Camera2: Use CameraMetadata wrapper class.

Wrap the use of the camera_metadata library inside a CameraMetadata
class to avoid memory leaks, improve code clarity, and increase type
safety.

Bug: 6243944
Change-Id: I90ca592b5875e27e4c58ea1ca680582dc3c3b56a

7 files changed, 680 insertions, 294 deletions

diff --git a/services/camera/libcameraservice/Android.mk b/services/camera/libcameraservice/Android.mk
index 8cccf49..079599a 100644
--- a/services/camera/libcameraservice/Android.mk
+++ b/services/camera/libcameraservice/Android.mk
@@ -10,7 +10,8 @@ LOCAL_SRC_FILES:=               \
     CameraService.cpp \
     CameraClient.cpp \
     Camera2Client.cpp \
-    Camera2Device.cpp
+    Camera2Device.cpp \
+    CameraMetadata.cpp
 
 LOCAL_SHARED_LIBRARIES:= \
     libui \
diff --git a/services/camera/libcameraservice/Camera2Client.cpp b/services/camera/libcameraservice/Camera2Client.cpp
index aa30501..c06f6ba 100644
--- a/services/camera/libcameraservice/Camera2Client.cpp
+++ b/services/camera/libcameraservice/Camera2Client.cpp
@@ -54,13 +54,10 @@ Camera2Client::Camera2Client(const sp<CameraService>& cameraService,
                 cameraId, cameraFacing, clientPid),
         mDeviceInfo(NULL),
         mPreviewStreamId(NO_STREAM),
-        mPreviewRequest(NULL),
         mCallbackStreamId(NO_STREAM),
         mCallbackHeapId(0),
         mCaptureStreamId(NO_STREAM),
-        mCaptureRequest(NULL),
         mRecordingStreamId(NO_STREAM),
-        mRecordingRequest(NULL),
         mRecordingHeapCount(kDefaultRecordingHeapCount)
 {
     ATRACE_CALL();
@@ -291,28 +288,28 @@ status_t Camera2Client::dump(int fd, const Vector<String16>& args) {
     result.appendFormat("    Recording stream ID: %d\n", mRecordingStreamId);
 
     result.append("  Current requests:\n");
-    if (mPreviewRequest != NULL) {
+    if (mPreviewRequest.entryCount() != 0) {
         result.append("    Preview request:\n");
         write(fd, result.string(), result.size());
-        dump_indented_camera_metadata(mPreviewRequest, fd, 2, 6);
+        mPreviewRequest.dump(fd, 2, 6);
     } else {
         result.append("    Preview request: undefined\n");
         write(fd, result.string(), result.size());
     }
 
-    if (mCaptureRequest != NULL) {
+    if (mCaptureRequest.entryCount() != 0) {
         result = "    Capture request:\n";
         write(fd, result.string(), result.size());
-        dump_indented_camera_metadata(mCaptureRequest, fd, 2, 6);
+        mCaptureRequest.dump(fd, 2, 6);
     } else {
         result = "    Capture request: undefined\n";
         write(fd, result.string(), result.size());
     }
 
-    if (mRecordingRequest != NULL) {
+    if (mRecordingRequest.entryCount() != 0) {
         result = "    Recording request:\n";
         write(fd, result.string(), result.size());
-        dump_indented_camera_metadata(mRecordingRequest, fd, 2, 6);
+        mRecordingRequest.dump(fd, 2, 6);
     } else {
         result = "    Recording request: undefined\n";
         write(fd, result.string(), result.size());
@@ -523,7 +520,7 @@ status_t Camera2Client::setPreviewWindowL(const sp<IBinder>& binder,
             // Already running preview - need to stop and create a new stream
             // TODO: Optimize this so that we don't wait for old stream to drain
             // before spinning up new stream
-            mDevice->setStreamingRequest(NULL);
+            mDevice->clearStreamingRequest();
             k.mParameters.state = WAITING_FOR_PREVIEW_WINDOW;
             break;
     }
@@ -634,7 +631,7 @@ status_t Camera2Client::startPreviewL(Parameters &params, bool restart) {
         }
     }
 
-    if (mPreviewRequest == NULL) {
+    if (mPreviewRequest.entryCount() == 0) {
         res = updatePreviewRequest(params);
         if (res != OK) {
             ALOGE("%s: Camera %d: Unable to create preview request: %s (%d)",
@@ -646,20 +643,21 @@ status_t Camera2Client::startPreviewL(Parameters &params, bool restart) {
     if (callbacksEnabled) {
         uint8_t outputStreams[2] =
                 { mPreviewStreamId, mCallbackStreamId };
-        res = updateEntry(mPreviewRequest,
+        res = mPreviewRequest.update(
                 ANDROID_REQUEST_OUTPUT_STREAMS,
                 outputStreams, 2);
     } else {
-        res = updateEntry(mPreviewRequest,
+        uint8_t outputStreams[1] = { mPreviewStreamId };
+        res = mPreviewRequest.update(
                 ANDROID_REQUEST_OUTPUT_STREAMS,
-                &mPreviewStreamId, 1);
+                outputStreams, 1);
     }
     if (res != OK) {
         ALOGE("%s: Camera %d: Unable to set up preview request: %s (%d)",
                 __FUNCTION__, mCameraId, strerror(-res), res);
         return res;
     }
-    res = sort_camera_metadata(mPreviewRequest);
+    res = mPreviewRequest.sort();
     if (res != OK) {
         ALOGE("%s: Camera %d: Error sorting preview request: %s (%d)",
                 __FUNCTION__, mCameraId, strerror(-res), res);
@@ -709,7 +707,7 @@ void Camera2Client::stopPreviewL() {
         case RECORD:
             // no break - identical to preview
         case PREVIEW:
-            mDevice->setStreamingRequest(NULL);
+            mDevice->clearStreamingRequest();
             mDevice->waitUntilDrained();
             // no break
         case WAITING_FOR_PREVIEW_WINDOW: {
@@ -814,7 +812,7 @@ status_t Camera2Client::startRecordingL(Parameters &params, bool restart) {
         }
     }
 
-    if (mRecordingRequest == NULL) {
+    if (mRecordingRequest.entryCount() == 0) {
         res = updateRecordingRequest(params);
         if (res != OK) {
             ALOGE("%s: Camera %d: Unable to create recording request: %s (%d)",
@@ -826,12 +824,12 @@ status_t Camera2Client::startRecordingL(Parameters &params, bool restart) {
     if (callbacksEnabled) {
         uint8_t outputStreams[3] =
                 { mPreviewStreamId, mRecordingStreamId, mCallbackStreamId };
-        res = updateEntry(mRecordingRequest,
+        res = mRecordingRequest.update(
                 ANDROID_REQUEST_OUTPUT_STREAMS,
                 outputStreams, 3);
     } else {
         uint8_t outputStreams[2] = { mPreviewStreamId, mRecordingStreamId };
-        res = updateEntry(mRecordingRequest,
+        res = mRecordingRequest.update(
                 ANDROID_REQUEST_OUTPUT_STREAMS,
                 outputStreams, 2);
     }
@@ -840,7 +838,7 @@ status_t Camera2Client::startRecordingL(Parameters &params, bool restart) {
                 __FUNCTION__, mCameraId, strerror(-res), res);
         return res;
     }
-    res = sort_camera_metadata(mRecordingRequest);
+    res = mRecordingRequest.sort();
     if (res != OK) {
         ALOGE("%s: Camera %d: Error sorting recording request: %s (%d)",
                 __FUNCTION__, mCameraId, strerror(-res), res);
@@ -1043,7 +1041,7 @@ status_t Camera2Client::takePicture(int msgType) {
         return res;
     }
 
-    if (mCaptureRequest == NULL) {
+    if (mCaptureRequest.entryCount() == 0) {
         res = updateCaptureRequest(k.mParameters);
         if (res != OK) {
             ALOGE("%s: Camera %d: Can't create still image capture request: "
@@ -1052,8 +1050,6 @@ status_t Camera2Client::takePicture(int msgType) {
         }
     }
 
-    camera_metadata_entry_t outputStreams;
-
     bool callbacksEnabled = k.mParameters.previewCallbackFlags &
             CAMERA_FRAME_CALLBACK_FLAG_ENABLE_MASK;
     bool recordingEnabled = (k.mParameters.state == RECORD);
@@ -1063,29 +1059,29 @@ status_t Camera2Client::takePicture(int msgType) {
     switch ( streamSwitch ) {
         case 0: { // No recording, callbacks
             uint8_t streamIds[2] = { mPreviewStreamId, mCaptureStreamId };
-            res = updateEntry(mCaptureRequest, ANDROID_REQUEST_OUTPUT_STREAMS,
-                    &streamIds, 2);
+            res = mCaptureRequest.update(ANDROID_REQUEST_OUTPUT_STREAMS,
+                    streamIds, 2);
             break;
         }
         case 1: { // Recording
             uint8_t streamIds[3] = { mPreviewStreamId, mRecordingStreamId,
                                      mCaptureStreamId };
-            res = updateEntry(mCaptureRequest, ANDROID_REQUEST_OUTPUT_STREAMS,
-                    &streamIds, 3);
+            res = mCaptureRequest.update(ANDROID_REQUEST_OUTPUT_STREAMS,
+                    streamIds, 3);
             break;
         }
         case 2: { // Callbacks
             uint8_t streamIds[3] = { mPreviewStreamId, mCallbackStreamId,
                                      mCaptureStreamId };
-            res = updateEntry(mCaptureRequest, ANDROID_REQUEST_OUTPUT_STREAMS,
-                    &streamIds, 3);
+            res = mCaptureRequest.update(ANDROID_REQUEST_OUTPUT_STREAMS,
+                    streamIds, 3);
             break;
         }
         case 3: { // Both
             uint8_t streamIds[4] = { mPreviewStreamId, mCallbackStreamId,
                                      mRecordingStreamId, mCaptureStreamId };
-            res = updateEntry(mCaptureRequest, ANDROID_REQUEST_OUTPUT_STREAMS,
-                    &streamIds, 4);
+            res = mCaptureRequest.update(ANDROID_REQUEST_OUTPUT_STREAMS,
+                    streamIds, 4);
             break;
         }
     };
@@ -1095,22 +1091,22 @@ status_t Camera2Client::takePicture(int msgType) {
                 __FUNCTION__, mCameraId, strerror(-res), res);
         return res;
     }
-    res = sort_camera_metadata(mCaptureRequest);
+    res = mCaptureRequest.sort();
     if (res != OK) {
         ALOGE("%s: Camera %d: Unable to sort capture request: %s (%d)",
                 __FUNCTION__, mCameraId, strerror(-res), res);
         return res;
     }
 
