+Passing cookies to youtube\-dl is a good way to workaround login when a
+particular extractor does not implement it explicitly.
+Another use case is working around
+CAPTCHA (https://en.wikipedia.org/wiki/CAPTCHA) some websites require
+you to solve in particular cases in order to get access (e.g.
+YouTube, CloudFlare).
+.SS How do I stream directly to media player?
+.PP
+You will first need to tell youtube\-dl to stream media to stdout with
+\f[C]\-o\ \-\f[], and also tell your media player to read from stdin (it
+must be capable of this for streaming) and then pipe former to latter.
+For example, streaming to vlc (https://www.videolan.org/) can be
+achieved with:
+.IP
+.nf
+\f[C]
+youtube\-dl\ \-o\ \-\ "https://www.youtube.com/watch?v=BaW_jenozKcj"\ |\ vlc\ \-
+\f[]
+.fi
+.SS How do I download only new videos from a playlist?
+.PP
+Use download\-archive feature.
+With this feature you should initially download the complete playlist
+with \f[C]\-\-download\-archive\ /path/to/download/archive/file.txt\f[]
+that will record identifiers of all the videos in a special file.
+Each subsequent run with the same \f[C]\-\-download\-archive\f[] will
+download only new videos and skip all videos that have been downloaded
+before.
+Note that only successful downloads are recorded in the file.
+.PP
+For example, at first,
+.IP
+.nf
+\f[C]
+youtube\-dl\ \-\-download\-archive\ archive.txt\ "https://www.youtube.com/playlist?list=PLwiyx1dc3P2JR9N8gQaQN_BCvlSlap7re"
+\f[]
+.fi
+.PP
+will download the complete \f[C]PLwiyx1dc3P2JR9N8gQaQN_BCvlSlap7re\f[]
+playlist and create a file \f[C]archive.txt\f[].
+Each subsequent run will only download new videos if any:
+.IP
+.nf
+\f[C]
+youtube\-dl\ \-\-download\-archive\ archive.txt\ "https://www.youtube.com/playlist?list=PLwiyx1dc3P2JR9N8gQaQN_BCvlSlap7re"
+\f[]
+.fi
+.SS Should I add \f[C]\-\-hls\-prefer\-native\f[] into my config?
+.PP
+When youtube\-dl detects an HLS video, it can download it either with
+the built\-in downloader or ffmpeg.
+Since many HLS streams are slightly invalid and ffmpeg/youtube\-dl each
+handle some invalid cases better than the other, there is an option to
+switch the downloader if needed.
+.PP
+When youtube\-dl knows that one particular downloader works better for a
+given website, that downloader will be picked.
+Otherwise, youtube\-dl will pick the best downloader for general
+compatibility, which at the moment happens to be ffmpeg.
+This choice may change in future versions of youtube\-dl, with
+improvements of the built\-in downloader and/or ffmpeg.
+.PP
+In particular, the generic extractor (used when your website is not in
+the list of supported sites by
+youtube\-dl (https://rg3.github.io/youtube-dl/supportedsites.html)
+cannot mandate one specific downloader.
+.PP
+If you put either \f[C]\-\-hls\-prefer\-native\f[] or
+\f[C]\-\-hls\-prefer\-ffmpeg\f[] into your configuration, a different
+subset of videos will fail to download correctly.
+Instead, it is much better to file an issue (https://yt-dl.org/bug) or a
+pull request which details why the native or the ffmpeg HLS downloader
+is a better choice for your use case.
+.SS Can you add support for this anime video site, or site which shows
+current movies for free?
+.PP
+As a matter of policy (as well as legality), youtube\-dl does not
+include support for services that specialize in infringing copyright.
+As a rule of thumb, if you cannot easily find a video that the service
+is quite obviously allowed to distribute (i.e.
+that has been uploaded by the creator, the creator\[aq]s distributor, or
+is published under a free license), the service is probably unfit for
+inclusion to youtube\-dl.
+.PP
+A note on the service that they don\[aq]t host the infringing content,
+but just link to those who do, is evidence that the service should
+\f[B]not\f[] be included into youtube\-dl.
