL
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid URL: %s' % url)
			return

		# At this point we have a new video
		self._downloader.increment_downloads()
		video_id = mobj.group(1)

		video_extension = 'flv'

		# Retrieve video webpage to extract further information
		request = urllib2.Request(url)
		request.add_header('Cookie', 'family_filter=off')
		try:
			self.report_download_webpage(video_id)
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable retrieve video webpage: %s' % str(err))
			return

		# Extract URL, uploader and title from webpage
		self.report_extraction(video_id)
		mobj = re.search(r'(?i)addVariable\(\"sequence\"\s*,\s*\"([^\"]+?)\"\)', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract media URL')
			return
		sequence = urllib.unquote(mobj.group(1))
		mobj = re.search(r',\"sdURL\"\:\"([^\"]+?)\",', sequence)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract media URL')
			return
		mediaURL = urllib.unquote(mobj.group(1)).replace('\\', '')

		# if needed add http://www.dailymotion.com/ if relative URL

		video_url = mediaURL

		mobj = re.search(r'<meta property="og:title" content="(?P<title>[^"]*)" />', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract title')
			return
		video_title = _unescapeHTML(mobj.group('title').decode('utf-8'))
		video_title = sanitize_title(video_title)
		simple_title = _simplify_title(video_title)

		mobj = re.search(r'(?im)<span class="owner[^\"]+?">[^<]+?<a [^>]+?>([^<]+?)</a></span>', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract uploader nickname')
			return
		video_uploader = mobj.group(1)

		try:
			# Process video information
			self._downloader.process_info({
				'id':		video_id.decode('utf-8'),
				'url':		video_url.decode('utf-8'),
				'uploader':	video_uploader.decode('utf-8'),
				'upload_date':	u'NA',
				'title':	video_title,
				'stitle':	simple_title,
				'ext':		video_extension.decode('utf-8'),
				'format':	u'NA',
				'player_url':	None,
			})
		except UnavailableVideoError:
			self._downloader.trouble(u'\nERROR: unable to download video')


class GoogleIE(InfoExtractor):
	"""Information extractor for video.google.com."""

	_VALID_URL = r'(?:http://)?video\.google\.(?:com(?:\.au)?|co\.(?:uk|jp|kr|cr)|ca|de|es|fr|it|nl|pl)/videoplay\?docid=([^\&]+).*'
	IE_NAME = u'video.google'

	def __init__(self, downloader=None):
		InfoExtractor.__init__(self, downloader)

	def report_download_webpage(self, video_id):
		"""Report webpage download."""
		self._downloader.to_screen(u'[video.google] %s: Downloading webpage' % video_id)

	def report_extraction(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[video.google] %s: Extracting information' % video_id)

	def _real_extract(self, url):
		# Extract id from URL
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: Invalid URL: %s' % url)
			return

		# At this point we have a new video
		self._downloader.increment_downloads()
		video_id = mobj.group(1)

		video_extension = 'mp4'

		# Retrieve video webpage to extract further information
		request = urllib2.Request('http://video.google.com/videoplay?docid=%s&hl=en&oe=utf-8' % video_id)
		try:
			self.report_download_webpage(video_id)
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: Unable to retrieve video webpage: %s' % str(err))
			return

		# Extract URL, uploader, and title from webpage
		self.report_extraction(video_id)
		mobj = re.search(r"download_url:'([^']+)'", webpage)
		if mobj is None:
			video_extension = 'flv'
			mobj = re.search(r"(?i)videoUrl\\x3d(.+?)\\x26", webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract media URL')
			return
		mediaURL = urllib.unquote(mobj.group(1))
		mediaURL = mediaURL.replace('\\x3d', '\x3d')
		mediaURL = mediaURL.replace('\\x26', '\x26')

		video_url = mediaURL

		mobj = re.search(r'<title>(.*)</title>', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract title')
			return
		video_title = mobj.group(1).decode('utf-8')
		video_title = sanitize_title(video_title)
		simple_title = _simplify_title(video_title)

		# Extract video description
		mobj = re.search(r'<span id=short-desc-content>([^<]*)</span>', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract video description')
			return
		video_description = mobj.group(1).decode('utf-8')
		if not video_description:
			video_description = 'No description available.'

		# Extract video thumbnail
		if self._downloader.params.get('forcethumbnail', False):
			request = urllib2.Request('http://video.google.com/videosearch?q=%s+site:video.google.com&hl=en' % abs(int(video_id)))
			try:
				webpage = urllib2.urlopen(request).read()
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				self._downloader.trouble(u'ERROR: Unable to retrieve video webpage: %s' % str(err))
				return
			mobj = re.search(r'<img class=thumbnail-img (?:.* )?src=(http.*)>', webpage)
			if mobj is None:
				self._downloader.trouble(u'ERROR: unable to extract video thumbnail')
				return
			video_thumbnail = mobj.group(1)
		else:	# we need something to pass to process_info
			video_thumbnail = ''

		try:
			# Process video information
			self._downloader.process_info({
				'id':		video_id.decode('utf-8'),
				'url':		video_url.decode('utf-8'),
				'uploader':	u'NA',
				'upload_date':	u'NA',
				'title':	video_title,
				'stitle':	simple_title,
				'ext':		video_extension.decode('utf-8'),
				'format':	u'NA',
				'player_url':	None,
			})
		except UnavailableVideoError:
			self._downloader.trouble(u'\nERROR: unable to download video')


class PhotobucketIE(InfoExtractor):
	"""Information extractor for photobucket.com."""

	_VALID_URL = r'(?:http://)?(?:[a-z0-9]+\.)?photobucket\.com/.*[\?\&]current=(.*\.flv)'
	IE_NAME = u'photobucket'

	def __init__(self, downloader=None):
		InfoExtractor.__init__(self, downloader)

	def report_download_webpage(self, video_id):
		"""Report webpage download."""
		self._downloader.to_screen(u'[photobucket] %s: Downloading webpage' % video_id)

	def report_extraction(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[photobucket] %s: Extracting information' % video_id)

	def _real_extract(self, url):
		# Extract id from URL
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: Invalid URL: %s' % url)
			return

		# At this point we have a new video
		self._downloader.increment_downloads()
		video_id = mobj.group(1)

		video_extension = 'flv'

		# Retrieve video webpage to extract further information
		request = urllib2.Request(url)
		try:
			self.report_download_webpage(video_id)
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: Unable to retrieve video webpage: %s' % str(err))
			return

		# Extract URL, uploader, and title from webpage
		self.report_extraction(video_id)
		mobj = re.search(r'<link rel="video_src" href=".*\?file=([^"]+)" />', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract media URL')
			return
		mediaURL = urllib.unquote(mobj.group(1))

		video_url = mediaURL

		mobj = re.search(r'<title>(.*) video by (.*) - Photobucket</title>', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract title')
			return
		video_title = mobj.group(1).decode('utf-8')
		video_title = sanitize_title(video_title)
		simple_title = _simplify_title(vide_title)

		video_uploader = mobj.group(2).decode('utf-8')

		try:
			# Process video information
			self._downloader.process_info({
				'id':		video_id.decode('utf-8'),
				'url':		video_url.decode('utf-8'),
				'uploader':	video_uploader,
				'upload_date':	u'NA',
				'title':	video_title,
				'stitle':	simple_title,
				'ext':		video_extension.decode('utf-8'),
				'format':	u'NA',
				'player_url':	None,
			})
		except UnavailableVideoError:
			self._downloader.trouble(u'\nERROR: unable to download video')


class YahooIE(InfoExtractor):
	"""Information extractor for video.yahoo.com."""

	# _VALID_URL matches all Yahoo! Video URLs
	# _VPAGE_URL matches only the extractable '/watch/' URLs
	_VALID_URL = r'(?:http://)?(?:[a-z]+\.)?video\.yahoo\.com/(?:watch|network)/([0-9]+)(?:/|\?v=)([0-9]+)(?:[#\?].*)?'
	_VPAGE_URL = r'(?:http://)?video\.yahoo\.com/watch/([0-9]+)/([0-9]+)(?:[#\?].*)?'
	IE_NAME = u'video.yahoo'

	def __init__(self, downloader=None):
		InfoExtractor.__init__(self, downloader)

	def report_download_webpage(self, video_id):
		"""Report webpage download."""
		self._downloader.to_screen(u'[video.yahoo] %s: Downloading webpage' % video_id)

	def report_extraction(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[video.yahoo] %s: Extracting information' % video_id)

	def _real_extract(self, url, new_video=True):
		# Extract ID from URL
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: Invalid URL: %s' % url)
			return

		# At this point we have a new video
		self._downloader.increment_downloads()
		video_id = mobj.group(2)
		video_extension = 'flv'

		# Rewrite valid but non-extractable URLs as
		# extractable English language /watch/ URLs
		if re.match(self._VPAGE_URL, url) is None:
			request = urllib2.Request(url)
			try:
				webpage = urllib2.urlopen(request).read()
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				self._downloader.trouble(u'ERROR: Unable to retrieve video webpage: %s' % str(err))
				return

			mobj = re.search(r'\("id", "([0-9]+)"\);', webpage)
			if mobj is None:
				self._downloader.trouble(u'ERROR: Unable to extract id field')
				return
			yahoo_id = mobj.group(1)

			mobj = re.search(r'\("vid", "([0-9]+)"\);', webpage)
			if mobj is None:
				self._downloader.trouble(u'ERROR: Unable to extract vid field')
				return
			yahoo_vid = mobj.group(1)

			url = 'http://video.yahoo.com/watch/%s/%s' % (yahoo_vid, yahoo_id)
			return self._real_extract(url, new_video=False)

		# Retrieve video webpage to extract further information
		request = urllib2.Request(url)
		try:
			self.report_download_webpage(video_id)
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: Unable to retrieve video webpage: %s' % str(err))
			return

		# Extract uploader and title from webpage
		self.report_extraction(video_id)
		mobj = re.search(r'<meta name="title" content="(.*)" />', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract video title')
			return
		video_title = mobj.group(1).decode('utf-8')
		simple_title = _simplify_title(video_title)

		mobj = re.search(r'<h2 class="ti-5"><a href="http://video\.yahoo\.com/(people|profile)/[0-9]+" beacon=".*">(.*)</a></h2>', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract video uploader')
			return
		video_uploader = mobj.group(1).decode('utf-8')

		# Extract video thumbnail
		mobj = re.search(r'<link rel="image_src" href="(.*)" />', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract video thumbnail')
			return
		video_thumbnail = mobj.group(1).decode('utf-8')

		# Extract video description
		mobj = re.search(r'<meta name="description" content="(.*)" />', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract video description')
			return
		video_description = mobj.group(1).decode('utf-8')
		if not video_description:
			video_description = 'No description available.'

		# Extract video height and width
		mobj = re.search(r'<meta name="video_height" content="([0-9]+)" />', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract video height')
			return
		yv_video_height = mobj.group(1)

		mobj = re.search(r'<meta name="video_width" content="([0-9]+)" />', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract video width')
			return
		yv_video_width = mobj.group(1)

		# Retrieve video playlist to extract media URL
		# I'm not completely sure what all these options are, but we
		# seem to need most of them, otherwise the server sends a 401.
		yv_lg = 'R0xx6idZnW2zlrKP8xxAIR'  # not sure what this represents
		yv_bitrate = '700'  # according to Wikipedia this is hard-coded
		request = urllib2.Request('http://cosmos.bcst.yahoo.com/up/yep/process/getPlaylistFOP.php?node_id=' + video_id +
				'&tech=flash&mode=playlist&lg=' + yv_lg + '&bitrate=' + yv_bitrate + '&vidH=' + yv_video_height +
				'&vidW=' + yv_video_width + '&swf=as3&rd=video.yahoo.com&tk=null&adsupported=v1,v2,&eventid=1301797')
		try:
			self.report_download_webpage(video_id)
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: Unable to retrieve video webpage: %s' % str(err))
			return

		# Extract media URL from playlist XML
		mobj = re.search(r'<STREAM APP="(http://.*)" FULLPATH="/?(/.*\.flv\?[^"]*)"', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: Unable to extract media URL')
			return
		video_url = urllib.unquote(mobj.group(1) + mobj.group(2)).decode('utf-8')
		video_url = re.sub(r'(?u)&(.+?);', htmlentity_transform, video_url)

		try:
			# Process video information
			self._downloader.process_info({
				'id':		video_id.decode('utf-8'),
				'url':		video_url,
				'uploader':	video_uploader,
				'upload_date':	u'NA',
				'title':	video_title,
				'stitle':	simple_title,
				'ext':		video_extension.decode('utf-8'),
				'thumbnail':	video_thumbnail.decode('utf-8'),
				'description':	video_description,
				'thumbnail':	video_thumbnail,
				'player_url':	None,
			})
		except UnavailableVideoError:
			self._downloader.trouble(u'\nERROR: unable to download video')


class VimeoIE(InfoExtractor):
	"""Information extractor for vimeo.com."""

