diff --git a/modules/camera/Metadata.cpp b/modules/camera/Metadata.cpp
new file mode 100644
index 0000000..77f5405
--- /dev/null
+++ b/modules/camera/Metadata.cpp
@@ -0,0 +1,184 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+#include <pthread.h>
+#include <system/camera_metadata.h>
+
+//#define LOG_NDEBUG 0
+#define LOG_TAG "Metadata"
+#include <cutils/log.h>
+
+#define ATRACE_TAG (ATRACE_TAG_CAMERA | ATRACE_TAG_HAL)
+#include <cutils/trace.h>
+#include "ScopedTrace.h"
+
+#include "Metadata.h"
+
+namespace default_camera_hal {
+
+Metadata::Metadata()
+  : mHead(NULL),
+    mTail(NULL),
+    mEntryCount(0),
+    mDataCount(0)
+{
+    // NULL (default) pthread mutex attributes
+    pthread_mutex_init(&mMutex, NULL);
+}
+
+Metadata::~Metadata()
+{
+}
+
+int Metadata::addUInt8(uint32_t tag, int count, uint8_t *data)
+{
+    if (!validate(tag, TYPE_BYTE, count)) return -EINVAL;
+    return add(tag, count, data);
+}
+
+int Metadata::addInt32(uint32_t tag, int count, int32_t *data)
+{
+    if (!validate(tag, TYPE_INT32, count)) return -EINVAL;
+    return add(tag, count, data);
+}
+
+int Metadata::addFloat(uint32_t tag, int count, float *data)
+{
+    if (!validate(tag, TYPE_FLOAT, count)) return -EINVAL;
+    return add(tag, count, data);
+}
+
+int Metadata::addInt64(uint32_t tag, int count, int64_t *data)
+{
+    if (!validate(tag, TYPE_INT64, count)) return -EINVAL;
+    return add(tag, count, data);
+}
+
+int Metadata::addDouble(uint32_t tag, int count, double *data)
+{
+    if (!validate(tag, TYPE_DOUBLE, count)) return -EINVAL;
+    return add(tag, count, data);
+}
+
+int Metadata::addRational(uint32_t tag, int count,
+        camera_metadata_rational_t *data)
+{
+    if (!validate(tag, TYPE_RATIONAL, count)) return -EINVAL;
+    return add(tag, count, data);
+}
+
+bool Metadata::validate(uint32_t tag, int tag_type, int count)
+{
+    if (get_camera_metadata_tag_type(tag) < 0) {
+        ALOGE("%s: Invalid metadata entry tag: %d", __func__, tag);
+        return false;
+    }
+    if (tag_type < 0 || tag_type >= NUM_TYPES) {
+        ALOGE("%s: Invalid metadata entry tag type: %d", __func__, tag_type);
+        return false;
+    }
+    if (tag_type != get_camera_metadata_tag_type(tag)) {
+        ALOGE("%s: Tag %d called with incorrect type: %s(%d)", __func__, tag,
+                camera_metadata_type_names[tag_type], tag_type);
+        return false;
+    }
+    if (count < 1) {
+        ALOGE("%s: Invalid metadata entry count: %d", __func__, count);
+        return false;
+    }
+    return true;
+}
+
+int Metadata::add(uint32_t tag, int count, void *tag_data)
+{
+    int tag_type = get_camera_metadata_tag_type(tag);
+    size_t type_sz = camera_metadata_type_size[tag_type];
+
+    // Allocate array to hold new metadata
+    void *data = malloc(count * type_sz);
+    if (data == NULL)
+        return -ENOMEM;
+    memcpy(data, tag_data, count * type_sz);
+
+    mEntryCount++;
+    mDataCount += calculate_camera_metadata_entry_data_size(tag_type, count);
+    push(new Entry(tag, data, count));
+    return 0;
+}
+
+camera_metadata_t* Metadata::generate()
+{
+    Entry *current = mHead;
+
+    pthread_mutex_lock(&mMutex);
+    if (mGenerated == NULL) {
+        ALOGV("Generating new camera metadata structure");
+        mGenerated = allocate_camera_metadata(mEntryCount, mDataCount);
+        if (mGenerated == NULL) {
+            ALOGE("%s: Failed to allocate metadata (%d entries %d data)",
+                    __func__, mEntryCount, mDataCount);
+        }
+    }
+    // Walk list of entries adding each one to newly allocated metadata
+    while (current != NULL) {
+        add_camera_metadata_entry(mGenerated, current->mTag, current->mData,
+                current->mCount);
+        current = current->mNext;
+    }
+    pthread_mutex_unlock(&mMutex);
+
+    return mGenerated;
+}
+
+Metadata::Entry::Entry(uint32_t tag, void *data, int count)
+  : mNext(NULL),
+    mPrev(NULL),
+    mTag(tag),
+    mData(data),
+    mCount(count)
+{
+}
+
+void Metadata::push(Entry *e)
+{
+    if (mHead == NULL) {
+        mHead = mTail = e;
+    } else {
+        mTail->insertAfter(e);
+        mTail = e;
+    }
+}
+
+Metadata::Entry::~Entry()
+{
+    if (mNext != NULL)
+        mNext->mPrev = mPrev;
+    if (mPrev != NULL)
+        mPrev->mNext = mNext;
+}
+
+void Metadata::Entry::insertAfter(Entry *e)
+{
+    if (e == NULL)
+        return;
+    if (mNext != NULL)
+        mNext->mPrev = e;
+    e->mNext = mNext;
+    e->mPrev = this;
+    mNext = e;
+}
+
+} // namespace default_camera_hal