Move youtube extractors to youtube_dl.extractor.youtube

1 files changed, 757 insertions, 0 deletions

diff --git a/youtube_dl/extractor/youtube.py b/youtube_dl/extractor/youtube.py
new file mode 100644
index 000000000..d09128555
--- /dev/null
+++ b/youtube_dl/extractor/youtube.py
@@ -0,0 +1,757 @@
+# coding: utf-8
+from __future__ import absolute_import
+
+import json
+import netrc
+import re
+import socket
+
+from .common import InfoExtractor
+from ..utils import (
+    compat_http_client,
+    compat_parse_qs,
+    compat_urllib_error,
+    compat_urllib_parse,
+    compat_urllib_request,
+    compat_str,
+
+    clean_html,
+    get_element_by_id,
+    ExtractorError,
+    unescapeHTML,
+    unified_strdate,
+)
+
+
+class YoutubeIE(InfoExtractor):
+    """Information extractor for youtube.com."""
+
+    _VALID_URL = r"""^
+                     (
+                         (?:https?://)?                                       # http(s):// (optional)
+                         (?:youtu\.be/|(?:\w+\.)?youtube(?:-nocookie)?\.com/|
+                            tube\.majestyc\.net/)                             # the various hostnames, with wildcard subdomains
+                         (?:.*?\#/)?                                          # handle anchor (#/) redirect urls
+                         (?:                                                  # the various things that can precede the ID:
+                             (?:(?:v|embed|e)/)                               # v/ or embed/ or e/
+                             |(?:                                             # or the v= param in all its forms
+                                 (?:watch(?:_popup)?(?:\.php)?)?              # preceding watch(_popup|.php) or nothing (like /?v=xxxx)
+                                 (?:\?|\#!?)                                  # the params delimiter ? or # or #!
+                                 (?:.*?&)?                                    # any other preceding param (like /?s=tuff&v=xxxx)
+                                 v=
+                             )
+                         )?                                                   # optional -> youtube.com/xxxx is OK
+                     )?                                                       # all until now is optional -> you can pass the naked ID
+                     ([0-9A-Za-z_-]+)                                         # here is it! the YouTube video ID
+                     (?(1).+)?                                                # if we found the ID, everything can follow
+                     $"""
+    _LANG_URL = r'https://www.youtube.com/?hl=en&persist_hl=1&gl=US&persist_gl=1&opt_out_ackd=1'
+    _LOGIN_URL = 'https://accounts.google.com/ServiceLogin'
+    _AGE_URL = 'http://www.youtube.com/verify_age?next_url=/&gl=US&hl=en'
+    _NEXT_URL_RE = r'[\?&]next_url=([^&]+)'
+    _NETRC_MACHINE = 'youtube'
+    # Listed in order of quality
+    _available_formats = ['38', '37', '46', '22', '45', '35', '44', '34', '18', '43', '6', '5', '17', '13']
+    _available_formats_prefer_free = ['38', '46', '37', '45', '22', '44', '35', '43', '34', '18', '6', '5', '17', '13']
+    _video_extensions = {
+        '13': '3gp',
+        '17': 'mp4',
+        '18': 'mp4',
+        '22': 'mp4',
+        '37': 'mp4',
+        '38': 'video', # You actually don't know if this will be MOV, AVI or whatever
+        '43': 'webm',
+        '44': 'webm',
+        '45': 'webm',
+        '46': 'webm',
+    }
+    _video_dimensions = {
+        '5': '240x400',
+        '6': '???',
+        '13': '???',
+        '17': '144x176',
+        '18': '360x640',
+        '22': '720x1280',
+        '34': '360x640',
+        '35': '480x854',
+        '37': '1080x1920',
+        '38': '3072x4096',
+        '43': '360x640',
+        '44': '480x854',
+        '45': '720x1280',
+        '46': '1080x1920',
+    }
+    IE_NAME = u'youtube'
+
+    @classmethod
+    def suitable(cls, url):
+        """Receives a URL and returns True if suitable for this IE."""