	# _VALID_URL matches Vimeo URLs
	_VALID_URL = r'(?:https?://)?(?:(?:www|player).)?vimeo\.com/(?:groups/[^/]+/)?(?:videos?/)?([0-9]+)'
	IE_NAME = u'vimeo'

	def __init__(self, downloader=None):
		InfoExtractor.__init__(self, downloader)

	def report_download_webpage(self, video_id):
		"""Report webpage download."""
		self._downloader.to_screen(u'[vimeo] %s: Downloading webpage' % video_id)

	def report_extraction(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[vimeo] %s: Extracting information' % video_id)

	def _real_extract(self, url, new_video=True):
		# Extract ID from URL
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: Invalid URL: %s' % url)
			return

		# At this point we have a new video
		self._downloader.increment_downloads()
		video_id = mobj.group(1)

		# Retrieve video webpage to extract further information
		request = urllib2.Request(url, None, std_headers)
		try:
			self.report_download_webpage(video_id)
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: Unable to retrieve video webpage: %s' % str(err))
			return

		# Now we begin extracting as much information as we can from what we
		# retrieved. First we extract the information common to all extractors,
		# and latter we extract those that are Vimeo specific.
		self.report_extraction(video_id)

		# Extract the config JSON
		config = webpage.split(' = {config:')[1].split(',assets:')[0]
		try:
			config = json.loads(config)
		except:
			self._downloader.trouble(u'ERROR: unable to extract info section')
			return
		
		# Extract title
		video_title = config["video"]["title"]
		simple_title = _simplify_title(video_title)

		# Extract uploader
		video_uploader = config["video"]["owner"]["name"]

		# Extract video thumbnail
		video_thumbnail = config["video"]["thumbnail"]

		# Extract video description
		video_description = get_element_by_id("description", webpage)
		if video_description: video_description = clean_html(video_description.decode('utf8'))
		else: video_description = ''

		# Extract upload date
		video_upload_date = u'NA'
		mobj = re.search(r'<span id="clip-date" style="display:none">[^:]*: (.*?)( \([^\(]*\))?</span>', webpage)
		if mobj is not None:
			video_upload_date = mobj.group(1)

		# Vimeo specific: extract request signature and timestamp
		sig = config['request']['signature']
		timestamp = config['request']['timestamp']

		# Vimeo specific: extract video codec and quality information
		# TODO bind to format param
		codecs = [('h264', 'mp4'), ('vp8', 'flv'), ('vp6', 'flv')]
		for codec in codecs:
			if codec[0] in config["video"]["files"]:
				video_codec = codec[0]
				video_extension = codec[1]
				if 'hd' in config["video"]["files"][codec[0]]: quality = 'hd'
				else: quality = 'sd'
				break
		else:
			self._downloader.trouble(u'ERROR: no known codec found')
			return

		video_url = "http://player.vimeo.com/play_redirect?clip_id=%s&sig=%s&time=%s&quality=%s&codecs=%s&type=moogaloop_local&embed_location=" \
					%(video_id, sig, timestamp, quality, video_codec.upper())

		try:
			# Process video information
			self._downloader.process_info({
				'id':		video_id,
				'url':		video_url,
				'uploader':	video_uploader,
				'upload_date':	video_upload_date,
				'title':	video_title,
				'stitle':	simple_title,
				'ext':		video_extension,
				'thumbnail':	video_thumbnail,
				'description':	video_description,
				'player_url':	None,
			})
		except UnavailableVideoError:
			self._downloader.trouble(u'ERROR: unable to download video')


class GenericIE(InfoExtractor):
	"""Generic last-resort information extractor."""

	_VALID_URL = r'.*'
	IE_NAME = u'generic'

	def __init__(self, downloader=None):
		InfoExtractor.__init__(self, downloader)

	def report_download_webpage(self, video_id):
		"""Report webpage download."""
		self._downloader.to_screen(u'WARNING: Falling back on generic information extractor.')
		self._downloader.to_screen(u'[generic] %s: Downloading webpage' % video_id)

	def report_extraction(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[generic] %s: Extracting information' % video_id)

	def _real_extract(self, url):
		# At this point we have a new video
		self._downloader.increment_downloads()

		video_id = url.split('/')[-1]
		request = urllib2.Request(url)
		try:
			self.report_download_webpage(video_id)
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: Unable to retrieve video webpage: %s' % str(err))
			return
		except ValueError, err:
			# since this is the last-resort InfoExtractor, if
			# this error is thrown, it'll be thrown here
			self._downloader.trouble(u'ERROR: Invalid URL: %s' % url)
			return

		self.report_extraction(video_id)
		# Start with something easy: JW Player in SWFObject
		mobj = re.search(r'flashvars: [\'"](?:.*&)?file=(http[^\'"&]*)', webpage)
		if mobj is None:
			# Broaden the search a little bit
			mobj = re.search(r'[^A-Za-z0-9]?(?:file|source)=(http[^\'"&]*)', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: Invalid URL: %s' % url)
			return

		# It's possible that one of the regexes
		# matched, but returned an empty group:
		if mobj.group(1) is None:
			self._downloader.trouble(u'ERROR: Invalid URL: %s' % url)
			return

		video_url = urllib.unquote(mobj.group(1))
		video_id = os.path.basename(video_url)

		# here's a fun little line of code for you:
		video_extension = os.path.splitext(video_id)[1][1:]
		video_id = os.path.splitext(video_id)[0]

		# it's tempting to parse this further, but you would
		# have to take into account all the variations like
		#   Video Title - Site Name
		#   Site Name | Video Title
		#   Video Title - Tagline | Site Name
		# and so on and so forth; it's just not practical
		mobj = re.search(r'<title>(.*)</title>', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract title')
			return
		video_title = mobj.group(1).decode('utf-8')
		video_title = sanitize_title(video_title)
		simple_title = _simplify_title(video_title)

		# video uploader is domain name
		mobj = re.match(r'(?:https?://)?([^/]*)/.*', url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract title')
			return
		video_uploader = mobj.group(1).decode('utf-8')

		try:
			# Process video information
			self._downloader.process_info({
				'id':		video_id.decode('utf-8'),
				'url':		video_url.decode('utf-8'),
				'uploader':	video_uploader,
				'upload_date':	u'NA',
				'title':	video_title,
				'stitle':	simple_title,
				'ext':		video_extension.decode('utf-8'),
				'format':	u'NA',
				'player_url':	None,
			})
		except UnavailableVideoError, err:
			self._downloader.trouble(u'\nERROR: unable to download video')


class YoutubeSearchIE(InfoExtractor):
	"""Information Extractor for YouTube search queries."""
	_VALID_URL = r'ytsearch(\d+|all)?:[\s\S]+'
	_API_URL = 'https://gdata.youtube.com/feeds/api/videos?q=%s&start-index=%i&max-results=50&v=2&alt=jsonc'
	_youtube_ie = None
	_max_youtube_results = 1000
	IE_NAME = u'youtube:search'

	def __init__(self, youtube_ie, downloader=None):
		InfoExtractor.__init__(self, downloader)
		self._youtube_ie = youtube_ie

	def report_download_page(self, query, pagenum):
		"""Report attempt to download playlist page with given number."""
		query = query.decode(preferredencoding())
		self._downloader.to_screen(u'[youtube] query "%s": Downloading page %s' % (query, pagenum))

	def _real_initialize(self):
		self._youtube_ie.initialize()

	def _real_extract(self, query):
		mobj = re.match(self._VALID_URL, query)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid search query "%s"' % query)
			return

		prefix, query = query.split(':')
		prefix = prefix[8:]
		query = query.encode('utf-8')
		if prefix == '':
			self._download_n_results(query, 1)
			return
		elif prefix == 'all':
			self._download_n_results(query, self._max_youtube_results)
			return
		else:
			try:
				n = long(prefix)
				if n <= 0:
					self._downloader.trouble(u'ERROR: invalid download number %s for query "%s"' % (n, query))
					return
				elif n > self._max_youtube_results:
					self._downloader.to_stderr(u'WARNING: ytsearch returns max %i results (you requested %i)' % (self._max_youtube_results, n))
					n = self._max_youtube_results
				self._download_n_results(query, n)
				return
			except ValueError: # parsing prefix as integer fails
				self._download_n_results(query, 1)
				return

	def _download_n_results(self, query, n):
		"""Downloads a specified number of results for a query"""

		video_ids = []
		pagenum = 0
		limit = n

		while (50 * pagenum) < limit:
			self.report_download_page(query, pagenum+1)
			result_url = self._API_URL % (urllib.quote_plus(query), (50*pagenum)+1)
			request = urllib2.Request(result_url)
			try:
				data = urllib2.urlopen(request).read()
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				self._downloader.trouble(u'ERROR: unable to download API page: %s' % str(err))
				return
			api_response = json.loads(data)['data']

			new_ids = list(video['id'] for video in api_response['items'])
			video_ids += new_ids

			limit = min(n, api_response['totalItems'])
			pagenum += 1

		if len(video_ids) > n:
			video_ids = video_ids[:n]
		for id in video_ids:
			self._youtube_ie.extract('http://www.youtube.com/watch?v=%s' % id)
		return


class GoogleSearchIE(InfoExtractor):
	"""Information Extractor for Google Video search queries."""
	_VALID_URL = r'gvsearch(\d+|all)?:[\s\S]+'
	_TEMPLATE_URL = 'http://video.google.com/videosearch?q=%s+site:video.google.com&start=%s&hl=en'
	_VIDEO_INDICATOR = r'<a href="http://video\.google\.com/videoplay\?docid=([^"\&]+)'
	_MORE_PAGES_INDICATOR = r'class="pn" id="pnnext"'
	_google_ie = None
	_max_google_results = 1000
	IE_NAME = u'video.google:search'

	def __init__(self, google_ie, downloader=None):
		InfoExtractor.__init__(self, downloader)
		self._google_ie = google_ie

	def report_download_page(self, query, pagenum):
		"""Report attempt to download playlist page with given number."""
		query = query.decode(preferredencoding())
		self._downloader.to_screen(u'[video.google] query "%s": Downloading page %s' % (query, pagenum))

	def _real_initialize(self):
		self._google_ie.initialize()

	def _real_extract(self, query):
		mobj = re.match(self._VALID_URL, query)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid search query "%s"' % query)
			return

		prefix, query = query.split(':')
		prefix = prefix[8:]
		query = query.encode('utf-8')
		if prefix == '':
			self._download_n_results(query, 1)
			return
		elif prefix == 'all':
			self._download_n_results(query, self._max_google_results)
			return
		else:
			try:
				n = long(prefix)
				if n <= 0:
					self._downloader.trouble(u'ERROR: invalid download number %s for query "%s"' % (n, query))
					return
				elif n > self._max_google_results:
					self._downloader.to_stderr(u'WARNING: gvsearch returns max %i results (you requested %i)' % (self._max_google_results, n))
					n = self._max_google_results
				self._download_n_results(query, n)
				return
			except ValueError: # parsing prefix as integer fails
				self._download_n_results(query, 1)
				return

	def _download_n_results(self, query, n):
		"""Downloads a specified number of results for a query"""

		video_ids = []
		pagenum = 0

		while True:
			self.report_download_page(query, pagenum)
			result_url = self._TEMPLATE_URL % (urllib.quote_plus(query), pagenum*10)
			request = urllib2.Request(result_url)
			try:
				page = urllib2.urlopen(request).read()
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				self._downloader.trouble(u'ERROR: unable to download webpage: %s' % str(err))
				return

