diff --git a/include/media/MediaExtractorPluginHelper.h b/include/media/MediaExtractorPluginHelper.h
index c817b30..a659660 100644
--- a/include/media/MediaExtractorPluginHelper.h
+++ b/include/media/MediaExtractorPluginHelper.h
@@ -129,11 +129,13 @@
         mSource = source->mSource;
     }
 
-    ssize_t readAt(off64_t offset, void *data, size_t size) {
+    virtual ~DataSourceHelper() {}
+
+    virtual ssize_t readAt(off64_t offset, void *data, size_t size) {
         return mSource->readAt(mSource->handle, offset, data, size);
     }
 
-    status_t getSize(off64_t *size) {
+    virtual status_t getSize(off64_t *size) {
         return mSource->getSize(mSource->handle, size);
     }
 
@@ -141,7 +143,7 @@
         return mSource->getUri(mSource->handle, uriString, bufferSize);
     }
 
-    uint32_t flags() {
+    virtual uint32_t flags() {
         return mSource->flags(mSource->handle);
     }
 
diff --git a/media/extractors/mp4/MPEG4Extractor.cpp b/media/extractors/mp4/MPEG4Extractor.cpp
index f52d451..9d2f5d2 100644
--- a/media/extractors/mp4/MPEG4Extractor.cpp
+++ b/media/extractors/mp4/MPEG4Extractor.cpp
@@ -198,13 +198,14 @@
 // possibly wrapping multiple times to cover all tracks, i.e.
 // Each CachedRangedDataSource caches the sampletable metadata for a single track.
 
-struct CachedRangedDataSource : public DataSourceHelper {
+class CachedRangedDataSource : public DataSourceHelper {
+public:
     explicit CachedRangedDataSource(DataSourceHelper *source);
     virtual ~CachedRangedDataSource();
 
-    virtual ssize_t readAt(off64_t offset, void *data, size_t size);
-    virtual status_t getSize(off64_t *size);
-    virtual uint32_t flags();
+    ssize_t readAt(off64_t offset, void *data, size_t size) override;
+    status_t getSize(off64_t *size) override;
+    uint32_t flags() override;
 
     status_t setCachedRange(off64_t offset, size_t size, bool assumeSourceOwnershipOnSuccess);
 
@@ -236,7 +237,7 @@
 CachedRangedDataSource::~CachedRangedDataSource() {
     clearCache();
     if (mOwnsDataSource) {
-        delete (CachedRangedDataSource*)mSource;
+        delete mSource;
     }
 }
 
@@ -366,7 +367,6 @@
       mMoofFound(false),
       mMdatFound(false),
       mDataSource(source),
-      mCachedSource(NULL),
       mInitCheck(NO_INIT),
       mHeaderTimescale(0),
       mIsQT(false),
@@ -393,9 +393,6 @@
     }
     mPssh.clear();
 
-    if (mCachedSource != mDataSource) {
-        delete mCachedSource;
-    }
     delete mDataSource;
 }
 
@@ -909,8 +906,8 @@
 
                     if (cachedSource->setCachedRange(
                             *offset, chunk_size,
-                            mCachedSource != NULL /* assume ownership on success */) == OK) {
-                        mDataSource = mCachedSource = cachedSource;
+                            true /* assume ownership on success */) == OK) {
+                        mDataSource = cachedSource;
                     } else {
                         delete cachedSource;
                     }
diff --git a/media/extractors/mp4/MPEG4Extractor.h b/media/extractors/mp4/MPEG4Extractor.h
index ca273e0..b1e04c7 100644
--- a/media/extractors/mp4/MPEG4Extractor.h
+++ b/media/extractors/mp4/MPEG4Extractor.h
@@ -33,7 +33,6 @@
 struct AMessage;
 struct CDataSource;
 class DataSourceHelper;
-struct CachedRangedDataSource;
 class SampleTable;
 class String8;
 namespace heif {
@@ -99,7 +98,6 @@
     Vector<Trex> mTrex;
 
     DataSourceHelper *mDataSource;
-    CachedRangedDataSource *mCachedSource;
     status_t mInitCheck;
     uint32_t mHeaderTimescale;
     bool mIsQT;
diff --git a/media/libheif/include/HeifDecoderAPI.h b/media/libheif/include/HeifDecoderAPI.h
index 5183c39..aa10f33 100644
--- a/media/libheif/include/HeifDecoderAPI.h
+++ b/media/libheif/include/HeifDecoderAPI.h
@@ -74,7 +74,7 @@
     int32_t  mRotationAngle;           // Rotation angle, clockwise, should be multiple of 90
     uint32_t mBytesPerPixel;           // Number of bytes for one pixel
     uint32_t mIccSize;                 // Number of bytes in mIccData
-    std::unique_ptr<uint8_t> mIccData; // Actual ICC data, memory is owned by this structure
+    std::unique_ptr<uint8_t[]> mIccData; // Actual ICC data, memory is owned by this structure
 };
 