+        if YoutubePlaylistIE.suitable(url): return False
+        return re.match(cls._VALID_URL, url, re.VERBOSE) is not None
+
+    def report_lang(self):
+        """Report attempt to set language."""
+        self.to_screen(u'Setting language')
+
+    def report_login(self):
+        """Report attempt to log in."""
+        self.to_screen(u'Logging in')
+
+    def report_video_webpage_download(self, video_id):
+        """Report attempt to download video webpage."""
+        self.to_screen(u'%s: Downloading video webpage' % video_id)
+
+    def report_video_info_webpage_download(self, video_id):
+        """Report attempt to download video info webpage."""
+        self.to_screen(u'%s: Downloading video info webpage' % video_id)
+
+    def report_video_subtitles_download(self, video_id):
+        """Report attempt to download video info webpage."""
+        self.to_screen(u'%s: Checking available subtitles' % video_id)
+
+    def report_video_subtitles_request(self, video_id, sub_lang, format):
+        """Report attempt to download video info webpage."""
+        self.to_screen(u'%s: Downloading video subtitles for %s.%s' % (video_id, sub_lang, format))
+
+    def report_video_subtitles_available(self, video_id, sub_lang_list):
+        """Report available subtitles."""
+        sub_lang = ",".join(list(sub_lang_list.keys()))
+        self.to_screen(u'%s: Available subtitles for video: %s' % (video_id, sub_lang))
+
+    def report_information_extraction(self, video_id):
+        """Report attempt to extract video information."""
+        self.to_screen(u'%s: Extracting video information' % video_id)
+
+    def report_unavailable_format(self, video_id, format):
+        """Report extracted video URL."""
+        self.to_screen(u'%s: Format %s not available' % (video_id, format))
+
+    def report_rtmp_download(self):
+        """Indicate the download will use the RTMP protocol."""
+        self.to_screen(u'RTMP download detected')
+
+    @staticmethod
+    def _decrypt_signature(s):
+        """Decrypt the key the two subkeys must have a length of 43"""
+        (a,b) = s.split('.')
+        if len(a) != 43 or len(b) != 43:
+            raise ExtractorError(u'Unable to decrypt signature, subkeys lengths not valid')
+        b = ''.join([b[:8],a[0],b[9:18],b[-4],b[19:39], b[18]])[0:40]
+        a = a[-40:]
+        s_dec = '.'.join((a,b))[::-1]
+        return s_dec
+
+    def _get_available_subtitles(self, video_id):
+        self.report_video_subtitles_download(video_id)
+        request = compat_urllib_request.Request('http://video.google.com/timedtext?hl=en&type=list&v=%s' % video_id)
+        try:
+            sub_list = compat_urllib_request.urlopen(request).read().decode('utf-8')
+        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
+            return (u'unable to download video subtitles: %s' % compat_str(err), None)
+        sub_lang_list = re.findall(r'name="([^"]*)"[^>]+lang_code="([\w\-]+)"', sub_list)
+        sub_lang_list = dict((l[1], l[0]) for l in sub_lang_list)
+        if not sub_lang_list:
+            return (u'video doesn\'t have subtitles', None)
+        return sub_lang_list
+
+    def _list_available_subtitles(self, video_id):
+        sub_lang_list = self._get_available_subtitles(video_id)
+        self.report_video_subtitles_available(video_id, sub_lang_list)
+
+    def _request_subtitle(self, sub_lang, sub_name, video_id, format):
+        """
+        Return tuple:
+        (error_message, sub_lang, sub)
+        """
+        self.report_video_subtitles_request(video_id, sub_lang, format)
+        params = compat_urllib_parse.urlencode({
+            'lang': sub_lang,
+            'name': sub_name,
+            'v': video_id,
+            'fmt': format,
+        })
+        url = 'http://www.youtube.com/api/timedtext?' + params
+        try:
+            sub = compat_urllib_request.urlopen(url).read().decode('utf-8')
+        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
+            return (u'unable to download video subtitles: %s' % compat_str(err), None, None)
+        if not sub:
+            return (u'Did not fetch video subtitles', None, None)
+        return (None, sub_lang, sub)
+
+    def _request_automatic_caption(self, video_id, webpage):
+        """We need the webpage for getting the captions url, pass it as an
+           argument to speed up the process."""
