diff --git a/media/extractors/mp4/MPEG4Extractor.cpp b/media/extractors/mp4/MPEG4Extractor.cpp
index b6b0ae2efc..c02d2fb10c 100644
--- a/media/extractors/mp4/MPEG4Extractor.cpp
+++ b/media/extractors/mp4/MPEG4Extractor.cpp
@@ -365,7 +365,7 @@ MPEG4Extractor::MPEG4Extractor(DataSourceHelper *source, const char *mime)
     : mMoofOffset(0),
       mMoofFound(false),
       mMdatFound(false),
-      mDataSource(new DataSourceHelper(source)),
+      mDataSource(source),
       mCachedSource(NULL),
       mInitCheck(NO_INIT),
       mHeaderTimescale(0),
diff --git a/media/extractors/ogg/OggExtractor.cpp b/media/extractors/ogg/OggExtractor.cpp
index d46ace4932..4e979219a2 100644
--- a/media/extractors/ogg/OggExtractor.cpp
+++ b/media/extractors/ogg/OggExtractor.cpp
@@ -1220,6 +1220,7 @@ OggExtractor::OggExtractor(DataSourceHelper *source)
 OggExtractor::~OggExtractor() {
     delete mImpl;
     mImpl = NULL;
+    delete mDataSource;
 }
 
 size_t OggExtractor::countTracks() {
diff --git a/media/extractors/wav/WAVExtractor.cpp b/media/extractors/wav/WAVExtractor.cpp
index 80dc9c8ce5..c739c2a7bf 100644
--- a/media/extractors/wav/WAVExtractor.cpp
+++ b/media/extractors/wav/WAVExtractor.cpp
@@ -568,16 +568,14 @@ static CreatorFunc Sniff(
         return NULL;
     }
 
-    WAVExtractor *extractor = new WAVExtractor(helper);
+    WAVExtractor *extractor = new WAVExtractor(helper); // extractor owns the helper
     int numTracks = extractor->countTracks();
     delete extractor;
     if (numTracks == 0) {
-        delete helper;
         return NULL;
     }
 
     *confidence = 0.3f;
-    delete helper;
 
     return CreateExtractor;
 }
diff --git a/media/libstagefright/MediaExtractorFactory.cpp b/media/libstagefright/MediaExtractorFactory.cpp
index 6e361497e8..7578b1e3e1 100644
--- a/media/libstagefright/MediaExtractorFactory.cpp
+++ b/media/libstagefright/MediaExtractorFactory.cpp
@@ -150,7 +150,8 @@ CreatorFunc MediaExtractorFactory::sniff(
         float newConfidence;
         void *newMeta = nullptr;
         FreeMetaFunc newFreeMeta = nullptr;
-        if ((curCreator = (*it)->def.sniff(source->wrap(), &newConfidence, &newMeta, &newFreeMeta))) {
+        if ((curCreator = (*it)->def.sniff(
+                        source->wrap(), &newConfidence, &newMeta, &newFreeMeta))) {
             if (newConfidence > *confidence) {
                 *confidence = newConfidence;
                 if (*meta != nullptr && *freeMeta != nullptr) {