Fix clang-tidy warnings in stagefright.

* Add explicit keyword to conversion constructors.
* Or add NOLINT to implicit conversion constructors.
Bug: 28341362
* Use const reference type for read-only parameters.
Bug: 30407689
* Use const reference type to avoid unnecessary copy.
Bug: 30413862
Test: build with WITH_TIDY=1

Change-Id: I7a15ac1e37973fe2c661f577a6106b913653de40
diff --git a/cmds/stagefright/mediafilter.cpp b/cmds/stagefright/mediafilter.cpp
index 1183112..d829df0 100644
--- a/cmds/stagefright/mediafilter.cpp
+++ b/cmds/stagefright/mediafilter.cpp
@@ -69,7 +69,7 @@
 namespace android {
 
 struct SaturationRSFilter : RenderScriptWrapper::RSFilterCallback {
-    void init(RSC::sp<RSC::RS> context) {
+    void init(const RSC::sp<RSC::RS> &context) {
         mScript = new ScriptC_saturation(context);
         mScript->set_gSaturation(3.f);
     }
@@ -90,7 +90,7 @@
 };
 
 struct NightVisionRSFilter : RenderScriptWrapper::RSFilterCallback {
-    void init(RSC::sp<RSC::RS> context) {
+    void init(const RSC::sp<RSC::RS> &context) {
         mScript = new ScriptC_nightvision(context);
     }
 
@@ -110,7 +110,7 @@
 };
 
 struct ARGBToRGBARSFilter : RenderScriptWrapper::RSFilterCallback {
-    void init(RSC::sp<RSC::RS> context) {
+    void init(const RSC::sp<RSC::RS> &context) {
         mScript = new ScriptC_argbtorgba(context);
     }
 
diff --git a/include/media/stagefright/MediaBuffer.h b/include/media/stagefright/MediaBuffer.h
index abfe068..6cdd0fa 100644
--- a/include/media/stagefright/MediaBuffer.h
+++ b/include/media/stagefright/MediaBuffer.h
@@ -56,11 +56,11 @@
     // The underlying data remains the responsibility of the caller!
     MediaBuffer(void *data, size_t size);
 
-    MediaBuffer(size_t size);
+    explicit MediaBuffer(size_t size);
 
-    MediaBuffer(const sp<GraphicBuffer>& graphicBuffer);
+    explicit MediaBuffer(const sp<GraphicBuffer>& graphicBuffer);
 
-    MediaBuffer(const sp<ABuffer> &buffer);
+    explicit MediaBuffer(const sp<ABuffer> &buffer);
 
     MediaBuffer(const sp<IMemory> &mem) :
         MediaBuffer((uint8_t *)mem->pointer() + sizeof(SharedControl), mem->size()) {
diff --git a/include/media/stagefright/MediaCodec.h b/include/media/stagefright/MediaCodec.h
index fe579b7..8291cec 100644
--- a/include/media/stagefright/MediaCodec.h
+++ b/include/media/stagefright/MediaCodec.h
@@ -175,7 +175,7 @@
     // by adding rendered frame information to a base notification message. Returns the number
     // of frames that were rendered.
     static size_t CreateFramesRenderedMessage(
-            std::list<FrameRenderTracker::Info> done, sp<AMessage> &msg);
+            const std::list<FrameRenderTracker::Info> &done, sp<AMessage> &msg);
 
 protected:
     virtual ~MediaCodec();
@@ -274,7 +274,7 @@
 
         void addResource(
                 int64_t clientId,
-                const sp<IResourceManagerClient> client,
+                const sp<IResourceManagerClient> &client,
                 const Vector<MediaResource> &resources);
 
         void removeResource(int64_t clientId);
diff --git a/include/media/stagefright/Utils.h b/include/media/stagefright/Utils.h
index 7db74ec..8eff914 100644
--- a/include/media/stagefright/Utils.h
+++ b/include/media/stagefright/Utils.h
@@ -75,7 +75,7 @@
     int64_t mTimeUs;
     sp<AMessage> mMeta;
 
-    HLSTime(const sp<AMessage> &meta = NULL);
+    explicit HLSTime(const sp<AMessage> &meta = NULL);
     int64_t getSegmentTimeUs() const;
 };
 
@@ -83,10 +83,10 @@
 
 // read and write various object to/from AMessage
 
-void writeToAMessage(sp<AMessage> msg, const AudioPlaybackRate &rate);
+void writeToAMessage(const sp<AMessage> &msg, const AudioPlaybackRate &rate);
 void readFromAMessage(const sp<AMessage> &msg, AudioPlaybackRate *rate /* nonnull */);
 
-void writeToAMessage(sp<AMessage> msg, const AVSyncSettings &sync, float videoFpsHint);
+void writeToAMessage(const sp<AMessage> &msg, const AVSyncSettings &sync, float videoFpsHint);
 void readFromAMessage(
         const sp<AMessage> &msg, AVSyncSettings *sync /* nonnull */, float *videoFps /* nonnull */);
 
diff --git a/include/media/stagefright/foundation/ABuffer.h b/include/media/stagefright/foundation/ABuffer.h
index dc9c778..ef11434 100644
--- a/include/media/stagefright/foundation/ABuffer.h
+++ b/include/media/stagefright/foundation/ABuffer.h
@@ -30,7 +30,7 @@
 class MediaBufferBase;
 
 struct ABuffer : public RefBase {
-    ABuffer(size_t capacity);
+    explicit ABuffer(size_t capacity);
     ABuffer(void *data, size_t capacity);
 
     uint8_t *base() { return (uint8_t *)mData; }
diff --git a/include/media/stagefright/foundation/AHandler.h b/include/media/stagefright/foundation/AHandler.h
index fe02a86..53d8a9b 100644
--- a/include/media/stagefright/foundation/AHandler.h
+++ b/include/media/stagefright/foundation/AHandler.h
@@ -60,7 +60,7 @@
     ALooper::handler_id mID;
     wp<ALooper> mLooper;
 
