How to use the youtube-dl.youtube_dl.utils.determine_ext function in youtube_dl

media_url = None
                # @href is introduced in 2.0, see section 11.6 of F4M spec
                if manifest_version == '2.0':
                    media_url = media_el.attrib.get('href')
                if media_url is None:
                    media_url = media_el.attrib.get('url')
                if not media_url:
                    continue
                manifest_url = (
                    media_url if media_url.startswith('http://') or media_url.startswith('https://')
                    else ((manifest_base_url or '/'.join(manifest_url.split('/')[:-1])) + '/' + media_url))
                # If media_url is itself a f4m manifest do the recursive extraction
                # since bitrates in parent manifest (this one) and media_url manifest
                # may differ leading to inability to resolve the format by requested
                # bitrate in f4m downloader
                ext = determine_ext(manifest_url)
                if ext == 'f4m':
                    f4m_formats = self._extract_f4m_formats(
                        manifest_url, video_id, preference=preference, f4m_id=f4m_id,
                        transform_source=transform_source, fatal=fatal)
                    # Sometimes stream-level manifest contains single media entry that
                    # does not contain any quality metadata (e.g. http://matchtv.ru/#live-player).
                    # At the same time parent's media entry in set-level manifest may
                    # contain it. We will copy it from parent in such cases.
                    if len(f4m_formats) == 1:
                        f = f4m_formats[0]
                        f.update({
                            'tbr': f.get('tbr') or tbr,
                            'width': f.get('width') or width,
                            'height': f.get('height') or height,
                            'format_id': f.get('format_id') if not tbr else format_id,
                            'vcodec': vcodec,

def _write_thumbnails(self, info_dict, filename):
        if self.params.get('writethumbnail', False):
            thumbnails = info_dict.get('thumbnails')
            if thumbnails:
                thumbnails = [thumbnails[-1]]
        elif self.params.get('write_all_thumbnails', False):
            thumbnails = info_dict.get('thumbnails')
        else:
            return

        if not thumbnails:
            # No thumbnails present, so return immediately
            return

        for t in thumbnails:
            thumb_ext = determine_ext(t['url'], 'jpg')
            suffix = '_%s' % t['id'] if len(thumbnails) > 1 else ''
            thumb_display_id = '%s ' % t['id'] if len(thumbnails) > 1 else ''
            t['filename'] = thumb_filename = os.path.splitext(filename)[0] + suffix + '.' + thumb_ext

            if self.params.get('nooverwrites', False) and os.path.exists(encodeFilename(thumb_filename)):
                self.to_screen('[%s] %s: Thumbnail %sis already present' %
                               (info_dict['extractor'], info_dict['id'], thumb_display_id))
            else:
                self.to_screen('[%s] %s: Downloading thumbnail %s...' %
                               (info_dict['extractor'], info_dict['id'], thumb_display_id))
                try:
                    uf = self.urlopen(t['url'])
                    with open(encodeFilename(thumb_filename), 'wb') as thumbf:
                        shutil.copyfileobj(uf, thumbf)
                    self.to_screen('[%s] %s: Writing thumbnail %sto: %s' %
                                   (info_dict['extractor'], info_dict['id'], thumb_display_id, thumb_filename))

m3u8_id=None, mpd_id=None, rtmp_params=None, base_url=None):
        urls = []
        formats = []
        for source in jwplayer_sources_data:
            if not isinstance(source, dict):
                continue
            source_url = self._proto_relative_url(source.get('file'))
            if not source_url:
                continue
            if base_url:
                source_url = compat_urlparse.urljoin(base_url, source_url)
            if source_url in urls:
                continue
            urls.append(source_url)
            source_type = source.get('type') or ''
            ext = mimetype2ext(source_type) or determine_ext(source_url)
            if source_type == 'hls' or ext == 'm3u8':
                formats.extend(self._extract_m3u8_formats(
                    source_url, video_id, 'mp4', entry_protocol='m3u8_native',
                    m3u8_id=m3u8_id, fatal=False))
            elif source_type == 'dash' or ext == 'mpd':
                formats.extend(self._extract_mpd_formats(
                    source_url, video_id, mpd_id=mpd_id, fatal=False))
            elif ext == 'smil':
                formats.extend(self._extract_smil_formats(
                    source_url, video_id, fatal=False))
            # https://github.com/jwplayer/jwplayer/blob/master/src/js/providers/default.js#L67
            elif source_type.startswith('audio') or ext in (
                    'oga', 'aac', 'mp3', 'mpeg', 'vorbis'):
                formats.append({
                    'url': source_url,
                    'vcodec': 'none',