+        sub_lang = self._downloader.params.get('subtitleslang') or 'en'
+        sub_format = self._downloader.params.get('subtitlesformat')
+        self.to_screen(u'%s: Looking for automatic captions' % video_id)
+        mobj = re.search(r';ytplayer.config = ({.*?});', webpage)
+        err_msg = u'Couldn\'t find automatic captions for "%s"' % sub_lang
+        if mobj is None:
+            return [(err_msg, None, None)]
+        player_config = json.loads(mobj.group(1))
+        try:
+            args = player_config[u'args']
+            caption_url = args[u'ttsurl']
+            timestamp = args[u'timestamp']
+            params = compat_urllib_parse.urlencode({
+                'lang': 'en',
+                'tlang': sub_lang,
+                'fmt': sub_format,
+                'ts': timestamp,
+                'kind': 'asr',
+            })
+            subtitles_url = caption_url + '&' + params
+            sub = self._download_webpage(subtitles_url, video_id, u'Downloading automatic captions')
+            return [(None, sub_lang, sub)]
+        except KeyError:
+            return [(err_msg, None, None)]
+
+    def _extract_subtitle(self, video_id):
+        """
+        Return a list with a tuple:
+        [(error_message, sub_lang, sub)]
+        """
+        sub_lang_list = self._get_available_subtitles(video_id)
+        sub_format = self._downloader.params.get('subtitlesformat')
+        if  isinstance(sub_lang_list,tuple): #There was some error, it didn't get the available subtitles
+            return [(sub_lang_list[0], None, None)]
+        if self._downloader.params.get('subtitleslang', False):
+            sub_lang = self._downloader.params.get('subtitleslang')
+        elif 'en' in sub_lang_list:
+            sub_lang = 'en'
+        else:
+            sub_lang = list(sub_lang_list.keys())[0]
+        if not sub_lang in sub_lang_list:
+            return [(u'no closed captions found in the specified language "%s"' % sub_lang, None, None)]
+
+        subtitle = self._request_subtitle(sub_lang, sub_lang_list[sub_lang].encode('utf-8'), video_id, sub_format)
+        return [subtitle]
+
+    def _extract_all_subtitles(self, video_id):
+        sub_lang_list = self._get_available_subtitles(video_id)
+        sub_format = self._downloader.params.get('subtitlesformat')
+        if  isinstance(sub_lang_list,tuple): #There was some error, it didn't get the available subtitles
+            return [(sub_lang_list[0], None, None)]
+        subtitles = []
+        for sub_lang in sub_lang_list:
+            subtitle = self._request_subtitle(sub_lang, sub_lang_list[sub_lang].encode('utf-8'), video_id, sub_format)
+            subtitles.append(subtitle)
+        return subtitles
+
+    def _print_formats(self, formats):
+        print('Available formats:')
+        for x in formats:
+            print('%s\t:\t%s\t[%s]' %(x, self._video_extensions.get(x, 'flv'), self._video_dimensions.get(x, '???')))