			# Extract video identifiers
			for mobj in re.finditer(self._VIDEO_INDICATOR, page):
				video_id = mobj.group(1)
				if video_id not in video_ids:
					video_ids.append(video_id)
					if len(video_ids) == n:
						# Specified n videos reached
						for id in video_ids:
							self._google_ie.extract('http://video.google.com/videoplay?docid=%s' % id)
						return

			if re.search(self._MORE_PAGES_INDICATOR, page) is None:
				for id in video_ids:
					self._google_ie.extract('http://video.google.com/videoplay?docid=%s' % id)
				return

			pagenum = pagenum + 1


class YahooSearchIE(InfoExtractor):
	"""Information Extractor for Yahoo! Video search queries."""
	_VALID_URL = r'yvsearch(\d+|all)?:[\s\S]+'
	_TEMPLATE_URL = 'http://video.yahoo.com/search/?p=%s&o=%s'
	_VIDEO_INDICATOR = r'href="http://video\.yahoo\.com/watch/([0-9]+/[0-9]+)"'
	_MORE_PAGES_INDICATOR = r'\s*Next'
	_yahoo_ie = None
	_max_yahoo_results = 1000
	IE_NAME = u'video.yahoo:search'

	def __init__(self, yahoo_ie, downloader=None):
		InfoExtractor.__init__(self, downloader)
		self._yahoo_ie = yahoo_ie

	def report_download_page(self, query, pagenum):
		"""Report attempt to download playlist page with given number."""
		query = query.decode(preferredencoding())
		self._downloader.to_screen(u'[video.yahoo] query "%s": Downloading page %s' % (query, pagenum))

	def _real_initialize(self):
		self._yahoo_ie.initialize()

	def _real_extract(self, query):
		mobj = re.match(self._VALID_URL, query)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid search query "%s"' % query)
			return

		prefix, query = query.split(':')
		prefix = prefix[8:]
		query = query.encode('utf-8')
		if prefix == '':
			self._download_n_results(query, 1)
			return
		elif prefix == 'all':
			self._download_n_results(query, self._max_yahoo_results)
			return
		else:
			try:
				n = long(prefix)
				if n <= 0:
					self._downloader.trouble(u'ERROR: invalid download number %s for query "%s"' % (n, query))
					return
				elif n > self._max_yahoo_results:
					self._downloader.to_stderr(u'WARNING: yvsearch returns max %i results (you requested %i)' % (self._max_yahoo_results, n))
					n = self._max_yahoo_results
				self._download_n_results(query, n)
				return
			except ValueError: # parsing prefix as integer fails
				self._download_n_results(query, 1)
				return

	def _download_n_results(self, query, n):
		"""Downloads a specified number of results for a query"""

		video_ids = []
		already_seen = set()
		pagenum = 1

		while True:
			self.report_download_page(query, pagenum)
			result_url = self._TEMPLATE_URL % (urllib.quote_plus(query), pagenum)
			request = urllib2.Request(result_url)
			try:
				page = urllib2.urlopen(request).read()
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				self._downloader.trouble(u'ERROR: unable to download webpage: %s' % str(err))
				return

			# Extract video identifiers
			for mobj in re.finditer(self._VIDEO_INDICATOR, page):
				video_id = mobj.group(1)
				if video_id not in already_seen:
					video_ids.append(video_id)
					already_seen.add(video_id)
					if len(video_ids) == n:
						# Specified n videos reached
						for id in video_ids:
							self._yahoo_ie.extract('http://video.yahoo.com/watch/%s' % id)
						return

			if re.search(self._MORE_PAGES_INDICATOR, page) is None:
				for id in video_ids:
					self._yahoo_ie.extract('http://video.yahoo.com/watch/%s' % id)
				return

			pagenum = pagenum + 1


class YoutubePlaylistIE(InfoExtractor):
	"""Information Extractor for YouTube playlists."""

	_VALID_URL = r'(?:https?://)?(?:\w+\.)?youtube\.com/(?:(?:course|view_play_list|my_playlists|artist|playlist)\?.*?(p|a|list)=|user/.*?/user/|p/|user/.*?#[pg]/c/)(?:PL)?([0-9A-Za-z-_]+)(?:/.*?/([0-9A-Za-z_-]+))?.*'
	_TEMPLATE_URL = 'http://www.youtube.com/%s?%s=%s&page=%s&gl=US&hl=en'
	_VIDEO_INDICATOR_TEMPLATE = r'/watch\?v=(.+?)&amp;list=PL%s&'
	_MORE_PAGES_INDICATOR = r'(?m)>\s*Next\s*</a>'
	_youtube_ie = None
	IE_NAME = u'youtube:playlist'

	def __init__(self, youtube_ie, downloader=None):
		InfoExtractor.__init__(self, downloader)
		self._youtube_ie = youtube_ie

	def report_download_page(self, playlist_id, pagenum):
		"""Report attempt to download playlist page with given number."""
		self._downloader.to_screen(u'[youtube] PL %s: Downloading page #%s' % (playlist_id, pagenum))

	def _real_initialize(self):
		self._youtube_ie.initialize()

	def _real_extract(self, url):
		# Extract playlist id
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid url: %s' % url)
			return

		# Single video case
		if mobj.group(3) is not None:
			self._youtube_ie.extract(mobj.group(3))
			return

		# Download playlist pages
		# prefix is 'p' as default for playlists but there are other types that need extra care
		playlist_prefix = mobj.group(1)
		if playlist_prefix == 'a':
			playlist_access = 'artist'
		else:
			playlist_prefix = 'p'
			playlist_access = 'view_play_list'
		playlist_id = mobj.group(2)
		video_ids = []
		pagenum = 1

		while True:
			self.report_download_page(playlist_id, pagenum)
			url = self._TEMPLATE_URL % (playlist_access, playlist_prefix, playlist_id, pagenum)
			request = urllib2.Request(url)
			try:
				page = urllib2.urlopen(request).read()
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				self._downloader.trouble(u'ERROR: unable to download webpage: %s' % str(err))
				return

			# Extract video identifiers
			ids_in_page = []
			for mobj in re.finditer(self._VIDEO_INDICATOR_TEMPLATE % playlist_id, page):
				if mobj.group(1) not in ids_in_page:
					ids_in_page.append(mobj.group(1))
			video_ids.extend(ids_in_page)

			if re.search(self._MORE_PAGES_INDICATOR, page) is None:
				break
			pagenum = pagenum + 1

		playliststart = self._downloader.params.get('playliststart', 1) - 1
		playlistend = self._downloader.params.get('playlistend', -1)
		if playlistend == -1:
			video_ids = video_ids[playliststart:]
		else:
			video_ids = video_ids[playliststart:playlistend]

		for id in video_ids:
			self._youtube_ie.extract('http://www.youtube.com/watch?v=%s' % id)
		return


class YoutubeUserIE(InfoExtractor):
	"""Information Extractor for YouTube users."""

	_VALID_URL = r'(?:(?:(?:https?://)?(?:\w+\.)?youtube\.com/user/)|ytuser:)([A-Za-z0-9_-]+)'
	_TEMPLATE_URL = 'http://gdata.youtube.com/feeds/api/users/%s'
	_GDATA_PAGE_SIZE = 50
	_GDATA_URL = 'http://gdata.youtube.com/feeds/api/users/%s/uploads?max-results=%d&start-index=%d'
	_VIDEO_INDICATOR = r'/watch\?v=(.+?)[\<&]'
	_youtube_ie = None
	IE_NAME = u'youtube:user'

	def __init__(self, youtube_ie, downloader=None):
		InfoExtractor.__init__(self, downloader)
		self._youtube_ie = youtube_ie

	def report_download_page(self, username, start_index):
		"""Report attempt to download user page."""
		self._downloader.to_screen(u'[youtube] user %s: Downloading video ids from %d to %d' %
				(username, start_index, start_index + self._GDATA_PAGE_SIZE))

	def _real_initialize(self):
		self._youtube_ie.initialize()

	def _real_extract(self, url):
		# Extract username
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid url: %s' % url)
			return

		username = mobj.group(1)

		# Download video ids using YouTube Data API. Result size per
		# query is limited (currently to 50 videos) so we need to query
		# page by page until there are no video ids - it means we got
		# all of them.

		video_ids = []
		pagenum = 0

		while True:
			start_index = pagenum * self._GDATA_PAGE_SIZE + 1
			self.report_download_page(username, start_index)

			request = urllib2.Request(self._GDATA_URL % (username, self._GDATA_PAGE_SIZE, start_index))

			try:
				page = urllib2.urlopen(request).read()
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				self._downloader.trouble(u'ERROR: unable to download webpage: %s' % str(err))
				return

			# Extract video identifiers
			ids_in_page = []

			for mobj in re.finditer(self._VIDEO_INDICATOR, page):
				if mobj.group(1) not in ids_in_page:
					ids_in_page.append(mobj.group(1))

			video_ids.extend(ids_in_page)

			# A little optimization - if current page is not
			# "full", ie. does not contain PAGE_SIZE video ids then
			# we can assume that this page is the last one - there
			# are no more ids on further pages - no need to query
			# again.

			if len(ids_in_page) < self._GDATA_PAGE_SIZE:
				break

			pagenum += 1

		all_ids_count = len(video_ids)
		playliststart = self._downloader.params.get('playliststart', 1) - 1
		playlistend = self._downloader.params.get('playlistend', -1)

		if playlistend == -1:
			video_ids = video_ids[playliststart:]
		else:
			video_ids = video_ids[playliststart:playlistend]

		self._downloader.to_screen(u"[youtube] user %s: Collected %d video ids (downloading %d of them)" %
				(username, all_ids_count, len(video_ids)))

		for video_id in video_ids:
			self._youtube_ie.extract('http://www.youtube.com/watch?v=%s' % video_id)


class DepositFilesIE(InfoExtractor):
	"""Information extractor for depositfiles.com"""

	_VALID_URL = r'(?:http://)?(?:\w+\.)?depositfiles\.com/(?:../(?#locale))?files/(.+)'
	IE_NAME = u'DepositFiles'

	def __init__(self, downloader=None):
		InfoExtractor.__init__(self, downloader)

	def report_download_webpage(self, file_id):
		"""Report webpage download."""
		self._downloader.to_screen(u'[DepositFiles] %s: Downloading webpage' % file_id)

	def report_extraction(self, file_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[DepositFiles] %s: Extracting information' % file_id)

	def _real_extract(self, url):
		# At this point we have a new file
		self._downloader.increment_downloads()

		file_id = url.split('/')[-1]
		# Rebuild url in english locale
		url = 'http://depositfiles.com/en/files/' + file_id

		# Retrieve file webpage with 'Free download' button pressed
		free_download_indication = { 'gateway_result' : '1' }
		request = urllib2.Request(url, urllib.urlencode(free_download_indication))
		try:
			self.report_download_webpage(file_id)
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: Unable to retrieve file webpage: %s' % str(err))
			return

		# Search for the real file URL
		mobj = re.search(r'<form action="(http://fileshare.+?)"', webpage)
		if (mobj is None) or (mobj.group(1) is None):
			# Try to figure out reason of the error.
			mobj = re.search(r'<strong>(Attention.*?)</strong>', webpage, re.DOTALL)
			if (mobj is not None) and (mobj.group(1) is not None):
				restriction_message = re.sub('\s+', ' ', mobj.group(1)).strip()
				self._downloader.trouble(u'ERROR: %s' % restriction_message)
			else:
				self._downloader.trouble(u'ERROR: unable to extract download URL from: %s' % url)
			return

		file_url = mobj.group(1)
		file_extension = os.path.splitext(file_url)[1][1:]

		# Search for file title
		mobj = re.search(r'<b title="(.*?)">', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract title')
			return
		file_title = mobj.group(1).decode('utf-8')

		try:
			# Process file information
			self._downloader.process_info({
				'id':		file_id.decode('utf-8'),
				'url':		file_url.decode('utf-8'),
				'uploader':	u'NA',
				'upload_date':	u'NA',
				'title':	file_title,
				'stitle':	file_title,
				'ext':		file_extension.decode('utf-8'),
				'format':	u'NA',
				'player_url':	None,
			})
		except UnavailableVideoError, err:
			self._downloader.trouble(u'ERROR: unable to download file')


class FacebookIE(InfoExtractor):
	"""Information Extractor for Facebook"""

	_VALID_URL = r'^(?:https?://)?(?:\w+\.)?facebook\.com/(?:video/video|photo)\.php\?(?:.*?)v=(?P<ID>\d+)(?:.*)'
	_LOGIN_URL = 'https://login.facebook.com/login.php?m&next=http%3A%2F%2Fm.facebook.com%2Fhome.php&'
	_NETRC_MACHINE = 'facebook'
	_available_formats = ['video', 'highqual', 'lowqual']
	_video_extensions = {
		'video': 'mp4',
		'highqual': 'mp4',
		'lowqual': 'mp4',
	}
	IE_NAME = u'facebook'

	def __init__(self, downloader=None):
		InfoExtractor.__init__(self, downloader)

	def _reporter(self, message):
		"""Add header and report message."""
		self._downloader.to_screen(u'[facebook] %s' % message)

	def report_login(self):
		"""Report attempt to log in."""
		self._reporter(u'Logging in')

	def report_video_webpage_download(self, video_id):
		"""Report attempt to download video webpage."""
		self._reporter(u'%s: Downloading video webpage' % video_id)

	def report_information_extraction(self, video_id):
		"""Report attempt to extract video information."""
		self._reporter(u'%s: Extracting video information' % video_id)

	def _parse_page(self, video_webpage):
		"""Extract video information from page"""
		# General data
		data = {'title': r'\("video_title", "(.*?)"\)',
			'description': r'<div class="datawrap">(.*?)</div>',
			'owner': r'\("video_owner_name", "(.*?)"\)',
			'thumbnail':  r'\("thumb_url", "(?P<THUMB>.*?)"\)',
			}
		video_info = {}
		for piece in data.keys():
			mobj = re.search(data[piece], video_webpage)
			if mobj is not None:
				video_info[piece] = urllib.unquote_plus(mobj.group(1).decode("unicode_escape"))