 /*
diff --git a/media/libstagefright/FrameDecoder.cpp b/media/libstagefright/FrameDecoder.cpp
index c0e65e8..c62c05a 100644
--- a/media/libstagefright/FrameDecoder.cpp
+++ b/media/libstagefright/FrameDecoder.cpp
@@ -501,10 +501,15 @@
         return ERROR_MALFORMED;
     }
 
-    int32_t width, height, stride;
-    CHECK(outputFormat->findInt32("width", &width));
-    CHECK(outputFormat->findInt32("height", &height));
-    CHECK(outputFormat->findInt32("stride", &stride));
+    int32_t width, height, stride, srcFormat;
+    if (!outputFormat->findInt32("width", &width) ||
+            !outputFormat->findInt32("height", &height) ||
+            !outputFormat->findInt32("stride", &stride) ||
+            !outputFormat->findInt32("color-format", &srcFormat)) {
+        ALOGE("format missing dimension or color: %s",
+                outputFormat->debugString().c_str());
+        return ERROR_MALFORMED;
+    }
 
     int32_t crop_left, crop_top, crop_right, crop_bottom;
     if (!outputFormat->findRect("crop", &crop_left, &crop_top, &crop_right, &crop_bottom)) {
@@ -523,9 +528,6 @@
     addFrame(frameMem);
     VideoFrame* frame = static_cast<VideoFrame*>(frameMem->pointer());
 
-    int32_t srcFormat;
-    CHECK(outputFormat->findInt32("color-format", &srcFormat));
-
     ColorConverter converter((OMX_COLOR_FORMATTYPE)srcFormat, dstFormat());
 
     uint32_t standard, range, transfer;
diff --git a/media/libstagefright/foundation/AString.cpp b/media/libstagefright/foundation/AString.cpp
index c6ef75f..a8adff5 100644
--- a/media/libstagefright/foundation/AString.cpp
+++ b/media/libstagefright/foundation/AString.cpp
@@ -125,12 +125,10 @@
 }
 
 void AString::clear() {
-    if (mData && mData != kEmptyString) {
+    if (mData != kEmptyString) {
         free(mData);
-        mData = NULL;
+        mData = (char *)kEmptyString;
     }
-
-    mData = (char *)kEmptyString;
     mSize = 0;
     mAllocSize = 1;
 }
diff --git a/media/libstagefright/foundation/include/media/stagefright/foundation/ADebug.h b/media/libstagefright/foundation/include/media/stagefright/foundation/ADebug.h
index bac8fa9..a8b88fd 100644
--- a/media/libstagefright/foundation/include/media/stagefright/foundation/ADebug.h
+++ b/media/libstagefright/foundation/include/media/stagefright/foundation/ADebug.h
@@ -63,38 +63,21 @@
             __FILE__ ":" LITERAL_TO_STRING(__LINE__)    \
             " CHECK(" #condition ") failed.")
 
-#define MAKE_COMPARATOR(suffix,op)                          \
-    template<class A, class B>                              \
-    AString Compare_##suffix(const A &a, const B &b) {      \
-        AString res;                                        \
-        if (!(a op b)) {                                    \
-            res.append(a);                                  \
-            res.append(" vs. ");                            \
-            res.append(b);                                  \
-        }                                                   \
-        return res;                                         \
-    }
-
-MAKE_COMPARATOR(EQ,==)
-MAKE_COMPARATOR(NE,!=)
-MAKE_COMPARATOR(LE,<=)
-MAKE_COMPARATOR(GE,>=)
-MAKE_COMPARATOR(LT,<)
-MAKE_COMPARATOR(GT,>)
-
 #ifdef CHECK_OP
 #undef CHECK_OP
 #endif
 
 #define CHECK_OP(x,y,suffix,op)                                         \
     do {                                                                \
-        AString ___res = Compare_##suffix(x, y);                        \
-        if (!___res.empty()) {                                          \
+        const auto &a = x;                                              \
+        const auto &b = y;                                              \
+        if (!(a op b)) {                                                \
             AString ___full =                                           \
                 __FILE__ ":" LITERAL_TO_STRING(__LINE__)                \
                     " CHECK_" #suffix "( " #x "," #y ") failed: ";      \
-            ___full.append(___res);                                     \
-                                                                        \
+            ___full.append(a);                                          \
+            ___full.append(" vs. ");                                    \
+            ___full.append(b);                                          \
             LOG_ALWAYS_FATAL("%s", ___full.c_str());                    \
         }                                                               \
     } while (false)