r'<title>(.+?)</title>', webpage, 'title')

        formats = []

        encodings = self._parse_json(
            self._search_regex(
                r'encodings\s*=\s*(\[.+?\]);\n', webpage, 'encodings',
                default='[]'),
            video_id, fatal=False)
        for encoding in encodings:
            if not isinstance(encoding, dict):
                continue
            format_url = encoding.get('filename')
            if not isinstance(format_url, compat_str):
                continue
            if determine_ext(format_url) == 'm3u8':
                formats.extend(self._extract_m3u8_formats(
                    format_url, video_id, 'mp4', entry_protocol='m3u8_native',
                    m3u8_id='hls', fatal=False))
            else:
                format_id = encoding.get('name') or encoding.get('quality')
                height = int_or_none(self._search_regex(
                    r'^(\d+)[pP]', format_id, 'height', default=None))
                formats.append({
                    'url': format_url,
                    'format_id': format_id,
                    'height': height,
                })

        if formats:
            info_dict = {
                'formats': formats,

if player_v5:
            player = self._parse_json(player_v5, video_id)
            metadata = player['metadata']

            self._check_error(metadata)

            formats = []
            for quality, media_list in metadata['qualities'].items():
                for media in media_list:
                    media_url = media.get('url')
                    if not media_url:
                        continue
                    type_ = media.get('type')
                    if type_ == 'application/vnd.lumberjack.manifest':
                        continue
                    ext = mimetype2ext(type_) or determine_ext(media_url)
                    if ext == 'm3u8':
                        formats.extend(self._extract_m3u8_formats(
                            media_url, video_id, 'mp4', preference=-1,
                            m3u8_id='hls', fatal=False))
                    elif ext == 'f4m':
                        formats.extend(self._extract_f4m_formats(
                            media_url, video_id, preference=-1, f4m_id='hds', fatal=False))
                    else:
                        f = {
                            'url': media_url,
                            'format_id': 'http-%s' % quality,
                            'ext': ext,
                        }
                        m = re.search(r'H264-(?P\d+)x(?P\d+)', media_url)
                        if m:
                            f.update({

pass

        # Auto generate title fields corresponding to the *_number fields when missing
        # in order to always have clean titles. This is very common for TV series.
        for field in ('chapter', 'season', 'episode'):
            if info_dict.get('%s_number' % field) is not None and not info_dict.get(field):
                info_dict[field] = '%s %d' % (field.capitalize(), info_dict['%s_number' % field])

        subtitles = info_dict.get('subtitles')
        if subtitles:
            for _, subtitle in subtitles.items():
                for subtitle_format in subtitle:
                    if subtitle_format.get('url'):
                        subtitle_format['url'] = sanitize_url(subtitle_format['url'])
                    if subtitle_format.get('ext') is None:
                        subtitle_format['ext'] = determine_ext(subtitle_format['url']).lower()

        if self.params.get('listsubtitles', False):
            if 'automatic_captions' in info_dict:
                self.list_subtitles(info_dict['id'], info_dict.get('automatic_captions'), 'automatic captions')
            self.list_subtitles(info_dict['id'], subtitles, 'subtitles')
            return
        info_dict['requested_subtitles'] = self.process_subtitles(
            info_dict['id'], subtitles,
            info_dict.get('automatic_captions'))