-    camera_metadata_t *captureCopy = clone_camera_metadata(mCaptureRequest);
-    if (captureCopy == NULL) {
+    CameraMetadata captureCopy = mCaptureRequest;
+    if (captureCopy.entryCount() == 0) {
         ALOGE("%s: Camera %d: Unable to copy capture request for HAL device",
                 __FUNCTION__, mCameraId);
         return NO_MEMORY;
     }
 
     if (k.mParameters.state == PREVIEW) {
-        res = mDevice->setStreamingRequest(NULL);
+        res = mDevice->clearStreamingRequest();
         if (res != OK) {
             ALOGE("%s: Camera %d: Unable to stop preview for still capture: "
                     "%s (%d)",
@@ -1182,7 +1178,7 @@ status_t Camera2Client::setParameters(const String8& params) {
                     previewWidth, previewHeight);
             return BAD_VALUE;
         }
-        camera_metadata_entry_t availablePreviewSizes =
+        camera_metadata_ro_entry_t availablePreviewSizes =
             staticInfo(ANDROID_SCALER_AVAILABLE_PROCESSED_SIZES);
         for (i = 0; i < availablePreviewSizes.count; i += 2 ) {
             if (availablePreviewSizes.data.i32[i] == previewWidth &&
@@ -1203,7 +1199,7 @@ status_t Camera2Client::setParameters(const String8& params) {
     if (previewFpsRange[0] != k.mParameters.previewFpsRange[0] ||
             previewFpsRange[1] != k.mParameters.previewFpsRange[1]) {
         fpsRangeChanged = true;
-        camera_metadata_entry_t availablePreviewFpsRanges =
+        camera_metadata_ro_entry_t availablePreviewFpsRanges =
             staticInfo(ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES, 2);
         for (i = 0; i < availablePreviewFpsRanges.count; i += 2) {
             if ((availablePreviewFpsRanges.data.i32[i] ==
@@ -1229,7 +1225,7 @@ status_t Camera2Client::setParameters(const String8& params) {
                     "is active!", __FUNCTION__);
             return BAD_VALUE;
         }
-        camera_metadata_entry_t availableFormats =
+        camera_metadata_ro_entry_t availableFormats =
             staticInfo(ANDROID_SCALER_AVAILABLE_FORMATS);
         for (i = 0; i < availableFormats.count; i++) {
             if (availableFormats.data.i32[i] == previewFormat) break;
@@ -1247,7 +1243,7 @@ status_t Camera2Client::setParameters(const String8& params) {
     if (!fpsRangeChanged) {
         previewFps = newParams.getPreviewFrameRate();
         if (previewFps != k.mParameters.previewFps) {
-            camera_metadata_entry_t availableFrameRates =
+            camera_metadata_ro_entry_t availableFrameRates =
                 staticInfo(ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES);
             for (i = 0; i < availableFrameRates.count; i+=2) {
                 if (availableFrameRates.data.i32[i] == previewFps) break;
@@ -1267,7 +1263,7 @@ status_t Camera2Client::setParameters(const String8& params) {
     newParams.getPictureSize(&pictureWidth, &pictureHeight);
     if (pictureWidth == k.mParameters.pictureWidth ||
             pictureHeight == k.mParameters.pictureHeight) {
-        camera_metadata_entry_t availablePictureSizes =
+        camera_metadata_ro_entry_t availablePictureSizes =
             staticInfo(ANDROID_SCALER_AVAILABLE_JPEG_SIZES);
         for (i = 0; i < availablePictureSizes.count; i+=2) {
             if (availablePictureSizes.data.i32[i] == pictureWidth &&
@@ -1288,7 +1284,7 @@ status_t Camera2Client::setParameters(const String8& params) {
             newParams.getInt(CameraParameters::KEY_JPEG_THUMBNAIL_HEIGHT);
     if (jpegThumbSize[0] != k.mParameters.jpegThumbSize[0] ||
             jpegThumbSize[1] != k.mParameters.jpegThumbSize[1]) {
-        camera_metadata_entry_t availableJpegThumbSizes =
+        camera_metadata_ro_entry_t availableJpegThumbSizes =
             staticInfo(ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES);
         for (i = 0; i < availableJpegThumbSizes.count; i+=2) {
             if (availableJpegThumbSizes.data.i32[i] == jpegThumbSize[0] &&
@@ -1392,7 +1388,7 @@ status_t Camera2Client::setParameters(const String8& params) {
     int wbMode = wbModeStringToEnum(
         newParams.get(CameraParameters::KEY_WHITE_BALANCE) );
     if (wbMode != k.mParameters.wbMode) {
-        camera_metadata_entry_t availableWbModes =
+        camera_metadata_ro_entry_t availableWbModes =
             staticInfo(ANDROID_CONTROL_AWB_AVAILABLE_MODES);
         for (i = 0; i < availableWbModes.count; i++) {
             if (wbMode == availableWbModes.data.u8[i]) break;
@@ -1409,7 +1405,7 @@ status_t Camera2Client::setParameters(const String8& params) {
     int effectMode = effectModeStringToEnum(
         newParams.get(CameraParameters::KEY_EFFECT) );
     if (effectMode != k.mParameters.effectMode) {
-        camera_metadata_entry_t availableEffectModes =
+        camera_metadata_ro_entry_t availableEffectModes =
             staticInfo(ANDROID_CONTROL_AVAILABLE_EFFECTS);
         for (i = 0; i < availableEffectModes.count; i++) {
             if (effectMode == availableEffectModes.data.u8[i]) break;
@@ -1426,7 +1422,7 @@ status_t Camera2Client::setParameters(const String8& params) {
     int antibandingMode = abModeStringToEnum(
         newParams.get(CameraParameters::KEY_ANTIBANDING) );
     if (antibandingMode != k.mParameters.antibandingMode) {
-        camera_metadata_entry_t availableAbModes =
+        camera_metadata_ro_entry_t availableAbModes =
             staticInfo(ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES);
         for (i = 0; i < availableAbModes.count; i++) {
             if (antibandingMode == availableAbModes.data.u8[i]) break;
@@ -1444,7 +1440,7 @@ status_t Camera2Client::setParameters(const String8& params) {
         newParams.get(CameraParameters::KEY_SCENE_MODE) );
     if (sceneMode != k.mParameters.sceneMode &&
             sceneMode != ANDROID_CONTROL_SCENE_MODE_UNSUPPORTED) {
-        camera_metadata_entry_t availableSceneModes =
+        camera_metadata_ro_entry_t availableSceneModes =
             staticInfo(ANDROID_CONTROL_AVAILABLE_SCENE_MODES);
         for (i = 0; i < availableSceneModes.count; i++) {
             if (sceneMode == availableSceneModes.data.u8[i]) break;
@@ -1461,7 +1457,7 @@ status_t Camera2Client::setParameters(const String8& params) {
     Parameters::flashMode_t flashMode = flashModeStringToEnum(
         newParams.get(CameraParameters::KEY_FLASH_MODE) );
     if (flashMode != k.mParameters.flashMode) {
-        camera_metadata_entry_t flashAvailable =
+        camera_metadata_ro_entry_t flashAvailable =
             staticInfo(ANDROID_FLASH_AVAILABLE, 1, 1);
         if (!flashAvailable.data.u8[0] &&
                 flashMode != Parameters::FLASH_MODE_OFF) {
@@ -1470,7 +1466,7 @@ status_t Camera2Client::setParameters(const String8& params) {
                     newParams.get(CameraParameters::KEY_FLASH_MODE));
             return BAD_VALUE;
         } else if (flashMode == Parameters::FLASH_MODE_RED_EYE) {
-            camera_metadata_entry_t availableAeModes =
+            camera_metadata_ro_entry_t availableAeModes =
                 staticInfo(ANDROID_CONTROL_AE_AVAILABLE_MODES);
             for (i = 0; i < availableAeModes.count; i++) {
                 if (flashMode == availableAeModes.data.u8[i]) break;
@@ -1494,7 +1490,7 @@ status_t Camera2Client::setParameters(const String8& params) {
         newParams.get(CameraParameters::KEY_FOCUS_MODE));
     if (focusMode != k.mParameters.focusMode) {
         if (focusMode != Parameters::FOCUS_MODE_FIXED) {
-            camera_metadata_entry_t minFocusDistance =
+            camera_metadata_ro_entry_t minFocusDistance =
                 staticInfo(ANDROID_LENS_MINIMUM_FOCUS_DISTANCE);
             if (minFocusDistance.data.f[0] == 0) {
                 ALOGE("%s: Requested focus mode \"%s\" is not available: "
@@ -1503,7 +1499,7 @@ status_t Camera2Client::setParameters(const String8& params) {
                         newParams.get(CameraParameters::KEY_FOCUS_MODE));
                 return BAD_VALUE;
             } else if (focusMode != Parameters::FOCUS_MODE_INFINITY) {
-                camera_metadata_entry_t availableFocusModes =
+                camera_metadata_ro_entry_t availableFocusModes =
                     staticInfo(ANDROID_CONTROL_AF_AVAILABLE_MODES);
                 for (i = 0; i < availableFocusModes.count; i++) {
                     if (focusMode == availableFocusModes.data.u8[i]) break;
@@ -1534,7 +1530,7 @@ status_t Camera2Client::setParameters(const String8& params) {
     // EXPOSURE_COMPENSATION
     int exposureCompensation =
         newParams.getInt(CameraParameters::KEY_EXPOSURE_COMPENSATION);
-    camera_metadata_entry_t exposureCompensationRange =
+    camera_metadata_ro_entry_t exposureCompensationRange =
         staticInfo(ANDROID_CONTROL_AE_EXP_COMPENSATION_RANGE);
     if (exposureCompensation < exposureCompensationRange.data.i32[0] ||
             exposureCompensation > exposureCompensationRange.data.i32[1]) {
@@ -1581,7 +1577,7 @@ status_t Camera2Client::setParameters(const String8& params) {
                     __FUNCTION__);
             return BAD_VALUE;
         }
-        camera_metadata_entry_t availableVideoSizes =
+        camera_metadata_ro_entry_t availableVideoSizes =
             staticInfo(ANDROID_SCALER_AVAILABLE_PROCESSED_SIZES);
         for (i = 0; i < availableVideoSizes.count; i += 2 ) {
             if (availableVideoSizes.data.i32[i] == videoWidth &&
@@ -1601,7 +1597,7 @@ status_t Camera2Client::setParameters(const String8& params) {
     // VIDEO_STABILIZATION
     bool videoStabilization = boolFromString(
         newParams.get(CameraParameters::KEY_VIDEO_STABILIZATION) );
-    camera_metadata_entry_t availableVideoStabilizationModes =
+    camera_metadata_ro_entry_t availableVideoStabilizationModes =
         staticInfo(ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES);
     if (videoStabilization && availableVideoStabilizationModes.count == 1) {
         ALOGE("%s: Video stabilization not supported", __FUNCTION__);
@@ -1992,64 +1988,50 @@ void Camera2Client::notifyAutoWhitebalance(uint8_t newState, int triggerId) {
 
