[doc] Minor improvements

Closes #3518, Closes #3560

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,28 +1,29 @@
-## Please follow the guide below
+<!--
+# Please follow the guide below
 
 - You will be asked some questions, please read them **carefully** and answer honestly
-- Put an `x` into all the boxes [ ] relevant to your *pull request* (like that [x])
+- Put an `x` into all the boxes `[ ]` relevant to your *pull request* (like [x])
 - Use *Preview* tab to see how your *pull request* will actually look like
 
----
+-->
 
 ### Before submitting a *pull request* make sure you have:
 - [ ] At least skimmed through [contributing guidelines](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#developer-instructions) including [yt-dlp coding conventions](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#yt-dlp-coding-conventions)
 - [ ] [Searched](https://github.com/yt-dlp/yt-dlp/search?q=is%3Apr&type=Issues) the bugtracker for similar pull requests
-- [ ] Checked the code with [flake8](https://pypi.python.org/pypi/flake8)
+- [ ] Checked the code with [flake8](https://pypi.python.org/pypi/flake8) and [ran relevant tests](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#developer-instructions)
 
 ### In order to be accepted and merged into yt-dlp each piece of code must be in public domain or released under [Unlicense](http://unlicense.org/). Check one of the following options:
 - [ ] I am the original author of this code and I am willing to release it under [Unlicense](http://unlicense.org/)
 - [ ] I am not the original author of this code but it is in public domain or released under [Unlicense](http://unlicense.org/) (provide reliable evidence)
 
 ### What is the purpose of your *pull request*?
-- [ ] Bug fix
+- [ ] Fix or improvement to an extractor (Make sure to add/update tests)
-- [ ] Improvement
+- [ ] New extractor ([Piracy websites will not be accepted](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#is-the-website-primarily-used-for-piracy))
-- [ ] New extractor
+- [ ] Core bug fix/improvement
-- [ ] New feature
+- [ ] New feature (It is strongly [recommended to open an issue first](https://github.com/yt-dlp/yt-dlp/blob/master/CONTRIBUTING.md#adding-new-feature-or-making-overarching-changes))
 
 ---
 
 ### Description of your *pull request* and other information
 
-Explanation of your *pull request* in arbitrary form goes here. Please make sure the description explains the purpose and effect of your *pull request* and is worded well enough to be understood. Provide as much context and examples as possible.
+Explanation of your *pull request* in arbitrary form goes here. Please **make sure the description explains the purpose and effect** of your *pull request* and is worded well enough to be understood. Provide as much **context and examples** as possible.

README.md

@@ -270,7 +270,7 @@ ## DEPENDENCIES
 * [**mutagen**](https://github.com/quodlibet/mutagen)\* - For embedding thumbnail in certain formats. Licensed under [GPLv2+](https://github.com/quodlibet/mutagen/blob/master/COPYING)
 * [**pycryptodomex**](https://github.com/Legrandin/pycryptodome)\* - For decrypting AES-128 HLS streams and various other data. Licensed under [BSD-2-Clause](https://github.com/Legrandin/pycryptodome/blob/master/LICENSE.rst)
 * [**websockets**](https://github.com/aaugustin/websockets)\* - For downloading over websocket. Licensed under [BSD-3-Clause](https://github.com/aaugustin/websockets/blob/main/LICENSE)
-* [**secretstorage**](https://github.com/mitya57/secretstorage)\* - For accessing the Gnome keyring while decrypting cookies of Chromium-based browsers on Linux. Licensed under [BSD-3-Clause](https://github.com/mitya57/secretstorage/blob/master/LICENSE)
+* [**secretstorage**](https://github.com/mitya57/secretstorage) - For accessing the Gnome keyring while decrypting cookies of Chromium-based browsers on Linux. Licensed under [BSD-3-Clause](https://github.com/mitya57/secretstorage/blob/master/LICENSE)
 * [**brotli**](https://github.com/google/brotli)\* or [**brotlicffi**](https://github.com/python-hyper/brotlicffi) - [Brotli](https://en.wikipedia.org/wiki/Brotli) content encoding support. Both licensed under MIT <sup>[1](https://github.com/google/brotli/blob/master/LICENSE) [2](https://github.com/python-hyper/brotlicffi/blob/master/LICENSE) </sup>
 * [**certifi**](https://github.com/certifi/python-certifi)\* - Provides Mozilla's root certificate bundle. Licensed under [MPLv2](https://github.com/certifi/python-certifi/blob/master/LICENSE)
 * [**AtomicParsley**](https://github.com/wez/atomicparsley) - For embedding thumbnail in mp4/m4a if mutagen/ffmpeg cannot. Licensed under [GPLv2+](https://github.com/wez/atomicparsley/blob/master/COPYING)
@@ -282,7 +282,7 @@ ## DEPENDENCIES
 
 To use or redistribute the dependencies, you must agree to their respective licensing terms.
 
-The Windows and MacOS standalone release binaries are already built with the python interpreter and all optional python packages (marked with \*) included.
+The Windows and MacOS standalone release binaries are built with the Python interpreter and the packages marked with \* included.
 
