diff --git a/media/libmediatranscoding/Android.bp b/media/libmediatranscoding/Android.bp
new file mode 100644
index 0000000..8f0e278
--- /dev/null
+++ b/media/libmediatranscoding/Android.bp
@@ -0,0 +1,15 @@
+// AIDL interfaces of MediaTranscoding.
+aidl_interface {
+    name: "mediatranscoding_aidl_interface",
+    local_include_dir: "aidl",
+    srcs: [
+        "aidl/android/media/IMediaTranscodingService.aidl",
+        "aidl/android/media/ITranscodingServiceClient.aidl",
+        "aidl/android/media/TranscodingErrorCode.aidl",
+        "aidl/android/media/TranscodingType.aidl",
+        "aidl/android/media/TranscodingVideoCodecType.aidl",
+        "aidl/android/media/TranscodingJob.aidl",
+        "aidl/android/media/TranscodingRequest.aidl",
+        "aidl/android/media/TranscodingResult.aidl",
+    ],
+}
diff --git a/media/libmediatranscoding/OWNERS b/media/libmediatranscoding/OWNERS
new file mode 100644
index 0000000..02287cb
--- /dev/null
+++ b/media/libmediatranscoding/OWNERS
@@ -0,0 +1,3 @@
+akersten@google.com
+hkuang@google.com
+lnilsson@google.com
diff --git a/media/libmediatranscoding/aidl/android/media/IMediaTranscodingService.aidl b/media/libmediatranscoding/aidl/android/media/IMediaTranscodingService.aidl
new file mode 100644
index 0000000..cae8ff0
--- /dev/null
+++ b/media/libmediatranscoding/aidl/android/media/IMediaTranscodingService.aidl
@@ -0,0 +1,81 @@
+/**
+ * Copyright (c) 2019, 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.
+ */
+
+package android.media;
+
+import android.media.TranscodingJob;
+import android.media.TranscodingRequest;
+import android.media.ITranscodingServiceClient;
+
+/**
+ * Binder interface for MediaTranscodingService.
+ *
+ * {@hide}
+ */
+interface IMediaTranscodingService {
+    /**
+     * Register the client with the MediaTranscodingService.
+     *
+     * Client must call this function to register itself with the service in order to perform
+     * transcoding. This function will return a unique positive Id assigned by the service.
+     * Client should save this Id and use it for all the transaction with the service.
+     *
+     * @param client interface for the MediaTranscodingService to call the client.
+     * @return a unique positive Id assigned to the client by the service, -1  means failed to
+     * register.
+     */
+    int registerClient(in ITranscodingServiceClient client);
+
+    /**
+    * Unregister the client with the MediaTranscodingService.
+    *
+    * Client will not be able to perform any more transcoding after unregister.
+    *
+    * @param clientId assigned Id of the client.
+    * @return true if succeeds, false otherwise.
+    */
+    boolean unregisterClient(in int clientId);
+
+    /**
+     * Submits a transcoding request to MediaTranscodingService.
+     *
+     * @param clientId assigned Id of the client.
+     * @param request a TranscodingRequest contains transcoding configuration.
+     * @param job(output variable) a TranscodingJob generated by the MediaTranscodingService.
+     * @return a unique positive jobId generated by the MediaTranscodingService, -1 means failure.
+     */
+    int submitRequest(in int clientId,
+                      in TranscodingRequest request,
+                      out TranscodingJob job);
+
+    /**
+     * Cancels a transcoding job.
+     *
+     * @param clientId assigned id of the client.
+     * @param jobId a TranscodingJob generated by the MediaTranscodingService.
+     * @return true if succeeds, false otherwise.
+     */
+    boolean cancelJob(in int clientId, in int jobId);
+
+    /**
+     * Queries the job detail associated with a jobId.
+     *
+     * @param jobId a TranscodingJob generated by the MediaTranscodingService.
+     * @param job(output variable) the TranscodingJob associated with the jobId.
+     * @return true if succeeds, false otherwise.
+     */
+    boolean getJobWithId(in int jobId, out TranscodingJob job);
+}
diff --git a/media/libmediatranscoding/aidl/android/media/ITranscodingServiceClient.aidl b/media/libmediatranscoding/aidl/android/media/ITranscodingServiceClient.aidl
new file mode 100644
index 0000000..29b6f35
--- /dev/null
+++ b/media/libmediatranscoding/aidl/android/media/ITranscodingServiceClient.aidl
@@ -0,0 +1,75 @@
+/**
+ * Copyright (c) 2019, 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.