 void Camera2Client::onNewFrameAvailable() {
     status_t res;
-    camera_metadata_t *frame = NULL;
-    do {
-        res = mDevice->getNextFrame(&frame);
-        if (res != OK) {
-            ALOGE("%s: Camera %d: Error getting next frame: %s (%d)",
+    CameraMetadata frame;
+    while ( (res = mDevice->getNextFrame(&frame)) == OK) {
+        camera_metadata_entry_t entry;
+        entry = frame.find(ANDROID_REQUEST_FRAME_COUNT);
+        if (entry.count == 0) {
+            ALOGE("%s: Camera %d: Error reading frame number: %s (%d)",
                     __FUNCTION__, mCameraId, strerror(-res), res);
-            return;
-        }
-        if (frame != NULL) {
-            camera_metadata_entry_t entry;
-            res = find_camera_metadata_entry(frame, ANDROID_REQUEST_FRAME_COUNT,
-                    &entry);
-            if (res != OK) {
-                ALOGE("%s: Camera %d: Error reading frame number: %s (%d)",
-                        __FUNCTION__, mCameraId, strerror(-res), res);
-                break;
-            }
-
-            res = processFrameFaceDetect(frame);
-            if (res != OK) break;
-
-            free_camera_metadata(frame);
+            break;
         }
-    } while (frame != NULL);
 
-    if (frame != NULL) {
-        free_camera_metadata(frame);
+        res = processFrameFaceDetect(frame);
+        if (res != OK) break;
+    }
+    if (res != NOT_ENOUGH_DATA) {
+        ALOGE("%s: Camera %d: Error getting next frame: %s (%d)",
+                __FUNCTION__, mCameraId, strerror(-res), res);
+        return;
     }
+
     return;
 }
 
-status_t Camera2Client::processFrameFaceDetect(camera_metadata_t *frame) {
+status_t Camera2Client::processFrameFaceDetect(const CameraMetadata &frame) {
     status_t res;
-    camera_metadata_entry_t entry;
+    camera_metadata_ro_entry_t entry;
     bool enableFaceDetect;
     {
         LockedParameters::Key k(mParameters);
         enableFaceDetect = k.mParameters.enableFaceDetect;
     }
-    res = find_camera_metadata_entry(frame, ANDROID_STATS_FACE_DETECT_MODE,
-            &entry);
-    // TODO: Remove this check once things are more compliant. For now, assume that
-    // if we can't find the face detect mode, then it's probably not working.
-    if (res == NAME_NOT_FOUND) {
+    entry = frame.find(ANDROID_STATS_FACE_DETECT_MODE);
+
+    // TODO: This should be an error once implementations are compliant
+    if (entry.count == 0) {
         return OK;
-    } else if (res != OK) {
-        ALOGE("%s: Camera %d: Error reading face mode: %s (%d)",
-                __FUNCTION__, mCameraId, strerror(-res), res);
-        return res;
     }
+
     uint8_t faceDetectMode = entry.data.u8[0];
 
     if (enableFaceDetect && faceDetectMode != ANDROID_STATS_FACE_DETECTION_OFF) {
-        res = find_camera_metadata_entry(frame, ANDROID_STATS_FACE_RECTANGLES,
-                &entry);
-        if (res != OK) {
-            ALOGE("%s: Camera %d: Error reading face rectangles: %s (%d)",
-                    __FUNCTION__, mCameraId, strerror(-res), res);
+        entry = frame.find(ANDROID_STATS_FACE_RECTANGLES);
+        if (entry.count == 0) {
+            ALOGE("%s: Camera %d: Unable to read face rectangles",
+                    __FUNCTION__, mCameraId);
             return res;
         }
         camera_frame_metadata metadata;
@@ -2061,35 +2043,33 @@ status_t Camera2Client::processFrameFaceDetect(camera_metadata_t *frame) {
                     metadata.number_of_faces, mDeviceInfo->maxFaces);
             return res;
         }
-        int32_t *faceRects = entry.data.i32;
+        const int32_t *faceRects = entry.data.i32;
 
-        res = find_camera_metadata_entry(frame, ANDROID_STATS_FACE_SCORES,
-                &entry);
-        if (res != OK) {
-            ALOGE("%s: Camera %d: Error reading face scores: %s (%d)",
-                    __FUNCTION__, mCameraId, strerror(-res), res);
+        entry = frame.find(ANDROID_STATS_FACE_SCORES);
+        if (entry.count == 0) {
+            ALOGE("%s: Camera %d: Unable to read face scores",
+                    __FUNCTION__, mCameraId);
             return res;
         }
-        uint8_t *faceScores = entry.data.u8;
+        const uint8_t *faceScores = entry.data.u8;
 
-        int32_t *faceLandmarks = NULL;
-        int32_t *faceIds = NULL;
+        const int32_t *faceLandmarks = NULL;
+        const int32_t *faceIds = NULL;
 
         if (faceDetectMode == ANDROID_STATS_FACE_DETECTION_FULL) {
-            res = find_camera_metadata_entry(frame, ANDROID_STATS_FACE_LANDMARKS,
-                    &entry);
-            if (res != OK) {
-                ALOGE("%s: Camera %d: Error reading face landmarks: %s (%d)",
-                        __FUNCTION__, mCameraId, strerror(-res), res);
+            entry = frame.find(ANDROID_STATS_FACE_LANDMARKS);
+            if (entry.count == 0) {
+                ALOGE("%s: Camera %d: Unable to read face landmarks",
+                        __FUNCTION__, mCameraId);
                 return res;
             }
             faceLandmarks = entry.data.i32;
 
-            res = find_camera_metadata_entry(frame, ANDROID_STATS_FACE_IDS,
-                    &entry);
-            if (res != OK) {
-                ALOGE("%s: Camera %d: Error reading face IDs: %s (%d)",
-                        __FUNCTION__, mCameraId, strerror(-res), res);
+            entry = frame.find(ANDROID_STATS_FACE_IDS);
+
+            if (entry.count == 0) {
+                ALOGE("%s: Camera %d: Unable to read face IDs",
+                        __FUNCTION__, mCameraId);
                 return res;
             }
             faceIds = entry.data.i32;
@@ -2426,23 +2406,19 @@ void Camera2Client::onRecordingFrameAvailable() {
     }
 }
 
-camera_metadata_entry_t Camera2Client::staticInfo(uint32_t tag,
-        size_t minCount, size_t maxCount) {
+camera_metadata_ro_entry_t Camera2Client::staticInfo(uint32_t tag,
+        size_t minCount, size_t maxCount) const {
     status_t res;
-    camera_metadata_entry_t entry;
-    res = find_camera_metadata_entry(mDevice->info(),
-            tag,
-            &entry);
-    if (CC_UNLIKELY( res != OK )) {
+    camera_metadata_ro_entry_t entry = mDevice->info().find(tag);
+
+    if (CC_UNLIKELY( entry.count == 0 )) {
         const char* tagSection = get_camera_metadata_section_name(tag);
         if (tagSection == NULL) tagSection = "<unknown>";
         const char* tagName = get_camera_metadata_tag_name(tag);
         if (tagName == NULL) tagName = "<unknown>";
 
-        ALOGE("Error finding static metadata entry '%s.%s' (%x): %s (%d)",
-                tagSection, tagName, tag, strerror(-res), res);
-        entry.count = 0;
-        entry.data.u8 = NULL;
+        ALOGE("Error finding static metadata entry '%s.%s' (%x)",
+                tagSection, tagName, tag);
     } else if (CC_UNLIKELY(
             (minCount != 0 && entry.count < minCount) ||
             (maxCount != 0 && entry.count > maxCount) ) ) {
@@ -2453,8 +2429,6 @@ camera_metadata_entry_t Camera2Client::staticInfo(uint32_t tag,
         ALOGE("Malformed static metadata entry '%s.%s' (%x):"
                 "Expected between %d and %d values, but got %d values",
                 tagSection, tagName, tag, minCount, maxCount, entry.count);
-        entry.count = 0;
-        entry.data.u8 = NULL;
     }
 
     return entry;
@@ -2469,13 +2443,13 @@ status_t Camera2Client::buildDeviceInfo() {
     DeviceInfo *deviceInfo = new DeviceInfo;
     mDeviceInfo = deviceInfo;
 
-    camera_metadata_entry_t activeArraySize =
+    camera_metadata_ro_entry_t activeArraySize =
         staticInfo(ANDROID_SENSOR_ACTIVE_ARRAY_SIZE, 2, 2);
     if (!activeArraySize.count) return NO_INIT;
     deviceInfo->arrayWidth = activeArraySize.data.i32[0];
     deviceInfo->arrayHeight = activeArraySize.data.i32[1];
 
