def _append_fragment(self, ctx, frag_content):
         try:
             ctx['dest_stream'].write(frag_content)
+            ctx['dest_stream'].flush()
         finally:
             if self.__do_ytdl_file(ctx):
                 self._write_ytdl_file(ctx)
             if not self.params.get('keep_fragments', False):
-                os.remove(ctx['fragment_filename_sanitized'])
+                os.remove(encodeFilename(ctx['fragment_filename_sanitized']))
             del ctx['fragment_filename_sanitized']
 
     def _prepare_frag_download(self, ctx):
             if os.path.isfile(encodeFilename(self.ytdl_filename(ctx['filename']))):
                 self._read_ytdl_file(ctx)
                 if ctx['fragment_index'] > 0 and resume_len == 0:
-                    self.report_error(
+                    self.report_warning(
                         'Inconsistent state of incomplete fragment download. '
                         'Restarting from the beginning...')
                     ctx['fragment_index'] = resume_len = 0
             if os.path.isfile(ytdl_filename):
                 os.remove(ytdl_filename)
         elapsed = time.time() - ctx['started']
-        self.try_rename(ctx['tmpfilename'], ctx['filename'])
-        fsize = os.path.getsize(encodeFilename(ctx['filename']))
+
+        if ctx['tmpfilename'] == '-':
+            downloaded_bytes = ctx['complete_frags_downloaded_bytes']
+        else:
+            self.try_rename(ctx['tmpfilename'], ctx['filename'])
+            downloaded_bytes = os.path.getsize(encodeFilename(ctx['filename']))
 
         self._hook_progress({
-            'downloaded_bytes': fsize,
-            'total_bytes': fsize,
+            'downloaded_bytes': downloaded_bytes,
+            'total_bytes': downloaded_bytes,
             'filename': ctx['filename'],
             'status': 'finished',
             'elapsed': elapsed,