+ */
+
+package android.media;
+
+import android.media.TranscodingErrorCode;
+import android.media.TranscodingJob;
+import android.media.TranscodingResult;
+
+/**
+ * ITranscodingServiceClient interface for the MediaTranscodingervice to communicate with the
+ * client.
+ *
+ * {@hide}
+ */
+//TODO(hkuang): Implement the interface.
+interface ITranscodingServiceClient {
+    /**
+     * Retrieves the name of the client.
+     */
+    @utf8InCpp String getName();
+
+    /**
+    * Called when the transcoding associated with the jobId finished.
+    *
+    * @param jobId jobId assigned by the MediaTranscodingService upon receiving request.
+    * @param result contains the transcoded file stats and other transcoding metrics if requested.
+    */
+    oneway void onTranscodingFinished(in int jobId, in TranscodingResult result);
+
+    /**
+    * Called when the transcoding associated with the jobId failed.
+    *
+    * @param jobId jobId assigned by the MediaTranscodingService upon receiving request.
+    * @param errorCode error code that indicates the error.
+    */
+    oneway void onTranscodingFailed(in int jobId, in TranscodingErrorCode errorCode);
+
+    /**
+    * Called when the transcoding configuration associated with the jobId gets updated, i.e. wait
+    * number in the job queue.
+    *
+    * <p> This will only be called if client set requestUpdate to be true in the TranscodingRequest
+    * submitted to the MediaTranscodingService.
+    *
+    * @param jobId jobId assigned by the MediaTranscodingService upon receiving request.
+    * @param oldAwaitNumber previous number of jobs ahead of current job.
+    * @param newAwaitNumber updated number of jobs ahead of current job.
+    */
+    oneway void onAwaitNumberOfJobsChanged(in int jobId, in int oldAwaitNumber, in int newAwaitNumber);
+
+    /**
+    * Called when there is an update on the progress of the TranscodingJob.
+    *
+    * <p> This will only be called if client set requestUpdate to be true in the TranscodingRequest
+    * submitted to the MediaTranscodingService.
+    *
+    * @param jobId jobId assigned by the MediaTranscodingService upon receiving request.
+    * @param progress an integer number ranging from 0 ~ 100 inclusive.
+    */
+    oneway void onProgressUpdate(in int jobId, in int progress);
+}
diff --git a/media/libmediatranscoding/aidl/android/media/TranscodingErrorCode.aidl b/media/libmediatranscoding/aidl/android/media/TranscodingErrorCode.aidl
new file mode 100644
index 0000000..7f47fdc
--- /dev/null
+++ b/media/libmediatranscoding/aidl/android/media/TranscodingErrorCode.aidl
@@ -0,0 +1,33 @@
+/**
+ * Copyright (c) 2019, 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.
+ */
+
+package android.media;
+
+/**
+ * Type enums of video transcoding errors.
+ *
+ * {@hide}
+ */
+@Backing(type = "int")
+enum TranscodingErrorCode {
+    kUnknown = 0,
+    kUnsupported = 1,
+    kDecoderError = 2,
+    kEncoderError = 3,
+    kExtractorError = 4,
+    kMuxerError = 5,
+    kInvalidBitstream = 6
+}
\ No newline at end of file
diff --git a/media/libmediatranscoding/aidl/android/media/TranscodingJob.aidl b/media/libmediatranscoding/aidl/android/media/TranscodingJob.aidl
new file mode 100644
index 0000000..42ad8ad
--- /dev/null
+++ b/media/libmediatranscoding/aidl/android/media/TranscodingJob.aidl
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+package android.media;
+
+import android.media.TranscodingRequest;
+
+/**
+ * TranscodingJob is generated by the MediaTranscodingService upon receiving a TranscodingRequest.
+ * It contains all the necessary configuration generated by the MediaTranscodingService for the
+ * TranscodingRequest.
+ *
+ * {@hide}
+ */
+//TODO(hkuang): Implement the parcelable.
+parcelable TranscodingJob {
+    /**
+     * A unique positive Id generated by the MediaTranscodingService.
