[yt-dlp.git] / youtube-dl

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author: Ricardo Garcia Gonzalez
# Author: Danny Colligan
# Author: Benjamin Johnson
# Author: Vasyl' Vavrychuk
# Author: Witold Baryluk
# Author: Paweł Paprota
# Author: Gergely Imreh
# License: Public domain code
import cookielib
import ctypes
import datetime
import email.utils
import gzip
import htmlentitydefs
import httplib
import locale
import math
import netrc
import os
import os.path
import re
import socket
import string
import StringIO
import subprocess
import sys
import time
import urllib
import urllib2
import zlib

# 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

std_headers = {
        'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:2.0b11) Gecko/20100101 Firefox/4.0b11',
        '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',
}

simple_title_chars = string.ascii_letters.decode('ascii') + string.digits.decode('ascii')

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 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(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(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

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 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.
        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.
        """

        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 pmkdir(filename):
                """Create directory components in filename. Similar to Unix "mkdir -p"."""
                components = filename.split(os.sep)
                aggregate = [os.sep.join(components[0:x]) for x in xrange(1, len(components))]
                aggregate = ['%s%s' % (x, os.sep) for x in aggregate] # Finish names with separator
                for dir in aggregate:
                        if not os.path.exists(dir):
                                os.mkdir(dir)

        @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, ignore_encoding_errors=False):
                """Print message to stdout if not in quiet mode."""
                try:
                        if not self.params.get('quiet', False):
                                terminator = [u'\n', u''][skip_eol]
                                print >>self._screen_file, (u'%s%s' % (message, terminator)).encode(preferredencoding()),
                        self._screen_file.flush()
                except (UnicodeEncodeError), err:
                        if not ignore_encoding_errors:
                                raise

        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(filename) and not os.path.isfile(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(old_filename, 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(filename):
                        return
                timestr = last_modified_hdr
                if timestr is None:
                        return
                filetime = timeconvert(timestr)
                if filetime is None:
                        return
                try:
                        os.utime(filename,(time.time(), filetime))
                except:
                        pass

        def report_destination(self, filename):
                """Report destination filename."""
                self.to_screen(u'[download] Destination: %s' % filename, ignore_encoding_errors=True)

        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 process_info(self, info_dict):
                """Process a single dictionary returned by an InfoExtractor."""
                filename = self.prepare_filename(info_dict)
                # Do nothing else if in simulate mode
                if self.params.get('simulate', False):
                        # 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')

                        return

                if filename is None:
                        return
                if self.params.get('nooverwrites', False) and os.path.exists(filename):
                        self.to_stderr(u'WARNING: file exists and will be skipped')
                        return

                try:
                        self.pmkdir(filename)
                except (OSError, IOError), err:
                        self.trouble(u'ERROR: unable to create directories: %s' % str(err))
                        return

                try:
                        success = self._do_download(filename, info_dict['url'].encode('utf-8'), info_dict.get('player_url', None))
                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]
                retval = subprocess.call(basic_args + [[], ['-e', '-k', '1']][self.params.get('continuedl', False)])
                while retval == 2 or retval == 1:
                        prevsize = os.path.getsize(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(tmpfilename)
                        if prevsize == cursize and retval == 1:
                                break
                if retval == 0:
                        self.to_screen(u'\r[rtmpdump] %s bytes' % os.path.getsize(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, url, player_url):
                # Check file already present
                if self.params.get('continuedl', False) and os.path.isfile(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
                open_mode = 'wb'

                # 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(tmpfilename):
                        resume_len = os.path.getsize(tmpfilename)
                else:
                        resume_len = 0

                # Request parameters in case of being able to resume
                if self.params.get('continuedl', False) and resume_len != 0:
                        self.report_resuming_byte(resume_len)
                        request.add_header('Range','bytes=%d-' % resume_len)
                        open_mode = 'ab'

                count = 0
                retries = self.params.get('retries', 0)
                while count <= retries:
                        # Establish connection
                        try:
                                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)
                                        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
                        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)
                        speed_str = self.calc_speed(start, time.time(), 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)

                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):
                        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, as well as the suitable() static method.
        Probably, they should also be instantiated and added to the main
        downloader.
        """

        _ready = False
        _downloader = None

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

        @staticmethod
        def suitable(url):
                """Receives a URL and returns True if suitable for this IE."""
                return False