        # We now pick which formats have to be downloaded
        if info_dict.get('formats') is None:
            # There's only one format available
            formats = [info_dict]
        else:
            formats = info_dict['formats']

comment_count = None

        formats = []
        download_request = sanitized_Request('https://vimeo.com/%s?action=load_download_config' % video_id, headers={
            'X-Requested-With': 'XMLHttpRequest'})
        download_data = self._download_json(download_request, video_id, fatal=False)
        if download_data:
            source_file = download_data.get('source_file')
            if isinstance(source_file, dict):
                download_url = source_file.get('download_url')
                if download_url and not source_file.get('is_cold') and not source_file.get('is_defrosting'):
                    source_name = source_file.get('public_name', 'Original')
                    if self._is_valid_url(download_url, video_id, '%s video' % source_name):
                        ext = (try_get(
                            source_file, lambda x: x['extension'],
                            compat_str) or determine_ext(
                            download_url, None) or 'mp4').lower()
                        formats.append({
                            'url': download_url,
                            'ext': ext,
                            'width': int_or_none(source_file.get('width')),
                            'height': int_or_none(source_file.get('height')),
                            'filesize': parse_filesize(source_file.get('size')),
                            'format_id': source_name,
                            'preference': 1,
                        })

        info_dict = self._parse_config(config, video_id)
        formats.extend(info_dict['formats'])
        self._vimeo_sort_formats(formats)

        if not cc_license:

try:
            streams = self._download_json(
                'http://playapi.mtgx.tv/v3/videos/stream/%s' % video_id,
                video_id, 'Downloading streams JSON')
        except ExtractorError as e:
            if isinstance(e.cause, compat_HTTPError) and e.cause.code == 403:
                msg = self._parse_json(e.cause.read().decode('utf-8'), video_id)
                raise ExtractorError(msg['msg'], expected=True)
            raise

        quality = qualities(['hls', 'medium', 'high'])
        formats = []
        for format_id, video_url in streams.get('streams', {}).items():
            if not video_url or not isinstance(video_url, compat_str):
                continue
            ext = determine_ext(video_url)
            if ext == 'f4m':
                formats.extend(self._extract_f4m_formats(
                    update_url_query(video_url, {
                        'hdcore': '3.5.0',
                        'plugin': 'aasp-3.5.0.151.81'
                    }), video_id, f4m_id='hds', fatal=False))
            elif ext == 'm3u8':
                formats.extend(self._extract_m3u8_formats(
                    video_url, video_id, 'mp4', 'm3u8_native',
                    m3u8_id='hls', fatal=False))
            else:
                fmt = {
                    'format_id': format_id,
                    'quality': quality(format_id),
                    'ext': ext,
                }

srcs = []
        media = smil.findall(self._xpath_ns('.//video', namespace)) + smil.findall(self._xpath_ns('.//audio', namespace))
        for medium in media:
            src = medium.get('src')
            if not src or src in srcs:
                continue
            srcs.append(src)

            bitrate = float_or_none(medium.get('system-bitrate') or medium.get('systemBitrate'), 1000)
            filesize = int_or_none(medium.get('size') or medium.get('fileSize'))
            width = int_or_none(medium.get('width'))
            height = int_or_none(medium.get('height'))
            proto = medium.get('proto')
            ext = medium.get('ext')
            src_ext = determine_ext(src)
            streamer = medium.get('streamer') or base

            if proto == 'rtmp' or streamer.startswith('rtmp'):
                rtmp_count += 1
                formats.append({
                    'url': streamer,
                    'play_path': src,
                    'ext': 'flv',
                    'format_id': 'rtmp-%d' % (rtmp_count if bitrate is None else bitrate),
                    'tbr': bitrate,
                    'filesize': filesize,
                    'width': width,
                    'height': height,
                })
                if transform_rtmp_url:
                    streamer, src = transform_rtmp_url(streamer, src)