-    inline void setID(ALooper::handler_id id, wp<ALooper> looper) {
+    inline void setID(ALooper::handler_id id, const wp<ALooper> &looper) {
         mID = id;
         mLooper = looper;
     }
diff --git a/include/media/stagefright/foundation/ALooperRoster.h b/include/media/stagefright/foundation/ALooperRoster.h
index 9912455..5873e68 100644
--- a/include/media/stagefright/foundation/ALooperRoster.h
+++ b/include/media/stagefright/foundation/ALooperRoster.h
@@ -28,7 +28,7 @@
     ALooperRoster();
 
     ALooper::handler_id registerHandler(
-            const sp<ALooper> looper, const sp<AHandler> &handler);
+            const sp<ALooper> &looper, const sp<AHandler> &handler);
 
     void unregisterHandler(ALooper::handler_id handlerID);
     void unregisterStaleHandlers();
diff --git a/include/media/stagefright/foundation/AMessage.h b/include/media/stagefright/foundation/AMessage.h
index 4b2b868..782f8e6 100644
--- a/include/media/stagefright/foundation/AMessage.h
+++ b/include/media/stagefright/foundation/AMessage.h
@@ -31,7 +31,7 @@
 class Parcel;
 
 struct AReplyToken : public RefBase {
-    AReplyToken(const sp<ALooper> &looper)
+    explicit AReplyToken(const sp<ALooper> &looper)
         : mLooper(looper),
           mReplied(false) {
     }
diff --git a/include/media/stagefright/foundation/AString.h b/include/media/stagefright/foundation/AString.h
index 2f6d532..ff086b3 100644
--- a/include/media/stagefright/foundation/AString.h
+++ b/include/media/stagefright/foundation/AString.h
@@ -28,9 +28,9 @@
 
 struct AString {
     AString();
-    AString(const char *s);
+    AString(const char *s);  // NOLINT, implicit conversion
     AString(const char *s, size_t size);
-    AString(const String8 &from);
+    AString(const String8 &from);  // NOLINT, implicit conversion
     AString(const AString &from);
     AString(const AString &from, size_t offset, size_t n);
     ~AString();
diff --git a/include/media/stagefright/foundation/AWakeLock.h b/include/media/stagefright/foundation/AWakeLock.h
index 57716c1..323e7d7 100644
--- a/include/media/stagefright/foundation/AWakeLock.h
+++ b/include/media/stagefright/foundation/AWakeLock.h
@@ -43,7 +43,7 @@
 
     class PMDeathRecipient : public IBinder::DeathRecipient {
     public:
-        PMDeathRecipient(AWakeLock *wakeLock) : mWakeLock(wakeLock) {}
+        explicit PMDeathRecipient(AWakeLock *wakeLock) : mWakeLock(wakeLock) {}
         virtual ~PMDeathRecipient() {}
 
         // IBinder::DeathRecipient
diff --git a/media/libmediaplayerservice/StagefrightRecorder.cpp b/media/libmediaplayerservice/StagefrightRecorder.cpp
index 24ca582..92a9613 100644
--- a/media/libmediaplayerservice/StagefrightRecorder.cpp
+++ b/media/libmediaplayerservice/StagefrightRecorder.cpp
@@ -1493,7 +1493,7 @@
 }
 
 status_t StagefrightRecorder::setupVideoEncoder(
-        sp<MediaSource> cameraSource,
+        const sp<MediaSource> &cameraSource,
         sp<MediaCodecSource> *source) {
     source->clear();
 
diff --git a/media/libmediaplayerservice/StagefrightRecorder.h b/media/libmediaplayerservice/StagefrightRecorder.h
index d7f43bc..4dbd039 100644
--- a/media/libmediaplayerservice/StagefrightRecorder.h
+++ b/media/libmediaplayerservice/StagefrightRecorder.h
@@ -44,7 +44,7 @@
 struct ALooper;
 
 struct StagefrightRecorder : public MediaRecorderBase {
-    StagefrightRecorder(const String16 &opPackageName);
+    explicit StagefrightRecorder(const String16 &opPackageName);
     virtual ~StagefrightRecorder();
 
     virtual status_t init();
@@ -59,9 +59,9 @@
     virtual status_t setPreviewSurface(const sp<IGraphicBufferProducer>& surface);
     virtual status_t setInputSurface(const sp<IGraphicBufferConsumer>& surface);
     virtual status_t setOutputFile(int fd, int64_t offset, int64_t length);
-    virtual status_t setParameters(const String8& params);
-    virtual status_t setListener(const sp<IMediaRecorderClient>& listener);
-    virtual status_t setClientName(const String16& clientName);
+    virtual status_t setParameters(const String8 &params);
+    virtual status_t setListener(const sp<IMediaRecorderClient> &listener);
+    virtual status_t setClientName(const String16 &clientName);
     virtual status_t prepare();
     virtual status_t start();
     virtual status_t pause();
@@ -70,7 +70,7 @@
     virtual status_t close();
     virtual status_t reset();
     virtual status_t getMaxAmplitude(int *max);
-    virtual status_t dump(int fd, const Vector<String16>& args) const;
+    virtual status_t dump(int fd, const Vector<String16> &args) const;
     // Querying a SurfaceMediaSourcer
     virtual sp<IGraphicBufferProducer> querySurfaceMediaSource() const;
 