        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/)(?:(?:(?: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', '34', '43', '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',
                '45': 'webm',
        }

        @staticmethod
        def suitable(url):
                return (re.match(YoutubeIE._VALID_URL, url) is not None)

        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_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 _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&amp;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 = re.sub(ur'(?u)([^%s]+)' % simple_title_chars, ur'_', video_title)
                simple_title = simple_title.strip(ur'_')

                # 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 = 'No description available.'
                if self._downloader.params.get('forcedescription', False):
                        mobj = re.search(r'<meta name="description" content="(.*)"(?:\s*/)?>', video_webpage)
                        if mobj is not None:
                                video_description = mobj.group(1)

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

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

                if 'fmt_url_map' in video_info and len(video_info['fmt_url_map']) >= 1 and ',' in video_info['fmt_url_map'][0]:
                        url_map = dict(tuple(pair.split('|')) for pair in video_info['fmt_url_map'][0].split(','))
                        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 == '-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

                elif 'conn' in video_info and video_info['conn'][0].startswith('rtmp'):
                        self.report_rtmp_download()
                        video_url_list = [(None, video_info['conn'][0])]

                else:
                        self._downloader.trouble(u'ERROR: no fmt_url_map or conn 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')

                        # Find the video URL in fmt_url_map or conn paramters
                        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':   player_url,
                                })
                        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

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

        @staticmethod
        def suitable(url):
                return (re.match(MetacafeIE._VALID_URL, url) is not None)

        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/([^_/]+)_([^/]+)'

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

        @staticmethod
        def suitable(url):
                return (re.match(DailymotionIE._VALID_URL, url) is not None)

        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_initialize(self):
                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

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

                simple_title = mobj.group(2).decode('utf-8')
                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 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\(\"video\"\s*,\s*\"([^\"]*)\"\)', webpage)
                if mobj is None:
                        self._downloader.trouble(u'ERROR: unable to extract media URL')
                        return
                mediaURL = urllib.unquote(mobj.group(1))

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

                video_url = mediaURL

                # '<meta\s+name="title"\s+content="Dailymotion\s*[:\-]\s*(.*?)"\s*\/\s*>'
                mobj = re.search(r'(?im)<title>Dailymotion\s*[\-:]\s*(.+?)</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'(?im)<Attribute name="owner">(.+?)</Attribute>', 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=([^\&]+).*'

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

        @staticmethod
        def suitable(url):
                return (re.match(GoogleIE._VALID_URL, url) is not None)

        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_initialize(self):
                return

        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 = re.sub(ur'(?u)([^%s]+)' % simple_title_chars, ur'_', 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)'

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

        @staticmethod
        def suitable(url):
                return (re.match(PhotobucketIE._VALID_URL, url) is not None)

        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_initialize(self):
                return

        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 = re.sub(ur'(?u)([^%s]+)' % simple_title_chars, ur'_', video_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]+)(?:[#\?].*)?'

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

        @staticmethod
        def suitable(url):
                return (re.match(YahooIE._VALID_URL, url) is not None)

        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_initialize(self):
                return

        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 = re.sub(ur'(?u)([^%s]+)' % simple_title_chars, ur'_', 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,
                                'description':  video_description,
                                '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'(?:http://)?(?:(?:www|player).)?vimeo\.com/(?:video/)?([0-9]+)'

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

        @staticmethod
        def suitable(url):
                return (re.match(VimeoIE._VALID_URL, url) is not None)

        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_initialize(self):
                return

        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)
                video_extension = 'flv' # FIXME

                # Retrieve video webpage to extract further information
                request = urllib2.Request("http://vimeo.com/moogaloop/load/clip:%s" % video_id, 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 title
                mobj = re.search(r'<caption>(.*?)</caption>', 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 = re.sub(ur'(?u)([^%s]+)' % simple_title_chars, ur'_', video_title)

                # Extract uploader
                mobj = re.search(r'<uploader_url>http://vimeo.com/(.*?)</uploader_url>', 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'<thumbnail>(.*?)</thumbnail>', 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 property="og: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.'
                video_description = 'Foo.'

