...

src/calibre/ebooks/metadata/sources/amazon.py

@@ -172,6 +172,8 @@ class Worker(Thread): # {{{
                 self.plugin.cache_identifier_to_cover_url(self.amazon_id,
                         self.cover_url)
 
+        self.plugin.clean_downloaded_metadata(mi)
+
         self.result_queue.put(mi)
 
     def parse_asin(self, root):

src/calibre/ebooks/metadata/sources/base.py

@@ -13,6 +13,7 @@ from calibre import browser, random_user_agent
 from calibre.customize import Plugin
 from calibre.utils.logging import ThreadSafeLog, FileStream
 from calibre.utils.config import JSONConfig
+from calibre.utils.titlecase import titlecase
 
 msprefs = JSONConfig('metadata_sources.json')
 
@@ -128,7 +129,7 @@ class Source(Plugin):
 
     # }}}
 
-    # Utility functions {{{
+    # Caching {{{
 
     def get_related_isbns(self, id_):
         with self.cache_lock:
@@ -152,6 +153,10 @@ class Source(Plugin):
         with self.cache_lock:
             return self._identifier_to_cover_url_cache.get(id_, None)
 
+    # }}}
+
+    # Utility functions {{{
+
     def get_author_tokens(self, authors, only_first_author=True):
         '''
         Take a list of authors and return a list of tokens useful for an
@@ -216,6 +221,20 @@ class Source(Plugin):
             elif mi.is_null(key):
                 return key
 
+    def clean_downloaded_metadata(self, mi):
+        '''
+        Call this method in your plugin's identify method to normalize metadata
+        before putting the Metadata object into result_queue. You can of
+        course, use a custom algorithm suited to your metadata source.
+        '''
+        def fixcase(x):
+            if x:
+                x = titlecase(x)
+            return x
+        if mi.title:
+            mi.title = fixcase(mi.title)
+        mi.authors = list(map(fixcase, mi.authors))
+        mi.tags = list(map(fixcase, mi.tags))
 
     # }}}
 

src/calibre/ebooks/metadata/sources/google.py

@@ -256,6 +256,7 @@ class GoogleBooks(Source):
                         if ans.has_google_cover:
                             self.cache_identifier_to_cover_url(goog,
                                     self.GOOGLE_COVER%goog)
+                    self.clean_downloaded_metadata(ans)
                     result_queue.put(ans)
             except:
                 log.exception(