+The same goes for any DMCA note when the whole front page of the service
+is filled with videos they are not allowed to distribute.
+A "fair use" note is equally unconvincing if the service shows
+copyright\-protected videos in full without authorization.
+.PP
+Support requests for services that \f[B]do\f[] purchase the rights to
+distribute their content are perfectly fine though.
+If in doubt, you can simply include a source that mentions the
+legitimate purchase of content.
+.SS How can I speed up work on my issue?
+.PP
+(Also known as: Help, my important issue not being solved!) The
+youtube\-dl core developer team is quite small.
+While we do our best to solve as many issues as possible, sometimes that
+can take quite a while.
+To speed up your issue, here\[aq]s what you can do:
+.PP
+First of all, please do report the issue at our issue
+tracker (https://yt-dl.org/bugs).
+That allows us to coordinate all efforts by users and developers, and
+serves as a unified point.
+Unfortunately, the youtube\-dl project has grown too large to use
+personal email as an effective communication channel.
+.PP
+Please read the bug reporting instructions (#bugs) below.
+A lot of bugs lack all the necessary information.
+If you can, offer proxy, VPN, or shell access to the youtube\-dl
+developers.
+If you are able to, test the issue from multiple computers in multiple
+countries to exclude local censorship or misconfiguration issues.
+.PP
+If nobody is interested in solving your issue, you are welcome to take
+matters into your own hands and submit a pull request (or coerce/pay
+somebody else to do so).
+.PP
+Feel free to bump the issue from time to time by writing a small comment
+("Issue is still present in youtube\-dl version ...from France, but
+fixed from Belgium"), but please not more than once a month.
+Please do not declare your issue as \f[C]important\f[] or
+\f[C]urgent\f[].
+.SS How can I detect whether a given URL is supported by youtube\-dl?
+.PP
+For one, have a look at the list of supported
+sites (docs/supportedsites.md).
+Note that it can sometimes happen that the site changes its URL scheme
+(say, from https://example.com/video/1234567 to
+https://example.com/v/1234567 ) and youtube\-dl reports an URL of a
+service in that list as unsupported.
+In that case, simply report a bug.
+.PP
+It is \f[I]not\f[] possible to detect whether a URL is supported or not.
+That\[aq]s because youtube\-dl contains a generic extractor which
+matches \f[B]all\f[] URLs.
+You may be tempted to disable, exclude, or remove the generic extractor,
+but the generic extractor not only allows users to extract videos from
+lots of websites that embed a video from another service, but may also
+be used to extract video from a service that it\[aq]s hosting itself.
+Therefore, we neither recommend nor support disabling, excluding, or
+removing the generic extractor.
+.PP
+If you want to find out whether a given URL is supported, simply call
+youtube\-dl with it.
+If you get no videos back, chances are the URL is either not referring
+to a video or unsupported.
+You can find out which by examining the output (if you run youtube\-dl
+on the console) or catching an \f[C]UnsupportedError\f[] exception if
+you run it from a Python program.
+.SH Why do I need to go through that much red tape when filing bugs?
+.PP
+Before we had the issue template, despite our extensive bug reporting
+instructions (#bugs), about 80% of the issue reports we got were
+useless, for instance because people used ancient versions hundreds of
+releases old, because of simple syntactic errors (not in youtube\-dl but
+in general shell usage), because the problem was already reported
+multiple times before, because people did not actually read an error
+message, even if it said "please install ffmpeg", because people did not
+mention the URL they were trying to download and many more simple,
+easy\-to\-avoid problems, many of whom were totally unrelated to
+youtube\-dl.
+.PP
+youtube\-dl is an open\-source project manned by too few volunteers, so
+we\[aq]d rather spend time fixing bugs where we are certain none of
+those simple problems apply, and where we can be reasonably confident to
+be able to reproduce the issue without asking the reporter repeatedly.
+As such, the output of \f[C]youtube\-dl\ \-v\ YOUR_URL_HERE\f[] is
+really all that\[aq]s required to file an issue.
+The issue template also guides you through some basic steps you can do,
+such as checking that your version of youtube\-dl is current.