                # Vimeo specific: extract request signature
                mobj = re.search(r'<request_signature>(.*?)</request_signature>', webpage)
                if mobj is None:
                        self._downloader.trouble(u'ERROR: unable to extract request signature')
                        return
                sig = mobj.group(1).decode('utf-8')

                # Vimeo specific: Extract request signature expiration
                mobj = re.search(r'<request_signature_expires>(.*?)</request_signature_expires>', webpage)
                if mobj is None:
                        self._downloader.trouble(u'ERROR: unable to extract request signature expiration')
                        return
                sig_exp = mobj.group(1).decode('utf-8')

                video_url = "http://vimeo.com/moogaloop/play/clip:%s/%s/%s" % (video_id, sig, sig_exp)

                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,
                                '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."""

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

        @staticmethod
        def suitable(url):
                return True

        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_initialize(self):
                return

        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 = re.sub(ur'(?u)([^%s]+)' % simple_title_chars, ur'_', 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_QUERY = r'ytsearch(\d+|all)?:[\s\S]+'
        _TEMPLATE_URL = 'http://www.youtube.com/results?search_query=%s&page=%s&gl=US&hl=en'
        _VIDEO_INDICATOR = r'href="/watch\?v=.+?"'
        _MORE_PAGES_INDICATOR = r'(?m)>\s*Next\s*</a>'
        _youtube_ie = None
        _max_youtube_results = 1000

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

        @staticmethod
        def suitable(url):
                return (re.match(YoutubeSearchIE._VALID_QUERY, url) is not None)

        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_QUERY, 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 = []
                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 = page[mobj.span()[0]:mobj.span()[1]].split('=')[2][:-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._youtube_ie.extract('http://www.youtube.com/watch?v=%s' % id)
                                                return

                        if re.search(self._MORE_PAGES_INDICATOR, page) is None:
                                for id in video_ids:
                                        self._youtube_ie.extract('http://www.youtube.com/watch?v=%s' % id)
                                return

                        pagenum = pagenum + 1

class GoogleSearchIE(InfoExtractor):
        """Information Extractor for Google Video search queries."""
        _VALID_QUERY = 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'videoplay\?docid=([^\&>]+)\&'
        _MORE_PAGES_INDICATOR = r'<span>Next</span>'
        _google_ie = None
        _max_google_results = 1000

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

        @staticmethod
        def suitable(url):
                return (re.match(GoogleSearchIE._VALID_QUERY, url) is not None)

        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_QUERY, 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 = []
                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._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_QUERY = 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

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

        @staticmethod
        def suitable(url):
                return (re.match(YahooSearchIE._VALID_QUERY, url) is not None)

        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_QUERY, 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'(?:http://)?(?:\w+\.)?youtube.com/(?:(?:view_play_list|my_playlists|artist)\?.*?(p|a)=|user/.*?/user/|p/|user/.*?#[pg]/c/)([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 = r'/watch\?v=(.+?)&'
        _MORE_PAGES_INDICATOR = r'(?m)>\s*Next\s*</a>'
        _youtube_ie = None

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

        @staticmethod
        def suitable(url):
                return (re.match(YoutubePlaylistIE._VALID_URL, url) is not None)

        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)
                        request = urllib2.Request(self._TEMPLATE_URL % (playlist_access, playlist_prefix, playlist_id, pagenum))
                        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)

                        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)
                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'(?:(?:(?:http://)?(?:\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

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

        @staticmethod
        def suitable(url):
                return (re.match(YoutubeUserIE._VALID_URL, url) is not None)

        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("[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/(.+)'

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

        @staticmethod
        def suitable(url):
                return (re.match(DepositFilesIE._VALID_URL, url) is not None)

        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_initialize(self):
                return

        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.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 = ['highqual', 'lowqual']
        _video_extensions = {
                'highqual': 'mp4',
                'lowqual': 'mp4',
        }

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

        @staticmethod
        def suitable(url):
                return (re.match(FacebookIE._VALID_URL, url) is not None)

        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'class="video_title datawrap">(.*?)</',
                        'description': r'<div class="datawrap">(.*?)</div>',
                        'owner': r'\("video_owner_name", "(.*?)"\)',
                        'upload_date': r'data-date="(.*?)"',
                        '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)

                # simplified title
                simple_title = re.sub(ur'(?u)([^%s]+)' % simple_title_chars, ur'_', video_title)
                simple_title = simple_title.strip(ur'_')

                # 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 = 'No description available.'
                if (self._downloader.params.get('forcedescription', False) and
                    'description' in video_info):
                        video_description = video_info['description']