-    camera_metadata_entry_t availableFaceDetectModes =
+    camera_metadata_ro_entry_t availableFaceDetectModes =
         staticInfo(ANDROID_STATS_AVAILABLE_FACE_DETECT_MODES);
     if (!availableFaceDetectModes.count) return NO_INIT;
 
@@ -2504,7 +2478,7 @@ status_t Camera2Client::buildDeviceInfo() {
         }
     }
 
-    camera_metadata_entry_t maxFacesDetected =
+    camera_metadata_ro_entry_t maxFacesDetected =
         staticInfo(ANDROID_STATS_MAX_FACE_COUNT, 1, 1);
     if (!maxFacesDetected.count) return NO_INIT;
 
@@ -2520,7 +2494,7 @@ status_t Camera2Client::buildDefaultParameters() {
     status_t res;
     CameraParameters params;
 
-    camera_metadata_entry_t availableProcessedSizes =
+    camera_metadata_ro_entry_t availableProcessedSizes =
         staticInfo(ANDROID_SCALER_AVAILABLE_PROCESSED_SIZES, 2);
     if (!availableProcessedSizes.count) return NO_INIT;
 
@@ -2549,7 +2523,7 @@ status_t Camera2Client::buildDefaultParameters() {
                 supportedPreviewSizes);
     }
 
-    camera_metadata_entry_t availableFpsRanges =
+    camera_metadata_ro_entry_t availableFpsRanges =
         staticInfo(ANDROID_CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES, 2);
     if (!availableFpsRanges.count) return NO_INIT;
 
@@ -2580,7 +2554,7 @@ status_t Camera2Client::buildDefaultParameters() {
     k.mParameters.previewTransform = degToTransform(0,
             mCameraFacing == CAMERA_FACING_FRONT);
 
-    camera_metadata_entry_t availableFormats =
+    camera_metadata_ro_entry_t availableFormats =
         staticInfo(ANDROID_SCALER_AVAILABLE_FORMATS);
 
     {
@@ -2648,7 +2622,7 @@ status_t Camera2Client::buildDefaultParameters() {
                 supportedPreviewFrameRates);
     }
 
-    camera_metadata_entry_t availableJpegSizes =
+    camera_metadata_ro_entry_t availableJpegSizes =
         staticInfo(ANDROID_SCALER_AVAILABLE_JPEG_SIZES, 2);
     if (!availableJpegSizes.count) return NO_INIT;
 
@@ -2675,7 +2649,7 @@ status_t Camera2Client::buildDefaultParameters() {
     params.set(CameraParameters::KEY_SUPPORTED_PICTURE_FORMATS,
             CameraParameters::PIXEL_FORMAT_JPEG);
 
-    camera_metadata_entry_t availableJpegThumbnailSizes =
+    camera_metadata_ro_entry_t availableJpegThumbnailSizes =
         staticInfo(ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES, 2);
     if (!availableJpegThumbnailSizes.count) return NO_INIT;
 
@@ -2718,7 +2692,7 @@ status_t Camera2Client::buildDefaultParameters() {
     params.set(CameraParameters::KEY_WHITE_BALANCE,
             CameraParameters::WHITE_BALANCE_AUTO);
 
-    camera_metadata_entry_t availableWhiteBalanceModes =
+    camera_metadata_ro_entry_t availableWhiteBalanceModes =
         staticInfo(ANDROID_CONTROL_AWB_AVAILABLE_MODES);
     {
         String8 supportedWhiteBalance;
@@ -2779,7 +2753,7 @@ status_t Camera2Client::buildDefaultParameters() {
     params.set(CameraParameters::KEY_EFFECT,
             CameraParameters::EFFECT_NONE);
 
-    camera_metadata_entry_t availableEffects =
+    camera_metadata_ro_entry_t availableEffects =
         staticInfo(ANDROID_CONTROL_AVAILABLE_EFFECTS);
     if (!availableEffects.count) return NO_INIT;
     {
@@ -2839,7 +2813,7 @@ status_t Camera2Client::buildDefaultParameters() {
     params.set(CameraParameters::KEY_ANTIBANDING,
             CameraParameters::ANTIBANDING_AUTO);
 
-    camera_metadata_entry_t availableAntibandingModes =
+    camera_metadata_ro_entry_t availableAntibandingModes =
         staticInfo(ANDROID_CONTROL_AE_AVAILABLE_ANTIBANDING_MODES);
     if (!availableAntibandingModes.count) return NO_INIT;
     {
@@ -2881,7 +2855,7 @@ status_t Camera2Client::buildDefaultParameters() {
     params.set(CameraParameters::KEY_SCENE_MODE,
             CameraParameters::SCENE_MODE_AUTO);
 
-    camera_metadata_entry_t availableSceneModes =
+    camera_metadata_ro_entry_t availableSceneModes =
         staticInfo(ANDROID_CONTROL_AVAILABLE_SCENE_MODES);
     if (!availableSceneModes.count) return NO_INIT;
     {
@@ -2973,11 +2947,11 @@ status_t Camera2Client::buildDefaultParameters() {
         }
     }
 
-    camera_metadata_entry_t flashAvailable =
+    camera_metadata_ro_entry_t flashAvailable =
         staticInfo(ANDROID_FLASH_AVAILABLE, 1, 1);
     if (!flashAvailable.count) return NO_INIT;
 
-    camera_metadata_entry_t availableAeModes =
+    camera_metadata_ro_entry_t availableAeModes =
         staticInfo(ANDROID_CONTROL_AE_AVAILABLE_MODES);
     if (!availableAeModes.count) return NO_INIT;
 
@@ -3009,11 +2983,11 @@ status_t Camera2Client::buildDefaultParameters() {
                 CameraParameters::FLASH_MODE_OFF);
     }
 
-    camera_metadata_entry_t minFocusDistance =
+    camera_metadata_ro_entry_t minFocusDistance =
         staticInfo(ANDROID_LENS_MINIMUM_FOCUS_DISTANCE, 1, 1);
     if (!minFocusDistance.count) return NO_INIT;
 
-    camera_metadata_entry_t availableAfModes =
+    camera_metadata_ro_entry_t availableAfModes =
         staticInfo(ANDROID_CONTROL_AF_AVAILABLE_MODES);
     if (!availableAfModes.count) return NO_INIT;
 
@@ -3070,7 +3044,7 @@ status_t Camera2Client::buildDefaultParameters() {
                 supportedFocusModes);
     }
 
-    camera_metadata_entry_t max3aRegions =
+    camera_metadata_ro_entry_t max3aRegions =
         staticInfo(ANDROID_CONTROL_MAX_REGIONS, 1, 1);
     if (!max3aRegions.count) return NO_INIT;
 
@@ -3081,14 +3055,14 @@ status_t Camera2Client::buildDefaultParameters() {
     k.mParameters.focusingAreas.clear();
     k.mParameters.focusingAreas.add(Parameters::Area(0,0,0,0,0));
 
-    camera_metadata_entry_t availableFocalLengths =
+    camera_metadata_ro_entry_t availableFocalLengths =
         staticInfo(ANDROID_LENS_AVAILABLE_FOCAL_LENGTHS);
     if (!availableFocalLengths.count) return NO_INIT;
 
     float minFocalLength = availableFocalLengths.data.f[0];
     params.setFloat(CameraParameters::KEY_FOCAL_LENGTH, minFocalLength);
 
-    camera_metadata_entry_t sensorSize =
+    camera_metadata_ro_entry_t sensorSize =
         staticInfo(ANDROID_SENSOR_PHYSICAL_SIZE, 2, 2);
     if (!sensorSize.count) return NO_INIT;
 
@@ -3104,7 +3078,7 @@ status_t Camera2Client::buildDefaultParameters() {
     params.set(CameraParameters::KEY_EXPOSURE_COMPENSATION,
                 k.mParameters.exposureCompensation);
 
-    camera_metadata_entry_t exposureCompensationRange =
+    camera_metadata_ro_entry_t exposureCompensationRange =
         staticInfo(ANDROID_CONTROL_AE_EXP_COMPENSATION_RANGE, 2, 2);
     if (!exposureCompensationRange.count) return NO_INIT;
 
@@ -3113,7 +3087,7 @@ status_t Camera2Client::buildDefaultParameters() {
     params.set(CameraParameters::KEY_MIN_EXPOSURE_COMPENSATION,
             exposureCompensationRange.data.i32[0]);
 
-    camera_metadata_entry_t exposureCompensationStep =
+    camera_metadata_ro_entry_t exposureCompensationStep =
         staticInfo(ANDROID_CONTROL_AE_EXP_COMPENSATION_STEP, 1, 1);
     if (!exposureCompensationStep.count) return NO_INIT;
 
@@ -3143,7 +3117,7 @@ status_t Camera2Client::buildDefaultParameters() {
     params.set(CameraParameters::KEY_ZOOM, k.mParameters.zoom);
     params.set(CameraParameters::KEY_MAX_ZOOM, NUM_ZOOM_STEPS - 1);
 
-    camera_metadata_entry_t maxDigitalZoom =
+    camera_metadata_ro_entry_t maxDigitalZoom =
         staticInfo(ANDROID_SCALER_AVAILABLE_MAX_ZOOM, 1, 1);
     if (!maxDigitalZoom.count) return NO_INIT;
 
@@ -3187,7 +3161,7 @@ status_t Camera2Client::buildDefaultParameters() {
     params.set(CameraParameters::KEY_VIDEO_STABILIZATION,
             CameraParameters::FALSE);
 
-    camera_metadata_entry_t availableVideoStabilizationModes =
+    camera_metadata_ro_entry_t availableVideoStabilizationModes =
         staticInfo(ANDROID_CONTROL_AVAILABLE_VIDEO_STABILIZATION_MODES);
     if (!availableVideoStabilizationModes.count) return NO_INIT;
 