+.SH DEVELOPER INSTRUCTIONS
+.PP
+Most users do not need to build youtube\-dl and can download the
+builds (https://rg3.github.io/youtube-dl/download.html) or get them from
+their distribution.
+.PP
+To run youtube\-dl as a developer, you don\[aq]t need to build anything
+either.
+Simply execute
+.IP
+.nf
+\f[C]
+python\ \-m\ youtube_dl
+\f[]
+.fi
+.PP
+To run the test, simply invoke your favorite test runner, or execute a
+test file directly; any of the following work:
+.IP
+.nf
+\f[C]
+python\ \-m\ unittest\ discover
+python\ test/test_download.py
+nosetests
+\f[]
+.fi
+.PP
+See item 6 of new extractor tutorial (#adding-support-for-a-new-site)
+for how to run extractor specific test cases.
+.PP
+If you want to create a build of youtube\-dl yourself, you\[aq]ll need
+.IP \[bu] 2
+python
+.IP \[bu] 2
+make (only GNU make is supported)
+.IP \[bu] 2
+pandoc
+.IP \[bu] 2
+zip
+.IP \[bu] 2
+nosetests
+.SS Adding support for a new site
+.PP
+If you want to add support for a new site, first of all \f[B]make
+sure\f[] this site is \f[B]not dedicated to copyright
+infringement (README.md#can-you-add-support-for-this-anime-video-site-or-site-which-shows-current-movies-for-free)\f[].
+youtube\-dl does \f[B]not support\f[] such sites thus pull requests
+adding support for them \f[B]will be rejected\f[].
+.PP
+After you have ensured this site is distributing its content legally,
+you can follow this quick list (assuming your service is called
+\f[C]yourextractor\f[]):
+.IP " 1." 4
+Fork this repository (https://github.com/rg3/youtube-dl/fork)
+.IP " 2." 4
+Check out the source code with:
+.RS 4
+.IP
+.nf
+\f[C]
+git\ clone\ git\@github.com:YOUR_GITHUB_USERNAME/youtube\-dl.git
+\f[]
+.fi
+.RE
+.IP " 3." 4
+Start a new git branch with
+.RS 4
+.IP
+.nf
+\f[C]
+cd\ youtube\-dl
+git\ checkout\ \-b\ yourextractor
+\f[]
+.fi
+.RE
+.IP " 4." 4
+Start with this simple template and save it to
+\f[C]youtube_dl/extractor/yourextractor.py\f[]:
+.RS 4
+.IP
+.nf
+\f[C]
+#\ coding:\ utf\-8
+from\ __future__\ import\ unicode_literals
+
+from\ .common\ import\ InfoExtractor
+
+
+class\ YourExtractorIE(InfoExtractor):
+\ \ \ \ _VALID_URL\ =\ r\[aq]https?://(?:www\\.)?yourextractor\\.com/watch/(?P<id>[0\-9]+)\[aq]
+\ \ \ \ _TEST\ =\ {
+\ \ \ \ \ \ \ \ \[aq]url\[aq]:\ \[aq]https://yourextractor.com/watch/42\[aq],
+\ \ \ \ \ \ \ \ \[aq]md5\[aq]:\ \[aq]TODO:\ md5\ sum\ of\ the\ first\ 10241\ bytes\ of\ the\ video\ file\ (use\ \-\-test)\[aq],
+\ \ \ \ \ \ \ \ \[aq]info_dict\[aq]:\ {
+\ \ \ \ \ \ \ \ \ \ \ \ \[aq]id\[aq]:\ \[aq]42\[aq],
+\ \ \ \ \ \ \ \ \ \ \ \ \[aq]ext\[aq]:\ \[aq]mp4\[aq],
+\ \ \ \ \ \ \ \ \ \ \ \ \[aq]title\[aq]:\ \[aq]Video\ title\ goes\ here\[aq],
+\ \ \ \ \ \ \ \ \ \ \ \ \[aq]thumbnail\[aq]:\ r\[aq]re:^https?://.*\\.jpg$\[aq],
+\ \ \ \ \ \ \ \ \ \ \ \ #\ TODO\ more\ properties,\ either\ as:
+\ \ \ \ \ \ \ \ \ \ \ \ #\ *\ A\ value
+\ \ \ \ \ \ \ \ \ \ \ \ #\ *\ MD5\ checksum;\ start\ the\ string\ with\ md5:
+\ \ \ \ \ \ \ \ \ \ \ \ #\ *\ A\ regular\ expression;\ start\ the\ string\ with\ re:
+\ \ \ \ \ \ \ \ \ \ \ \ #\ *\ Any\ Python\ type\ (for\ example\ int\ or\ float)
+\ \ \ \ \ \ \ \ }
+\ \ \ \ }
+
+\ \ \ \ def\ _real_extract(self,\ url):
+\ \ \ \ \ \ \ \ video_id\ =\ self._match_id(url)
+\ \ \ \ \ \ \ \ webpage\ =\ self._download_webpage(url,\ video_id)
+
+\ \ \ \ \ \ \ \ #\ TODO\ more\ code\ goes\ here,\ for\ example\ ...
