diff --git a/media/libmedia/tests/mediaplayer/Android.bp b/media/libmedia/tests/mediaplayer/Android.bp
new file mode 100644
index 0000000..5538ea0
--- /dev/null
+++ b/media/libmedia/tests/mediaplayer/Android.bp
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2021 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.
+ */
+
+cc_test {
+    name: "IMediaPlayerTest",
+    test_suites: ["device-tests", "mts"],
+    gtest: true,
+
+    srcs: [
+        "IMediaPlayerTest.cpp",
+    ],
+
+    shared_libs: [
+        "libbinder",
+        "liblog",
+        "libmedia",
+        "libstagefright",
+        "libstagefright_foundation",
+        "libutils",
+    ],
+    compile_multilib: "first",
+    cflags: [
+        "-Werror",
+        "-Wall",
+    ],
+}
diff --git a/media/libmedia/tests/mediaplayer/IMediaPlayerTest.cpp b/media/libmedia/tests/mediaplayer/IMediaPlayerTest.cpp
new file mode 100644
index 0000000..097e8ef
--- /dev/null
+++ b/media/libmedia/tests/mediaplayer/IMediaPlayerTest.cpp
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2021 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 <binder/IServiceManager.h>
+#include <binder/Parcel.h>
+#include <gtest/gtest.h>
+#include <media/stagefright/foundation/ABuffer.h>
+#include <media/IMediaPlayer.h>
+#include <media/IMediaPlayerService.h>
+#include <media/mediaplayer.h>
+
+namespace android {
+
+constexpr uint8_t kMockByteArray[16] = {};
+
+ class IMediaPlayerTest : public testing::Test {
+  protected:
+   static constexpr uint32_t PREPARE_DRM = IMediaPlayer::PREPARE_DRM;
+
+   void SetUp() override {
+    mediaPlayer_ = new MediaPlayer();
+    sp<IServiceManager> serviceManager = defaultServiceManager();
+    sp<IBinder> mediaPlayerService = serviceManager->getService(String16("media.player"));
+    sp<IMediaPlayerService> iMediaPlayerService =
+            IMediaPlayerService::asInterface(mediaPlayerService);
+    iMediaPlayer_ = iMediaPlayerService->create(mediaPlayer_);
+   }
+
+   sp<MediaPlayer> mediaPlayer_;
+   sp<IMediaPlayer> iMediaPlayer_;
+ };
+
+TEST_F(IMediaPlayerTest, PrepareDrmInvalidTransaction) {
+    Parcel data, reply;
+    data.writeInterfaceToken(iMediaPlayer_->getInterfaceDescriptor());
+    data.write(kMockByteArray, 16);
+
+    // We write a length greater than the following session id array. Should be discarded.
+    data.writeUint32(2);
+    data.writeUnpadded(kMockByteArray, 1);
+
+    status_t result = IMediaPlayer::asBinder(iMediaPlayer_)
+            ->transact(PREPARE_DRM, data, &reply);
+    ASSERT_EQ(result, BAD_VALUE);
+}
+
+TEST_F(IMediaPlayerTest, PrepareDrmValidTransaction) {
+    Parcel data, reply;
+    data.writeInterfaceToken(iMediaPlayer_->getInterfaceDescriptor());
+    data.write(kMockByteArray, 16);
+
+    // We write a length equal to the length of the following data. The transaction should be valid.
+    data.writeUint32(1);
+    data.write(kMockByteArray, 1);
+
+    status_t result = IMediaPlayer::asBinder(iMediaPlayer_)
+            ->transact(PREPARE_DRM, data, &reply);
+    ASSERT_EQ(result, OK);
+}
+}  // namespace android