		# Video urls
		video_urls = {}
		for fmt in self._available_formats:
			mobj = re.search(r'\("%s_src\", "(.+?)"\)' % fmt, video_webpage)
			if mobj is not None:
				# URL is in a Javascript segment inside an escaped Unicode format within
				# the generally utf-8 page
				video_urls[fmt] = urllib.unquote_plus(mobj.group(1).decode("unicode_escape"))
		video_info['video_urls'] = video_urls

		return video_info

	def _real_initialize(self):
		if self._downloader is None:
			return

		useremail = None
		password = None
		downloader_params = self._downloader.params

		# Attempt to use provided username and password or .netrc data
		if downloader_params.get('username', None) is not None:
			useremail = downloader_params['username']
			password = downloader_params['password']
		elif downloader_params.get('usenetrc', False):
			try:
				info = netrc.netrc().authenticators(self._NETRC_MACHINE)
				if info is not None:
					useremail = info[0]
					password = info[2]
				else:
					raise netrc.NetrcParseError('No authenticators for %s' % self._NETRC_MACHINE)
			except (IOError, netrc.NetrcParseError), err:
				self._downloader.to_stderr(u'WARNING: parsing .netrc: %s' % str(err))
				return

		if useremail is None:
			return

		# Log in
		login_form = {
			'email': useremail,
			'pass': password,
			'login': 'Log+In'
			}
		request = urllib2.Request(self._LOGIN_URL, urllib.urlencode(login_form))
		try:
			self.report_login()
			login_results = urllib2.urlopen(request).read()
			if re.search(r'<form(.*)name="login"(.*)</form>', login_results) is not None:
				self._downloader.to_stderr(u'WARNING: unable to log in: bad username/password, or exceded login rate limit (~3/min). Check credentials or wait.')
				return
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.to_stderr(u'WARNING: unable to log in: %s' % str(err))
			return

	def _real_extract(self, url):
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid URL: %s' % url)
			return
		video_id = mobj.group('ID')

		# Get video webpage
		self.report_video_webpage_download(video_id)
		request = urllib2.Request('https://www.facebook.com/video/video.php?v=%s' % video_id)
		try:
			page = urllib2.urlopen(request)
			video_webpage = page.read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to download video webpage: %s' % str(err))
			return

		# Start extracting information
		self.report_information_extraction(video_id)

		# Extract information
		video_info = self._parse_page(video_webpage)

		# uploader
		if 'owner' not in video_info:
			self._downloader.trouble(u'ERROR: unable to extract uploader nickname')
			return
		video_uploader = video_info['owner']

		# title
		if 'title' not in video_info:
			self._downloader.trouble(u'ERROR: unable to extract video title')
			return
		video_title = video_info['title']
		video_title = video_title.decode('utf-8')
		video_title = sanitize_title(video_title)

		simple_title = _simplify_title(video_title)

		# thumbnail image
		if 'thumbnail' not in video_info:
			self._downloader.trouble(u'WARNING: unable to extract video thumbnail')
			video_thumbnail = ''
		else:
			video_thumbnail = video_info['thumbnail']

		# upload date
		upload_date = u'NA'
		if 'upload_date' in video_info:
			upload_time = video_info['upload_date']
			timetuple = email.utils.parsedate_tz(upload_time)
			if timetuple is not None:
				try:
					upload_date = time.strftime('%Y%m%d', timetuple[0:9])
				except:
					pass

		# description
		video_description = video_info.get('description', 'No description available.')

		url_map = video_info['video_urls']
		if len(url_map.keys()) > 0:
			# Decide which formats to download
			req_format = self._downloader.params.get('format', None)
			format_limit = self._downloader.params.get('format_limit', None)

			if format_limit is not None and format_limit in self._available_formats:
				format_list = self._available_formats[self._available_formats.index(format_limit):]
			else:
				format_list = self._available_formats
			existing_formats = [x for x in format_list if x in url_map]
			if len(existing_formats) == 0:
				self._downloader.trouble(u'ERROR: no known formats available for video')
				return
			if req_format is None:
				video_url_list = [(existing_formats[0], url_map[existing_formats[0]])] # Best quality
			elif req_format == 'worst':
				video_url_list = [(existing_formats[len(existing_formats)-1], url_map[existing_formats[len(existing_formats)-1]])] # worst quality
			elif req_format == '-1':
				video_url_list = [(f, url_map[f]) for f in existing_formats] # All formats
			else:
				# Specific format
				if req_format not in url_map:
					self._downloader.trouble(u'ERROR: requested format not available')
					return
				video_url_list = [(req_format, url_map[req_format])] # Specific format

		for format_param, video_real_url in video_url_list:

			# At this point we have a new video
			self._downloader.increment_downloads()

			# Extension
			video_extension = self._video_extensions.get(format_param, 'mp4')

			try:
				# Process video information
				self._downloader.process_info({
					'id':		video_id.decode('utf-8'),
					'url':		video_real_url.decode('utf-8'),
					'uploader':	video_uploader.decode('utf-8'),
					'upload_date':	upload_date,
					'title':	video_title,
					'stitle':	simple_title,
					'ext':		video_extension.decode('utf-8'),
					'format':	(format_param is None and u'NA' or format_param.decode('utf-8')),
					'thumbnail':	video_thumbnail.decode('utf-8'),
					'description':	video_description.decode('utf-8'),
					'player_url':	None,
				})
			except UnavailableVideoError, err:
				self._downloader.trouble(u'\nERROR: unable to download video')

class BlipTVIE(InfoExtractor):
	"""Information extractor for blip.tv"""

	_VALID_URL = r'^(?:https?://)?(?:\w+\.)?blip\.tv(/.+)$'
	_URL_EXT = r'^.*\.([a-z0-9]+)$'
	IE_NAME = u'blip.tv'

	def report_extraction(self, file_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Extracting information' % (self.IE_NAME, file_id))

	def report_direct_download(self, title):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Direct download detected' % (self.IE_NAME, title))

	def _real_extract(self, url):
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid URL: %s' % url)
			return

		if '?' in url:
			cchar = '&'
		else:
			cchar = '?'
		json_url = url + cchar + 'skin=json&version=2&no_wrap=1'
		request = urllib2.Request(json_url)
		self.report_extraction(mobj.group(1))
		info = None
		try:
			urlh = urllib2.urlopen(request)
			if urlh.headers.get('Content-Type', '').startswith('video/'): # Direct download
				basename = url.split('/')[-1]
				title,ext = os.path.splitext(basename)
				title = title.decode('UTF-8')
				ext = ext.replace('.', '')
				self.report_direct_download(title)
				info = {
					'id': title,
					'url': url,
					'title': title,
					'stitle': _simplify_title(title),
					'ext': ext,
					'urlhandle': urlh
				}
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to download video info webpage: %s' % str(err))
			return
		if info is None: # Regular URL
			try:
				json_code = urlh.read()
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				self._downloader.trouble(u'ERROR: unable to read video info webpage: %s' % str(err))
				return

			try:
				json_data = json.loads(json_code)
				if 'Post' in json_data:
					data = json_data['Post']
				else:
					data = json_data
	
				upload_date = datetime.datetime.strptime(data['datestamp'], '%m-%d-%y %H:%M%p').strftime('%Y%m%d')
				video_url = data['media']['url']
				umobj = re.match(self._URL_EXT, video_url)
				if umobj is None:
					raise ValueError('Can not determine filename extension')
				ext = umobj.group(1)
	
				info = {
					'id': data['item_id'],
					'url': video_url,
					'uploader': data['display_name'],
					'upload_date': upload_date,
					'title': data['title'],
					'stitle': _simplify_title(data['title']),
					'ext': ext,
					'format': data['media']['mimeType'],
					'thumbnail': data['thumbnailUrl'],
					'description': data['description'],
					'player_url': data['embedUrl']
				}
			except (ValueError,KeyError), err:
				self._downloader.trouble(u'ERROR: unable to parse video information: %s' % repr(err))
				return

		self._downloader.increment_downloads()

		try:
			self._downloader.process_info(info)
		except UnavailableVideoError, err:
			self._downloader.trouble(u'\nERROR: unable to download video')


class MyVideoIE(InfoExtractor):
	"""Information Extractor for myvideo.de."""

	_VALID_URL = r'(?:http://)?(?:www\.)?myvideo\.de/watch/([0-9]+)/([^?/]+).*'
	IE_NAME = u'myvideo'

	def __init__(self, downloader=None):
		InfoExtractor.__init__(self, downloader)
	
	def report_download_webpage(self, video_id):
		"""Report webpage download."""
		self._downloader.to_screen(u'[myvideo] %s: Downloading webpage' % video_id)

	def report_extraction(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[myvideo] %s: Extracting information' % video_id)

	def _real_extract(self,url):
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._download.trouble(u'ERROR: invalid URL: %s' % url)
			return

		video_id = mobj.group(1)

		# Get video webpage
		request = urllib2.Request('http://www.myvideo.de/watch/%s' % video_id)
		try:
			self.report_download_webpage(video_id)
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: Unable to retrieve video webpage: %s' % str(err))
			return

		self.report_extraction(video_id)
		mobj = re.search(r'<link rel=\'image_src\' href=\'(http://is[0-9].myvideo\.de/de/movie[0-9]+/[a-f0-9]+)/thumbs/[^.]+\.jpg\' />',
				 webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract media URL')
			return
		video_url = mobj.group(1) + ('/%s.flv' % video_id)

		mobj = re.search('<title>([^<]+)</title>', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract title')
			return

		video_title = mobj.group(1)
		video_title = sanitize_title(video_title)

		simple_title = _simplify_title(video_title)

		try:
			self._downloader.process_info({
				'id':		video_id,
				'url':		video_url,
				'uploader':	u'NA',
				'upload_date':  u'NA',
				'title':	video_title,
				'stitle':	simple_title,
				'ext':		u'flv',
				'format':	u'NA',
				'player_url':	None,
			})
		except UnavailableVideoError:
			self._downloader.trouble(u'\nERROR: Unable to download video')

class ComedyCentralIE(InfoExtractor):
	"""Information extractor for The Daily Show and Colbert Report """

	_VALID_URL = r'^(:(?P<shortname>tds|thedailyshow|cr|colbert|colbertnation|colbertreport))|(https?://)?(www\.)?(?P<showname>thedailyshow|colbertnation)\.com/full-episodes/(?P<episode>.*)$'
	IE_NAME = u'comedycentral'

	def report_extraction(self, episode_id):
		self._downloader.to_screen(u'[comedycentral] %s: Extracting information' % episode_id)
	
	def report_config_download(self, episode_id):
		self._downloader.to_screen(u'[comedycentral] %s: Downloading configuration' % episode_id)

	def report_index_download(self, episode_id):
		self._downloader.to_screen(u'[comedycentral] %s: Downloading show index' % episode_id)

	def report_player_url(self, episode_id):
		self._downloader.to_screen(u'[comedycentral] %s: Determining player URL' % episode_id)

	def _real_extract(self, url):
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid URL: %s' % url)
			return

		if mobj.group('shortname'):
			if mobj.group('shortname') in ('tds', 'thedailyshow'):
				url = u'http://www.thedailyshow.com/full-episodes/'
			else:
				url = u'http://www.colbertnation.com/full-episodes/'
			mobj = re.match(self._VALID_URL, url)
			assert mobj is not None

		dlNewest = not mobj.group('episode')
		if dlNewest:
			epTitle = mobj.group('showname')
		else:
			epTitle = mobj.group('episode')

		req = urllib2.Request(url)
		self.report_extraction(epTitle)
		try:
			htmlHandle = urllib2.urlopen(req)
			html = htmlHandle.read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to download webpage: %s' % unicode(err))
			return
		if dlNewest:
			url = htmlHandle.geturl()
			mobj = re.match(self._VALID_URL, url)
			if mobj is None:
				self._downloader.trouble(u'ERROR: Invalid redirected URL: ' + url)
				return
			if mobj.group('episode') == '':
				self._downloader.trouble(u'ERROR: Redirected URL is still not specific: ' + url)
				return
			epTitle = mobj.group('episode')

		mMovieParams = re.findall('(?:<param name="movie" value="|var url = ")(http://media.mtvnservices.com/([^"]*episode.*?:.*?))"', html)
		if len(mMovieParams) == 0:
			self._downloader.trouble(u'ERROR: unable to find Flash URL in webpage ' + url)
			return