+\ \ \ \ \ \ \ \ title\ =\ self._html_search_regex(r\[aq]<h1>(.+?)</h1>\[aq],\ webpage,\ \[aq]title\[aq])
+
+\ \ \ \ \ \ \ \ return\ {
+\ \ \ \ \ \ \ \ \ \ \ \ \[aq]id\[aq]:\ video_id,
+\ \ \ \ \ \ \ \ \ \ \ \ \[aq]title\[aq]:\ title,
+\ \ \ \ \ \ \ \ \ \ \ \ \[aq]description\[aq]:\ self._og_search_description(webpage),
+\ \ \ \ \ \ \ \ \ \ \ \ \[aq]uploader\[aq]:\ self._search_regex(r\[aq]<div[^>]+id="uploader"[^>]*>([^<]+)<\[aq],\ webpage,\ \[aq]uploader\[aq],\ fatal=False),
+\ \ \ \ \ \ \ \ \ \ \ \ #\ TODO\ more\ properties\ (see\ youtube_dl/extractor/common.py)
+\ \ \ \ \ \ \ \ }
+\f[]
+.fi
+.RE
+.IP " 5." 4
+Add an import in
+\f[C]youtube_dl/extractor/extractors.py\f[] (https://github.com/rg3/youtube-dl/blob/master/youtube_dl/extractor/extractors.py).
+.IP " 6." 4
+Run
+\f[C]python\ test/test_download.py\ TestDownload.test_YourExtractor\f[].
+This \f[I]should fail\f[] at first, but you can continually re\-run it
+until you\[aq]re done.
+If you decide to add more than one test, then rename \f[C]_TEST\f[] to
+\f[C]_TESTS\f[] and make it into a list of dictionaries.
+The tests will then be named \f[C]TestDownload.test_YourExtractor\f[],
+\f[C]TestDownload.test_YourExtractor_1\f[],
+\f[C]TestDownload.test_YourExtractor_2\f[], etc.
+Note that tests with \f[C]only_matching\f[] key in test\[aq]s dict are
+not counted in.
+.IP " 7." 4
+Have a look at
+\f[C]youtube_dl/extractor/common.py\f[] (https://github.com/rg3/youtube-dl/blob/master/youtube_dl/extractor/common.py)
+for possible helper methods and a detailed description of what your
+extractor should and may
+return (https://github.com/rg3/youtube-dl/blob/master/youtube_dl/extractor/common.py#L74-L252).
+Add tests and code for as many as you want.
+.IP " 8." 4
+Make sure your code follows youtube\-dl coding
+conventions (#youtube-dl-coding-conventions) and check the code with
+flake8 (https://pypi.python.org/pypi/flake8).
+Also make sure your code works under all
+Python (https://www.python.org/) versions claimed supported by
+youtube\-dl, namely 2.6, 2.7, and 3.2+.
