Add option --throttled-rate below which video data is re-extracted

Currently only for HTTP downloads

Closes #430, workaround for https://github.com/ytdl-org/youtube-dl/issues/29326

yt_dlp/downloader/http.py

@@ -18,6 +18,7 @@ from ..utils import (
     int_or_none,
     sanitize_open,
     sanitized_Request,
+    ThrottledDownload,
     write_xattr,
     XAttrMetadataError,
     XAttrUnavailableError,
@@ -223,6 +224,7 @@ class HttpFD(FileDownloader):
             # measure time over whole while-loop, so slow_down() and best_block_size() work together properly
             now = None  # needed for slow_down() in the first loop run
             before = start  # start measuring
+            throttle_start = None
 
             def retry(e):
                 to_stdout = ctx.tmpfilename == '-'
@@ -313,6 +315,18 @@ class HttpFD(FileDownloader):
                 if data_len is not None and byte_counter == data_len:
                     break
 
+                if speed and speed < (self.params.get('throttledratelimit') or 0):
+                    # The speed must stay below the limit for 3 seconds
+                    # This prevents raising error when the speed temporarily goes down
+                    if throttle_start is None:
+                        throttle_start = now
+                    elif now - throttle_start > 3:
+                        if ctx.stream is not None and ctx.tmpfilename != '-':
+                            ctx.stream.close()
+                        raise ThrottledDownload()
+                else:
+                    throttle_start = None
+
             if not is_test and ctx.chunk_size and ctx.data_len is not None and byte_counter < ctx.data_len:
                 ctx.resume_len = byte_counter
                 # ctx.block_size = block_size