[fd] Support `available_at` format field

Authored by: bashonly

yt_dlp/YoutubeDL.py

@@ -599,7 +599,7 @@ class YoutubeDL:
     _NUMERIC_FIELDS = {
         'width', 'height', 'asr', 'audio_channels', 'fps',
         'tbr', 'abr', 'vbr', 'filesize', 'filesize_approx',
-        'timestamp', 'release_timestamp',
+        'timestamp', 'release_timestamp', 'available_at',
         'duration', 'view_count', 'like_count', 'dislike_count', 'repost_count',
         'average_rating', 'comment_count', 'age_limit',
         'start_time', 'end_time',
@@ -609,7 +609,7 @@ class YoutubeDL:
 
     _format_fields = {
         # NB: Keep in sync with the docstring of extractor/common.py
-        'url', 'manifest_url', 'manifest_stream_number', 'ext', 'format', 'format_id', 'format_note',
+        'url', 'manifest_url', 'manifest_stream_number', 'ext', 'format', 'format_id', 'format_note', 'available_at',
         'width', 'height', 'aspect_ratio', 'resolution', 'dynamic_range', 'tbr', 'abr', 'acodec', 'asr', 'audio_channels',
         'vbr', 'fps', 'vcodec', 'container', 'filesize', 'filesize_approx', 'rows', 'columns', 'hls_media_playlist_data',
         'player_url', 'protocol', 'fragment_base_url', 'fragments', 'is_from_start', 'is_dash_periods', 'request_data',

yt_dlp/downloader/common.py

@@ -455,14 +455,26 @@ class FileDownloader:
                 self._finish_multiline_status()
                 return True, False
 
+        sleep_note = ''
         if subtitle:
             sleep_interval = self.params.get('sleep_interval_subtitles') or 0
         else:
             min_sleep_interval = self.params.get('sleep_interval') or 0
+            max_sleep_interval = self.params.get('max_sleep_interval') or 0
+
+            if available_at := info_dict.get('available_at'):
+                forced_sleep_interval = available_at - int(time.time())
+                if forced_sleep_interval > min_sleep_interval:
+                    sleep_note = 'as required by the site'
+                    min_sleep_interval = forced_sleep_interval
+                if forced_sleep_interval > max_sleep_interval:
+                    max_sleep_interval = forced_sleep_interval
+
             sleep_interval = random.uniform(
-                min_sleep_interval, self.params.get('max_sleep_interval') or min_sleep_interval)
+                min_sleep_interval, max_sleep_interval or min_sleep_interval)
+
         if sleep_interval > 0:
-            self.to_screen(f'[download] Sleeping {sleep_interval:.2f} seconds ...')
+            self.to_screen(f'[download] Sleeping {sleep_interval:.2f} seconds {sleep_note}...')
             time.sleep(sleep_interval)
 
         ret = self.real_download(filename, info_dict)

yt_dlp/extractor/common.py

@@ -263,6 +263,7 @@ class InfoExtractor:
                                 * a string in the format of CLIENT[:OS]
                                 * a list or a tuple of CLIENT[:OS] strings or ImpersonateTarget instances
                                 * a boolean value; True means any impersonate target is sufficient
+                    * available_at  Unix timestamp of when a format will be available to download
                     * downloader_options  A dictionary of downloader options
                                  (For internal use only)
                                  * http_chunk_size Chunk size for HTTP downloads