Question : Extract the video title without additional requests?

[Elite]

I would like to know how to extract the video title without additional requests using the official example as below:

import youtube_dl


class MyLogger(object):
    def debug(self, msg):
        pass

    def warning(self, msg):
        pass

    def error(self, msg):
        print(msg)


def my_hook(d):
    if d['status'] == 'finished':
        print('Done downloading, now converting ...')


ydl_opts = {
    'format': 'bestaudio/best',
    'postprocessors': [{
        'key': 'FFmpegExtractAudio',
        'preferredcodec': 'mp3',
        'preferredquality': '192',
    }],
    'logger': MyLogger(),
    'progress_hooks': [my_hook],
}
with youtube_dl.YoutubeDL(ydl_opts) as ydl:
    ydl.download(['http://www.youtube.com/watch?v=BaW_jenozKc'])

[phihag]

You don't need any of the advanced options / hooks for that. Simply call extract_info, like this:

import youtube_dl


ydl_opts = {
    'quiet': True,
    'skip_download': True,
}
with youtube_dl.YoutubeDL(ydl_opts) as ydl:
    info = ydl.extract_info('http://www.youtube.com/watch?v=BaW_jenozKc')

print('Title of the extracted video/playlist: %s' % info['title'])

[Elite]

Thanks for the information but my question is how to Download the video and extract the information in a single step without multiple page-fetches. The below works for me but is slow and also ignores the 'continuedl': True, directive.

    def download(self):
        #self.statusSignal.emit('Starting...')
        ydl_options = {
            'outtmpl': '{0}%(title)s-%(id)s.%(ext)s'.format(self.directory),
            'format': 'bestaudio',
            'postprocessors': [{
            'key': 'FFmpegExtractAudio',
            'preferredcodec': 'mp3',
            'preferredquality': '192',
            }],
            'continuedl': True,
            'quiet' : True,
            'restrictfilenames':True, 
        }
        with youtube_dl.YoutubeDL(ydl_options) as ydl:
            info = ydl.extract_info(self.url)
            self.statusSignal.emit(info['title'])
            ydl.add_default_info_extractors()
            ydl.add_progress_hook(self.hook)
            try:
                ydl.download([self.url])
            except (youtube_dl.utils.DownloadError,youtube_dl.utils.ContentTooShortError,youtube_dl.utils.ExtractorError) as e:
                self.error_occured = True
                self.statusSignal.emit(str(e))

[jaimeMF]

extract_info already downloads the video by default, try with this:

import youtube_dl
url = 'test:youtube'
ydl_options = {
            'outtmpl': '%(title)s-%(id)s.%(ext)s',
            'format': 'bestaudio',
            'postprocessors': [{
            'key': 'FFmpegExtractAudio',
            'preferredcodec': 'mp3',
            'preferredquality': '192',
            }],
            'continuedl': True,
            'quiet' : True,
            'restrictfilenames':True, 
        }
def hook(s):
    print(s)
with youtube_dl.YoutubeDL(ydl_options) as ydl:
    try:
        ydl.add_default_info_extractors()
        ydl.add_progress_hook(hook)
        info = ydl.extract_info(url,
            download=True # it's the default value, but to make it clearer
        )
        print(info['title'])
    except (youtube_dl.utils.DownloadError,youtube_dl.utils.ContentTooShortError,youtube_dl.utils.ExtractorError) as e:
        self.error_occured = True
        self.statusSignal.emit(str(e))

The reason why it downloads the video again is that the postprocessor deletes the original file, so we can't detect if it has been downloaded, you can use the keepvideo option for that.

[Elite]

Thanks @jaimeMF, this works but does not prints the title nor emits the signal!!!

    def download(self):
        #self.statusSignal.emit('Starting...')
        ydl_options = {
            'outtmpl': '{0}%(title)s-%(id)s.%(ext)s'.format(self.directory),
            'format': 'bestaudio',
            'postprocessors': [{
            'key': 'FFmpegExtractAudio',
            'preferredcodec': 'mp3',
            'preferredquality': '192',
            }],
            'continuedl': True,
            'quiet' : True,
            'restrictfilenames':True, 
        }
        with youtube_dl.YoutubeDL(ydl_options) as ydl:
            try:
                ydl.add_default_info_extractors()
                ydl.add_progress_hook(self.hook)
                info = ydl.extract_info(self.url, download=True )
                self.statusSignal.emit(info['title'])
                print(info['title'])
            except (youtube_dl.utils.DownloadError,youtube_dl.utils.ContentTooShortError,youtube_dl.utils.ExtractorError) as e:
                self.error_occured = True
                self.statusSignal.emit(str(e))

[Elite]

@jaimeMF @phihag any pointers guys?

[jaimeMF]

I have adapted the script to remove the self references and it works fine:

import youtube_dl

def download(url):
        #self.statusSignal.emit('Starting...')
        ydl_options = {
            'outtmpl': '%(title)s-%(id)s.%(ext)s',
            'format': 'bestaudio',
            'postprocessors': [{
            'key': 'FFmpegExtractAudio',
            'preferredcodec': 'mp3',
            'preferredquality': '192',
            }],
            'continuedl': True,
            'quiet' : True,
            'restrictfilenames':True, 
        }
        def hook(s):
            print(s)
        with youtube_dl.YoutubeDL(ydl_options) as ydl:
            try:
                ydl.add_default_info_extractors()
                ydl.add_progress_hook(hook)
                info = ydl.extract_info(url, download=True )
                print(info['title'])
            except (youtube_dl.utils.DownloadError,youtube_dl.utils.ContentTooShortError,youtube_dl.utils.ExtractorError) as e:
                print(e)

download('test:youtube')

Could you try with that script and post the output?