		playerUrl_raw = mMovieParams[0][0]
		self.report_player_url(epTitle)
		try:
			urlHandle = urllib2.urlopen(playerUrl_raw)
			playerUrl = urlHandle.geturl()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to find out player URL: ' + unicode(err))
			return

		uri = mMovieParams[0][1]
		indexUrl = 'http://shadow.comedycentral.com/feeds/video_player/mrss/?' + urllib.urlencode({'uri': uri})
		self.report_index_download(epTitle)
		try:
			indexXml = urllib2.urlopen(indexUrl).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to download episode index: ' + unicode(err))
			return

		idoc = xml.etree.ElementTree.fromstring(indexXml)
		itemEls = idoc.findall('.//item')
		for itemEl in itemEls:
			mediaId = itemEl.findall('./guid')[0].text
			shortMediaId = mediaId.split(':')[-1]
			showId = mediaId.split(':')[-2].replace('.com', '')
			officialTitle = itemEl.findall('./title')[0].text
			officialDate = itemEl.findall('./pubDate')[0].text

			configUrl = ('http://www.comedycentral.com/global/feeds/entertainment/media/mediaGenEntertainment.jhtml?' +
						urllib.urlencode({'uri': mediaId}))
			configReq = urllib2.Request(configUrl)
			self.report_config_download(epTitle)
			try:
				configXml = urllib2.urlopen(configReq).read()
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				self._downloader.trouble(u'ERROR: unable to download webpage: %s' % unicode(err))
				return

			cdoc = xml.etree.ElementTree.fromstring(configXml)
			turls = []
			for rendition in cdoc.findall('.//rendition'):
				finfo = (rendition.attrib['bitrate'], rendition.findall('./src')[0].text)
				turls.append(finfo)

			if len(turls) == 0:
				self._downloader.trouble(u'\nERROR: unable to download ' + mediaId + ': No videos found')
				continue

			# For now, just pick the highest bitrate
			format,video_url = turls[-1]

			self._downloader.increment_downloads()

			effTitle = showId + u'-' + epTitle
			info = {
				'id': shortMediaId,
				'url': video_url,
				'uploader': showId,
				'upload_date': officialDate,
				'title': effTitle,
				'stitle': _simplify_title(effTitle),
				'ext': 'mp4',
				'format': format,
				'thumbnail': None,
				'description': officialTitle,
				'player_url': playerUrl
			}

			try:
				self._downloader.process_info(info)
			except UnavailableVideoError, err:
				self._downloader.trouble(u'\nERROR: unable to download ' + mediaId)
				continue


class EscapistIE(InfoExtractor):
	"""Information extractor for The Escapist """

	_VALID_URL = r'^(https?://)?(www\.)?escapistmagazine\.com/videos/view/(?P<showname>[^/]+)/(?P<episode>[^/?]+)[/?]?.*$'
	IE_NAME = u'escapist'

	def report_extraction(self, showName):
		self._downloader.to_screen(u'[escapist] %s: Extracting information' % showName)

	def report_config_download(self, showName):
		self._downloader.to_screen(u'[escapist] %s: Downloading configuration' % showName)

	def _real_extract(self, url):
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid URL: %s' % url)
			return
		showName = mobj.group('showname')
		videoId = mobj.group('episode')

		self.report_extraction(showName)
		try:
			webPage = urllib2.urlopen(url).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to download webpage: ' + unicode(err))
			return

		descMatch = re.search('<meta name="description" content="([^"]*)"', webPage)
		description = unescapeHTML(descMatch.group(1))
		imgMatch = re.search('<meta property="og:image" content="([^"]*)"', webPage)
		imgUrl = unescapeHTML(imgMatch.group(1))
		playerUrlMatch = re.search('<meta property="og:video" content="([^"]*)"', webPage)
		playerUrl = unescapeHTML(playerUrlMatch.group(1))
		configUrlMatch = re.search('config=(.*)$', playerUrl)
		configUrl = urllib2.unquote(configUrlMatch.group(1))

		self.report_config_download(showName)
		try:
			configJSON = urllib2.urlopen(configUrl).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to download configuration: ' + unicode(err))
			return

		# Technically, it's JavaScript, not JSON
		configJSON = configJSON.replace("'", '"')

		try:
			config = json.loads(configJSON)
		except (ValueError,), err:
			self._downloader.trouble(u'ERROR: Invalid JSON in configuration file: ' + unicode(err))
			return

		playlist = config['playlist']
		videoUrl = playlist[1]['url']

		self._downloader.increment_downloads()
		info = {
			'id': videoId,
			'url': videoUrl,
			'uploader': showName,
			'upload_date': None,
			'title': showName,
			'stitle': _simplify_title(showName),
			'ext': 'flv',
			'format': 'flv',
			'thumbnail': imgUrl,
			'description': description,
			'player_url': playerUrl,
		}

		try:
			self._downloader.process_info(info)
		except UnavailableVideoError, err:
			self._downloader.trouble(u'\nERROR: unable to download ' + videoId)


class CollegeHumorIE(InfoExtractor):
	"""Information extractor for collegehumor.com"""

	_VALID_URL = r'^(?:https?://)?(?:www\.)?collegehumor\.com/video/(?P<videoid>[0-9]+)/(?P<shorttitle>.*)$'
	IE_NAME = u'collegehumor'

	def report_webpage(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Downloading webpage' % (self.IE_NAME, video_id))

	def report_extraction(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Extracting information' % (self.IE_NAME, video_id))

	def _real_extract(self, url):
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid URL: %s' % url)
			return
		video_id = mobj.group('videoid')

		self.report_webpage(video_id)
		request = urllib2.Request(url)
		try:
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to download video webpage: %s' % str(err))
			return

		m = re.search(r'id="video:(?P<internalvideoid>[0-9]+)"', webpage)
		if m is None:
			self._downloader.trouble(u'ERROR: Cannot extract internal video ID')
			return
		internal_video_id = m.group('internalvideoid')

		info = {
			'id': video_id,
			'internal_id': internal_video_id,
		}

		self.report_extraction(video_id)
		xmlUrl = 'http://www.collegehumor.com/moogaloop/video:' + internal_video_id
		try:
			metaXml = urllib2.urlopen(xmlUrl).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to download video info XML: %s' % str(err))
			return

		mdoc = xml.etree.ElementTree.fromstring(metaXml)
		try:
			videoNode = mdoc.findall('./video')[0]
			info['description'] = videoNode.findall('./description')[0].text
			info['title'] = videoNode.findall('./caption')[0].text
			info['stitle'] = _simplify_title(info['title'])
			info['url'] = videoNode.findall('./file')[0].text
			info['thumbnail'] = videoNode.findall('./thumbnail')[0].text
			info['ext'] = info['url'].rpartition('.')[2]
			info['format'] = info['ext']
		except IndexError:
			self._downloader.trouble(u'\nERROR: Invalid metadata XML file')
			return

		self._downloader.increment_downloads()

		try:
			self._downloader.process_info(info)
		except UnavailableVideoError, err:
			self._downloader.trouble(u'\nERROR: unable to download video')


class XVideosIE(InfoExtractor):
	"""Information extractor for xvideos.com"""

	_VALID_URL = r'^(?:https?://)?(?:www\.)?xvideos\.com/video([0-9]+)(?:.*)'
	IE_NAME = u'xvideos'

	def report_webpage(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Downloading webpage' % (self.IE_NAME, video_id))

	def report_extraction(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Extracting information' % (self.IE_NAME, video_id))

	def _real_extract(self, url):
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid URL: %s' % url)
			return
		video_id = mobj.group(1).decode('utf-8')

		self.report_webpage(video_id)

		request = urllib2.Request(r'http://www.xvideos.com/video' + video_id)
		try:
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to download video webpage: %s' % str(err))
			return

		self.report_extraction(video_id)


		# Extract video URL
		mobj = re.search(r'flv_url=(.+?)&', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract video url')
			return
		video_url = urllib2.unquote(mobj.group(1).decode('utf-8'))


		# Extract title
		mobj = re.search(r'<title>(.*?)\s+-\s+XVID', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract video title')
			return
		video_title = mobj.group(1).decode('utf-8')


		# Extract video thumbnail
		mobj = re.search(r'http://(?:img.*?\.)xvideos.com/videos/thumbs/[a-fA-F0-9]/[a-fA-F0-9]/[a-fA-F0-9]/([a-fA-F0-9.]+jpg)', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract video thumbnail')
			return
		video_thumbnail = mobj.group(1).decode('utf-8')



		self._downloader.increment_downloads()
		info = {
			'id': video_id,
			'url': video_url,
			'uploader': None,
			'upload_date': None,
			'title': video_title,
			'stitle': _simplify_title(video_title),
			'ext': 'flv',
			'format': 'flv',
			'thumbnail': video_thumbnail,
			'description': None,
			'player_url': None,
		}

		try:
			self._downloader.process_info(info)
		except UnavailableVideoError, err:
			self._downloader.trouble(u'\nERROR: unable to download ' + video_id)


class SoundcloudIE(InfoExtractor):
	"""Information extractor for soundcloud.com
	   To access the media, the uid of the song and a stream token
	   must be extracted from the page source and the script must make
	   a request to media.soundcloud.com/crossdomain.xml. Then
	   the media can be grabbed by requesting from an url composed
	   of the stream token and uid
	 """

	_VALID_URL = r'^(?:https?://)?(?:www\.)?soundcloud\.com/([\w\d-]+)/([\w\d-]+)'
	IE_NAME = u'soundcloud'

	def __init__(self, downloader=None):
		InfoExtractor.__init__(self, downloader)

	def report_webpage(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Downloading webpage' % (self.IE_NAME, video_id))

	def report_extraction(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Extracting information' % (self.IE_NAME, video_id))

	def _real_extract(self, url):
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid URL: %s' % url)
			return

		# extract uploader (which is in the url)
		uploader = mobj.group(1).decode('utf-8')
		# extract simple title (uploader + slug of song title)
		slug_title =  mobj.group(2).decode('utf-8')
		simple_title = uploader + '-' + slug_title

		self.report_webpage('%s/%s' % (uploader, slug_title))

		request = urllib2.Request('http://soundcloud.com/%s/%s' % (uploader, slug_title))
		try:
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to download video webpage: %s' % str(err))
			return

		self.report_extraction('%s/%s' % (uploader, slug_title))

		# extract uid and stream token that soundcloud hands out for access
		mobj = re.search('"uid":"([\w\d]+?)".*?stream_token=([\w\d]+)', webpage)
		if mobj:
			video_id = mobj.group(1)
			stream_token = mobj.group(2)

		# extract unsimplified title
		mobj = re.search('"title":"(.*?)",', webpage)
		if mobj:
			title = mobj.group(1)

		# construct media url (with uid/token)
		mediaURL = "http://media.soundcloud.com/stream/%s?stream_token=%s"
		mediaURL = mediaURL % (video_id, stream_token)

		# description
		description = u'No description available'
		mobj = re.search('track-description-value"><p>(.*?)</p>', webpage)
		if mobj:
			description = mobj.group(1)
		
		# upload date
		upload_date = None
		mobj = re.search("pretty-date'>on ([\w]+ [\d]+, [\d]+ \d+:\d+)</abbr></h2>", webpage)
		if mobj:
			try:
				upload_date = datetime.datetime.strptime(mobj.group(1), '%B %d, %Y %H:%M').strftime('%Y%m%d')
			except Exception, e:
				print str(e)

		# for soundcloud, a request to a cross domain is required for cookies
		request = urllib2.Request('http://media.soundcloud.com/crossdomain.xml', std_headers)

		try:
			self._downloader.process_info({
				'id':		video_id.decode('utf-8'),
				'url':		mediaURL,
				'uploader':	uploader.decode('utf-8'),
				'upload_date':  upload_date,
				'title':	simple_title.decode('utf-8'),
				'stitle':	simple_title.decode('utf-8'),
				'ext':		u'mp3',
				'format':	u'NA',
				'player_url':	None,
				'description': description.decode('utf-8')
			})
		except UnavailableVideoError:
			self._downloader.trouble(u'\nERROR: unable to download video')


class InfoQIE(InfoExtractor):
	"""Information extractor for infoq.com"""

	_VALID_URL = r'^(?:https?://)?(?:www\.)?infoq\.com/[^/]+/[^/]+$'
	IE_NAME = u'infoq'

	def report_webpage(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Downloading webpage' % (self.IE_NAME, video_id))

	def report_extraction(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Extracting information' % (self.IE_NAME, video_id))

	def _real_extract(self, url):
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid URL: %s' % url)
			return

		self.report_webpage(url)

		request = urllib2.Request(url)
		try:
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to download video webpage: %s' % str(err))
			return

		self.report_extraction(url)


