Thumbnail of Hotstar.com videos

[GourangaDas]

Hi!
Currently, youtube-dl doesn't provide the link of thumbnail of hotstar.com videos.

I've found a way to get thumbnail url by modifying the code 'hotstar.py'

Here's the code of '_real_extract(self, url)' as below. Please consider to check it out.

def _real_extract(self, url):
        video_id = self._match_id(url)

        video_data = self._download_content_info(video_id)

        # here I will try to get thubnail image from webpage
        page = self._download_webpage(url, video_id)
        thumbUrl = self._og_search_thumbnail(page)
        
        title = video_data.get('contentTitle')
        if video_data.get('encrypted') == 'Y':
            raise ExtractorError('This video is DRM protected.', expected=True)

        formats = []
        for f in ('JIO',):
            format_data = self._download_json(
                'http://getcdn.hotstar.com/AVS/besc',
                video_id, 'Downloading %s JSON metadata' % f,
                fatal=False, query={
                    'action': 'GetCDN',
                    'asJson': 'Y',
                    'channel': f,
                    'id': video_id,
                    'type': 'VOD',
                })
            if format_data:
                format_url = format_data.get('src')
                if not format_url:
                    continue
                ext = determine_ext(format_url)
                if ext == 'm3u8':
                    formats.extend(self._extract_m3u8_formats(
                        format_url, video_id, 'mp4',
                        m3u8_id='hls', fatal=False))
                elif ext == 'f4m':
                    # produce broken files
                    continue
                else:
                    formats.append({
                        'url': format_url,
                        'width': int_or_none(format_data.get('width')),
                        'height': int_or_none(format_data.get('height')),
                    })
        self._sort_formats(formats)
        return {
            'id': video_id,
            'description': video_data.get('description'),
            'duration': int_or_none(video_data.get('duration')),
            'timestamp': int_or_none(video_data.get('broadcastDate')),
            'formats': formats,
            'episode': title,
            'episode_number': int_or_none(video_data.get('episodeNumber')),
            'series': video_data.get('contentTitle'),
            'title': title,
            'thumbnail': thumbUrl
        }

[remitamine]

for instuction on how to contribute code look at https://github.com/rg3/youtube-dl#developer-instructions.
Duplicate of #16079.