@@ -158,7 +158,7 @@
     status_t setupMediaSource(sp<MediaSource> *mediaSource);
     status_t setupCameraSource(sp<CameraSource> *cameraSource);
     status_t setupAudioEncoder(const sp<MediaWriter>& writer);
-    status_t setupVideoEncoder(sp<MediaSource> cameraSource, sp<MediaCodecSource> *source);
+    status_t setupVideoEncoder(const sp<MediaSource>& cameraSource, sp<MediaCodecSource> *source);
 
     // Encoding parameter handling utilities
     status_t setParameter(const String8 &key, const String8 &value);
diff --git a/media/libstagefright/MPEG4Extractor.cpp b/media/libstagefright/MPEG4Extractor.cpp
index 4bd7800..fcd0873 100644
--- a/media/libstagefright/MPEG4Extractor.cpp
+++ b/media/libstagefright/MPEG4Extractor.cpp
@@ -596,7 +596,7 @@
 
 // Reads an encoded integer 7 bits at a time until it encounters the high bit clear.
 static int32_t readSize(off64_t offset,
-        const sp<DataSource> DataSource, uint8_t *numOfBytes) {
+        const sp<DataSource> &DataSource, uint8_t *numOfBytes) {
     uint32_t size = 0;
     uint8_t data;
     bool moreData = true;
diff --git a/media/libstagefright/MediaCodec.cpp b/media/libstagefright/MediaCodec.cpp
index e5d97ef..a4f7042 100644
--- a/media/libstagefright/MediaCodec.cpp
+++ b/media/libstagefright/MediaCodec.cpp
@@ -53,7 +53,7 @@
 
 namespace android {
 
-static int64_t getId(sp<IResourceManagerClient> client) {
+static int64_t getId(const sp<IResourceManagerClient> &client) {
     return (int64_t) client.get();
 }
 
@@ -142,7 +142,7 @@
 
 void MediaCodec::ResourceManagerServiceProxy::addResource(
         int64_t clientId,
-        const sp<IResourceManagerClient> client,
+        const sp<IResourceManagerClient> &client,
         const Vector<MediaResource> &resources) {
     Mutex::Autolock _l(mLock);
     if (mService == NULL) {
@@ -2564,7 +2564,7 @@
 
 //static
 size_t MediaCodec::CreateFramesRenderedMessage(
-        std::list<FrameRenderTracker::Info> done, sp<AMessage> &msg) {
+        const std::list<FrameRenderTracker::Info> &done, sp<AMessage> &msg) {
     size_t index = 0;
 
     for (std::list<FrameRenderTracker::Info>::const_iterator it = done.cbegin();
diff --git a/media/libstagefright/MediaCodecList.cpp b/media/libstagefright/MediaCodecList.cpp
index 08bb45d..f75706b 100644
--- a/media/libstagefright/MediaCodecList.cpp
+++ b/media/libstagefright/MediaCodecList.cpp
@@ -888,18 +888,18 @@
     return -ENOENT;
 }
 
-static status_t limitFoundMissingAttr(AString name, const char *attr, bool found = true) {
+static status_t limitFoundMissingAttr(const AString &name, const char *attr, bool found = true) {
     ALOGE("limit '%s' with %s'%s' attribute", name.c_str(),
             (found ? "" : "no "), attr);
     return -EINVAL;
 }
 
-static status_t limitError(AString name, const char *msg) {
+static status_t limitError(const AString &name, const char *msg) {
     ALOGE("limit '%s' %s", name.c_str(), msg);
     return -EINVAL;
 }
 
-static status_t limitInvalidAttr(AString name, const char *attr, AString value) {
+static status_t limitInvalidAttr(const AString &name, const char *attr, const AString &value) {
     ALOGE("limit '%s' with invalid '%s' attribute (%s)", name.c_str(),
             attr, value.c_str());
     return -EINVAL;
diff --git a/media/libstagefright/MediaCodecListOverrides.cpp b/media/libstagefright/MediaCodecListOverrides.cpp
index 4ec36b5..33795f3 100644
--- a/media/libstagefright/MediaCodecListOverrides.cpp
+++ b/media/libstagefright/MediaCodecListOverrides.cpp
@@ -49,7 +49,7 @@
 static const int kMaxInstances = 32;
 
 // TODO: move MediaCodecInfo to C++. Until then, some temp methods to parse out info.
-static bool getMeasureSize(sp<MediaCodecInfo::Capabilities> caps, int32_t *width, int32_t *height) {
+static bool getMeasureSize(const sp<MediaCodecInfo::Capabilities> &caps, int32_t *width, int32_t *height) {
     AString sizeRange;
     if (!caps->getDetails()->findString("size-range", &sizeRange)) {
         return false;
@@ -72,7 +72,7 @@
     return (*width > 0) && (*height > 0);
 }
 
-static void getMeasureBitrate(sp<MediaCodecInfo::Capabilities> caps, int32_t *bitrate) {
+static void getMeasureBitrate(const sp<MediaCodecInfo::Capabilities> &caps, int32_t *bitrate) {
     // Until have native MediaCodecInfo, we cannot get bitrates based on profile/levels.
     // We use 200000 as default value for our measurement.
     *bitrate = 200000;
@@ -90,7 +90,7 @@
 }
 
 static sp<AMessage> getMeasureFormat(
-        bool isEncoder, AString mime, sp<MediaCodecInfo::Capabilities> caps) {
+        bool isEncoder, const AString &mime, const sp<MediaCodecInfo::Capabilities> &caps) {
     sp<AMessage> format = new AMessage();
     format->setString("mime", mime);
 