 <!-- TODO: ffmpeg has merged this patch. Remove this note once there is new release -->
 **Note**: There are some regressions in newer ffmpeg versions that causes various issues when used alongside yt-dlp. Since ffmpeg is such an important dependency, we provide [custom builds](https://github.com/yt-dlp/FFmpeg-Builds#ffmpeg-static-auto-builds) with patches for these issues at [yt-dlp/FFmpeg-Builds](https://github.com/yt-dlp/FFmpeg-Builds). See [the readme](https://github.com/yt-dlp/FFmpeg-Builds#patches-applied) for details on the specific issues solved by these builds
@@ -533,10 +533,10 @@ ## Download Options:
                                      (http, ftp, m3u8, dash, rstp, rtmp, mms) to
                                      use it for. Currently supports native,
                                      aria2c, avconv, axel, curl, ffmpeg, httpie,
-                                     wget (Recommended: aria2c). You can use
+                                     wget. You can use this option multiple
-                                     this option multiple times to set different
+                                     times to set different downloaders for
-                                     downloaders for different protocols. For
+                                     different protocols. For example,
-                                     example, --downloader aria2c --downloader
+                                     --downloader aria2c --downloader
                                      "dash,m3u8:native" will use aria2c for
                                      http/ftp downloads, and the native
                                      downloader for dash/m3u8 downloads (Alias:
@@ -1801,7 +1801,7 @@ #### Extract audio
 URLS = ['https://www.youtube.com/watch?v=BaW_jenozKc']
 
 ydl_opts = {
-    'format': 'm4a/bestaudio/best'
+    'format': 'm4a/bestaudio/best',
     # ℹ️ See help(yt_dlp.postprocessor) for a list of available Postprocessors and their arguments
     'postprocessors': [{  # Extract audio using ffmpeg
         'key': 'FFmpegExtractAudio',
@@ -1812,6 +1812,28 @@ #### Extract audio
 with yt_dlp.YoutubeDL(ydl_opts) as ydl:
     error_code = ydl.download(URLS)
 ```
+
+#### Filter videos
+
+```python
+import yt_dlp
+
+URLS = ['https://www.youtube.com/watch?v=BaW_jenozKc']
+
+def longer_than_a_minute(info, *, incomplete):
+    """Download only videos longer than a minute (or with unknown duration)"""
+    duration = info.get('duration')
+    if duration and duration < 60:
+        return 'The video is too short'
+
+ydl_opts = {
+    'match_filter': longer_than_a_minute,
+}
+
+with yt_dlp.YoutubeDL(ydl_opts) as ydl:
+    error_code = ydl.download(URLS)
+```
+
 #### Adding logger and progress hook
 
 ```python

setup.py

@@ -127,7 +127,7 @@ def run(self):
     packages=packages,
     install_requires=REQUIREMENTS,
     project_urls={
-        'Documentation': 'https://yt-dlp.readthedocs.io',
+        'Documentation': 'https://github.com/yt-dlp/yt-dlp#readme',
         'Source': 'https://github.com/yt-dlp/yt-dlp',
         'Tracker': 'https://github.com/yt-dlp/yt-dlp/issues',
         'Funding': 'https://github.com/yt-dlp/yt-dlp/blob/master/Collaborators.md#collaborators',

yt_dlp/YoutubeDL.py

@@ -409,12 +409,14 @@ class YoutubeDL:
     sleep_interval_subtitles: Number of seconds to sleep before each subtitle download
     listformats:       Print an overview of available video formats and exit.
     list_thumbnails:   Print a table of all thumbnails and exit.
-    match_filter:      A function that gets called with the info_dict of
+    match_filter:      A function that gets called for every video with the signature
-                       every video.
+                       (info_dict, *, incomplete: bool) -> Optional[str]
-                       If it returns a message, the video is ignored.
+                       For backward compatibility with youtube-dl, the signature
-                       If it returns None, the video is downloaded.
+                       (info_dict) -> Optional[str] is also allowed.
-                       If it returns utils.NO_DEFAULT, the user is interactively
+                       - If it returns a message, the video is ignored.
-                       asked whether to download the video.
+                       - If it returns None, the video is downloaded.
+                       - If it returns utils.NO_DEFAULT, the user is interactively
+                         asked whether to download the video.
                        match_filter_func in utils.py is one example for this.
     no_color:          Do not emit color codes in output.
     geo_bypass:        Bypass geographic restriction via faking X-Forwarded-For

yt_dlp/extractor/youtube.py

@@ -287,7 +287,7 @@ class YoutubeBaseInfoExtractor(InfoExtractor):
         # invidious-redirect websites
         r'(?:www\.)?redirect\.invidious\.io',
         r'(?:(?:www|dev)\.)?invidio\.us',
-        # Invidious instances taken from https://github.com/iv-org/documentation/blob/master/Invidious-Instances.md
+        # Invidious instances taken from https://github.com/iv-org/documentation/blob/master/docs/instances.md
         r'(?:www\.)?invidious\.pussthecat\.org',
         r'(?:www\.)?invidious\.zee\.li',
         r'(?:www\.)?invidious\.ethibox\.fr',

yt_dlp/options.py

@@ -814,11 +814,11 @@ def _dict_from_options_callback(
         }, help=(
             'Name or path of the external downloader to use (optionally) prefixed by '
             'the protocols (http, ftp, m3u8, dash, rstp, rtmp, mms) to use it for. '
-            'Currently supports native, %s (Recommended: aria2c). '
+            f'Currently supports native, {", ".join(list_external_downloaders())}. '
             'You can use this option multiple times to set different downloaders for different protocols. '
             'For example, --downloader aria2c --downloader "dash,m3u8:native" will use '
             'aria2c for http/ftp downloads, and the native downloader for dash/m3u8 downloads '
-            '(Alias: --external-downloader)' % ', '.join(list_external_downloaders())))
+            '(Alias: --external-downloader)'))
     downloader.add_option(
         '--downloader-args', '--external-downloader-args',
         metavar='NAME:ARGS', dest='external_downloader_args', default={}, type='str',