+.IP " 9." 4
+When the tests pass, add (https://git-scm.com/docs/git-add) the new
+files and commit (https://git-scm.com/docs/git-commit) them and
+push (https://git-scm.com/docs/git-push) the result, like this:
+.RS 4
+.IP
+.nf
+\f[C]
+$\ git\ add\ youtube_dl/extractor/extractors.py
+$\ git\ add\ youtube_dl/extractor/yourextractor.py
+$\ git\ commit\ \-m\ \[aq][yourextractor]\ Add\ new\ extractor\[aq]
+$\ git\ push\ origin\ yourextractor
+\f[]
+.fi
+.RE
+.IP "10." 4
+Finally, create a pull
+request (https://help.github.com/articles/creating-a-pull-request).
+We\[aq]ll then review and merge it.
+.PP
+In any case, thank you very much for your contributions!
+.SS youtube\-dl coding conventions
+.PP
+This section introduces a guide lines for writing idiomatic, robust and
+future\-proof extractor code.
+.PP
+Extractors are very fragile by nature since they depend on the layout of
+the source data provided by 3rd party media hosters out of your control
+and this layout tends to change.
+As an extractor implementer your task is not only to write code that
+will extract media links and metadata correctly but also to minimize
+dependency on the source\[aq]s layout and even to make the code foresee
+potential future changes and be ready for that.
+This is important because it will allow the extractor not to break on
+minor layout changes thus keeping old youtube\-dl versions working.
+Even though this breakage issue is easily fixed by emitting a new
+version of youtube\-dl with a fix incorporated, all the previous
+versions become broken in all repositories and distros\[aq] packages
+that may not be so prompt in fetching the update from us.
+Needless to say, some non rolling release distros may never receive an
+update at all.
+.SS Mandatory and optional metafields
+.PP
+For extraction to work youtube\-dl relies on metadata your extractor
+extracts and provides to youtube\-dl expressed by an information
+dictionary (https://github.com/rg3/youtube-dl/blob/master/youtube_dl/extractor/common.py#L75-L257)
+or simply \f[I]info dict\f[].
+Only the following meta fields in the \f[I]info dict\f[] are considered
+mandatory for a successful extraction process by youtube\-dl:
+.IP \[bu] 2
+\f[C]id\f[] (media identifier)
+.IP \[bu] 2
+\f[C]title\f[] (media title)
+.IP \[bu] 2
+\f[C]url\f[] (media download URL) or \f[C]formats\f[]
+.PP
+In fact only the last option is technically mandatory (i.e.
+if you can\[aq]t figure out the download location of the media the
+extraction does not make any sense).
+But by convention youtube\-dl also treats \f[C]id\f[] and \f[C]title\f[]
+as mandatory.
+Thus the aforementioned metafields are the critical data that the
+extraction does not make any sense without and if any of them fail to be
+extracted then the extractor is considered completely broken.
+.PP
+Any
+field (https://github.com/rg3/youtube-dl/blob/master/youtube_dl/extractor/common.py#L149-L257)
+apart from the aforementioned ones are considered \f[B]optional\f[].
+That means that extraction should be \f[B]tolerant\f[] to situations
+when sources for these fields can potentially be unavailable (even if
+they are always available at the moment) and \f[B]future\-proof\f[] in
+order not to break the extraction of general purpose mandatory fields.
+.SS Example
+.PP
+Say you have some source dictionary \f[C]meta\f[] that you\[aq]ve
+fetched as JSON with HTTP request and it has a key \f[C]summary\f[]:
+.IP
+.nf
+\f[C]
+meta\ =\ self._download_json(url,\ video_id)
+\f[]
+.fi
+.PP
+Assume at this point \f[C]meta\f[]\[aq]s layout is:
+.IP
+.nf
+\f[C]
+{
+\ \ \ \ ...
+\ \ \ \ "summary":\ "some\ fancy\ summary\ text",
+\ \ \ \ ...
+}
+\f[]
+.fi
+.PP
+Assume you want to extract \f[C]summary\f[] and put it into the
+resulting info dict as \f[C]description\f[].