+
+    def _real_initialize(self):
+        if self._downloader is None:
+            return
+
+        username = None
+        password = None
+        downloader_params = self._downloader.params
+
+        # Attempt to use provided username and password or .netrc data
+        if downloader_params.get('username', None) is not None:
+            username = downloader_params['username']
+            password = downloader_params['password']
+        elif downloader_params.get('usenetrc', False):
+            try:
+                info = netrc.netrc().authenticators(self._NETRC_MACHINE)
+                if info is not None:
+                    username = info[0]
+                    password = info[2]
+                else:
+                    raise netrc.NetrcParseError('No authenticators for %s' % self._NETRC_MACHINE)
+            except (IOError, netrc.NetrcParseError) as err:
+                self._downloader.report_warning(u'parsing .netrc: %s' % compat_str(err))
+                return
+
+        # Set language
+        request = compat_urllib_request.Request(self._LANG_URL)
+        try:
+            self.report_lang()
+            compat_urllib_request.urlopen(request).read()
+        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
+            self._downloader.report_warning(u'unable to set language: %s' % compat_str(err))
+            return
+
+        # No authentication to be performed
+        if username is None:
+            return
+
+        request = compat_urllib_request.Request(self._LOGIN_URL)
+        try:
+            login_page = compat_urllib_request.urlopen(request).read().decode('utf-8')
+        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
+            self._downloader.report_warning(u'unable to fetch login page: %s' % compat_str(err))
+            return
+
+        galx = None
+        dsh = None
+        match = re.search(re.compile(r'<input.+?name="GALX".+?value="(.+?)"', re.DOTALL), login_page)
+        if match:
+          galx = match.group(1)
+
+        match = re.search(re.compile(r'<input.+?name="dsh".+?value="(.+?)"', re.DOTALL), login_page)
+        if match:
+          dsh = match.group(1)
+
+        # Log in
+        login_form_strs = {
+                u'continue': u'https://www.youtube.com/signin?action_handle_signin=true&feature=sign_in_button&hl=en_US&nomobiletemp=1',
+                u'Email': username,
+                u'GALX': galx,
+                u'Passwd': password,
+                u'PersistentCookie': u'yes',
+                u'_utf8': u'霱',
+                u'bgresponse': u'js_disabled',
+                u'checkConnection': u'',
+                u'checkedDomains': u'youtube',
+                u'dnConn': u'',
+                u'dsh': dsh,
+                u'pstMsg': u'0',
+                u'rmShown': u'1',
+                u'secTok': u'',
+                u'signIn': u'Sign in',
+                u'timeStmp': u'',
+                u'service': u'youtube',
+                u'uilel': u'3',
+                u'hl': u'en_US',
+        }
+        # Convert to UTF-8 *before* urlencode because Python 2.x's urlencode
+        # chokes on unicode
+        login_form = dict((k.encode('utf-8'), v.encode('utf-8')) for k,v in login_form_strs.items())
+        login_data = compat_urllib_parse.urlencode(login_form).encode('ascii')
+        request = compat_urllib_request.Request(self._LOGIN_URL, login_data)
+        try:
+            self.report_login()
+            login_results = compat_urllib_request.urlopen(request).read().decode('utf-8')
+            if re.search(r'(?i)<form[^>]* id="gaia_loginform"', login_results) is not None:
+                self._downloader.report_warning(u'unable to log in: bad username or password')
+                return
+        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
+            self._downloader.report_warning(u'unable to log in: %s' % compat_str(err))
+            return
+
+        # Confirm age
+        age_form = {
+                'next_url':     '/',
+                'action_confirm':   'Confirm',
+                }
+        request = compat_urllib_request.Request(self._AGE_URL, compat_urllib_parse.urlencode(age_form))
+        try:
+            self.report_age_confirmation()
+            age_results = compat_urllib_request.urlopen(request).read().decode('utf-8')
+        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
+            raise ExtractorError(u'Unable to confirm age: %s' % compat_str(err))
+
+    def _extract_id(self, url):
+        mobj = re.match(self._VALID_URL, url, re.VERBOSE)
+        if mobj is None:
+            raise ExtractorError(u'Invalid URL: %s' % url)
+        video_id = mobj.group(2)
+        return video_id
+