@@ -128,7 +128,7 @@
 }
 
 static size_t doProfileEncoderInputBuffers(
-        AString name, AString mime, sp<MediaCodecInfo::Capabilities> caps) {
+        const AString &name, const AString &mime, const sp<MediaCodecInfo::Capabilities> &caps) {
     ALOGV("doProfileEncoderInputBuffers: name %s, mime %s", name.c_str(), mime.c_str());
 
     sp<AMessage> format = getMeasureFormat(true /* isEncoder */, mime, caps);
@@ -183,7 +183,7 @@
 }
 
 static size_t doProfileCodecs(
-        bool isEncoder, AString name, AString mime, sp<MediaCodecInfo::Capabilities> caps) {
+        bool isEncoder, const AString &name, const AString &mime, const sp<MediaCodecInfo::Capabilities> &caps) {
     sp<AMessage> format = getMeasureFormat(isEncoder, mime, caps);
     if (format == NULL) {
         return 0;
@@ -337,7 +337,7 @@
     global_results->add(kPolicySupportsMultipleSecureCodecs, supportMultipleSecureCodecs);
 }
 
-static AString globalResultsToXml(const CodecSettings& results) {
+static AString globalResultsToXml(const CodecSettings &results) {
     AString ret;
     for (size_t i = 0; i < results.size(); ++i) {
         AString setting = AStringPrintf(
@@ -349,7 +349,7 @@
     return ret;
 }
 
-static AString codecResultsToXml(const KeyedVector<AString, CodecSettings>& results) {
+static AString codecResultsToXml(const KeyedVector<AString, CodecSettings> &results) {
     AString ret;
     for (size_t i = 0; i < results.size(); ++i) {
         AString name;
@@ -362,7 +362,7 @@
                               name.c_str(),
                               mime.c_str());
         ret.append(codec);
-        CodecSettings settings = results.valueAt(i);
+        const CodecSettings &settings = results.valueAt(i);
         for (size_t i = 0; i < settings.size(); ++i) {
             // WARNING: we assume all the settings are "Limit". Currently we have only one type
             // of setting in this case, which is "max-supported-instances".
@@ -379,9 +379,9 @@
 
 void exportResultsToXML(
         const char *fileName,
-        const CodecSettings& global_results,
-        const KeyedVector<AString, CodecSettings>& encoder_results,
-        const KeyedVector<AString, CodecSettings>& decoder_results) {
+        const CodecSettings &global_results,
+        const KeyedVector<AString, CodecSettings> &encoder_results,
+        const KeyedVector<AString, CodecSettings> &decoder_results) {
     if (global_results.size() == 0 && encoder_results.size() == 0 && decoder_results.size() == 0) {
         return;
     }
diff --git a/media/libstagefright/Utils.cpp b/media/libstagefright/Utils.cpp
index 3df54bf..34d7546 100644
--- a/media/libstagefright/Utils.cpp
+++ b/media/libstagefright/Utils.cpp
@@ -1075,7 +1075,7 @@
     return res != NULL && res < data + length - 4 ? res : &data[length];
 }
 
-static size_t reassembleAVCC(const sp<ABuffer> &csd0, const sp<ABuffer> csd1, char *avcc) {
+static size_t reassembleAVCC(const sp<ABuffer> &csd0, const sp<ABuffer> &csd1, char *avcc) {
     avcc[0] = 1;        // version
     avcc[1] = 0x64;     // profile (default to high)
     avcc[2] = 0;        // constraints (default to none)
@@ -1724,7 +1724,7 @@
             || (t0.mSeq == t1.mSeq && t0.mTimeUs < t1.mTimeUs);
 }
 
-void writeToAMessage(sp<AMessage> msg, const AudioPlaybackRate &rate) {
+void writeToAMessage(const sp<AMessage> &msg, const AudioPlaybackRate &rate) {
     msg->setFloat("speed", rate.mSpeed);
     msg->setFloat("pitch", rate.mPitch);
     msg->setInt32("audio-fallback-mode", rate.mFallbackMode);
@@ -1739,7 +1739,7 @@
     CHECK(msg->findInt32("audio-stretch-mode", (int32_t *)&rate->mStretchMode));
 }
 
-void writeToAMessage(sp<AMessage> msg, const AVSyncSettings &sync, float videoFpsHint) {
+void writeToAMessage(const sp<AMessage> &msg, const AVSyncSettings &sync, float videoFpsHint) {
     msg->setInt32("sync-source", sync.mSource);
     msg->setInt32("audio-adjust-mode", sync.mAudioAdjustMode);
     msg->setFloat("tolerance", sync.mTolerance);
diff --git a/media/libstagefright/codecs/m4v_h263/dec/include/m4vh263_decoder_pv_types.h b/media/libstagefright/codecs/m4v_h263/dec/include/m4vh263_decoder_pv_types.h
index ec6871f..711ec58 100644
--- a/media/libstagefright/codecs/m4v_h263/dec/include/m4vh263_decoder_pv_types.h
+++ b/media/libstagefright/codecs/m4v_h263/dec/include/m4vh263_decoder_pv_types.h
@@ -51,7 +51,7 @@
 {
     public:
         OsclAOStatus();
-        OsclAOStatus(int32 aStatus);
+        explicit OsclAOStatus(int32 aStatus);
         int32 operator=(int32 aStatus);
         int32 operator==(int32 aStatus) const;
         int32 operator!=(int32 aStatus) const;
diff --git a/media/libstagefright/foundation/ALooperRoster.cpp b/media/libstagefright/foundation/ALooperRoster.cpp
index 647a9fd..8a7c3eb 100644
--- a/media/libstagefright/foundation/ALooperRoster.cpp
+++ b/media/libstagefright/foundation/ALooperRoster.cpp
@@ -34,7 +34,7 @@
 }
 