+Since \f[C]description\f[] is an optional meta field you should be ready
+that this key may be missing from the \f[C]meta\f[] dict, so that you
+should extract it like:
+.IP
+.nf
+\f[C]
+description\ =\ meta.get(\[aq]summary\[aq])\ \ #\ correct
+\f[]
+.fi
+.PP
+and not like:
+.IP
+.nf
+\f[C]
+description\ =\ meta[\[aq]summary\[aq]]\ \ #\ incorrect
+\f[]
+.fi
+.PP
+The latter will break extraction process with \f[C]KeyError\f[] if
+\f[C]summary\f[] disappears from \f[C]meta\f[] at some later time but
+with the former approach extraction will just go ahead with
+\f[C]description\f[] set to \f[C]None\f[] which is perfectly fine
+(remember \f[C]None\f[] is equivalent to the absence of data).
+.PP
+Similarly, you should pass \f[C]fatal=False\f[] when extracting optional
+data from a webpage with \f[C]_search_regex\f[],
+\f[C]_html_search_regex\f[] or similar methods, for instance:
+.IP
+.nf
+\f[C]
+description\ =\ self._search_regex(
+\ \ \ \ r\[aq]<span[^>]+id="title"[^>]*>([^<]+)<\[aq],
+\ \ \ \ webpage,\ \[aq]description\[aq],\ fatal=False)
+\f[]
+.fi
+.PP
+With \f[C]fatal\f[] set to \f[C]False\f[] if \f[C]_search_regex\f[]
+fails to extract \f[C]description\f[] it will emit a warning and
+continue extraction.
+.PP
+You can also pass \f[C]default=<some\ fallback\ value>\f[], for example:
+.IP
+.nf
+\f[C]
+description\ =\ self._search_regex(
+\ \ \ \ r\[aq]<span[^>]+id="title"[^>]*>([^<]+)<\[aq],
+\ \ \ \ webpage,\ \[aq]description\[aq],\ default=None)
+\f[]
+.fi
+.PP
+On failure this code will silently continue the extraction with
+\f[C]description\f[] set to \f[C]None\f[].
+That is useful for metafields that may or may not be present.
+.SS Provide fallbacks
+.PP
+When extracting metadata try to do so from multiple sources.
+For example if \f[C]title\f[] is present in several places, try
+extracting from at least some of them.
+This makes it more future\-proof in case some of the sources become
+unavailable.
+.SS Example
+.PP
+Say \f[C]meta\f[] from the previous example has a \f[C]title\f[] and you
+are about to extract it.
+Since \f[C]title\f[] is a mandatory meta field you should end up with
+something like:
+.IP
+.nf
+\f[C]
+title\ =\ meta[\[aq]title\[aq]]
+\f[]
+.fi
+.PP
+If \f[C]title\f[] disappears from \f[C]meta\f[] in future due to some
+changes on the hoster\[aq]s side the extraction would fail since
+\f[C]title\f[] is mandatory.
+That\[aq]s expected.
+.PP
+Assume that you have some another source you can extract \f[C]title\f[]
+from, for example \f[C]og:title\f[] HTML meta of a \f[C]webpage\f[].
+In this case you can provide a fallback scenario:
+.IP
+.nf
+\f[C]
+title\ =\ meta.get(\[aq]title\[aq])\ or\ self._og_search_title(webpage)
+\f[]
+.fi
+.PP
+This code will try to extract from \f[C]meta\f[] first and if it fails
+it will try extracting \f[C]og:title\f[] from a \f[C]webpage\f[].
+.SS Make regular expressions flexible
+.PP
+When using regular expressions try to write them fuzzy and flexible.
