Added --autonumber-start [number] option

youtube_dl/YoutubeDL.py

@@ -578,10 +578,13 @@ class YoutubeDL(object):
 
             template_dict['epoch'] = int(time.time())
             autonumber_size = self.params.get('autonumber_size')
+            autonumber_start = self.params.get('autonumber_start')
             if autonumber_size is None:
                 autonumber_size = 5
+            if autonumber_start is None or autonumber_start < 1:
+                autonumber_start = 1
             autonumber_templ = '%0' + str(autonumber_size) + 'd'
-            template_dict['autonumber'] = autonumber_templ % self._num_downloads
+            template_dict['autonumber'] = autonumber_templ % (self._num_downloads + int(autonumber_start)-1)
             if template_dict.get('playlist_index') is not None:
                 template_dict['playlist_index'] = '%0*d' % (len(str(template_dict['n_entries'])), template_dict['playlist_index'])
             if template_dict.get('resolution') is None:

youtube_dl/__init__.py

@@ -311,6 +311,7 @@ def _real_main(argv=None):
         'listformats': opts.listformats,
         'outtmpl': outtmpl,
         'autonumber_size': opts.autonumber_size,
+        'autonumber_start': opts.autonumber_start,
         'restrictfilenames': opts.restrictfilenames,
         'ignoreerrors': opts.ignoreerrors,
         'force_generic_extractor': opts.force_generic_extractor,

youtube_dl/options.py

@@ -633,6 +633,10 @@ def parseOpts(overrideArguments=None):
         '--autonumber-size',
         dest='autonumber_size', metavar='NUMBER',
         help='Specify the number of digits in %(autonumber)s when it is present in output filename template or --auto-number option is given')
+    filesystem.add_option(
+        '--autonumber-start',
+        dest='autonumber_start', metavar='NUMBER', default=0,
+        help='Starts %(autonumber)s at the passed number (positive numbers only).')
     filesystem.add_option(
         '--restrict-filenames',
         action='store_true', dest='restrictfilenames', default=False,
@@ -700,6 +704,7 @@ def parseOpts(overrideArguments=None):
         action='store_true', dest='rm_cachedir',
         help='Delete all filesystem cache files')
 
+
     thumbnail = optparse.OptionGroup(parser, 'Thumbnail images')
     thumbnail.add_option(
         '--write-thumbnail',