 ALooper::handler_id ALooperRoster::registerHandler(
-        const sp<ALooper> looper, const sp<AHandler> &handler) {
+        const sp<ALooper> &looper, const sp<AHandler> &handler) {
     Mutex::Autolock autoLock(mLock);
 
     if (handler->id() != 0) {
diff --git a/media/libstagefright/httplive/LiveSession.h b/media/libstagefright/httplive/LiveSession.h
index 90d56d0..de7cefd 100644
--- a/media/libstagefright/httplive/LiveSession.h
+++ b/media/libstagefright/httplive/LiveSession.h
@@ -165,7 +165,7 @@
         int64_t mLastSampleDurationUs;
         StreamItem()
             : StreamItem("") {}
-        StreamItem(const char *type)
+        explicit StreamItem(const char *type)
             : mType(type),
               mSeekMode(kSeekModeExactPosition) {
                   reset();
diff --git a/media/libstagefright/include/AMRExtractor.h b/media/libstagefright/include/AMRExtractor.h
index ba2b674..8abcb12 100644
--- a/media/libstagefright/include/AMRExtractor.h
+++ b/media/libstagefright/include/AMRExtractor.h
@@ -29,7 +29,7 @@
 
 class AMRExtractor : public MediaExtractor {
 public:
-    AMRExtractor(const sp<DataSource> &source);
+    explicit AMRExtractor(const sp<DataSource> &source);
 
     virtual size_t countTracks();
     virtual sp<IMediaSource> getTrack(size_t index);
diff --git a/media/libstagefright/include/CallbackDataSource.h b/media/libstagefright/include/CallbackDataSource.h
index d2187d5..80cd1f7 100644
--- a/media/libstagefright/include/CallbackDataSource.h
+++ b/media/libstagefright/include/CallbackDataSource.h
@@ -29,7 +29,7 @@
 // DataSource because it calls back to the IDataSource for data.
 class CallbackDataSource : public DataSource {
 public:
-    CallbackDataSource(const sp<IDataSource>& iDataSource);
+    explicit CallbackDataSource(const sp<IDataSource>& iDataSource);
     virtual ~CallbackDataSource();
 
     // DataSource implementation.
@@ -59,7 +59,7 @@
 // impact on time taken for filetype sniffing and metadata extraction.
 class TinyCacheSource : public DataSource {
 public:
-    TinyCacheSource(const sp<DataSource>& source);
+    explicit TinyCacheSource(const sp<DataSource>& source);
 
     virtual status_t initCheck() const;
     virtual ssize_t readAt(off64_t offset, void* data, size_t size);
diff --git a/media/libstagefright/include/FLACExtractor.h b/media/libstagefright/include/FLACExtractor.h
index 5d030b1..51bc139 100644
--- a/media/libstagefright/include/FLACExtractor.h
+++ b/media/libstagefright/include/FLACExtractor.h
@@ -29,7 +29,7 @@
 
 public:
     // Extractor assumes ownership of source
-    FLACExtractor(const sp<DataSource> &source);
+    explicit FLACExtractor(const sp<DataSource> &source);
 
     virtual size_t countTracks();
     virtual sp<IMediaSource> getTrack(size_t index);
diff --git a/media/libstagefright/include/ID3.h b/media/libstagefright/include/ID3.h
index c2c4a6d..11682f8 100644
--- a/media/libstagefright/include/ID3.h
+++ b/media/libstagefright/include/ID3.h
@@ -35,7 +35,7 @@
         ID3_V2_4,
     };
 
-    ID3(const sp<DataSource> &source, bool ignoreV1 = false, off64_t offset = 0);
+    explicit ID3(const sp<DataSource> &source, bool ignoreV1 = false, off64_t offset = 0);
     ID3(const uint8_t *data, size_t size, bool ignoreV1 = false);
     ~ID3();
 
diff --git a/media/libstagefright/include/MPEG2PSExtractor.h b/media/libstagefright/include/MPEG2PSExtractor.h
index c8abfb6..f5471b3 100644
--- a/media/libstagefright/include/MPEG2PSExtractor.h
+++ b/media/libstagefright/include/MPEG2PSExtractor.h
@@ -31,7 +31,7 @@
 class String8;
 
 struct MPEG2PSExtractor : public MediaExtractor {
-    MPEG2PSExtractor(const sp<DataSource> &source);
+    explicit MPEG2PSExtractor(const sp<DataSource> &source);
 
     virtual size_t countTracks();
     virtual sp<IMediaSource> getTrack(size_t index);
diff --git a/media/libstagefright/include/MPEG2TSExtractor.h b/media/libstagefright/include/MPEG2TSExtractor.h
index 34b9606..93e9a4b 100644
--- a/media/libstagefright/include/MPEG2TSExtractor.h
+++ b/media/libstagefright/include/MPEG2TSExtractor.h
@@ -37,7 +37,7 @@
 class String8;
 
 struct MPEG2TSExtractor : public MediaExtractor {
-    MPEG2TSExtractor(const sp<DataSource> &source);
+    explicit MPEG2TSExtractor(const sp<DataSource> &source);
 
     virtual size_t countTracks();
     virtual sp<IMediaSource> getTrack(size_t index);
diff --git a/media/libstagefright/include/MPEG4Extractor.h b/media/libstagefright/include/MPEG4Extractor.h
index fe8db9d..6b57e6f 100644
--- a/media/libstagefright/include/MPEG4Extractor.h
+++ b/media/libstagefright/include/MPEG4Extractor.h
@@ -50,7 +50,7 @@
 class MPEG4Extractor : public MediaExtractor {
 public:
     // Extractor assumes ownership of "source".
-    MPEG4Extractor(const sp<DataSource> &source);
+    explicit MPEG4Extractor(const sp<DataSource> &source);
 
