diff --git a/media/ndk/NdkMediaDataSourceCallbacksPriv.h b/media/ndk/NdkMediaDataSourceCallbacksPriv.h
new file mode 100644
index 0000000..65fb0aa
--- /dev/null
+++ b/media/ndk/NdkMediaDataSourceCallbacksPriv.h
@@ -0,0 +1,48 @@
+/*
+ * 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.
+ */
+
+#ifndef A_MEDIA_DATA_SOURCE_CALLBACKS_H
+
+#define A_MEDIA_DATA_SOURCE_CALLBACKS_H
+
+#include <media/DataSource.h>
+#include <media/NdkMediaDataSource.h>
+#include <media/NdkMediaError.h>
+#include <sys/types.h>
+
+namespace android {
+
+ssize_t DataSource_getSize(void *userdata);
+
+ssize_t DataSource_readAt(void *userdata, off64_t offset, void * buf, size_t size);
+
+void DataSource_close(void *userdata);
+
+static inline AMediaDataSource* convertDataSourceToAMediaDataSource(const sp<DataSource> &source) {
+    if (source == NULL) {
+        return NULL;
+    }
+    AMediaDataSource *mSource = AMediaDataSource_new();
+    AMediaDataSource_setUserdata(mSource, source.get());
+    AMediaDataSource_setReadAt(mSource, DataSource_readAt);
+    AMediaDataSource_setGetSize(mSource, DataSource_getSize);
+    AMediaDataSource_setClose(mSource, DataSource_close);
+    return mSource;
+}
+
+}  // namespace android
+
+#endif  // A_MEDIA_DATA_SOURCE_CALLBACKS_H