+    def _real_extract(self, url):
+        # Extract original video URL from URL with redirection, like age verification, using next_url parameter
+        mobj = re.search(self._NEXT_URL_RE, url)
+        if mobj:
+            url = 'https://www.youtube.com/' + compat_urllib_parse.unquote(mobj.group(1)).lstrip('/')
+        video_id = self._extract_id(url)
+
+        # Get video webpage
+        self.report_video_webpage_download(video_id)
+        url = 'https://www.youtube.com/watch?v=%s&gl=US&hl=en&has_verified=1' % video_id
+        request = compat_urllib_request.Request(url)
+        try:
+            video_webpage_bytes = compat_urllib_request.urlopen(request).read()
+        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
+            raise ExtractorError(u'Unable to download video webpage: %s' % compat_str(err))
+
+        video_webpage = video_webpage_bytes.decode('utf-8', 'ignore')
+
+        # 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 = ('https://www.youtube.com/get_video_info?&video_id=%s%s&ps=default&eurl=&gl=US&hl=en'
+                    % (video_id, el_type))
+            video_info_webpage = self._download_webpage(video_info_url, video_id,
+                                    note=False,
+                                    errnote='unable to download video info webpage')
+            video_info = compat_parse_qs(video_info_webpage)
+            if 'token' in video_info:
+                break
+        if 'token' not in video_info:
+            if 'reason' in video_info:
+                raise ExtractorError(u'YouTube said: %s' % video_info['reason'][0])
+            else:
+                raise ExtractorError(u'"token" parameter not in video info for unknown reason')
+
+        # Check for "rental" videos
+        if 'ypc_video_rental_bar_text' in video_info and 'author' not in video_info:
+            raise ExtractorError(u'"rental" videos not supported')
+
+        # Start extracting information
+        self.report_information_extraction(video_id)
+
+        # uploader
+        if 'author' not in video_info:
+            raise ExtractorError(u'Unable to extract uploader name')
+        video_uploader = compat_urllib_parse.unquote_plus(video_info['author'][0])
+
+        # uploader_id
+        video_uploader_id = None
+        mobj = re.search(r'<link itemprop="url" href="http://www.youtube.com/(?:user|channel)/([^"]+)">', video_webpage)
+        if mobj is not None:
+            video_uploader_id = mobj.group(1)
+        else:
+            self._downloader.report_warning(u'unable to extract uploader nickname')
+
+        # title
+        if 'title' not in video_info:
+            raise ExtractorError(u'Unable to extract video title')
+        video_title = compat_urllib_parse.unquote_plus(video_info['title'][0])
+
+        # thumbnail image
+        if 'thumbnail_url' not in video_info:
+            self._downloader.report_warning(u'unable to extract video thumbnail')
+            video_thumbnail = ''
+        else:   # don't panic if we can't find it
+            video_thumbnail = compat_urllib_parse.unquote_plus(video_info['thumbnail_url'][0])
+
+        # upload date
+        upload_date = None
+        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())
+            upload_date = unified_strdate(upload_date)
+
+        # description
+        video_description = get_element_by_id("eow-description", video_webpage)
+        if video_description:
+            video_description = clean_html(video_description)
+        else:
+            fd_mobj = re.search(r'<meta name="description" content="([^"]+)"', video_webpage)
+            if fd_mobj:
+                video_description = unescapeHTML(fd_mobj.group(1))
+            else:
+                video_description = u''
+
+        # subtitles
+        video_subtitles = None
+
+        if self._downloader.params.get('writesubtitles', False):
+            video_subtitles = self._extract_subtitle(video_id)
+            if video_subtitles:
+                (sub_error, sub_lang, sub) = video_subtitles[0]
+                if sub_error:
+                    # We try with the automatic captions
+                    video_subtitles = self._request_automatic_caption(video_id, video_webpage)
+                    (sub_error_auto, sub_lang, sub) = video_subtitles[0]
+                    if sub is not None:
+                        pass
+                    else:
+                        # We report the original error
+                        self._downloader.report_warning(sub_error)
+
+        if self._downloader.params.get('allsubtitles', False):
+            video_subtitles = self._extract_all_subtitles(video_id)
+            for video_subtitle in video_subtitles:
