From f93fdcbc068c57d17815a1e8c7192f7d45be07f6 Mon Sep 17 00:00:00 2001
From: Simon Sawicki <contact@grub4k.xyz>
Date: Sun, 6 Apr 2025 16:24:48 +0200
Subject: [PATCH] Add preset alias help output

---
 yt_dlp/options.py | 39 ++++++++++++++++++++++++++++-----------
 1 file changed, 28 insertions(+), 11 deletions(-)

diff --git a/yt_dlp/options.py b/yt_dlp/options.py
index 5569837786..efddb6e0d0 100644
--- a/yt_dlp/options.py
+++ b/yt_dlp/options.py
@@ -150,6 +150,15 @@ class _YoutubeDLHelpFormatter(optparse.IndentedHelpFormatter):
         return opts
 
 
+_PRESET_ALIASES = {
+    'mp3': ['-f', 'ba[acodec=mp3]/ba/b', '-x', '--audio-format', 'mp3'],
+    'aac': ['-f', 'ba[acodec*=aac]/ba[acodec^=mp4a.40.]/ba/b', '-x', '--audio-format', 'aac'],
+    'mp4': ['--merge-output-format', 'mp4', '--remux', 'mp4', '-S', 'vcodec:h264,lang,quality,res,fps,hdr:12,acodec:aac'],
+    'mkv': ['--merge-output-format', 'mkv', '--remux', 'mkv'],
+    'embed': ['--embed-subs', '--embed-thumbnail', '--embed-metadata'],
+}
+
+
 class _YoutubeDLOptionParser(optparse.OptionParser):
     # optparse is deprecated since Python 3.2. So assume a stable interface even for private methods
     ALIAS_DEST = '_triggered_aliases'
@@ -215,6 +224,21 @@ class _YoutubeDLOptionParser(optparse.OptionParser):
                 return e.possibilities[0]
             raise
 
+    def format_option_help(self, formatter=None):
+        assert formatter, ''
+        formatted_help = super().format_option_help(formatter=formatter)
+        formatter.indent()
+        heading = formatter.format_heading('Preset aliases')
+        formatter.indent()
+        result = []
+        for name, args in _PRESET_ALIASES.items():
+            option = optparse.Option('-t', help=shlex.join(args))
+            formatter.option_strings[option] = f'-t {name}'
+            result.append(formatter.format_option(option))
+        formatter.dedent()
+        formatter.dedent()
+        return f'{formatted_help}\n{heading}{"\n".join(result)}'
+
 
 def create_parser():
     def _list_from_options_callback(option, opt_str, value, parser, append=True, delim=',', process=str.strip):
@@ -317,20 +341,12 @@ def create_parser():
         parser.rargs[:0] = shlex.split(
             opts if value is None else opts.format(*map(shlex.quote, value)))
 
-    PRESET_ALIASES = {
-        'mp3': ['-f', 'ba[acodec=mp3]/ba/b', '-x', '--audio-format', 'mp3'],
-        'aac': ['-f', 'ba[acodec*=aac]/ba[acodec^=mp4a.40.]/ba/b', '-x', '--audio-format', 'aac'],
-        'mp4': ['--merge-output-format', 'mp4', '--remux', 'mp4', '-S', 'vcodec:h264,lang,quality,res,fps,hdr:12,acodec:aac'],
-        'mkv': ['--merge-output-format', 'mkv', '--remux', 'mkv'],
-        'embed': ['--embed-subs', '--embed-thumbnail', '--embed-metadata'],
-    }
-
     def _preset_alias_callback(option, opt_str, value, parser):
         if not value:
             return
-        if value not in PRESET_ALIASES:
+        if value not in _PRESET_ALIASES:
             raise optparse.OptionValueError(f'Unknown preset alias: {value}')
-        parser.rargs[:0] = PRESET_ALIASES[value]
+        parser.rargs[:0] = _PRESET_ALIASES[value]
 
     general = optparse.OptionGroup(parser, 'General Options')
     general.add_option(
@@ -539,7 +555,8 @@ def create_parser():
         action='callback', callback=_preset_alias_callback,
         help=(
             'Applies a predefined preset. e.g. --preset-alias mp3. '
-            f'The following presets are available: {", ".join(PRESET_ALIASES)}. '
+            f'The following presets are available: {", ".join(_PRESET_ALIASES)}. '
+            'See the "Preset aliases" section at the end for more infos. '
             'This option can be used multiple times.'))
 
     network = optparse.OptionGroup(parser, 'Network Options')