@@ -3321,7 +3295,7 @@ status_t Camera2Client::updatePreviewStream(const Parameters &params) {
 status_t Camera2Client::updatePreviewRequest(const Parameters &params) {
     ATRACE_CALL();
     status_t res;
-    if (mPreviewRequest == NULL) {
+    if (mPreviewRequest.entryCount() == 0) {
         res = mDevice->createDefaultRequest(CAMERA2_TEMPLATE_PREVIEW,
                 &mPreviewRequest);
         if (res != OK) {
@@ -3331,7 +3305,7 @@ status_t Camera2Client::updatePreviewRequest(const Parameters &params) {
         }
     }
 
-    res = updateRequestCommon(mPreviewRequest, params);
+    res = updateRequestCommon(&mPreviewRequest, params);
     if (res != OK) {
         ALOGE("%s: Camera %d: Unable to update common entries of preview "
                 "request: %s (%d)", __FUNCTION__, mCameraId,
@@ -3404,7 +3378,7 @@ status_t Camera2Client::updateCaptureStream(const Parameters &params) {
     ATRACE_CALL();
     status_t res;
     // Find out buffer size for JPEG
-    camera_metadata_entry_t maxJpegSize =
+    camera_metadata_ro_entry_t maxJpegSize =
             staticInfo(ANDROID_JPEG_MAX_SIZE);
     if (maxJpegSize.count == 0) {
         ALOGE("%s: Camera %d: Can't find ANDROID_JPEG_MAX_SIZE!",
@@ -3471,7 +3445,7 @@ status_t Camera2Client::updateCaptureStream(const Parameters &params) {
 status_t Camera2Client::updateCaptureRequest(const Parameters &params) {
     ATRACE_CALL();
     status_t res;
-    if (mCaptureRequest == NULL) {
+    if (mCaptureRequest.entryCount() == 0) {
         res = mDevice->createDefaultRequest(CAMERA2_TEMPLATE_STILL_CAPTURE,
                 &mCaptureRequest);
         if (res != OK) {
@@ -3481,7 +3455,7 @@ status_t Camera2Client::updateCaptureRequest(const Parameters &params) {
         }
     }
 
-    res = updateRequestCommon(mCaptureRequest, params);
+    res = updateRequestCommon(&mCaptureRequest, params);
     if (res != OK) {
         ALOGE("%s: Camera %d: Unable to update common entries of capture "
                 "request: %s (%d)", __FUNCTION__, mCameraId,
@@ -3489,46 +3463,39 @@ status_t Camera2Client::updateCaptureRequest(const Parameters &params) {
         return res;
     }
 
-    res = updateEntry(mCaptureRequest,
-            ANDROID_JPEG_THUMBNAIL_SIZE,
+    res = mCaptureRequest.update(ANDROID_JPEG_THUMBNAIL_SIZE,
             params.jpegThumbSize, 2);
     if (res != OK) return res;
-    res = updateEntry(mCaptureRequest,
-            ANDROID_JPEG_THUMBNAIL_QUALITY,
+    res = mCaptureRequest.update(ANDROID_JPEG_THUMBNAIL_QUALITY,
             &params.jpegThumbQuality, 1);
     if (res != OK) return res;
-    res = updateEntry(mCaptureRequest,
-            ANDROID_JPEG_QUALITY,
+    res = mCaptureRequest.update(ANDROID_JPEG_QUALITY,
             &params.jpegQuality, 1);
     if (res != OK) return res;
-    res = updateEntry(mCaptureRequest,
+    res = mCaptureRequest.update(
             ANDROID_JPEG_ORIENTATION,
             &params.jpegRotation, 1);
     if (res != OK) return res;
 
     if (params.gpsEnabled) {
-        res = updateEntry(mCaptureRequest,
+        res = mCaptureRequest.update(
                 ANDROID_JPEG_GPS_COORDINATES,
                 params.gpsCoordinates, 3);
         if (res != OK) return res;
-        res = updateEntry(mCaptureRequest,
+        res = mCaptureRequest.update(
                 ANDROID_JPEG_GPS_TIMESTAMP,
                 &params.gpsTimestamp, 1);
         if (res != OK) return res;
-        res = updateEntry(mCaptureRequest,
+        res = mCaptureRequest.update(
                 ANDROID_JPEG_GPS_PROCESSING_METHOD,
-                params.gpsProcessingMethod.string(),
-                params.gpsProcessingMethod.size());
+                params.gpsProcessingMethod);
         if (res != OK) return res;
     } else {
-        res = deleteEntry(mCaptureRequest,
-                ANDROID_JPEG_GPS_COORDINATES);
+        res = mCaptureRequest.erase(ANDROID_JPEG_GPS_COORDINATES);
         if (res != OK) return res;
-        res = deleteEntry(mCaptureRequest,
-                ANDROID_JPEG_GPS_TIMESTAMP);
+        res = mCaptureRequest.erase(ANDROID_JPEG_GPS_TIMESTAMP);
         if (res != OK) return res;
-        res = deleteEntry(mCaptureRequest,
-                ANDROID_JPEG_GPS_PROCESSING_METHOD);
+        res = mCaptureRequest.erase(ANDROID_JPEG_GPS_PROCESSING_METHOD);
         if (res != OK) return res;
     }
 
@@ -3538,7 +3505,7 @@ status_t Camera2Client::updateCaptureRequest(const Parameters &params) {
 status_t Camera2Client::updateRecordingRequest(const Parameters &params) {
     ATRACE_CALL();
     status_t res;
-    if (mRecordingRequest == NULL) {
+    if (mRecordingRequest.entryCount() == 0) {
         res = mDevice->createDefaultRequest(CAMERA2_TEMPLATE_VIDEO_RECORD,
                 &mRecordingRequest);
         if (res != OK) {
@@ -3548,7 +3515,7 @@ status_t Camera2Client::updateRecordingRequest(const Parameters &params) {
         }
     }
 
-    res = updateRequestCommon(mRecordingRequest, params);
+    res = updateRequestCommon(&mRecordingRequest, params);
     if (res != OK) {
         ALOGE("%s: Camera %d: Unable to update common entries of recording "
                 "request: %s (%d)", __FUNCTION__, mCameraId,
@@ -3616,36 +3583,34 @@ status_t Camera2Client::updateRecordingStream(const Parameters &params) {
     return OK;
 }
 
-status_t Camera2Client::updateRequestCommon(camera_metadata_t *request,
+status_t Camera2Client::updateRequestCommon(CameraMetadata *request,
         const Parameters &params) {
     ATRACE_CALL();
     status_t res;
-    res = updateEntry(request,
-            ANDROID_CONTROL_AE_TARGET_FPS_RANGE, params.previewFpsRange, 2);
+    res = request->update(ANDROID_CONTROL_AE_TARGET_FPS_RANGE,
+            params.previewFpsRange, 2);
     if (res != OK) return res;
 
     uint8_t wbMode = params.autoWhiteBalanceLock ?
-            ANDROID_CONTROL_AWB_LOCKED : params.wbMode;
-    res = updateEntry(request,
-            ANDROID_CONTROL_AWB_MODE, &wbMode, 1);
+            (uint8_t)ANDROID_CONTROL_AWB_LOCKED : params.wbMode;
+    res = request->update(ANDROID_CONTROL_AWB_MODE,
+            &wbMode, 1);
     if (res != OK) return res;
-    res = updateEntry(request,
-            ANDROID_CONTROL_EFFECT_MODE, &params.effectMode, 1);
+    res = request->update(ANDROID_CONTROL_EFFECT_MODE,
+            &params.effectMode, 1);
     if (res != OK) return res;
-    res = updateEntry(request,
-            ANDROID_CONTROL_AE_ANTIBANDING_MODE,
+    res = request->update(ANDROID_CONTROL_AE_ANTIBANDING_MODE,
             &params.antibandingMode, 1);
     if (res != OK) return res;
 
     uint8_t controlMode =
             (params.sceneMode == ANDROID_CONTROL_SCENE_MODE_UNSUPPORTED) ?
             ANDROID_CONTROL_AUTO : ANDROID_CONTROL_USE_SCENE_MODE;
-    res = updateEntry(request,
-            ANDROID_CONTROL_MODE, &controlMode, 1);
+    res = request->update(ANDROID_CONTROL_MODE,
+            &controlMode, 1);
     if (res != OK) return res;
     if (controlMode == ANDROID_CONTROL_USE_SCENE_MODE) {
-        res = updateEntry(request,
-                ANDROID_CONTROL_SCENE_MODE,
+        res = request->update(ANDROID_CONTROL_SCENE_MODE,
                 &params.sceneMode, 1);
         if (res != OK) return res;
     }
@@ -3672,11 +3637,11 @@ status_t Camera2Client::updateRequestCommon(camera_metadata_t *request,
     }
     if (params.autoExposureLock) aeMode = ANDROID_CONTROL_AE_LOCKED;
 
-    res = updateEntry(request,
-            ANDROID_FLASH_MODE, &flashMode, 1);
+    res = request->update(ANDROID_FLASH_MODE,
+            &flashMode, 1);
     if (res != OK) return res;
-    res = updateEntry(request,
-            ANDROID_CONTROL_AE_MODE, &aeMode, 1);
+    res = request->update(ANDROID_CONTROL_AE_MODE,
+            &aeMode, 1);
     if (res != OK) return res;
 
     float focusDistance = 0; // infinity focus in diopters
@@ -3698,11 +3663,11 @@ status_t Camera2Client::updateRequestCommon(camera_metadata_t *request,
                     mCameraId, params.focusMode);
             return BAD_VALUE;
     }
-    res = updateEntry(request,
-            ANDROID_LENS_FOCUS_DISTANCE, &focusDistance, 1);
+    res = request->update(ANDROID_LENS_FOCUS_DISTANCE,
+            &focusDistance, 1);
     if (res != OK) return res;
-    res = updateEntry(request,
-            ANDROID_CONTROL_AF_MODE, &focusMode, 1);
+    res = request->update(ANDROID_CONTROL_AF_MODE,
+            &focusMode, 1);
     if (res != OK) return res;
 
     size_t focusingAreasSize = params.focusingAreas.size() * 5;
@@ -3714,13 +3679,12 @@ status_t Camera2Client::updateRequestCommon(camera_metadata_t *request,
         focusingAreas[i + 3] = params.focusingAreas[i].bottom;
         focusingAreas[i + 4] = params.focusingAreas[i].weight;
     }
-    res = updateEntry(request,
-            ANDROID_CONTROL_AF_REGIONS, focusingAreas,focusingAreasSize);
+    res = request->update(ANDROID_CONTROL_AF_REGIONS,
+            focusingAreas,focusingAreasSize);
     if (res != OK) return res;
     delete[] focusingAreas;
 