     virtual size_t countTracks();
     virtual sp<IMediaSource> getTrack(size_t index);
diff --git a/media/libstagefright/include/MidiExtractor.h b/media/libstagefright/include/MidiExtractor.h
index 5a7d90e..94d2d08 100644
--- a/media/libstagefright/include/MidiExtractor.h
+++ b/media/libstagefright/include/MidiExtractor.h
@@ -53,7 +53,7 @@
 
 public:
     // Extractor assumes ownership of source
-    MidiExtractor(const sp<DataSource> &source);
+    explicit MidiExtractor(const sp<DataSource> &source);
 
     virtual size_t countTracks();
     virtual sp<IMediaSource> getTrack(size_t index);
diff --git a/media/libstagefright/include/OMXNodeInstance.h b/media/libstagefright/include/OMXNodeInstance.h
index 56ab3f6..bdd4811 100644
--- a/media/libstagefright/include/OMXNodeInstance.h
+++ b/media/libstagefright/include/OMXNodeInstance.h
@@ -251,10 +251,10 @@
             OMX::buffer_id buffer, OMX_BUFFERHEADERTYPE *header, bool updateCodecBuffer);
 
     status_t createGraphicBufferSource(
-            OMX_U32 portIndex, sp<IGraphicBufferConsumer> consumer /* nullable */,
+            OMX_U32 portIndex, const sp<IGraphicBufferConsumer> &consumer /* nullable */,
             MetadataBufferType *type);
     sp<GraphicBufferSource> getGraphicBufferSource();
-    void setGraphicBufferSource(const sp<GraphicBufferSource>& bufferSource);
+    void setGraphicBufferSource(const sp<GraphicBufferSource> &bufferSource);
 
     // Handles |msg|, and may modify it. Returns true iff completely handled it and
     // |msg| does not need to be sent to the event listener.
diff --git a/media/libstagefright/include/OggExtractor.h b/media/libstagefright/include/OggExtractor.h
index 592c264..55aafed 100644
--- a/media/libstagefright/include/OggExtractor.h
+++ b/media/libstagefright/include/OggExtractor.h
@@ -31,7 +31,7 @@
 struct OggSource;
 
 struct OggExtractor : public MediaExtractor {
-    OggExtractor(const sp<DataSource> &source);
+    explicit OggExtractor(const sp<DataSource> &source);
 
     virtual size_t countTracks();
     virtual sp<IMediaSource> getTrack(size_t index);
diff --git a/media/libstagefright/include/SampleIterator.h b/media/libstagefright/include/SampleIterator.h
index 2ef41ae..6a3fd3b 100644
--- a/media/libstagefright/include/SampleIterator.h
+++ b/media/libstagefright/include/SampleIterator.h
@@ -25,7 +25,7 @@
 class SampleTable;
 
 struct SampleIterator {
-    SampleIterator(SampleTable *table);
+    explicit SampleIterator(SampleTable *table);
 
     status_t seekTo(uint32_t sampleIndex);
 
diff --git a/media/libstagefright/include/SampleTable.h b/media/libstagefright/include/SampleTable.h
index 2100ca6..eb1a674 100644
--- a/media/libstagefright/include/SampleTable.h
+++ b/media/libstagefright/include/SampleTable.h
@@ -32,7 +32,7 @@
 
 class SampleTable : public RefBase {
 public:
-    SampleTable(const sp<DataSource> &source);
+    explicit SampleTable(const sp<DataSource> &source);
 
     bool isValid() const;
 
diff --git a/media/libstagefright/include/WAVExtractor.h b/media/libstagefright/include/WAVExtractor.h
index 91ee870..12ad441 100644
--- a/media/libstagefright/include/WAVExtractor.h
+++ b/media/libstagefright/include/WAVExtractor.h
@@ -30,7 +30,7 @@
 class WAVExtractor : public MediaExtractor {
 public:
     // Extractor assumes ownership of "source".
-    WAVExtractor(const sp<DataSource> &source);
+    explicit WAVExtractor(const sp<DataSource> &source);
 
     virtual size_t countTracks();
     virtual sp<IMediaSource> getTrack(size_t index);
diff --git a/media/libstagefright/include/WVMExtractor.h b/media/libstagefright/include/WVMExtractor.h
index 5b91072..65cb99a 100644
--- a/media/libstagefright/include/WVMExtractor.h
+++ b/media/libstagefright/include/WVMExtractor.h
@@ -43,7 +43,7 @@
 
 class WVMExtractor : public MediaExtractor {
 public:
-    WVMExtractor(const sp<DataSource> &source);
+    explicit WVMExtractor(const sp<DataSource> &source);
 
     virtual size_t countTracks();
     virtual sp<IMediaSource> getTrack(size_t index);
diff --git a/media/libstagefright/matroska/MatroskaExtractor.h b/media/libstagefright/matroska/MatroskaExtractor.h
index 298ebde..19775ce 100644
--- a/media/libstagefright/matroska/MatroskaExtractor.h
+++ b/media/libstagefright/matroska/MatroskaExtractor.h
@@ -34,7 +34,7 @@
 struct MatroskaSource;
 
 struct MatroskaExtractor : public MediaExtractor {
-    MatroskaExtractor(const sp<DataSource> &source);
+    explicit MatroskaExtractor(const sp<DataSource> &source);
 
     virtual size_t countTracks();
 
diff --git a/media/libstagefright/mpeg2ts/ATSParser.h b/media/libstagefright/mpeg2ts/ATSParser.h
index 9d9102d..2b166f0 100644
--- a/media/libstagefright/mpeg2ts/ATSParser.h
+++ b/media/libstagefright/mpeg2ts/ATSParser.h
@@ -64,7 +64,7 @@
 
     // Event is used to signal sync point event at feedTSPacket().
     struct SyncEvent {
-        SyncEvent(off64_t offset);
+        explicit SyncEvent(off64_t offset);
 
         void init(off64_t offset, const sp<MediaSource> &source,
                 int64_t timeUs);
@@ -89,7 +89,7 @@
         int64_t mTimeUs;
     };
 