+.SS Example
+.PP
+Say you need to extract \f[C]title\f[] from the following HTML code:
+.IP
+.nf
+\f[C]
+<span\ style="position:\ absolute;\ left:\ 910px;\ width:\ 90px;\ float:\ right;\ z\-index:\ 9999;"\ class="title">some\ fancy\ title</span>
+\f[]
+.fi
+.PP
+The code for that task should look similar to:
+.IP
+.nf
+\f[C]
+title\ =\ self._search_regex(
+\ \ \ \ r\[aq]<span[^>]+class="title"[^>]*>([^<]+)\[aq],\ webpage,\ \[aq]title\[aq])
+\f[]
+.fi
+.PP
+Or even better:
+.IP
+.nf
+\f[C]
+title\ =\ self._search_regex(
+\ \ \ \ r\[aq]<span[^>]+class=(["\\\[aq]])title\\1[^>]*>(?P<title>[^<]+)\[aq],
+\ \ \ \ webpage,\ \[aq]title\[aq],\ group=\[aq]title\[aq])
+\f[]
+.fi
+.PP
+Note how you tolerate potential changes in the \f[C]style\f[]
+attribute\[aq]s value or switch from using double quotes to single for
+\f[C]class\f[] attribute:
+.PP
+The code definitely should not look like:
+.IP
+.nf
+\f[C]
+title\ =\ self._search_regex(
+\ \ \ \ r\[aq]<span\ style="position:\ absolute;\ left:\ 910px;\ width:\ 90px;\ float:\ right;\ z\-index:\ 9999;"\ class="title">(.*?)</span>\[aq],
+\ \ \ \ webpage,\ \[aq]title\[aq],\ group=\[aq]title\[aq])
+\f[]
+.fi
+.SS Use safe conversion functions
+.PP
+Wrap all extracted numeric data into safe functions from \f[C]utils\f[]:
+\f[C]int_or_none\f[], \f[C]float_or_none\f[].
+Use them for string to number conversions as well.
+.SH EMBEDDING YOUTUBE\-DL
+.PP
+youtube\-dl makes the best effort to be a good command\-line program,
+and thus should be callable from any programming language.
+If you encounter any problems parsing its output, feel free to create a
+report (https://github.com/rg3/youtube-dl/issues/new).
+.PP
+From a Python program, you can embed youtube\-dl in a more powerful
+fashion, like this:
+.IP
+.nf
+\f[C]
+from\ __future__\ import\ unicode_literals
+import\ youtube_dl
+
+ydl_opts\ =\ {}
+with\ youtube_dl.YoutubeDL(ydl_opts)\ as\ ydl:
+\ \ \ \ ydl.download([\[aq]https://www.youtube.com/watch?v=BaW_jenozKc\[aq]])
+\f[]
+.fi
+.PP
+Most likely, you\[aq]ll want to use various options.
+For a list of options available, have a look at
+\f[C]youtube_dl/YoutubeDL.py\f[] (https://github.com/rg3/youtube-dl/blob/3e4cedf9e8cd3157df2457df7274d0c842421945/youtube_dl/YoutubeDL.py#L137-L312).
+For a start, if you want to intercept youtube\-dl\[aq]s output, set a
+\f[C]logger\f[] object.
+.PP
+Here\[aq]s a more complete example of a program that outputs only errors
+(and a short message after the download is finished), and
+downloads/converts the video to an mp3 file:
+.IP
+.nf
+\f[C]
+from\ __future__\ import\ unicode_literals
+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[\[aq]status\[aq]]\ ==\ \[aq]finished\[aq]:
+\ \ \ \ \ \ \ \ print(\[aq]Done\ downloading,\ now\ converting\ ...\[aq])
+
+
+ydl_opts\ =\ {
+\ \ \ \ \[aq]format\[aq]:\ \[aq]bestaudio/best\[aq],
+\ \ \ \ \[aq]postprocessors\[aq]:\ [{
+\ \ \ \ \ \ \ \ \[aq]key\[aq]:\ \[aq]FFmpegExtractAudio\[aq],
+\ \ \ \ \ \ \ \ \[aq]preferredcodec\[aq]:\ \[aq]mp3\[aq],
+\ \ \ \ \ \ \ \ \[aq]preferredquality\[aq]:\ \[aq]192\[aq],
+\ \ \ \ }],
+\ \ \ \ \[aq]logger\[aq]:\ MyLogger(),
+\ \ \ \ \[aq]progress_hooks\[aq]:\ [my_hook],
+}
+with\ youtube_dl.YoutubeDL(ydl_opts)\ as\ ydl:
+\ \ \ \ ydl.download([\[aq]https://www.youtube.com/watch?v=BaW_jenozKc\[aq]])
+\f[]
+.fi
Rapsys Git / youtubedl / blobdiff