-    res = updateEntry(request,
-            ANDROID_CONTROL_AE_EXP_COMPENSATION,
+    res = request->update(ANDROID_CONTROL_AE_EXP_COMPENSATION,
             &params.exposureCompensation, 1);
     if (res != OK) return res;
 
@@ -3733,19 +3697,19 @@ status_t Camera2Client::updateRequestCommon(camera_metadata_t *request,
         meteringAreas[i + 3] = params.meteringAreas[i].bottom;
         meteringAreas[i + 4] = params.meteringAreas[i].weight;
     }
-    res = updateEntry(request,
-            ANDROID_CONTROL_AE_REGIONS, meteringAreas, meteringAreasSize);
+    res = request->update(ANDROID_CONTROL_AE_REGIONS,
+            meteringAreas, meteringAreasSize);
     if (res != OK) return res;
 
-    res = updateEntry(request,
-            ANDROID_CONTROL_AWB_REGIONS, meteringAreas, meteringAreasSize);
+    res = request->update(ANDROID_CONTROL_AWB_REGIONS,
+            meteringAreas, meteringAreasSize);
     if (res != OK) return res;
     delete[] meteringAreas;
 
     // Need to convert zoom index into a crop rectangle. The rectangle is
     // chosen to maximize its area on the sensor
 
-    camera_metadata_entry_t maxDigitalZoom =
+    camera_metadata_ro_entry_t maxDigitalZoom =
             staticInfo(ANDROID_SCALER_AVAILABLE_MAX_ZOOM);
     float zoomIncrement = (maxDigitalZoom.data.f[0] - 1) /
             (NUM_ZOOM_STEPS-1);
@@ -3765,8 +3729,8 @@ status_t Camera2Client::updateRequestCommon(camera_metadata_t *request,
     zoomTop = (mDeviceInfo->arrayHeight - zoomHeight) / 2;
 
     int32_t cropRegion[3] = { zoomLeft, zoomTop, zoomWidth };
-    res = updateEntry(request,
-            ANDROID_SCALER_CROP_REGION, cropRegion, 3);
+    res = request->update(ANDROID_SCALER_CROP_REGION,
+            cropRegion, 3);
     if (res != OK) return res;
 
     // TODO: Decide how to map recordingHint, or whether just to ignore it
@@ -3774,16 +3738,14 @@ status_t Camera2Client::updateRequestCommon(camera_metadata_t *request,
     uint8_t vstabMode = params.videoStabilization ?
             ANDROID_CONTROL_VIDEO_STABILIZATION_ON :
             ANDROID_CONTROL_VIDEO_STABILIZATION_OFF;
-    res = updateEntry(request,
-            ANDROID_CONTROL_VIDEO_STABILIZATION_MODE,
+    res = request->update(ANDROID_CONTROL_VIDEO_STABILIZATION_MODE,
             &vstabMode, 1);
     if (res != OK) return res;
 
     uint8_t faceDetectMode = params.enableFaceDetect ?
             mDeviceInfo->bestFaceDetectMode :
             (uint8_t)ANDROID_STATS_FACE_DETECTION_OFF;
-    res = updateEntry(request,
-            ANDROID_STATS_FACE_DETECT_MODE,
+    res = request->update(ANDROID_STATS_FACE_DETECT_MODE,
             &faceDetectMode, 1);
     if (res != OK) return res;
 
@@ -3798,50 +3760,6 @@ int Camera2Client::arrayYToNormalized(int height) const {
     return height * 2000 / (mDeviceInfo->arrayHeight - 1) - 1000;
 }
 
-status_t Camera2Client::updateEntry(camera_metadata_t *buffer,
-        uint32_t tag, const void *data, size_t data_count) {
-    camera_metadata_entry_t entry;
-    status_t res;
-    res = find_camera_metadata_entry(buffer, tag, &entry);
-    if (res == NAME_NOT_FOUND) {
-        res = add_camera_metadata_entry(buffer,
-                tag, data, data_count);
-    } else if (res == OK) {
-        res = update_camera_metadata_entry(buffer,
-                entry.index, data, data_count, NULL);
-    }
-
-    if (res != OK) {
-        ALOGE("%s: Unable to update metadata entry %s.%s (%x): %s (%d)",
-                __FUNCTION__, get_camera_metadata_section_name(tag),
-                get_camera_metadata_tag_name(tag), tag, strerror(-res), res);
-    }
-    return res;
-}
-
-status_t Camera2Client::deleteEntry(camera_metadata_t *buffer, uint32_t tag) {
-    camera_metadata_entry_t entry;
-    status_t res;
-    res = find_camera_metadata_entry(buffer, tag, &entry);
-    if (res == NAME_NOT_FOUND) {
-        return OK;
-    } else if (res != OK) {
-        ALOGE("%s: Error looking for entry %s.%s (%x): %s %d",
-                __FUNCTION__,
-                get_camera_metadata_section_name(tag),
-                get_camera_metadata_tag_name(tag), tag, strerror(-res), res);
-        return res;
-    }
-    res = delete_camera_metadata_entry(buffer, entry.index);
-    if (res != OK) {
-        ALOGE("%s: Error deleting entry %s.%s (%x): %s %d",
-                __FUNCTION__,
-                get_camera_metadata_section_name(tag),
-                get_camera_metadata_tag_name(tag), tag, strerror(-res), res);
-    }
-    return res;
-}
-
 int Camera2Client::formatStringToEnum(const char *format) {
     return
         !strcmp(format, CameraParameters::PIXEL_FORMAT_YUV422SP) ?
diff --git a/services/camera/libcameraservice/Camera2Client.h b/services/camera/libcameraservice/Camera2Client.h
index 028d458..e03aaba 100644
--- a/services/camera/libcameraservice/Camera2Client.h
+++ b/services/camera/libcameraservice/Camera2Client.h
@@ -84,6 +84,7 @@ public:
     virtual void notifyAutoWhitebalance(uint8_t newState, int triggerId);
 
     virtual void onNewFrameAvailable();
+
 private:
     enum State {
         DISCONNECTED,
@@ -153,10 +154,10 @@ private:
         int64_t gpsTimestamp;
         String8 gpsProcessingMethod;
 
-        int wbMode;
-        int effectMode;
-        int antibandingMode;
-        int sceneMode;
+        uint8_t wbMode;
+        uint8_t effectMode;
+        uint8_t antibandingMode;
+        uint8_t sceneMode;
 
         enum flashMode_t {
             FLASH_MODE_OFF = 0,
@@ -300,12 +301,12 @@ private:
 
     /* Output frame metadata processing methods */
 
-    status_t processFrameFaceDetect(camera_metadata_t *frame);
+    status_t processFrameFaceDetect(const CameraMetadata &frame);
 
     /* Preview related members */
 
     int mPreviewStreamId;
-    camera_metadata_t *mPreviewRequest;
+    CameraMetadata mPreviewRequest;
     sp<IBinder> mPreviewSurface;
     sp<ANativeWindow> mPreviewWindow;
 
@@ -351,7 +352,7 @@ private:
         Camera2Client *mParent;
     };
     sp<CaptureWaiter>  mCaptureWaiter;
-    camera_metadata_t *mCaptureRequest;
+    CameraMetadata mCaptureRequest;
     sp<Camera2Heap>    mCaptureHeap;
     // Handle captured image buffers
     void onCaptureAvailable();
@@ -375,7 +376,7 @@ private:
         Camera2Client *mParent;
     };
     sp<RecordingWaiter>  mRecordingWaiter;
-    camera_metadata_t *mRecordingRequest;
+    CameraMetadata mRecordingRequest;
     sp<Camera2Heap> mRecordingHeap;
 
     static const size_t kDefaultRecordingHeapCount = 8;
@@ -431,8 +432,8 @@ private:
     // checking the number of values in the entry. 0 for max/minCount means to
     // do no bounds check in that direction. In case of error, the entry data
     // pointer is null and the count is 0.
-    camera_metadata_entry_t staticInfo(uint32_t tag,
-            size_t minCount=0, size_t maxCount=0);
+    camera_metadata_ro_entry_t staticInfo(uint32_t tag,
+            size_t minCount=0, size_t maxCount=0) const;
 
     // Extract frequently-used camera static information into mDeviceInfo
     status_t buildDeviceInfo();
@@ -441,7 +442,7 @@ private:
     status_t buildDefaultParameters();
 
     // Update parameters all requests use, based on mParameters
-    status_t updateRequestCommon(camera_metadata_t *request, const Parameters &params);
+    status_t updateRequestCommon(CameraMetadata *request, const Parameters &params);
 
     // Map from sensor active array pixel coordinates to normalized camera
     // parameter coordinates. The former are (0,0)-(array width - 1, array height
@@ -449,16 +450,6 @@ private:
     int arrayXToNormalized(int width) const;
     int arrayYToNormalized(int height) const;
 
-    // Update specific metadata entry with new values. Adds entry if it does not
-    // exist, which will invalidate sorting
-    static status_t updateEntry(camera_metadata_t *buffer,
-            uint32_t tag, const void *data, size_t data_count);
-
-    // Remove metadata entry. Will invalidate sorting. If entry does not exist,
-    // does nothing.
-    static status_t deleteEntry(camera_metadata_t *buffer,
-            uint32_t tag);
-
     // Convert camera1 preview format string to camera2 enum
     static int formatStringToEnum(const char *format);
     static const char *formatEnumToString(int format);
diff --git a/services/camera/libcameraservice/Camera2Device.cpp b/services/camera/libcameraservice/Camera2Device.cpp
index 583701d..3390ff3 100644
--- a/services/camera/libcameraservice/Camera2Device.cpp
+++ b/services/camera/libcameraservice/Camera2Device.cpp
@@ -155,25 +155,28 @@ status_t Camera2Device::dump(int fd, const Vector<String16>& args) {
     return res;
 }
 