-    ATSParser(uint32_t flags = 0);
+    explicit ATSParser(uint32_t flags = 0);
 
     // Feed a TS packet into the parser. uninitialized event with the start
     // offset of this TS packet goes in, and if the parser detects PES with
diff --git a/media/libstagefright/mpeg2ts/AnotherPacketSource.h b/media/libstagefright/mpeg2ts/AnotherPacketSource.h
index 28a0e89..dd6849e 100644
--- a/media/libstagefright/mpeg2ts/AnotherPacketSource.h
+++ b/media/libstagefright/mpeg2ts/AnotherPacketSource.h
@@ -30,7 +30,7 @@
 struct ABuffer;
 
 struct AnotherPacketSource : public MediaSource {
-    AnotherPacketSource(const sp<MetaData> &meta);
+    explicit AnotherPacketSource(const sp<MetaData> &meta);
 
     void setFormat(const sp<MetaData> &meta);
 
diff --git a/media/libstagefright/mpeg2ts/ESQueue.h b/media/libstagefright/mpeg2ts/ESQueue.h
index e9f96b7..56f0706 100644
--- a/media/libstagefright/mpeg2ts/ESQueue.h
+++ b/media/libstagefright/mpeg2ts/ESQueue.h
@@ -44,7 +44,7 @@
         // Data appended to the queue is always at access unit boundaries.
         kFlag_AlignedData = 1,
     };
-    ElementaryStreamQueue(Mode mode, uint32_t flags = 0);
+    explicit ElementaryStreamQueue(Mode mode, uint32_t flags = 0);
 
     status_t appendData(const void *data, size_t size, int64_t timeUs);
     void signalEOS();
diff --git a/media/libstagefright/omx/GraphicBufferSource.cpp b/media/libstagefright/omx/GraphicBufferSource.cpp
index 0c8fd67..390cddc 100644
--- a/media/libstagefright/omx/GraphicBufferSource.cpp
+++ b/media/libstagefright/omx/GraphicBufferSource.cpp
@@ -929,7 +929,7 @@
  */
 void GraphicBufferSource::releaseBuffer(
         int &id, uint64_t frameNum,
-        const sp<GraphicBuffer> buffer, const sp<Fence> &fence) {
+        const sp<GraphicBuffer> &buffer, const sp<Fence> &fence) {
     if (mIsPersistent) {
         mConsumer->detachBuffer(id);
         mBufferSlot[id] = NULL;
diff --git a/media/libstagefright/omx/GraphicBufferSource.h b/media/libstagefright/omx/GraphicBufferSource.h
index c8b0e62..3fcab2b 100644
--- a/media/libstagefright/omx/GraphicBufferSource.h
+++ b/media/libstagefright/omx/GraphicBufferSource.h
@@ -242,7 +242,7 @@
     // Release buffer to the consumer
     void releaseBuffer(
             int &id, uint64_t frameNum,
-            const sp<GraphicBuffer> buffer, const sp<Fence> &fence);
+            const sp<GraphicBuffer> &buffer, const sp<Fence> &fence);
 
     void setLatestBuffer_l(const BufferItem &item, bool dropped);
     bool repeatLatestBuffer_l();
diff --git a/media/libstagefright/omx/OMXNodeInstance.cpp b/media/libstagefright/omx/OMXNodeInstance.cpp
index 1c6e0dc..0c1b2a2 100644
--- a/media/libstagefright/omx/OMXNodeInstance.cpp
+++ b/media/libstagefright/omx/OMXNodeInstance.cpp
@@ -942,7 +942,7 @@
 }
 
 status_t OMXNodeInstance::createGraphicBufferSource(
-        OMX_U32 portIndex, sp<IGraphicBufferConsumer> bufferConsumer, MetadataBufferType *type) {
+        OMX_U32 portIndex, const sp<IGraphicBufferConsumer> &bufferConsumer, MetadataBufferType *type) {
     status_t err;
 
     const sp<GraphicBufferSource>& surfaceCheck = getGraphicBufferSource();
diff --git a/media/libstagefright/rtsp/AAVCAssembler.h b/media/libstagefright/rtsp/AAVCAssembler.h
index bf389ec..e19480c 100644
--- a/media/libstagefright/rtsp/AAVCAssembler.h
+++ b/media/libstagefright/rtsp/AAVCAssembler.h
@@ -29,7 +29,7 @@
 struct AMessage;
 
 struct AAVCAssembler : public ARTPAssembler {
-    AAVCAssembler(const sp<AMessage> &notify);
+    explicit AAVCAssembler(const sp<AMessage> &notify);
 
 protected:
     virtual ~AAVCAssembler();
diff --git a/media/libstagefright/rtsp/AH263Assembler.h b/media/libstagefright/rtsp/AH263Assembler.h
index 2b6c625..1448661 100644
--- a/media/libstagefright/rtsp/AH263Assembler.h
+++ b/media/libstagefright/rtsp/AH263Assembler.h
@@ -29,7 +29,7 @@
 struct AMessage;
 
 struct AH263Assembler : public ARTPAssembler {
-    AH263Assembler(const sp<AMessage> &notify);
+    explicit AH263Assembler(const sp<AMessage> &notify);
 
 protected:
     virtual ~AH263Assembler();
diff --git a/media/libstagefright/rtsp/ARTPConnection.h b/media/libstagefright/rtsp/ARTPConnection.h
index edbcc35..d5f7c2e 100644
--- a/media/libstagefright/rtsp/ARTPConnection.h
+++ b/media/libstagefright/rtsp/ARTPConnection.h
@@ -32,7 +32,7 @@
         kRegularlyRequestFIR = 2,
     };
 