+                (sub_error, sub_lang, sub) = video_subtitle
+                if sub_error:
+                    self._downloader.report_warning(sub_error)
+
+        if self._downloader.params.get('listsubtitles', False):
+            sub_lang_list = self._list_available_subtitles(video_id)
+            return
+
+        if 'length_seconds' not in video_info:
+            self._downloader.report_warning(u'unable to extract video duration')
+            video_duration = ''
+        else:
+            video_duration = compat_urllib_parse.unquote_plus(video_info['length_seconds'][0])
+
+        # token
+        video_token = compat_urllib_parse.unquote_plus(video_info['token'][0])
+
+        # Decide which formats to download
+        req_format = self._downloader.params.get('format', None)
+
+        try:
+            mobj = re.search(r';ytplayer.config = ({.*?});', video_webpage)
+            info = json.loads(mobj.group(1))
+            args = info['args']
+            if args.get('ptk','') == 'vevo' or 'dashmpd':
+                # Vevo videos with encrypted signatures
+                self.to_screen(u'%s: Vevo video detected.' % video_id)
+                video_info['url_encoded_fmt_stream_map'] = [args['url_encoded_fmt_stream_map']]
+        except ValueError:
+            pass
+
+        if 'conn' in video_info and video_info['conn'][0].startswith('rtmp'):
+            self.report_rtmp_download()
+            video_url_list = [(None, video_info['conn'][0])]
+        elif 'url_encoded_fmt_stream_map' in video_info and len(video_info['url_encoded_fmt_stream_map']) >= 1:
+            url_map = {}
+            for url_data_str in video_info['url_encoded_fmt_stream_map'][0].split(','):
+                url_data = compat_parse_qs(url_data_str)
+                if 'itag' in url_data and 'url' in url_data:
+                    url = url_data['url'][0]
+                    if 'sig' in url_data:
+                        url += '&signature=' + url_data['sig'][0]
+                    elif 's' in url_data:
+                        signature = self._decrypt_signature(url_data['s'][0])
+                        url += '&signature=' + signature
+                    if 'ratebypass' not in url:
+                        url += '&ratebypass=yes'
+                    url_map[url_data['itag'][0]] = url
+
+            format_limit = self._downloader.params.get('format_limit', None)
+            available_formats = self._available_formats_prefer_free if self._downloader.params.get('prefer_free_formats', False) else self._available_formats
+            if format_limit is not None and format_limit in available_formats:
+                format_list = available_formats[available_formats.index(format_limit):]
+            else:
+                format_list = available_formats
+            existing_formats = [x for x in format_list if x in url_map]
+            if len(existing_formats) == 0:
+                raise ExtractorError(u'no known formats available for video')
+            if self._downloader.params.get('listformats', None):
+                self._print_formats(existing_formats)
+                return
+            if req_format is None or req_format == 'best':
+                video_url_list = [(existing_formats[0], url_map[existing_formats[0]])] # Best quality
+            elif req_format == 'worst':
+                video_url_list = [(existing_formats[len(existing_formats)-1], url_map[existing_formats[len(existing_formats)-1]])] # worst quality
+            elif req_format in ('-1', 'all'):
+                video_url_list = [(f, url_map[f]) for f in existing_formats] # All formats
+            else:
+                # Specific formats. We pick the first in a slash-delimeted sequence.
+                # For example, if '1/2/3/4' is requested and '2' and '4' are available, we pick '2'.
+                req_formats = req_format.split('/')
+                video_url_list = None
+                for rf in req_formats:
+                    if rf in url_map:
+                        video_url_list = [(rf, url_map[rf])]
+                        break
+                if video_url_list is None:
+                    raise ExtractorError(u'requested format not available')
+        else:
+            raise ExtractorError(u'no conn or url_encoded_fmt_stream_map information found in video info')
+
+        results = []
+        for format_param, video_real_url in video_url_list:
+            # Extension
+            video_extension = self._video_extensions.get(format_param, 'flv')
+
+            video_format = '{0} - {1}'.format(format_param if format_param else video_extension,
+                                              self._video_dimensions.get(format_param, '???'))