		# Extract video URL
		mobj = re.search(r"jsclassref='([^']*)'", webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract video url')
			return
		video_url = 'rtmpe://video.infoq.com/cfx/st/' + urllib2.unquote(mobj.group(1).decode('base64'))


		# Extract title
		mobj = re.search(r'contentTitle = "(.*?)";', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract video title')
			return
		video_title = mobj.group(1).decode('utf-8')

		# Extract description
		video_description = u'No description available.'
		mobj = re.search(r'<meta name="description" content="(.*)"(?:\s*/)?>', webpage)
		if mobj is not None:
			video_description = mobj.group(1).decode('utf-8')

		video_filename = video_url.split('/')[-1]
		video_id, extension = video_filename.split('.')

		self._downloader.increment_downloads()
		info = {
			'id': video_id,
			'url': video_url,
			'uploader': None,
			'upload_date': None,
			'title': video_title,
			'stitle': _simplify_title(video_title),
			'ext': extension,
			'format': extension, # Extension is always(?) mp4, but seems to be flv
			'thumbnail': None,
			'description': video_description,
			'player_url': None,
		}

		try:
			self._downloader.process_info(info)
		except UnavailableVideoError, err:
			self._downloader.trouble(u'\nERROR: unable to download ' + video_url)

class MixcloudIE(InfoExtractor):
	"""Information extractor for www.mixcloud.com"""
	_VALID_URL = r'^(?:https?://)?(?:www\.)?mixcloud\.com/([\w\d-]+)/([\w\d-]+)'
	IE_NAME = u'mixcloud'

	def __init__(self, downloader=None):
		InfoExtractor.__init__(self, downloader)

	def report_download_json(self, file_id):
		"""Report JSON download."""
		self._downloader.to_screen(u'[%s] Downloading json' % self.IE_NAME)

	def report_extraction(self, file_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Extracting information' % (self.IE_NAME, file_id))

	def get_urls(self, jsonData, fmt, bitrate='best'):
		"""Get urls from 'audio_formats' section in json"""
		file_url = None
		try:
			bitrate_list = jsonData[fmt]
			if bitrate is None or bitrate == 'best' or bitrate not in bitrate_list:
				bitrate = max(bitrate_list) # select highest

			url_list = jsonData[fmt][bitrate]
		except TypeError: # we have no bitrate info.
			url_list = jsonData[fmt]
				
		return url_list

	def check_urls(self, url_list):
		"""Returns 1st active url from list"""
		for url in url_list:
			try:
				urllib2.urlopen(url)
				return url
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				url = None

		return None

	def _print_formats(self, formats):
		print 'Available formats:'
		for fmt in formats.keys():
			for b in formats[fmt]:
				try:
					ext = formats[fmt][b][0]
					print '%s\t%s\t[%s]' % (fmt, b, ext.split('.')[-1])
				except TypeError: # we have no bitrate info
					ext = formats[fmt][0]
					print '%s\t%s\t[%s]' % (fmt, '??', ext.split('.')[-1])
					break

	def _real_extract(self, url):
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid URL: %s' % url)
			return
		# extract uploader & filename from url
		uploader = mobj.group(1).decode('utf-8')
		file_id = uploader + "-" + mobj.group(2).decode('utf-8')

		# construct API request
		file_url = 'http://www.mixcloud.com/api/1/cloudcast/' + '/'.join(url.split('/')[-3:-1]) + '.json'
		# retrieve .json file with links to files
		request = urllib2.Request(file_url)
		try:
			self.report_download_json(file_url)
			jsonData = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: Unable to retrieve file: %s' % str(err))
			return

		# parse JSON
		json_data = json.loads(jsonData)
		player_url = json_data['player_swf_url']
		formats = dict(json_data['audio_formats'])

		req_format = self._downloader.params.get('format', None)
		bitrate = None

		if self._downloader.params.get('listformats', None):
			self._print_formats(formats)
			return

		if req_format is None or req_format == 'best':
			for format_param in formats.keys():
				url_list = self.get_urls(formats, format_param)
				# check urls
				file_url = self.check_urls(url_list)
				if file_url is not None:
					break # got it!
		else:
			if req_format not in formats.keys():
				self._downloader.trouble(u'ERROR: format is not available')
				return

			url_list = self.get_urls(formats, req_format)
			file_url = self.check_urls(url_list)
			format_param = req_format

		# We have audio
		self._downloader.increment_downloads()
		try:
			# Process file information
			self._downloader.process_info({
				'id': file_id.decode('utf-8'),
				'url': file_url.decode('utf-8'),
				'uploader':	uploader.decode('utf-8'),
				'upload_date': u'NA',
				'title': json_data['name'],
				'stitle': _simplify_title(json_data['name']),
				'ext': file_url.split('.')[-1].decode('utf-8'),
				'format': (format_param is None and u'NA' or format_param.decode('utf-8')),
				'thumbnail': json_data['thumbnail_url'],
				'description': json_data['description'],
				'player_url': player_url.decode('utf-8'),
			})
		except UnavailableVideoError, err:
			self._downloader.trouble(u'ERROR: unable to download file')

class StanfordOpenClassroomIE(InfoExtractor):
	"""Information extractor for Stanford's Open ClassRoom"""

	_VALID_URL = r'^(?:https?://)?openclassroom.stanford.edu(?P<path>/?|(/MainFolder/(?:HomePage|CoursePage|VideoPage)\.php([?]course=(?P<course>[^&]+)(&video=(?P<video>[^&]+))?(&.*)?)?))$'
	IE_NAME = u'stanfordoc'

	def report_download_webpage(self, objid):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Downloading webpage' % (self.IE_NAME, objid))

	def report_extraction(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Extracting information' % (self.IE_NAME, video_id))

	def _real_extract(self, url):
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid URL: %s' % url)
			return

		if mobj.group('course') and mobj.group('video'): # A specific video
			course = mobj.group('course')
			video = mobj.group('video')
			info = {
				'id': _simplify_title(course + '_' + video),
			}
	
			self.report_extraction(info['id'])
			baseUrl = 'http://openclassroom.stanford.edu/MainFolder/courses/' + course + '/videos/'
			xmlUrl = baseUrl + video + '.xml'
			try:
				metaXml = urllib2.urlopen(xmlUrl).read()
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				self._downloader.trouble(u'ERROR: unable to download video info XML: %s' % unicode(err))
				return
			mdoc = xml.etree.ElementTree.fromstring(metaXml)
			try:
				info['title'] = mdoc.findall('./title')[0].text
				info['url'] = baseUrl + mdoc.findall('./videoFile')[0].text
			except IndexError:
				self._downloader.trouble(u'\nERROR: Invalid metadata XML file')
				return
			info['stitle'] = _simplify_title(info['title'])
			info['ext'] = info['url'].rpartition('.')[2]
			info['format'] = info['ext']
			self._downloader.increment_downloads()
			try:
				self._downloader.process_info(info)
			except UnavailableVideoError, err:
				self._downloader.trouble(u'\nERROR: unable to download video')
		elif mobj.group('course'): # A course page
			course = mobj.group('course')
			info = {
				'id': _simplify_title(course),
				'type': 'playlist',
			}

			self.report_download_webpage(info['id'])
			try:
				coursepage = urllib2.urlopen(url).read()
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				self._downloader.trouble(u'ERROR: unable to download course info page: ' + unicode(err))
				return

			m = re.search('<h1>([^<]+)</h1>', coursepage)
			if m:
				info['title'] = unescapeHTML(m.group(1))
			else:
				info['title'] = info['id']
			info['stitle'] = _simplify_title(info['title'])

			m = re.search('<description>([^<]+)</description>', coursepage)
			if m:
				info['description'] = unescapeHTML(m.group(1))

			links = _orderedSet(re.findall('<a href="(VideoPage.php\?[^"]+)">', coursepage))
			info['list'] = [
				{
					'type': 'reference',
					'url': 'http://openclassroom.stanford.edu/MainFolder/' + unescapeHTML(vpage),
				}
					for vpage in links]

			for entry in info['list']:
				assert entry['type'] == 'reference'
				self.extract(entry['url'])
		else: # Root page
			info = {
				'id': 'Stanford OpenClassroom',
				'type': 'playlist',
			}

			self.report_download_webpage(info['id'])
			rootURL = 'http://openclassroom.stanford.edu/MainFolder/HomePage.php'
			try:
				rootpage = urllib2.urlopen(rootURL).read()
			except (urllib2.URLError, httplib.HTTPException, socket.error), err:
				self._downloader.trouble(u'ERROR: unable to download course info page: ' + unicode(err))
				return

			info['title'] = info['id']
			info['stitle'] = _simplify_title(info['title'])

			links = _orderedSet(re.findall('<a href="(CoursePage.php\?[^"]+)">', rootpage))
			info['list'] = [
				{
					'type': 'reference',
					'url': 'http://openclassroom.stanford.edu/MainFolder/' + unescapeHTML(cpage),
				}
					for cpage in links]

			for entry in info['list']:
				assert entry['type'] == 'reference'
				self.extract(entry['url'])

class MTVIE(InfoExtractor):
	"""Information extractor for MTV.com"""

	_VALID_URL = r'^(?P<proto>https?://)?(?:www\.)?mtv\.com/videos/[^/]+/(?P<videoid>[0-9]+)/[^/]+$'
	IE_NAME = u'mtv'

	def report_webpage(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Downloading webpage' % (self.IE_NAME, video_id))

	def report_extraction(self, video_id):
		"""Report information extraction."""
		self._downloader.to_screen(u'[%s] %s: Extracting information' % (self.IE_NAME, video_id))

	def _real_extract(self, url):
		mobj = re.match(self._VALID_URL, url)
		if mobj is None:
			self._downloader.trouble(u'ERROR: invalid URL: %s' % url)
			return
		if not mobj.group('proto'):
			url = 'http://' + url
		video_id = mobj.group('videoid')
		self.report_webpage(video_id)

		request = urllib2.Request(url)
		try:
			webpage = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to download video webpage: %s' % str(err))
			return

		mobj = re.search(r'<meta name="mtv_vt" content="([^"]+)"/>', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract song name')
			return
		song_name = _unescapeHTML(mobj.group(1).decode('iso-8859-1'))
		mobj = re.search(r'<meta name="mtv_an" content="([^"]+)"/>', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract performer')
			return
		performer = _unescapeHTML(mobj.group(1).decode('iso-8859-1'))
		video_title = performer + ' - ' + song_name 

		mobj = re.search(r'<meta name="mtvn_uri" content="([^"]+)"/>', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to mtvn_uri')
			return
		mtvn_uri = mobj.group(1)

		mobj = re.search(r'MTVN.Player.defaultPlaylistId = ([0-9]+);', webpage)
		if mobj is None:
			self._downloader.trouble(u'ERROR: unable to extract content id')
			return
		content_id = mobj.group(1)

		videogen_url = 'http://www.mtv.com/player/includes/mediaGen.jhtml?uri=' + mtvn_uri + '&id=' + content_id + '&vid=' + video_id + '&ref=www.mtvn.com&viewUri=' + mtvn_uri
		self.report_extraction(video_id)
		request = urllib2.Request(videogen_url)
		try:
			metadataXml = urllib2.urlopen(request).read()
		except (urllib2.URLError, httplib.HTTPException, socket.error), err:
			self._downloader.trouble(u'ERROR: unable to download video metadata: %s' % str(err))
			return

		mdoc = xml.etree.ElementTree.fromstring(metadataXml)
		renditions = mdoc.findall('.//rendition')

		# For now, always pick the highest quality.
		rendition = renditions[-1]

		try:
			_,_,ext = rendition.attrib['type'].partition('/')
			format = ext + '-' + rendition.attrib['width'] + 'x' + rendition.attrib['height'] + '_' + rendition.attrib['bitrate']
			video_url = rendition.find('./src').text
		except KeyError:
			self._downloader.trouble('Invalid rendition field.')
			return

		self._downloader.increment_downloads()
		info = {
			'id': video_id,
			'url': video_url,
			'uploader': performer,
			'title': video_title,
			'stitle': _simplify_title(video_title),
			'ext': ext,
			'format': format,
		}

		try:
			self._downloader.process_info(info)
		except UnavailableVideoError, err:
			self._downloader.trouble(u'\nERROR: unable to download ' + video_id)


class PostProcessor(object):
	"""Post Processor class.

	PostProcessor objects can be added to downloaders with their
	add_post_processor() method. When the downloader has finished a
	successful download, it will take its internal chain of PostProcessors
	and start calling the run() method on each one of them, first with
	an initial argument and then with the returned value of the previous
	PostProcessor.