+     */
+    int jobId;
+
+    /**
+     * The request associated with the TranscodingJob.
+     */
+    TranscodingRequest request;
+
+    /**
+    * Current number of jobs ahead of this job. The service schedules the job based on the priority
+    * passed from the client. Client could specify whether to receive updates when the
+    * awaitNumberOfJobs changes through setting requestProgressUpdate in the TranscodingRequest.
+    */
+    int awaitNumberOfJobs;
+}
diff --git a/media/libmediatranscoding/aidl/android/media/TranscodingRequest.aidl b/media/libmediatranscoding/aidl/android/media/TranscodingRequest.aidl
new file mode 100644
index 0000000..6b51ee3
--- /dev/null
+++ b/media/libmediatranscoding/aidl/android/media/TranscodingRequest.aidl
@@ -0,0 +1,58 @@
+/**
+ * Copyright (c) 2019, 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.
+ */
+
+package android.media;
+
+import android.media.TranscodingType;
+
+/**
+ * TranscodingRequest contains the desired configuration for the transcoding.
+ *
+ * {@hide}
+ */
+//TODO(hkuang): Implement the parcelable.
+parcelable TranscodingRequest {
+    /**
+     * Name of file to be transcoded.
+     */
+    @utf8InCpp String fileName;
+
+    /**
+     * Type of the transcoding.
+     */
+    TranscodingType transcodingType;
+
+    /**
+     * Input source file descriptor.
+     */
+    ParcelFileDescriptor inFd;
+
+    /**
+     * Output transcoded file descriptor.
+     */
+    ParcelFileDescriptor outFd;
+
+    /**
+     * Priority of this transcoding. Service will schedule the transcoding based on the priority.
+     */
+    // TODO(hkuang): Define the priority level.
+    int priority;
+
+    /**
+     * Whether to receive update on progress and change of awaitNumJobs.
+     */
+    boolean requestUpdate;
+}
diff --git a/media/libmediatranscoding/aidl/android/media/TranscodingResult.aidl b/media/libmediatranscoding/aidl/android/media/TranscodingResult.aidl
new file mode 100644
index 0000000..a41e025
--- /dev/null
+++ b/media/libmediatranscoding/aidl/android/media/TranscodingResult.aidl
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+package android.media;
+
+import android.media.TranscodingJob;
+
+/**
+ * Result of the transcoding.
+ *
+ * {@hide}
+ */
+//TODO(hkuang): Implement the parcelable.
+parcelable TranscodingResult {
+    /**
+     * The jobId associated with the TranscodingResult.
+     */
+    int jobId;
+
+    /**
+     * Actual bitrate of the transcoded video in bits per second. This will only present for video
+     * transcoding. -1 means not available.
+     */
+    int actualBitrateBps;
+
+    // TODO(hkuang): Add more fields.
+}
\ No newline at end of file
diff --git a/media/libmediatranscoding/aidl/android/media/TranscodingType.aidl b/media/libmediatranscoding/aidl/android/media/TranscodingType.aidl
new file mode 100644
index 0000000..9184c87
--- /dev/null
+++ b/media/libmediatranscoding/aidl/android/media/TranscodingType.aidl
@@ -0,0 +1,29 @@
+/**
+ * Copyright (c) 2019, 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.
+ */
+
+package android.media;
+
+/**
+ * Type of transcoding.
+ *
+ * {@hide}
+ */
+@Backing(type = "int")
+enum TranscodingType {
+    kUnknown = 0,
+    kVideoTranscoding = 1,
+    kImageTranscoding = 2,
+}
diff --git a/media/libmediatranscoding/aidl/android/media/TranscodingVideoCodecType.aidl b/media/libmediatranscoding/aidl/android/media/TranscodingVideoCodecType.aidl
new file mode 100644
index 0000000..5dab4f2
--- /dev/null
+++ b/media/libmediatranscoding/aidl/android/media/TranscodingVideoCodecType.aidl
@@ -0,0 +1,29 @@
+/**
+ * Copyright (c) 2019, 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.
+ */
+
+package android.media;
+
+/**
+ * Type enums of video codec type.
+ *
+ * {@hide}
+ */
+@Backing(type = "int")
+enum TranscodingVideoCodecType {
+    kUnspecified = 0,
+    kAvc = 1,
+    kHevc = 2,
+}
\ No newline at end of file