-camera_metadata_t *Camera2Device::info() {
+const CameraMetadata& Camera2Device::info() const {
     ALOGVV("%s: E", __FUNCTION__);
 
     return mDeviceInfo;
 }
 
-status_t Camera2Device::capture(camera_metadata_t* request) {
+status_t Camera2Device::capture(CameraMetadata &request) {
     ALOGV("%s: E", __FUNCTION__);
 
-    mRequestQueue.enqueue(request);
+    mRequestQueue.enqueue(request.release());
     return OK;
 }
 
 
-status_t Camera2Device::setStreamingRequest(camera_metadata_t* request) {
+status_t Camera2Device::setStreamingRequest(const CameraMetadata &request) {
     ALOGV("%s: E", __FUNCTION__);
+    CameraMetadata streamRequest(request);
+    return mRequestQueue.setStreamSlot(streamRequest.release());
+}
 
-    mRequestQueue.setStreamSlot(request);
-    return OK;
+status_t Camera2Device::clearStreamingRequest() {
+    return mRequestQueue.setStreamSlot(NULL);
 }
 
 status_t Camera2Device::createStream(sp<ANativeWindow> consumer,
@@ -269,10 +272,14 @@ status_t Camera2Device::deleteStream(int id) {
 }
 
 status_t Camera2Device::createDefaultRequest(int templateId,
-        camera_metadata_t **request) {
+        CameraMetadata *request) {
+    status_t err;
     ALOGV("%s: E", __FUNCTION__);
-    return mDevice->ops->construct_default_request(
-        mDevice, templateId, request);
+    camera_metadata_t *rawRequest;
+    err = mDevice->ops->construct_default_request(
+        mDevice, templateId, &rawRequest);
+    request->acquire(rawRequest);
+    return err;
 }
 
 status_t Camera2Device::waitUntilDrained() {
@@ -344,8 +351,16 @@ status_t Camera2Device::setFrameListener(FrameListener *listener) {
     return mFrameQueue.setListener(listener);
 }
 
-status_t Camera2Device::getNextFrame(camera_metadata_t **frame) {
-    return mFrameQueue.dequeue(frame);
+status_t Camera2Device::getNextFrame(CameraMetadata *frame) {
+    status_t res;
+    camera_metadata_t *rawFrame;
+    res = mFrameQueue.dequeue(&rawFrame);
+    if (rawFrame  == NULL) {
+        return NOT_ENOUGH_DATA;
+    } else if (res == OK) {
+        frame->acquire(rawFrame);
+    }
+    return res;
 }
 
 status_t Camera2Device::triggerAutofocus(uint32_t id) {
diff --git a/services/camera/libcameraservice/Camera2Device.h b/services/camera/libcameraservice/Camera2Device.h
index 790b946..06047b8 100644
--- a/services/camera/libcameraservice/Camera2Device.h
+++ b/services/camera/libcameraservice/Camera2Device.h
@@ -27,6 +27,7 @@
 #include <utils/Vector.h>
 
 #include "hardware/camera2.h"
+#include "CameraMetadata.h"
 
 namespace android {
 
@@ -41,21 +42,26 @@ class Camera2Device : public virtual RefBase {
     status_t dump(int fd, const Vector<String16>& args);
 
     /**
-     * Get a pointer to the device's static characteristics metadata buffer
+     * The device's static characteristics metadata buffer
      */
-    camera_metadata_t* info();
+    const CameraMetadata& info() const;
 
     /**
      * Submit request for capture. The Camera2Device takes ownership of the
      * passed-in buffer.
      */
-    status_t capture(camera_metadata_t *request);
+    status_t capture(CameraMetadata &request);
 
     /**
      * Submit request for streaming. The Camera2Device makes a copy of the
      * passed-in buffer and the caller retains ownership.
      */
-    status_t setStreamingRequest(camera_metadata_t *request);
+    status_t setStreamingRequest(const CameraMetadata &request);
+
+    /**
+     * Clear the streaming request slot.
+     */
+    status_t clearStreamingRequest();
 
     /**
      * Create an output stream of the requested size and format.
@@ -92,8 +98,7 @@ class Camera2Device : public virtual RefBase {
      * Create a metadata buffer with fields that the HAL device believes are
      * best for the given use case
      */
-    status_t createDefaultRequest(int templateId,
-            camera_metadata_t **request);
+    status_t createDefaultRequest(int templateId, CameraMetadata *request);
 
     /**
      * Wait until all requests have been processed. Returns INVALID_OPERATION if
@@ -142,7 +147,7 @@ class Camera2Device : public virtual RefBase {
      * Get next metadata frame from the frame queue. Returns NULL if the queue
      * is empty; caller takes ownership of the metadata buffer.
      */
-    status_t getNextFrame(camera_metadata_t **frame);
+    status_t getNextFrame(CameraMetadata *frame);
 
     /**
      * Trigger auto-focus. The latest ID used in a trigger autofocus or cancel
@@ -170,7 +175,7 @@ class Camera2Device : public virtual RefBase {
     const int mId;
     camera2_device_t *mDevice;
 
-    camera_metadata_t *mDeviceInfo;
+    CameraMetadata mDeviceInfo;
     vendor_tag_query_ops_t *mVendorTagOps;
 