	The chain will be stopped if one of them ever returns None or the end
	of the chain is reached.

	PostProcessor objects follow a "mutual registration" process similar
	to InfoExtractor objects.
	"""

	_downloader = None

	def __init__(self, downloader=None):
		self._downloader = downloader

	def set_downloader(self, downloader):
		"""Sets the downloader for this PP."""
		self._downloader = downloader

	def run(self, information):
		"""Run the PostProcessor.

		The "information" argument is a dictionary like the ones
		composed by InfoExtractors. The only difference is that this
		one has an extra field called "filepath" that points to the
		downloaded file.

		When this method returns None, the postprocessing chain is
		stopped. However, this method may return an information
		dictionary that will be passed to the next postprocessing
		object in the chain. It can be the one it received after
		changing some fields.

		In addition, this method may raise a PostProcessingError
		exception that will be taken into account by the downloader
		it was called from.
		"""
		return information # by default, do nothing

class AudioConversionError(BaseException):
	def __init__(self, message):
		self.message = message

class FFmpegExtractAudioPP(PostProcessor):

	def __init__(self, downloader=None, preferredcodec=None, preferredquality=None, keepvideo=False):
		PostProcessor.__init__(self, downloader)
		if preferredcodec is None:
			preferredcodec = 'best'
		self._preferredcodec = preferredcodec
		self._preferredquality = preferredquality
		self._keepvideo = keepvideo

	@staticmethod
	def get_audio_codec(path):
		try:
			cmd = ['ffprobe', '-show_streams', '--', _encodeFilename(path)]
			handle = subprocess.Popen(cmd, stderr=file(os.path.devnull, 'w'), stdout=subprocess.PIPE)
			output = handle.communicate()[0]
			if handle.wait() != 0:
				return None
		except (IOError, OSError):
			return None
		audio_codec = None
		for line in output.split('\n'):
			if line.startswith('codec_name='):
				audio_codec = line.split('=')[1].strip()
			elif line.strip() == 'codec_type=audio' and audio_codec is not None:
				return audio_codec
		return None

	@staticmethod
	def run_ffmpeg(path, out_path, codec, more_opts):
		if codec is None:
			acodec_opts = []
		else:
			acodec_opts = ['-acodec', codec]
		cmd = ['ffmpeg', '-y', '-i', _encodeFilename(path), '-vn'] + acodec_opts + more_opts + ['--', _encodeFilename(out_path)]
		try:
			p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
			stdout,stderr = p.communicate()
		except (IOError, OSError):
			e = sys.exc_info()[1]
			if isinstance(e, OSError) and e.errno == 2:
				raise AudioConversionError('ffmpeg not found. Please install ffmpeg.')
			else:
				raise e
		if p.returncode != 0:
			msg = stderr.strip().split('\n')[-1]
			raise AudioConversionError(msg)

	def run(self, information):
		path = information['filepath']

		filecodec = self.get_audio_codec(path)
		if filecodec is None:
			self._downloader.to_stderr(u'WARNING: unable to obtain file audio codec with ffprobe')
			return None

		more_opts = []
		if self._preferredcodec == 'best' or self._preferredcodec == filecodec or (self._preferredcodec == 'm4a' and filecodec == 'aac'):
			if self._preferredcodec == 'm4a' and filecodec == 'aac':
				# Lossless, but in another container
				acodec = 'copy'
				extension = self._preferredcodec
				more_opts = ['-absf', 'aac_adtstoasc']
			elif filecodec in ['aac', 'mp3', 'vorbis']:
				# Lossless if possible
				acodec = 'copy'
				extension = filecodec
				if filecodec == 'aac':
					more_opts = ['-f', 'adts']
				if filecodec == 'vorbis':
					extension = 'ogg'
			else:
				# MP3 otherwise.
				acodec = 'libmp3lame'
				extension = 'mp3'
				more_opts = []
				if self._preferredquality is not None:
					more_opts += ['-ab', self._preferredquality]
		else:
			# We convert the audio (lossy)
			acodec = {'mp3': 'libmp3lame', 'aac': 'aac', 'm4a': 'aac', 'vorbis': 'libvorbis', 'wav': None}[self._preferredcodec]
			extension = self._preferredcodec
			more_opts = []
			if self._preferredquality is not None:
				more_opts += ['-ab', self._preferredquality]
			if self._preferredcodec == 'aac':
				more_opts += ['-f', 'adts']
			if self._preferredcodec == 'm4a':
				more_opts += ['-absf', 'aac_adtstoasc']
			if self._preferredcodec == 'vorbis':
				extension = 'ogg'
			if self._preferredcodec == 'wav':
				extension = 'wav'
				more_opts += ['-f', 'wav']

		prefix, sep, ext = path.rpartition(u'.') # not os.path.splitext, since the latter does not work on unicode in all setups
		new_path = prefix + sep + extension
		self._downloader.to_screen(u'[ffmpeg] Destination: ' + new_path)
		try:
			self.run_ffmpeg(path, new_path, acodec, more_opts)
		except:
			etype,e,tb = sys.exc_info()
			if isinstance(e, AudioConversionError):
				self._downloader.to_stderr(u'ERROR: audio conversion failed: ' + e.message)
			else:
				self._downloader.to_stderr(u'ERROR: error running ffmpeg')
			return None

 		# Try to update the date time for extracted audio file.
		if information.get('filetime') is not None:
			try:
				os.utime(_encodeFilename(new_path), (time.time(), information['filetime']))
			except:
				self._downloader.to_stderr(u'WARNING: Cannot update utime of audio file')

		if not self._keepvideo:
			try:
				os.remove(_encodeFilename(path))
			except (IOError, OSError):
				self._downloader.to_stderr(u'WARNING: Unable to remove downloaded video file')
				return None

		information['filepath'] = new_path
		return information


def updateSelf(downloader, filename):
	''' Update the program file with the latest version from the repository '''
	# Note: downloader only used for options
	if not os.access(filename, os.W_OK):
		sys.exit('ERROR: no write permissions on %s' % filename)

	downloader.to_screen(u'Updating to latest version...')

	try:
		try:
			urlh = urllib.urlopen(UPDATE_URL)
			newcontent = urlh.read()
			
			vmatch = re.search("__version__ = '([^']+)'", newcontent)
			if vmatch is not None and vmatch.group(1) == __version__:
				downloader.to_screen(u'youtube-dl is up-to-date (' + __version__ + ')')
				return
		finally:
			urlh.close()
	except (IOError, OSError), err:
		sys.exit('ERROR: unable to download latest version')

	try:
		outf = open(filename, 'wb')
		try:
			outf.write(newcontent)
		finally:
			outf.close()
	except (IOError, OSError), err:
		sys.exit('ERROR: unable to overwrite current version')

	downloader.to_screen(u'Updated youtube-dl. Restart youtube-dl to use the new version.')

def parseOpts():
	def _readOptions(filename_bytes):
		try:
			optionf = open(filename_bytes)
		except IOError:
			return [] # silently skip if file is not present
		try:
			res = []
			for l in optionf:
				res += shlex.split(l, comments=True)
		finally:
			optionf.close()
		return res

	def _format_option_string(option):
		''' ('-o', '--option') -> -o, --format METAVAR'''

		opts = []

		if option._short_opts: opts.append(option._short_opts[0])
		if option._long_opts: opts.append(option._long_opts[0])
		if len(opts) > 1: opts.insert(1, ', ')

		if option.takes_value(): opts.append(' %s' % option.metavar)

		return "".join(opts)

	def _find_term_columns():
		columns = os.environ.get('COLUMNS', None)
		if columns:
			return int(columns)

		try:
			sp = subprocess.Popen(['stty', 'size'], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
			out,err = sp.communicate()
			return int(out.split()[1])
		except:
			pass
		return None

	max_width = 80
	max_help_position = 80

	# No need to wrap help messages if we're on a wide console
	columns = _find_term_columns()
	if columns: max_width = columns

	fmt = optparse.IndentedHelpFormatter(width=max_width, max_help_position=max_help_position)
	fmt.format_option_strings = _format_option_string

	kw = {
		'version'   : __version__,
		'formatter' : fmt,
		'usage' : '%prog [options] url [url...]',
		'conflict_handler' : 'resolve',
	}

	parser = optparse.OptionParser(**kw)

	# option groups
	general        = optparse.OptionGroup(parser, 'General Options')
	selection      = optparse.OptionGroup(parser, 'Video Selection')
	authentication = optparse.OptionGroup(parser, 'Authentication Options')
	video_format   = optparse.OptionGroup(parser, 'Video Format Options')
	postproc       = optparse.OptionGroup(parser, 'Post-processing Options')
	filesystem     = optparse.OptionGroup(parser, 'Filesystem Options')
	verbosity      = optparse.OptionGroup(parser, 'Verbosity / Simulation Options')

	general.add_option('-h', '--help',
			action='help', help='print this help text and exit')
	general.add_option('-v', '--version',
			action='version', help='print program version and exit')
	general.add_option('-U', '--update',
			action='store_true', dest='update_self', help='update this program to latest version')
	general.add_option('-i', '--ignore-errors',
			action='store_true', dest='ignoreerrors', help='continue on download errors', default=False)
	general.add_option('-r', '--rate-limit',
			dest='ratelimit', metavar='LIMIT', help='download rate limit (e.g. 50k or 44.6m)')
	general.add_option('-R', '--retries',
			dest='retries', metavar='RETRIES', help='number of retries (default is 10)', default=10)
	general.add_option('--dump-user-agent',
			action='store_true', dest='dump_user_agent',
			help='display the current browser identification', default=False)
	general.add_option('--list-extractors',
			action='store_true', dest='list_extractors',
			help='List all supported extractors and the URLs they would handle', default=False)

	selection.add_option('--playlist-start',
			dest='playliststart', metavar='NUMBER', help='playlist video to start at (default is 1)', default=1)
	selection.add_option('--playlist-end',
			dest='playlistend', metavar='NUMBER', help='playlist video to end at (default is last)', default=-1)
	selection.add_option('--match-title', dest='matchtitle', metavar='REGEX',help='download only matching titles (regex or caseless sub-string)')
	selection.add_option('--reject-title', dest='rejecttitle', metavar='REGEX',help='skip download for matching titles (regex or caseless sub-string)')
	selection.add_option('--max-downloads', metavar='NUMBER', dest='max_downloads', help='Abort after downloading NUMBER files', default=None)

	authentication.add_option('-u', '--username',
			dest='username', metavar='USERNAME', help='account username')
	authentication.add_option('-p', '--password',
			dest='password', metavar='PASSWORD', help='account password')
	authentication.add_option('-n', '--netrc',
			action='store_true', dest='usenetrc', help='use .netrc authentication data', default=False)


	video_format.add_option('-f', '--format',
			action='store', dest='format', metavar='FORMAT', help='video format code')
	video_format.add_option('--all-formats',
			action='store_const', dest='format', help='download all available video formats', const='all')
	video_format.add_option('--prefer-free-formats',
			action='store_true', dest='prefer_free_formats', default=False, help='prefer free video formats unless a specific one is requested')
	video_format.add_option('--max-quality',
			action='store', dest='format_limit', metavar='FORMAT', help='highest quality format to download')
	video_format.add_option('-F', '--list-formats',
			action='store_true', dest='listformats', help='list all available formats (currently youtube only)')
	video_format.add_option('--write-srt',
			action='store_true', dest='writesubtitles',
			help='write video closed captions to a .srt file (currently youtube only)', default=False)
	video_format.add_option('--srt-lang',
			action='store', dest='subtitleslang', metavar='LANG',
			help='language of the closed captions to download (optional) use IETF language tags like \'en\'')


	verbosity.add_option('-q', '--quiet',
			action='store_true', dest='quiet', help='activates quiet mode', default=False)
	verbosity.add_option('-s', '--simulate',
			action='store_true', dest='simulate', help='do not download the video and do not write anything to disk', default=False)
	verbosity.add_option('--skip-download',
			action='store_true', dest='skip_download', help='do not download the video', default=False)
	verbosity.add_option('-g', '--get-url',
			action='store_true', dest='geturl', help='simulate, quiet but print URL', default=False)
	verbosity.add_option('-e', '--get-title',
			action='store_true', dest='gettitle', help='simulate, quiet but print title', default=False)
	verbosity.add_option('--get-thumbnail',
			action='store_true', dest='getthumbnail',
			help='simulate, quiet but print thumbnail URL', default=False)
	verbosity.add_option('--get-description',
			action='store_true', dest='getdescription',
			help='simulate, quiet but print video description', default=False)
	verbosity.add_option('--get-filename',
			action='store_true', dest='getfilename',
			help='simulate, quiet but print output filename', default=False)
	verbosity.add_option('--get-format',
			action='store_true', dest='getformat',
			help='simulate, quiet but print output format', default=False)
	verbosity.add_option('--no-progress',
			action='store_true', dest='noprogress', help='do not print progress bar', default=False)
	verbosity.add_option('--console-title',
			action='store_true', dest='consoletitle',
			help='display progress in console titlebar', default=False)
	verbosity.add_option('-v', '--verbose',
			action='store_true', dest='verbose', help='print various debugging information', default=False)


