will download the best quality format with the webm extension served as
a single file.
-You can also use special names to select particular edge case formats: -
-best: Select the best quality format represented by a single file with
-video and audio. - worst: Select the worst quality format represented by
-a single file with video and audio. - bestvideo: Select the best quality
-video-only format (e.g. DASH video). May not be available. - worstvideo:
-Select the worst quality video-only format. May not be available. -
-bestaudio: Select the best quality audio only-format. May not be
-available. - worstaudio: Select the worst quality audio only-format. May
-not be available.
+You can also use special names to select particular edge case formats:
+
+- best: Select the best quality format represented by a single file
+ with video and audio.
+- worst: Select the worst quality format represented by a single file
+ with video and audio.
+- bestvideo: Select the best quality video-only format (e.g. DASH
+ video). May not be available.
+- worstvideo: Select the worst quality video-only format. May not be
+ available.
+- bestaudio: Select the best quality audio only-format. May not be
+ available.
+- worstaudio: Select the worst quality audio only-format. May not be
+ available.
For example, to download the worst quality video-only format you can use
-f worstvideo.
brackets, as in -f "best[height=720]" (or -f "[filesize>10M]").
The following numeric meta fields can be used with comparisons <, <=, >,
->=, = (equals), != (not equals): - filesize: The number of bytes, if
-known in advance - width: Width of the video, if known - height: Height
-of the video, if known - tbr: Average bitrate of audio and video in
-KBit/s - abr: Average audio bitrate in KBit/s - vbr: Average video
-bitrate in KBit/s - asr: Audio sampling rate in Hertz - fps: Frame rate
-
-Also filtering work for comparisons = (equals), != (not equals), ^=
-(begins with), $= (ends with), *= (contains) and following string meta
-fields: - ext: File extension - acodec: Name of the audio codec in use -
-vcodec: Name of the video codec in use - container: Name of the
-container format - protocol: The protocol that will be used for the
-actual download, lower-case (http, https, rtsp, rtmp, rtmpe, mms, f4m,
-ism, http_dash_segments, m3u8, or m3u8_native) - format_id: A short
-description of the format
+>=, = (equals), != (not equals):
+
+- filesize: The number of bytes, if known in advance
+- width: Width of the video, if known
+- height: Height of the video, if known
+- tbr: Average bitrate of audio and video in KBit/s
+- abr: Average audio bitrate in KBit/s
+- vbr: Average video bitrate in KBit/s
+- asr: Audio sampling rate in Hertz
+- fps: Frame rate
+
+Also filtering work for comparisons = (equals), ^= (starts with), $=
+(ends with), *= (contains) and following string meta fields:
+
+- ext: File extension
+- acodec: Name of the audio codec in use
+- vcodec: Name of the video codec in use
+- container: Name of the container format
+- protocol: The protocol that will be used for the actual download,
+ lower-case (http, https, rtsp, rtmp, rtmpe, mms, f4m, ism,
+ http_dash_segments, m3u8, or m3u8_native)
+- format_id: A short description of the format
+
+Any string comparison may be prefixed with negation ! in order to
+produce an opposite comparison, e.g. !*= (does not contain).
Note that none of the aforementioned meta fields are guaranteed to be
present since this solely depends on the metadata obtained by particular
# Download best mp4 format available or any other best if no mp4 available
$ youtube-dl -f 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/best[ext=mp4]/best'
- # Download best format available but not better that 480p
+ # Download best format available but no better than 480p
$ youtube-dl -f 'bestvideo[height<=480]+bestaudio/best[height<=480]'
# Download best video only format but no bigger than 50 MB
'https://www.youtube.com/watch?v=FqZTN594JQw&list='
'PLMYEtVRpaqY00V9W81Cwmzp6N6vZqfUKD4'
-Use safe conversion functions
+Inline values
+
+Extracting variables is acceptable for reducing code duplication and
+improving readability of complex expressions. However, you should avoid
+extracting variables used only once and moving them to opposite parts of
+the extractor file, which makes reading the linear flow difficult.
+
+Example
+
+Correct:
+
+ title = self._html_search_regex(r'<title>([^<]+)</title>', webpage, 'title')
+
+Incorrect:
+
+ TITLE_RE = r'<title>([^<]+)</title>'
+ # ...some lines of code...
+ title = self._html_search_regex(TITLE_RE, webpage, 'title')
+
+Collapse fallbacks
+
+Multiple fallback values can quickly become unwieldy. Collapse multiple
+fallback values into a single expression via a list of patterns.
+
+Example
+
+Good:
+
+ description = self._html_search_meta(
+ ['og:description', 'description', 'twitter:description'],
+ webpage, 'description', default=None)
+
+Unwieldy:
+
+ description = (
+ self._og_search_description(webpage, default=None)
+ or self._html_search_meta('description', webpage, default=None)
+ or self._html_search_meta('twitter:description', webpage, default=None))
+
+Methods supporting list of patterns are: _search_regex,
+_html_search_regex, _og_search_property, _html_search_meta.
+
+Trailing parentheses
+
+Always move trailing parentheses after the last argument.
+
+Example
+
+Correct:
+
+ lambda x: x['ResultSet']['Result'][0]['VideoUrlSet']['VideoUrl'],
+ list)
+
+Incorrect:
+
+ lambda x: x['ResultSet']['Result'][0]['VideoUrlSet']['VideoUrl'],
+ list,
+ )
+
+Use convenience conversion and parsing functions
Wrap all extracted numeric data into safe functions from
youtube_dl/utils.py: int_or_none, float_or_none. Use them for string to
Use try_get for safe metadata extraction from parsed JSON.
+Use unified_strdate for uniform upload_date or any YYYYMMDD meta field
+extraction, unified_timestamp for uniform timestamp extraction,
+parse_filesize for filesize extraction, parse_count for count meta
+fields extraction, parse_resolution, parse_duration for duration
+extraction, parse_age_limit for age_limit extraction.
+
Explore youtube_dl/utils.py for more useful convenience functions.
More examples
Bugs and suggestions should be reported at:
-https://github.com/rg3/youtube-dl/issues. Unless you were prompted to or
-there is another pertinent reason (e.g. GitHub fails to accept the bug
-report), please do not send bug reports via personal email. For
+https://github.com/ytdl-org/youtube-dl/issues. Unless you were prompted
+to or there is another pertinent reason (e.g. GitHub fails to accept the
+bug report), please do not send bug reports via personal email. For
discussions, join us in the IRC channel #youtube-dl on freenode
(webchat).