diff --git a/media/ndk/NdkMediaDataSourceCallbacks.cpp b/media/ndk/NdkMediaDataSourceCallbacks.cpp
new file mode 100644
index 0000000..4338048
--- /dev/null
+++ b/media/ndk/NdkMediaDataSourceCallbacks.cpp
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2018, 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_NDEBUG 0
+#define LOG_TAG "NdkMediaDataSourceCallbacks"
+
+#include "NdkMediaDataSourceCallbacksPriv.h"
+#include <media/DataSource.h>
+
+namespace android {
+
+ssize_t DataSource_getSize(void *userdata) {
+    DataSource *source = static_cast<DataSource *>(userdata);
+    off64_t size = -1;
+    source->getSize(&size);
+    return size;
+}
+
+ssize_t DataSource_readAt(void *userdata, off64_t offset, void * buf, size_t size) {
+    DataSource *source = static_cast<DataSource *>(userdata);
+    return source->readAt(offset, buf, size);
+}
+
+void DataSource_close(void *userdata) {
+    DataSource *source = static_cast<DataSource *>(userdata);
+    source->close();
+}
+
+}  // namespace android