+
+            results.append({
+                'id':       video_id,
+                'url':      video_real_url,
+                'uploader': video_uploader,
+                'uploader_id': video_uploader_id,
+                'upload_date':  upload_date,
+                'title':    video_title,
+                'ext':      video_extension,
+                'format':   video_format,
+                'thumbnail':    video_thumbnail,
+                'description':  video_description,
+                'player_url':   player_url,
+                'subtitles':    video_subtitles,
+                'duration':     video_duration
+            })
+        return results
+
+class YoutubePlaylistIE(InfoExtractor):
+    """Information Extractor for YouTube playlists."""
+
+    _VALID_URL = r"""(?:
+                        (?:https?://)?
+                        (?:\w+\.)?
+                        youtube\.com/
+                        (?:
+                           (?:course|view_play_list|my_playlists|artist|playlist|watch)
+                           \? (?:.*?&)*? (?:p|a|list)=
+                        |  p/
+                        )
+                        ((?:PL|EC|UU)?[0-9A-Za-z-_]{10,})
+                        .*
+                     |
+                        ((?:PL|EC|UU)[0-9A-Za-z-_]{10,})
+                     )"""
+    _TEMPLATE_URL = 'https://gdata.youtube.com/feeds/api/playlists/%s?max-results=%i&start-index=%i&v=2&alt=json&safeSearch=none'
+    _MAX_RESULTS = 50
+    IE_NAME = u'youtube:playlist'
+
+    @classmethod
+    def suitable(cls, url):
+        """Receives a URL and returns True if suitable for this IE."""
+        return re.match(cls._VALID_URL, url, re.VERBOSE) is not None
+
+    def _real_extract(self, url):
+        # Extract playlist id
+        mobj = re.match(self._VALID_URL, url, re.VERBOSE)
+        if mobj is None:
+            raise ExtractorError(u'Invalid URL: %s' % url)
+
+        # Download playlist videos from API
+        playlist_id = mobj.group(1) or mobj.group(2)
+        page_num = 1
+        videos = []
+
+        while True:
+            url = self._TEMPLATE_URL % (playlist_id, self._MAX_RESULTS, self._MAX_RESULTS * (page_num - 1) + 1)
+            page = self._download_webpage(url, playlist_id, u'Downloading page #%s' % page_num)
+
+            try:
+                response = json.loads(page)
+            except ValueError as err:
+                raise ExtractorError(u'Invalid JSON in API response: ' + compat_str(err))
+
+            if 'feed' not in response:
+                raise ExtractorError(u'Got a malformed response from YouTube API')
+            playlist_title = response['feed']['title']['$t']
+            if 'entry' not in response['feed']:
+                # Number of videos is a multiple of self._MAX_RESULTS
+                break
+
+            for entry in response['feed']['entry']:
+                index = entry['yt$position']['$t']
+                if 'media$group' in entry and 'media$player' in entry['media$group']:
+                    videos.append((index, entry['media$group']['media$player']['url']))
+
+            if len(response['feed']['entry']) < self._MAX_RESULTS:
+                break
+            page_num += 1
+
+        videos = [v[1] for v in sorted(videos)]
+
+        url_results = [self.url_result(url, 'Youtube') for url in videos]
+        return [self.playlist_result(url_results, playlist_id, playlist_title)]
+
+
+class YoutubeChannelIE(InfoExtractor):
+    """Information Extractor for YouTube channels."""