                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 == '-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')

                        # Find the video URL in fmt_url_map or conn paramters
                        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 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 FFmpegExtractAudioPP(PostProcessor):

        def __init__(self, downloader=None, preferredcodec=None):
                PostProcessor.__init__(self, downloader)
                if preferredcodec is None:
                        preferredcodec = 'best'
                self._preferredcodec = preferredcodec

        @staticmethod
        def get_audio_codec(path):
                try:
                        cmd = ['ffprobe', '-show_streams', '--', 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):
                try:
                        cmd = ['ffmpeg', '-y', '-i', path, '-vn', '-acodec', codec] + more_opts + ['--', out_path]
                        ret = subprocess.call(cmd, stdout=file(os.path.devnull, 'w'), stderr=subprocess.STDOUT)
                        return (ret == 0)
                except (IOError, OSError):
                        return False

        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:
                        if filecodec == 'aac' or filecodec == 'mp3':
                                # Lossless if possible
                                acodec = 'copy'
                                extension = filecodec
                                if filecodec == 'aac':
                                        more_opts = ['-f', 'adts']
                        else:
                                # MP3 otherwise.
                                acodec = 'libmp3lame'
                                extension = 'mp3'
                                more_opts = ['-ab', '128k']
                else:
                        # We convert the audio (lossy)
                        acodec = {'mp3': 'libmp3lame', 'aac': 'aac'}[self._preferredcodec]
                        extension = self._preferredcodec
                        more_opts = ['-ab', '128k']
                        if self._preferredcodec == 'aac':
                                more_opts += ['-f', 'adts']

                (prefix, ext) = os.path.splitext(path)
                new_path = prefix + '.' + extension
                self._downloader.to_screen(u'[ffmpeg] Destination: %s' % new_path)
                status = self.run_ffmpeg(path, new_path, acodec, more_opts)

                if not status:
                        self._downloader.to_stderr(u'WARNING: error running ffmpeg')
                        return None

                try:
                        os.remove(path)
                except (IOError, OSError):
                        self._downloader.to_stderr(u'WARNING: Unable to remove downloaded video file')
                        return None

                information['filepath'] = new_path
                return information

### MAIN PROGRAM ###
if __name__ == '__main__':
        try:
                # Modules needed only when running the main program
                import getpass
                import optparse

                # Function to update the program file with the latest version from the repository.
                def update_self(downloader, filename):
                        # 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('Updating to latest stable version...')
                        try:
                                latest_url = 'http://github.com/rg3/youtube-dl/raw/master/LATEST_VERSION'
                                latest_version = urllib.urlopen(latest_url).read().strip()
                                prog_url = 'http://github.com/rg3/youtube-dl/raw/%s/youtube-dl' % latest_version
                                newcontent = urllib.urlopen(prog_url).read()
                        except (IOError, OSError), err:
                                sys.exit('ERROR: unable to download latest version')
                        try:
                                stream = open(filename, 'w')
                                stream.write(newcontent)
                                stream.close()
                        except (IOError, OSError), err:
                                sys.exit('ERROR: unable to overwrite current version')
                        downloader.to_screen('Updated to version %s' % latest_version)

                # Parse command line
                parser = optparse.OptionParser(
                        usage='Usage: %prog [options] url...',
                        version='2011.03.29',
                        conflict_handler='resolve',
                )

                parser.add_option('-h', '--help',
                                action='help', help='print this help text and exit')
                parser.add_option('-v', '--version',
                                action='version', help='print program version and exit')
                parser.add_option('-U', '--update',
                                action='store_true', dest='update_self', help='update this program to latest stable version')
                parser.add_option('-i', '--ignore-errors',
                                action='store_true', dest='ignoreerrors', help='continue on download errors', default=False)
                parser.add_option('-r', '--rate-limit',
                                dest='ratelimit', metavar='LIMIT', help='download rate limit (e.g. 50k or 44.6m)')
                parser.add_option('-R', '--retries',
                                dest='retries', metavar='RETRIES', help='number of retries (default is 10)', default=10)
                parser.add_option('--playlist-start',
                                dest='playliststart', metavar='NUMBER', help='playlist video to start at (default is 1)', default=1)
                parser.add_option('--playlist-end',
                                dest='playlistend', metavar='NUMBER', help='playlist video to end at (default is last)', default=-1)
                parser.add_option('--dump-user-agent',
                                action='store_true', dest='dump_user_agent',
                                help='display the current browser identification', default=False)