-    ARTPConnection(uint32_t flags = 0);
+    explicit ARTPConnection(uint32_t flags = 0);
 
     void addStream(
             int rtpSocket, int rtcpSocket,
diff --git a/media/libstagefright/rtsp/ARTPWriter.h b/media/libstagefright/rtsp/ARTPWriter.h
index 62abd0a..3c7042e 100644
--- a/media/libstagefright/rtsp/ARTPWriter.h
+++ b/media/libstagefright/rtsp/ARTPWriter.h
@@ -35,7 +35,7 @@
 class MediaBuffer;
 
 struct ARTPWriter : public MediaWriter {
-    ARTPWriter(int fd);
+    explicit ARTPWriter(int fd);
 
     virtual status_t addSource(const sp<IMediaSource> &source);
     virtual bool reachedEOS();
diff --git a/media/libstagefright/rtsp/ARTSPConnection.h b/media/libstagefright/rtsp/ARTSPConnection.h
index 1fe9c99..8df2676 100644
--- a/media/libstagefright/rtsp/ARTSPConnection.h
+++ b/media/libstagefright/rtsp/ARTSPConnection.h
@@ -33,7 +33,7 @@
 };
 
 struct ARTSPConnection : public AHandler {
-    ARTSPConnection(bool uidValid = false, uid_t uid = 0);
+    explicit ARTSPConnection(bool uidValid = false, uid_t uid = 0);
 
     void connect(const char *url, const sp<AMessage> &reply);
     void disconnect(const sp<AMessage> &reply);
diff --git a/media/libstagefright/tests/DummyRecorder.h b/media/libstagefright/tests/DummyRecorder.h
index cd4d0ee..0759777 100644
--- a/media/libstagefright/tests/DummyRecorder.h
+++ b/media/libstagefright/tests/DummyRecorder.h
@@ -43,7 +43,7 @@
     // static function to wrap the actual thread entry point
     static void *threadWrapper(void *pthis);
 
-    DummyRecorder(const sp<MediaSource> &source) : mSource(source)
+    explicit DummyRecorder(const sp<MediaSource> &source) : mSource(source)
                                                     , mStarted(false) {}
     ~DummyRecorder( ) {}
 
diff --git a/media/libstagefright/tests/MediaCodecListOverrides_test.cpp b/media/libstagefright/tests/MediaCodecListOverrides_test.cpp
index ab547be..2599608 100644
--- a/media/libstagefright/tests/MediaCodecListOverrides_test.cpp
+++ b/media/libstagefright/tests/MediaCodecListOverrides_test.cpp
@@ -74,11 +74,11 @@
     void verifyProfileResults(const KeyedVector<AString, CodecSettings> &results) {
         EXPECT_LT(0u, results.size());
         for (size_t i = 0; i < results.size(); ++i) {
-            AString key = results.keyAt(i);
-            CodecSettings settings = results.valueAt(i);
+            const AString &key = results.keyAt(i);
+            const CodecSettings &settings = results.valueAt(i);
             EXPECT_EQ(1u, settings.size());
             EXPECT_TRUE(settings.keyAt(0) == "max-supported-instances");
-            AString valueS = settings.valueAt(0);
+            const AString &valueS = settings.valueAt(0);
             int32_t value = strtol(valueS.c_str(), NULL, 10);
             EXPECT_LT(0, value);
             ALOGV("profileCodecs results %s %s", key.c_str(), valueS.c_str());
diff --git a/media/libstagefright/webm/WebmElement.h b/media/libstagefright/webm/WebmElement.h
index 4e90793..ffbba1b 100644
--- a/media/libstagefright/webm/WebmElement.h
+++ b/media/libstagefright/webm/WebmElement.h
@@ -114,14 +114,14 @@
 
 struct EbmlVoid : public WebmElement {
     const uint64_t mSizeWidth;
-    EbmlVoid(uint64_t totalSize);
+    explicit EbmlVoid(uint64_t totalSize);
     int serializePayloadSize(uint8_t *buf);
     void serializePayload(uint8_t *buf);
 };
 
 struct WebmMaster : public WebmElement {
     const List<sp<WebmElement> > mChildren;
-    WebmMaster(uint64_t id);
+    explicit WebmMaster(uint64_t id);
     WebmMaster(uint64_t id, const List<sp<WebmElement> > &children);
     int serializePayloadSize(uint8_t *buf);
     void serializePayload(uint8_t *buf);
diff --git a/media/libstagefright/webm/WebmWriter.h b/media/libstagefright/webm/WebmWriter.h
index dd1fba3..9f3b19f 100644
--- a/media/libstagefright/webm/WebmWriter.h
+++ b/media/libstagefright/webm/WebmWriter.h
@@ -36,7 +36,7 @@
 
 class WebmWriter : public MediaWriter {
 public:
-    WebmWriter(int fd);
+    explicit WebmWriter(int fd);
     ~WebmWriter() { reset(); }
 
 
diff --git a/media/libstagefright/wifi-display/source/TSPacketizer.h b/media/libstagefright/wifi-display/source/TSPacketizer.h
index 4a664ee..0dcb179 100644
--- a/media/libstagefright/wifi-display/source/TSPacketizer.h
+++ b/media/libstagefright/wifi-display/source/TSPacketizer.h
@@ -36,7 +36,7 @@
         EMIT_HDCP20_DESCRIPTOR = 1,
         EMIT_HDCP21_DESCRIPTOR = 2,
     };
-    TSPacketizer(uint32_t flags);
+    explicit TSPacketizer(uint32_t flags);
 
     // Returns trackIndex or error.
     ssize_t addTrack(const sp<AMessage> &format);