	filesystem.add_option('-t', '--title',
			action='store_true', dest='usetitle', help='use title in file name', default=False)
	filesystem.add_option('-l', '--literal',
			action='store_true', dest='useliteral', help='use literal title in file name', default=False)
	filesystem.add_option('-A', '--auto-number',
			action='store_true', dest='autonumber',
			help='number downloaded files starting from 00000', default=False)
	filesystem.add_option('-o', '--output',
			dest='outtmpl', metavar='TEMPLATE', help='output filename template. Use %(stitle)s to get the title, %(uploader)s for the uploader name, %(autonumber)s to get an automatically incremented number, %(ext)s for the filename extension, %(upload_date)s for the upload date (YYYYMMDD), and %% for a literal percent. Use - to output to stdout.')
	filesystem.add_option('-a', '--batch-file',
			dest='batchfile', metavar='FILE', help='file containing URLs to download (\'-\' for stdin)')
	filesystem.add_option('-w', '--no-overwrites',
			action='store_true', dest='nooverwrites', help='do not overwrite files', default=False)
	filesystem.add_option('-c', '--continue',
			action='store_true', dest='continue_dl', help='resume partially downloaded files', default=True)
	filesystem.add_option('--no-continue',
			action='store_false', dest='continue_dl',
			help='do not resume partially downloaded files (restart from beginning)')
	filesystem.add_option('--cookies',
			dest='cookiefile', metavar='FILE', help='file to read cookies from and dump cookie jar in')
	filesystem.add_option('--no-part',
			action='store_true', dest='nopart', help='do not use .part files', default=False)
	filesystem.add_option('--no-mtime',
			action='store_false', dest='updatetime',
			help='do not use the Last-modified header to set the file modification time', default=True)
	filesystem.add_option('--write-description',
			action='store_true', dest='writedescription',
			help='write video description to a .description file', default=False)
	filesystem.add_option('--write-info-json',
			action='store_true', dest='writeinfojson',
			help='write video metadata to a .info.json file', default=False)


	postproc.add_option('--extract-audio', action='store_true', dest='extractaudio', default=False,
			help='convert video files to audio-only files (requires ffmpeg and ffprobe)')
	postproc.add_option('--audio-format', metavar='FORMAT', dest='audioformat', default='best',
			help='"best", "aac", "vorbis", "mp3", "m4a", or "wav"; best by default')
	postproc.add_option('--audio-quality', metavar='QUALITY', dest='audioquality', default='128K',
			help='ffmpeg audio bitrate specification, 128k by default')
	postproc.add_option('-k', '--keep-video', action='store_true', dest='keepvideo', default=False,
			help='keeps the video file on disk after the post-processing; the video is erased by default')


	parser.add_option_group(general)
	parser.add_option_group(selection)
	parser.add_option_group(filesystem)
	parser.add_option_group(verbosity)
	parser.add_option_group(video_format)
	parser.add_option_group(authentication)
	parser.add_option_group(postproc)

	xdg_config_home = os.environ.get('XDG_CONFIG_HOME')
	if xdg_config_home:
		userConf = os.path.join(xdg_config_home, 'youtube-dl.conf')
	else:
		userConf = os.path.join(os.path.expanduser('~'), '.config', 'youtube-dl.conf')
	argv = _readOptions('/etc/youtube-dl.conf') + _readOptions(userConf) + sys.argv[1:]
	opts, args = parser.parse_args(argv)

	return parser, opts, args

def gen_extractors():
	""" Return a list of an instance of every supported extractor.
	The order does matter; the first extractor matched is the one handling the URL.
	"""
	youtube_ie = YoutubeIE()
	google_ie = GoogleIE()
	yahoo_ie = YahooIE()
	return [
		YoutubePlaylistIE(youtube_ie),
		YoutubeUserIE(youtube_ie),
		YoutubeSearchIE(youtube_ie),
		youtube_ie,
		MetacafeIE(youtube_ie),
		DailymotionIE(),
		google_ie,
		GoogleSearchIE(google_ie),
		PhotobucketIE(),
		yahoo_ie,
		YahooSearchIE(yahoo_ie),
		DepositFilesIE(),
		FacebookIE(),
		BlipTVIE(),
		VimeoIE(),
		MyVideoIE(),
		ComedyCentralIE(),
		EscapistIE(),
		CollegeHumorIE(),
		XVideosIE(),
		SoundcloudIE(),
		InfoQIE(),
		MixcloudIE(),
		StanfordOpenClassroomIE(),
		MTVIE(),

		GenericIE()
	]

def _real_main():
	parser, opts, args = parseOpts()

	# Open appropriate CookieJar
	if opts.cookiefile is None:
		jar = cookielib.CookieJar()
	else:
		try:
			jar = cookielib.MozillaCookieJar(opts.cookiefile)
			if os.path.isfile(opts.cookiefile) and os.access(opts.cookiefile, os.R_OK):
				jar.load()
		except (IOError, OSError), err:
			sys.exit(u'ERROR: unable to open cookie file')

	# Dump user agent
	if opts.dump_user_agent:
		print std_headers['User-Agent']
		sys.exit(0)

	# Batch file verification
	batchurls = []
	if opts.batchfile is not None:
		try:
			if opts.batchfile == '-':
				batchfd = sys.stdin
			else:
				batchfd = open(opts.batchfile, 'r')
			batchurls = batchfd.readlines()
			batchurls = [x.strip() for x in batchurls]
			batchurls = [x for x in batchurls if len(x) > 0 and not re.search(r'^[#/;]', x)]
		except IOError:
			sys.exit(u'ERROR: batch file could not be read')
	all_urls = batchurls + args

	# General configuration
	cookie_processor = urllib2.HTTPCookieProcessor(jar)
	proxy_handler = urllib2.ProxyHandler()
	opener = urllib2.build_opener(proxy_handler, cookie_processor, YoutubeDLHandler())
	urllib2.install_opener(opener)
	socket.setdefaulttimeout(300) # 5 minutes should be enough (famous last words)

	if opts.verbose:
		print(u'[debug] Proxy map: ' + str(proxy_handler.proxies))

	extractors = gen_extractors()

	if opts.list_extractors:
		for ie in extractors:
			print(ie.IE_NAME)
			matchedUrls = filter(lambda url: ie.suitable(url), all_urls)
			all_urls = filter(lambda url: url not in matchedUrls, all_urls)
			for mu in matchedUrls:
				print(u'  ' + mu)
		sys.exit(0)

	# Conflicting, missing and erroneous options
	if opts.usenetrc and (opts.username is not None or opts.password is not None):
		parser.error(u'using .netrc conflicts with giving username/password')
	if opts.password is not None and opts.username is None:
		parser.error(u'account username missing')
	if opts.outtmpl is not None and (opts.useliteral or opts.usetitle or opts.autonumber):
		parser.error(u'using output template conflicts with using title, literal title or auto number')
	if opts.usetitle and opts.useliteral:
		parser.error(u'using title conflicts with using literal title')
	if opts.username is not None and opts.password is None:
		opts.password = getpass.getpass(u'Type account password and press return:')
	if opts.ratelimit is not None:
		numeric_limit = FileDownloader.parse_bytes(opts.ratelimit)
		if numeric_limit is None:
			parser.error(u'invalid rate limit specified')
		opts.ratelimit = numeric_limit
	if opts.retries is not None:
		try:
			opts.retries = long(opts.retries)
		except (TypeError, ValueError), err:
			parser.error(u'invalid retry count specified')
	try:
		opts.playliststart = int(opts.playliststart)
		if opts.playliststart <= 0:
			raise ValueError(u'Playlist start must be positive')
	except (TypeError, ValueError), err:
		parser.error(u'invalid playlist start number specified')
	try:
		opts.playlistend = int(opts.playlistend)
		if opts.playlistend != -1 and (opts.playlistend <= 0 or opts.playlistend < opts.playliststart):
			raise ValueError(u'Playlist end must be greater than playlist start')
	except (TypeError, ValueError), err:
		parser.error(u'invalid playlist end number specified')
	if opts.extractaudio:
		if opts.audioformat not in ['best', 'aac', 'mp3', 'vorbis', 'm4a', 'wav']:
			parser.error(u'invalid audio format specified')

	# File downloader
	fd = FileDownloader({
		'usenetrc': opts.usenetrc,
		'username': opts.username,
		'password': opts.password,
		'quiet': (opts.quiet or opts.geturl or opts.gettitle or opts.getthumbnail or opts.getdescription or opts.getfilename or opts.getformat),
		'forceurl': opts.geturl,
		'forcetitle': opts.gettitle,
		'forcethumbnail': opts.getthumbnail,
		'forcedescription': opts.getdescription,
		'forcefilename': opts.getfilename,
		'forceformat': opts.getformat,
		'simulate': opts.simulate,
		'skip_download': (opts.skip_download or opts.simulate or opts.geturl or opts.gettitle or opts.getthumbnail or opts.getdescription or opts.getfilename or opts.getformat),
		'format': opts.format,
		'format_limit': opts.format_limit,
		'listformats': opts.listformats,
		'outtmpl': ((opts.outtmpl is not None and opts.outtmpl.decode(preferredencoding()))
			or (opts.format == '-1' and opts.usetitle and u'%(stitle)s-%(id)s-%(format)s.%(ext)s')
			or (opts.format == '-1' and opts.useliteral and u'%(title)s-%(id)s-%(format)s.%(ext)s')
			or (opts.format == '-1' and u'%(id)s-%(format)s.%(ext)s')
			or (opts.usetitle and opts.autonumber and u'%(autonumber)s-%(stitle)s-%(id)s.%(ext)s')
			or (opts.useliteral and opts.autonumber and u'%(autonumber)s-%(title)s-%(id)s.%(ext)s')
			or (opts.usetitle and u'%(stitle)s-%(id)s.%(ext)s')
			or (opts.useliteral and u'%(title)s-%(id)s.%(ext)s')
			or (opts.autonumber and u'%(autonumber)s-%(id)s.%(ext)s')
			or u'%(id)s.%(ext)s'),
		'ignoreerrors': opts.ignoreerrors,
		'ratelimit': opts.ratelimit,
		'nooverwrites': opts.nooverwrites,
		'retries': opts.retries,
		'continuedl': opts.continue_dl,
		'noprogress': opts.noprogress,
		'playliststart': opts.playliststart,
		'playlistend': opts.playlistend,
		'logtostderr': opts.outtmpl == '-',
		'consoletitle': opts.consoletitle,
		'nopart': opts.nopart,
		'updatetime': opts.updatetime,
		'writedescription': opts.writedescription,
		'writeinfojson': opts.writeinfojson,
		'writesubtitles': opts.writesubtitles,
		'subtitleslang': opts.subtitleslang,
		'matchtitle': opts.matchtitle,
		'rejecttitle': opts.rejecttitle,
		'max_downloads': opts.max_downloads,
		'prefer_free_formats': opts.prefer_free_formats,
		'verbose': opts.verbose,
		})
	for extractor in extractors:
		fd.add_info_extractor(extractor)

	# PostProcessors
	if opts.extractaudio:
		fd.add_post_processor(FFmpegExtractAudioPP(preferredcodec=opts.audioformat, preferredquality=opts.audioquality, keepvideo=opts.keepvideo))

	# Update version
	if opts.update_self:
		updateSelf(fd, sys.argv[0])

	# Maybe do nothing
	if len(all_urls) < 1:
		if not opts.update_self:
			parser.error(u'you must provide at least one URL')
		else:
			sys.exit()
	
	try:
		retcode = fd.download(all_urls)
	except MaxDownloadsReached:
		fd.to_screen(u'--max-download limit reached, aborting.')
		retcode = 101

	# Dump cookie jar if requested
	if opts.cookiefile is not None:
		try:
			jar.save()
		except (IOError, OSError), err:
			sys.exit(u'ERROR: unable to save cookie jar')

	sys.exit(retcode)

def main():
	try:
		_real_main()
	except DownloadError:
		sys.exit(1)
	except SameFileError:
		sys.exit(u'ERROR: fixed output name but more than one file to download')
	except KeyboardInterrupt:
		sys.exit(u'\nERROR: Interrupted by user')

if __name__ == '__main__':
	main()

# vim: set ts=4 sw=4 sts=4 noet ai si filetype=python: