diff --git a/youtube_dl/extractor/firedrive.py b/youtube_dl/extractor/firedrive.py
index d26145db1..6d73c8a4a 100644
--- a/youtube_dl/extractor/firedrive.py
+++ b/youtube_dl/extractor/firedrive.py
@@ -8,7 +8,6 @@ from ..utils import (
     ExtractorError,
     compat_urllib_parse,
     compat_urllib_request,
-    determine_ext,
 )
 
 
diff --git a/youtube_dl/extractor/livestream.py b/youtube_dl/extractor/livestream.py
index 2c100d424..1ea1bbab4 100644
--- a/youtube_dl/extractor/livestream.py
+++ b/youtube_dl/extractor/livestream.py
@@ -28,11 +28,13 @@ class LivestreamIE(InfoExtractor):
     }
 
     def _extract_video_info(self, video_data):
-        video_url = video_data.get('progressive_url_hd') or video_data.get('progressive_url')
+        video_url = (
+            video_data.get('progressive_url_hd') or
+            video_data.get('progressive_url')
+        )
         return {
             'id': compat_str(video_data['id']),
             'url': video_url,
-            'ext': 'mp4',
             'title': video_data['caption'],
             'thumbnail': video_data['thumbnail_url'],
             'upload_date': video_data['updated_at'].replace('-', '')[:8],
@@ -50,7 +52,8 @@ class LivestreamIE(InfoExtractor):
                 r'window.config = ({.*?});', webpage, 'window config')
             info = json.loads(config_json)['event']
             videos = [self._extract_video_info(video_data['data'])
-                for video_data in info['feed']['data'] if video_data['type'] == 'video']
+                for video_data in info['feed']['data']
+                if video_data['type'] == 'video']
             return self.playlist_result(videos, info['id'], info['full_name'])
         else:
             og_video = self._og_search_video_url(webpage, 'player url')
diff --git a/youtube_dl/extractor/tenplay.py b/youtube_dl/extractor/tenplay.py
index 8477840fc..81ba169fb 100644
--- a/youtube_dl/extractor/tenplay.py
+++ b/youtube_dl/extractor/tenplay.py
@@ -1,8 +1,6 @@
 # coding: utf-8
 from __future__ import unicode_literals
 
-import re
-
 from .common import InfoExtractor
 
 
diff --git a/youtube_dl/extractor/youtube.py b/youtube_dl/extractor/youtube.py
index 071aa7519..072e711c2 100644
--- a/youtube_dl/extractor/youtube.py
+++ b/youtube_dl/extractor/youtube.py
@@ -1,15 +1,12 @@
 # coding: utf-8
 
-import collections
 import errno
 import io
 import itertools
 import json
 import os.path
 import re
-import struct
 import traceback
-import zlib
 
 from .common import InfoExtractor, SearchInfoExtractor
 from .subtitles import SubtitlesInfoExtractor
diff --git a/youtube_dl/swfinterp.py b/youtube_dl/swfinterp.py
index 79d86152d..b63c65b20 100644
--- a/youtube_dl/swfinterp.py
+++ b/youtube_dl/swfinterp.py
@@ -2,12 +2,12 @@ from __future__ import unicode_literals
 
 import collections
 import io
-import struct
 import zlib
 
 from .utils import (
     compat_str,
     ExtractorError,
+    struct_unpack,
 )
 
 
@@ -23,17 +23,17 @@ def _extract_tags(file_contents):
             file_contents[:1])
 
     # Determine number of bits in framesize rectangle
-    framesize_nbits = struct.unpack('!B', content[:1])[0] >> 3
+    framesize_nbits = struct_unpack('!B', content[:1])[0] >> 3
     framesize_len = (5 + 4 * framesize_nbits + 7) // 8
 
     pos = framesize_len + 2 + 2
     while pos < len(content):
-        header16 = struct.unpack('<H', content[pos:pos + 2])[0]
+        header16 = struct_unpack('<H', content[pos:pos + 2])[0]
         pos += 2
         tag_code = header16 >> 6
         tag_len = header16 & 0x3f
         if tag_len == 0x3f:
-            tag_len = struct.unpack('<I', content[pos:pos + 4])[0]
+            tag_len = struct_unpack('<I', content[pos:pos + 4])[0]
             pos += 4
         assert pos + tag_len <= len(content), \
             ('Tag %d ends at %d+%d - that\'s longer than the file (%d)'
@@ -99,7 +99,7 @@ def _read_int(reader):
     for _ in range(5):
         buf = reader.read(1)
         assert len(buf) == 1
-        b = struct.unpack('<B', buf)[0]
+        b = struct_unpack('<B', buf)[0]
         res = res | ((b & 0x7f) << shift)
         if b & 0x80 == 0:
             break
@@ -111,7 +111,7 @@ def _u30(reader):
     res = _read_int(reader)
     assert res & 0xf0000000 == 0
     return res
-u32 = _read_int
+_u32 = _read_int
 
 
 def _s32(reader):
@@ -125,7 +125,7 @@ def _s24(reader):
     bs = reader.read(3)
     assert len(bs) == 3
     last_byte = b'\xff' if (ord(bs[2:3]) >= 0x80) else b'\x00'
-    return struct.unpack('<i', bs + last_byte)[0]
+    return struct_unpack('<i', bs + last_byte)[0]
 
 
 def _read_string(reader):
@@ -144,7 +144,7 @@ def _read_bytes(count, reader):
 
 def _read_byte(reader):
     resb = _read_bytes(1, reader=reader)
-    res = struct.unpack('<B', resb)[0]
+    res = struct_unpack('<B', resb)[0]
     return res
 
 
@@ -470,8 +470,7 @@ class SWFInterpreter(object):
 
                     mname = self.multinames[index]
                     assert isinstance(obj, _AVMClass)
-                    construct_method = self.extract_function(
-                        obj, mname)
+
                     # We do not actually call the constructor for now;
                     # we just pretend it does nothing
                     stack.append(obj.make_object())
diff --git a/youtube_dl/version.py b/youtube_dl/version.py
index c68062059..e2e0ee25c 100644
--- a/youtube_dl/version.py
+++ b/youtube_dl/version.py
@@ -1,2 +1,2 @@
 
-__version__ = '2014.07.20.1'
+__version__ = '2014.07.20.2'