+
+    _VALID_URL = r"^(?:https?://)?(?:youtu\.be|(?:\w+\.)?youtube(?:-nocookie)?\.com)/channel/([0-9A-Za-z_-]+)"
+    _TEMPLATE_URL = 'http://www.youtube.com/channel/%s/videos?sort=da&flow=list&view=0&page=%s&gl=US&hl=en'
+    _MORE_PAGES_INDICATOR = 'yt-uix-load-more'
+    _MORE_PAGES_URL = 'http://www.youtube.com/channel_ajax?action_load_more_videos=1&flow=list&paging=%s&view=0&sort=da&channel_id=%s'
+    IE_NAME = u'youtube:channel'
+
+    def extract_videos_from_page(self, page):
+        ids_in_page = []
+        for mobj in re.finditer(r'href="/watch\?v=([0-9A-Za-z_-]+)&?', page):
+            if mobj.group(1) not in ids_in_page:
+                ids_in_page.append(mobj.group(1))
+        return ids_in_page
+
+    def _real_extract(self, url):
+        # Extract channel id
+        mobj = re.match(self._VALID_URL, url)
+        if mobj is None:
+            raise ExtractorError(u'Invalid URL: %s' % url)
+
+        # Download channel page
+        channel_id = mobj.group(1)
+        video_ids = []
+        pagenum = 1
+
+        url = self._TEMPLATE_URL % (channel_id, pagenum)
+        page = self._download_webpage(url, channel_id,
+                                      u'Downloading page #%s' % pagenum)
+
+        # Extract video identifiers
+        ids_in_page = self.extract_videos_from_page(page)
+        video_ids.extend(ids_in_page)
+
+        # Download any subsequent channel pages using the json-based channel_ajax query
+        if self._MORE_PAGES_INDICATOR in page:
+            while True:
+                pagenum = pagenum + 1
+
+                url = self._MORE_PAGES_URL % (pagenum, channel_id)
+                page = self._download_webpage(url, channel_id,
+                                              u'Downloading page #%s' % pagenum)
+
+                page = json.loads(page)
+
+                ids_in_page = self.extract_videos_from_page(page['content_html'])
+                video_ids.extend(ids_in_page)
+
+                if self._MORE_PAGES_INDICATOR  not in page['load_more_widget_html']:
+                    break
+
+        self._downloader.to_screen(u'[youtube] Channel %s: Found %i videos' % (channel_id, len(video_ids)))
+
+        urls = ['http://www.youtube.com/watch?v=%s' % id for id in video_ids]
+        url_entries = [self.url_result(url, 'Youtube') for url in urls]
+        return [self.playlist_result(url_entries, channel_id)]
+
+
+class YoutubeUserIE(InfoExtractor):
+    """Information Extractor for YouTube users."""
+
+    _VALID_URL = r'(?:(?:(?:https?://)?(?:\w+\.)?youtube\.com/user/)|ytuser:)([A-Za-z0-9_-]+)'
+    _TEMPLATE_URL = 'http://gdata.youtube.com/feeds/api/users/%s'
+    _GDATA_PAGE_SIZE = 50
+    _GDATA_URL = 'http://gdata.youtube.com/feeds/api/users/%s/uploads?max-results=%d&start-index=%d'
+    _VIDEO_INDICATOR = r'/watch\?v=(.+?)[\<&]'
+    IE_NAME = u'youtube:user'
+
+    def _real_extract(self, url):
+        # Extract username
+        mobj = re.match(self._VALID_URL, url)
+        if mobj is None:
+            raise ExtractorError(u'Invalid URL: %s' % url)
+
+        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
+
+            gdata_url = self._GDATA_URL % (username, self._GDATA_PAGE_SIZE, start_index)
+            page = self._download_webpage(gdata_url, username,
+                                          u'Downloading video ids from %d to %d' % (start_index, start_index + self._GDATA_PAGE_SIZE))
+
+            # 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
+
+        urls = ['http://www.youtube.com/watch?v=%s' % video_id for video_id in video_ids]
+        url_results = [self.url_result(url, 'Youtube') for url in urls]
+        return [self.playlist_result(url_results, playlist_title = username)]