     /**
diff --git a/services/camera/libcameraservice/CameraMetadata.cpp b/services/camera/libcameraservice/CameraMetadata.cpp
new file mode 100644
index 0000000..b402115
--- /dev/null
+++ b/services/camera/libcameraservice/CameraMetadata.cpp
@@ -0,0 +1,290 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "CameraMetadata"
+#include <utils/Log.h>
+#include <utils/Errors.h>
+
+#include "CameraMetadata.h"
+
+namespace android {
+
+CameraMetadata::CameraMetadata() :
+        mBuffer(NULL) {
+}
+
+CameraMetadata::CameraMetadata(size_t entryCapacity, size_t dataCapacity)
+{
+    mBuffer = allocate_camera_metadata(entryCapacity, dataCapacity);
+}
+
+CameraMetadata::CameraMetadata(const CameraMetadata &other) {
+    mBuffer = clone_camera_metadata(other.mBuffer);
+}
+
+CameraMetadata &CameraMetadata::operator=(const CameraMetadata &other) {
+    return operator=(other.mBuffer);
+}
+
+CameraMetadata &CameraMetadata::operator=(const camera_metadata_t *buffer) {
+    if (CC_LIKELY(buffer != mBuffer)) {
+        camera_metadata_t *newBuffer = clone_camera_metadata(buffer);
+        clear();
+        mBuffer = newBuffer;
+    }
+    return *this;
+}
+
+CameraMetadata::~CameraMetadata() {
+    clear();
+}
+
+camera_metadata_t* CameraMetadata::release() {
+    camera_metadata_t *released = mBuffer;
+    mBuffer = NULL;
+    return released;
+}
+
+void CameraMetadata::clear() {
+    if (mBuffer) {
+        free_camera_metadata(mBuffer);
+        mBuffer = NULL;
+    }
+}
+
+void CameraMetadata::acquire(camera_metadata_t *buffer) {
+    clear();
+    mBuffer = buffer;
+}
+
+void CameraMetadata::acquire(CameraMetadata &other) {
+    acquire(other.release());
+}
+
+status_t CameraMetadata::append(const CameraMetadata &other) {
+    return append_camera_metadata(mBuffer, other.mBuffer);
+}
+
+size_t CameraMetadata::entryCount() const {
+    return (mBuffer == NULL) ? 0 :
+            get_camera_metadata_entry_count(mBuffer);
+}
+
+status_t CameraMetadata::sort() {
+    return sort_camera_metadata(mBuffer);
+}
+
+status_t CameraMetadata::checkType(uint32_t tag, uint8_t expectedType) {
+    int tagType = get_camera_metadata_tag_type(tag);
+    if ( CC_UNLIKELY(tagType == -1)) {
+        ALOGE("Update metadata entry: Unknown tag %d", tag);
+        return INVALID_OPERATION;
+    }
+    if ( CC_UNLIKELY(tagType != expectedType) ) {
+        ALOGE("Mismatched tag type when updating entry %s (%d) of type %s; "
+                "got type %s data instead ",
+                get_camera_metadata_tag_name(tag), tag,
+                camera_metadata_type_names[tagType],
+                camera_metadata_type_names[expectedType]);
+        return INVALID_OPERATION;
+    }
+    return OK;
+}
+
+status_t CameraMetadata::update(uint32_t tag,
+        const int32_t *data, size_t data_count) {
+    status_t res;
+    if ( (res = checkType(tag, TYPE_INT32)) != OK) {
+        return res;
+    }
+    return update(tag, (const void*)data, data_count);
+}
+
+status_t CameraMetadata::update(uint32_t tag,
+        const uint8_t *data, size_t data_count) {
+    status_t res;
+    if ( (res = checkType(tag, TYPE_BYTE)) != OK) {
+        return res;
+    }
+    return update(tag, (const void*)data, data_count);
+}
+
+status_t CameraMetadata::update(uint32_t tag,
+        const float *data, size_t data_count) {
+    status_t res;
+    if ( (res = checkType(tag, TYPE_FLOAT)) != OK) {
+        return res;
+    }
+    return update(tag, (const void*)data, data_count);
+}
+
+status_t CameraMetadata::update(uint32_t tag,
+        const int64_t *data, size_t data_count) {
+    status_t res;
+    if ( (res = checkType(tag, TYPE_INT64)) != OK) {
+        return res;
+    }
+    return update(tag, (const void*)data, data_count);
+}
+
+status_t CameraMetadata::update(uint32_t tag,
+        const double *data, size_t data_count) {
+    status_t res;
+    if ( (res = checkType(tag, TYPE_DOUBLE)) != OK) {
+        return res;
+    }
+    return update(tag, (const void*)data, data_count);
+}
+
+status_t CameraMetadata::update(uint32_t tag,
+        const camera_metadata_rational_t *data, size_t data_count) {
+    status_t res;
+    if ( (res = checkType(tag, TYPE_RATIONAL)) != OK) {
+        return res;
+    }
+    return update(tag, (const void*)data, data_count);
+}
+
+status_t CameraMetadata::update(uint32_t tag,
+        const String8 &string) {
+    status_t res;
+    if ( (res = checkType(tag, TYPE_BYTE)) != OK) {
+        return res;
+    }
+    return update(tag, (const void*)string.string(), string.size());
+}
+
+status_t CameraMetadata::update(uint32_t tag, const void *data,
+        size_t data_count) {
+    status_t res;
+    int type = get_camera_metadata_tag_type(tag);
+    if (type == -1) {
+        ALOGE("%s: Tag %d not found", __FUNCTION__, tag);
+        return BAD_VALUE;
+    }
+    size_t data_size = calculate_camera_metadata_entry_data_size(type,
+            data_count);
+
+    res = resizeIfNeeded(1, data_size);
+
+    if (res == OK) {
+        camera_metadata_entry_t entry;
+        res = find_camera_metadata_entry(mBuffer, tag, &entry);
+        if (res == NAME_NOT_FOUND) {
+            res = add_camera_metadata_entry(mBuffer,
+                    tag, data, data_count);
+        } else if (res == OK) {
+            res = update_camera_metadata_entry(mBuffer,
+                    entry.index, data, data_count, NULL);
+        }
+    }
+
+    if (res != OK) {
+        ALOGE("%s: Unable to update metadata entry %s.%s (%x): %s (%d)",
+                __FUNCTION__, get_camera_metadata_section_name(tag),
+                get_camera_metadata_tag_name(tag), tag, strerror(-res), res);
+    }
+    return res;
+}
+
+camera_metadata_entry_t CameraMetadata::find(uint32_t tag) {
+    status_t res;
+    camera_metadata_entry entry;
+    res = find_camera_metadata_entry(mBuffer, tag, &entry);
+    if (CC_UNLIKELY( res != OK )) {
+        entry.count = 0;
+        entry.data.u8 = NULL;
+    }
+    return entry;
+}
+
+camera_metadata_ro_entry_t CameraMetadata::find(uint32_t tag) const {
+    status_t res;
+    camera_metadata_ro_entry entry;
+    res = find_camera_metadata_ro_entry(mBuffer, tag, &entry);
+    if (CC_UNLIKELY( res != OK )) {
+        entry.count = 0;
+        entry.data.u8 = NULL;
+    }
+    return entry;
+}
+
+status_t CameraMetadata::erase(uint32_t tag) {
+    camera_metadata_entry_t entry;
+    status_t res;
+    res = find_camera_metadata_entry(mBuffer, tag, &entry);
+    if (res == NAME_NOT_FOUND) {
+        return OK;
+    } else if (res != OK) {
+        ALOGE("%s: Error looking for entry %s.%s (%x): %s %d",
+                __FUNCTION__,
+                get_camera_metadata_section_name(tag),
+                get_camera_metadata_tag_name(tag), tag, strerror(-res), res);
+        return res;
+    }
+    res = delete_camera_metadata_entry(mBuffer, entry.index);
+    if (res != OK) {
+        ALOGE("%s: Error deleting entry %s.%s (%x): %s %d",
+                __FUNCTION__,
+                get_camera_metadata_section_name(tag),
+                get_camera_metadata_tag_name(tag), tag, strerror(-res), res);
+    }
+    return res;
+}
+
+void CameraMetadata::dump(int fd, int verbosity, int indentation) const {
+    dump_indented_camera_metadata(mBuffer, fd, verbosity, indentation);
+}
+
+status_t CameraMetadata::resizeIfNeeded(size_t extraEntries, size_t extraData) {
+    if (mBuffer == NULL) {
+        mBuffer = allocate_camera_metadata(extraEntries * 2, extraData * 2);
+        if (mBuffer == NULL) {
+            ALOGE("%s: Can't allocate larger metadata buffer", __FUNCTION__);
+            return NO_MEMORY;
+        }
+    } else {
+        size_t currentEntryCount = get_camera_metadata_entry_count(mBuffer);
+        size_t currentEntryCap = get_camera_metadata_entry_capacity(mBuffer);
+        size_t newEntryCount = currentEntryCount +
+                extraEntries;
+        newEntryCount = (newEntryCount > currentEntryCap) ?
+                newEntryCount * 2 : currentEntryCap;
+
+        size_t currentDataCount = get_camera_metadata_data_count(mBuffer);
+        size_t currentDataCap = get_camera_metadata_data_capacity(mBuffer);
+        size_t newDataCount = currentDataCount +
+                extraData;
+        newDataCount = (newDataCount > currentDataCap) ?
+                newDataCount * 2 : currentDataCap;
+
+        if (newEntryCount > currentEntryCap ||
+                newDataCount > currentDataCap) {
+            camera_metadata_t *oldBuffer = mBuffer;
+            mBuffer = allocate_camera_metadata(newEntryCount,
+                    newDataCount);
+            if (mBuffer == NULL) {
+                ALOGE("%s: Can't allocate larger metadata buffer", __FUNCTION__);
+                return NO_MEMORY;
+            }
+            append_camera_metadata(mBuffer, oldBuffer);
+            free_camera_metadata(oldBuffer);
+        }
+    }
+    return OK;
+}
+
+}; // namespace android
diff --git a/services/camera/libcameraservice/CameraMetadata.h b/services/camera/libcameraservice/CameraMetadata.h
new file mode 100644
index 0000000..afb8318
--- /dev/null
+++ b/services/camera/libcameraservice/CameraMetadata.h
@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_SERVERS_CAMERA_METADATA_CPP
+#define ANDROID_SERVERS_CAMERA_METADATA_CPP
+
+#include "system/camera_metadata.h"
+#include <utils/String8.h>
+#include <utils/Vector.h>
+
+namespace android {
+
+/**
+ * A convenience wrapper around the C-based camera_metadata_t library.
+ */
+class CameraMetadata {
+  public:
+    /** Creates an empty object; best used when expecting to acquire contents
+     * from elsewhere */
+    CameraMetadata();
+    /** Creates an object with space for entryCapacity entries, with
+     * dataCapacity extra storage */
+    CameraMetadata(size_t entryCapacity, size_t dataCapacity = 10);
+
+    ~CameraMetadata();
+
+    /** Takes ownership of passed-in buffer */
+    CameraMetadata(camera_metadata_t *buffer);
+    /** Clones the metadata */
+    CameraMetadata(const CameraMetadata &other);
+
+    /**
+     * Assignment clones metadata buffer.
+     */
+    CameraMetadata &operator=(const CameraMetadata &other);
+    CameraMetadata &operator=(const camera_metadata_t *buffer);
+
+    /**
+     * Release a raw metadata buffer to the caller. After this call,
+     * CameraMetadata no longer references the buffer, and the caller takes
+     * responsibility for freeing the raw metadata buffer (using
+     * free_camera_metadata()), or for handing it to another CameraMetadata
+     * instance.
+     */
+    camera_metadata_t* release();
+
+    /**
+     * Clear the metadata buffer and free all storage used by it
+     */
+    void clear();
+
+    /**
+     * Acquire a raw metadata buffer from the caller. After this call,
+     * the caller no longer owns the raw buffer, and must not free or manipulate it.
+     * If CameraMetadata already contains metadata, it is freed.
+     */
+    void acquire(camera_metadata_t* buffer);
+
+    /**
+     * Acquires raw buffer from other CameraMetadata object. After the call, the argument
+     * object no longer has any metadata.
+     */
+    void acquire(CameraMetadata &other);
+
+    /**
+     * Append metadata from another CameraMetadata object.
+     */
+    status_t append(const CameraMetadata &other);
+
+    /**
+     * Number of metadata entries.
+     */
+    size_t entryCount() const;
+
+    /**
+     * Sort metadata buffer for faster find
+     */
+    status_t sort();
+
+    /**
+     * Update metadata entry. Will create entry if it doesn't exist already, and
+     * will reallocate the buffer if insufficient space exists. Overloaded for
+     * the various types of valid data.
+     */
+    status_t update(uint32_t tag,
+            const uint8_t *data, size_t data_count);
+    status_t update(uint32_t tag,
+            const int32_t *data, size_t data_count);
+    status_t update(uint32_t tag,
+            const float *data, size_t data_count);
+    status_t update(uint32_t tag,
+            const int64_t *data, size_t data_count);
+    status_t update(uint32_t tag,
+            const double *data, size_t data_count);
+    status_t update(uint32_t tag,
+            const camera_metadata_rational_t *data, size_t data_count);
+    status_t update(uint32_t tag,
+            const String8 &string);
+
+    template<typename T>
+    status_t update(uint32_t tag, Vector<T> data) {
+        return update(tag, data.array(), data.size());
+    }
+
+    /**
+     * Get metadata entry by tag id
+     */
+    camera_metadata_entry find(uint32_t tag);
+
+    /**
+     * Get metadata entry by tag id, with no editing
+     */
+    camera_metadata_ro_entry find(uint32_t tag) const;
+
+    /**
+     * Delete metadata entry by tag
+     */
+    status_t erase(uint32_t tag);
+
+    /**
+     * Dump contents into FD for debugging. The verbosity levels are
+     * 0: Tag entry information only, no data values
+     * 1: Level 0 plus at most 16 data values per entry
+     * 2: All information
+     *
+     * The indentation parameter sets the number of spaces to add to the start
+     * each line of output.
+     */
+    void dump(int fd, int verbosity = 1, int indentation = 0) const;
+
+  private:
+    camera_metadata_t *mBuffer;
+
+    /**
+     * Check if tag has a given type
+     */
+    status_t checkType(uint32_t tag, uint8_t expectedType);
+
+    /**
+     * Base update entry method
+     */
+    status_t update(uint32_t tag, const void *data, size_t data_count);
+
+    /**
+     * Resize metadata buffer if needed by reallocating it and copying it over.
+     */
+    status_t resizeIfNeeded(size_t extraEntries, size_t extraData);
+
+};
+
+}; // namespace android
+
+#endif