                authentication = optparse.OptionGroup(parser, 'Authentication Options')
                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)
                parser.add_option_group(authentication)

                video_format = optparse.OptionGroup(parser, 'Video Format Options')
                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='-1')
                video_format.add_option('--max-quality',
                                action='store', dest='format_limit', metavar='FORMAT', help='highest quality format to download')
                parser.add_option_group(video_format)

                verbosity = optparse.OptionGroup(parser, 'Verbosity / Simulation Options')
                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 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('--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)
                parser.add_option_group(verbosity)

                filesystem = optparse.OptionGroup(parser, 'Filesystem Options')
                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')
                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=False)
                filesystem.add_option('--cookies',
                                dest='cookiefile', metavar='FILE', help='file to dump cookie jar to')
                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)
                parser.add_option_group(filesystem)

                postproc = optparse.OptionGroup(parser, 'Post-processing Options')
                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" or "mp3"; best by default')
                parser.add_option_group(postproc)

                (opts, args) = parser.parse_args()

                # 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)

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

                # 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

                # 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 = long(opts.playliststart)
                        if opts.playliststart <= 0:
                                raise ValueError
                except (TypeError, ValueError), err:
                        parser.error(u'invalid playlist start number specified')
                try:
                        opts.playlistend = long(opts.playlistend)
                        if opts.playlistend != -1 and (opts.playlistend <= 0 or opts.playlistend < opts.playliststart):
                                raise ValueError
                except (TypeError, ValueError), err:
                        parser.error(u'invalid playlist end number specified')
                if opts.extractaudio:
                        if opts.audioformat not in ['best', 'aac', 'mp3']:
                                parser.error(u'invalid audio format specified')

                # Information extractors
                vimeo_ie = VimeoIE()
                youtube_ie = YoutubeIE()
                metacafe_ie = MetacafeIE(youtube_ie)
                dailymotion_ie = DailymotionIE()
                youtube_pl_ie = YoutubePlaylistIE(youtube_ie)
                youtube_user_ie = YoutubeUserIE(youtube_ie)
                youtube_search_ie = YoutubeSearchIE(youtube_ie)
                google_ie = GoogleIE()
                google_search_ie = GoogleSearchIE(google_ie)
                photobucket_ie = PhotobucketIE()
                yahoo_ie = YahooIE()
                yahoo_search_ie = YahooSearchIE(yahoo_ie)
                deposit_files_ie = DepositFilesIE()
                facebook_ie = FacebookIE()
                generic_ie = GenericIE()

                # 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),
                        'forceurl': opts.geturl,
                        'forcetitle': opts.gettitle,
                        'forcethumbnail': opts.getthumbnail,
                        'forcedescription': opts.getdescription,
                        'forcefilename': opts.getfilename,
                        'simulate': (opts.simulate or opts.geturl or opts.gettitle or opts.getthumbnail or opts.getdescription or opts.getfilename),
                        'format': opts.format,
                        'format_limit': opts.format_limit,
                        '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,
                        })
                fd.add_info_extractor(vimeo_ie)
                fd.add_info_extractor(youtube_search_ie)
                fd.add_info_extractor(youtube_pl_ie)
                fd.add_info_extractor(youtube_user_ie)
                fd.add_info_extractor(metacafe_ie)
                fd.add_info_extractor(dailymotion_ie)
                fd.add_info_extractor(youtube_ie)
                fd.add_info_extractor(google_ie)
                fd.add_info_extractor(google_search_ie)
                fd.add_info_extractor(photobucket_ie)
                fd.add_info_extractor(yahoo_ie)
                fd.add_info_extractor(yahoo_search_ie)
                fd.add_info_extractor(deposit_files_ie)
                fd.add_info_extractor(facebook_ie)

                # This must come last since it's the
                # fallback if none of the others work
                fd.add_info_extractor(generic_ie)

                # PostProcessors
                if opts.extractaudio:
                        fd.add_post_processor(FFmpegExtractAudioPP(preferredcodec=opts.audioformat))

                # Update version
                if opts.update_self:
                        update_self(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()
                retcode = fd.download(all_urls)

                # 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)

        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')