diff --git a/media/libmediatranscoding/transcoder/Android.bp b/media/libmediatranscoding/transcoder/Android.bp
index e352245..44f7959 100644
--- a/media/libmediatranscoding/transcoder/Android.bp
+++ b/media/libmediatranscoding/transcoder/Android.bp
@@ -20,12 +20,15 @@
     srcs: [
         "MediaSampleQueue.cpp",
         "MediaSampleReaderNDK.cpp",
+        "MediaTrackTranscoder.cpp",
+        "VideoTrackTranscoder.cpp",
     ],
 
     shared_libs: [
         "libbase",
         "libcutils",
         "libmediandk",
+        "libnativewindow",
         "libutils",
     ],
 
diff --git a/media/libmediatranscoding/transcoder/MediaSampleReaderNDK.cpp b/media/libmediatranscoding/transcoder/MediaSampleReaderNDK.cpp
index d0f117d..a0096c7 100644
--- a/media/libmediatranscoding/transcoder/MediaSampleReaderNDK.cpp
+++ b/media/libmediatranscoding/transcoder/MediaSampleReaderNDK.cpp
@@ -25,6 +25,10 @@
 
 namespace android {
 
+// Check that the extractor sample flags have the expected NDK meaning.
+static_assert(SAMPLE_FLAG_SYNC_SAMPLE == AMEDIAEXTRACTOR_SAMPLE_FLAG_SYNC,
+              "Sample flag mismatch: SYNC_SAMPLE");
+
 // static
 std::shared_ptr<MediaSampleReader> MediaSampleReaderNDK::createFromFd(int fd, size_t offset,
                                                                       size_t size) {
diff --git a/media/libmediatranscoding/transcoder/MediaTrackTranscoder.cpp b/media/libmediatranscoding/transcoder/MediaTrackTranscoder.cpp
new file mode 100644
index 0000000..1673b5b
--- /dev/null
+++ b/media/libmediatranscoding/transcoder/MediaTrackTranscoder.cpp
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2020 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 "MediaTrackTranscoder"
+
+#include <android-base/logging.h>
+#include <media/MediaTrackTranscoder.h>
+
+namespace android {
+
+media_status_t MediaTrackTranscoder::configure(
+        const std::shared_ptr<MediaSampleReader>& mediaSampleReader, int trackIndex,
+        const std::shared_ptr<AMediaFormat>& destinationFormat) {
+    std::scoped_lock lock{mStateMutex};
+
+    if (mState != UNINITIALIZED) {
+        LOG(ERROR) << "Configure can only be called once";
+        return AMEDIA_ERROR_UNSUPPORTED;
+    }
+
+    if (mediaSampleReader == nullptr) {
+        LOG(ERROR) << "MediaSampleReader is null";
+        return AMEDIA_ERROR_INVALID_PARAMETER;
+    }
+    if (trackIndex < 0 || trackIndex >= mediaSampleReader->getTrackCount()) {
+        LOG(ERROR) << "TrackIndex is invalid " << trackIndex;
+        return AMEDIA_ERROR_INVALID_PARAMETER;
+    }
+
+    mMediaSampleReader = mediaSampleReader;
+    mTrackIndex = trackIndex;
+
+    mSourceFormat =
+            std::shared_ptr<AMediaFormat>(mMediaSampleReader->getTrackFormat(mTrackIndex),
+                                          std::bind(AMediaFormat_delete, std::placeholders::_1));
+    if (mSourceFormat == nullptr) {
+        LOG(ERROR) << "Unable to get format for track #" << mTrackIndex;
+        return AMEDIA_ERROR_MALFORMED;
+    }
+
+    media_status_t status = configureDestinationFormat(destinationFormat);
+    if (status != AMEDIA_OK) {
+        LOG(ERROR) << "configure failed with error " << status;
+        return status;
+    }
+
+    mState = CONFIGURED;
+    return AMEDIA_OK;
+}
+
+bool MediaTrackTranscoder::start() {
+    std::scoped_lock lock{mStateMutex};
+
+    if (mState != CONFIGURED) {
+        LOG(ERROR) << "TrackTranscoder must be configured before started";
+        return false;
+    }
+
+    mTranscodingThread = std::thread([this] {
+        media_status_t status = runTranscodeLoop();
+
+        // Notify the client.
+        if (auto callbacks = mTranscoderCallback.lock()) {
+            if (status != AMEDIA_OK) {
+                callbacks->onTrackError(this, status);
+            } else {
+                callbacks->onTrackFinished(this);
+            }
+        }
+    });
+
+    mState = STARTED;
+    return true;
+}
+
+bool MediaTrackTranscoder::stop() {
+    std::scoped_lock lock{mStateMutex};
+
+    if (mState == STARTED) {
+        abortTranscodeLoop();
+        mTranscodingThread.join();
+        mState = STOPPED;
+        return true;
+    }
+
+    LOG(ERROR) << "TrackTranscoder must be started before stopped";
+    return false;
+}
+
+}  // namespace android
\ No newline at end of file
diff --git a/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp b/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp
new file mode 100644
index 0000000..9cd36cf
--- /dev/null
+++ b/media/libmediatranscoding/transcoder/VideoTrackTranscoder.cpp
@@ -0,0 +1,335 @@
+/*
+ * Copyright (C) 2020 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 "VideoTrackTranscoder"
+
+#include <android-base/logging.h>
+#include <media/VideoTrackTranscoder.h>
+
+namespace android {
+
+// Check that the codec sample flags have the expected NDK meaning.
+static_assert(SAMPLE_FLAG_CODEC_CONFIG == AMEDIACODEC_BUFFER_FLAG_CODEC_CONFIG,
+              "Sample flag mismatch: CODEC_CONFIG");
+static_assert(SAMPLE_FLAG_END_OF_STREAM == AMEDIACODEC_BUFFER_FLAG_END_OF_STREAM,
+              "Sample flag mismatch: END_OF_STREAM");
+static_assert(SAMPLE_FLAG_PARTIAL_FRAME == AMEDIACODEC_BUFFER_FLAG_PARTIAL_FRAME,
+              "Sample flag mismatch: PARTIAL_FRAME");
+
+template <typename T>
+void VideoTrackTranscoder::BlockingQueue<T>::push(T const& value, bool front) {
+    {
+        std::unique_lock<std::mutex> lock(mMutex);
+        if (front) {
+            mQueue.push_front(value);
+        } else {
+            mQueue.push_back(value);
+        }
+    }
+    mCondition.notify_one();
+}
+
+template <typename T>
+T VideoTrackTranscoder::BlockingQueue<T>::pop() {
+    std::unique_lock<std::mutex> lock(mMutex);
+    while (mQueue.empty()) {
+        mCondition.wait(lock);
+    }
+    T value = mQueue.front();
+    mQueue.pop_front();
+    return value;
+}
+
+// Dispatch responses to codec callbacks onto the message queue.
+struct AsyncCodecCallbackDispatch {
+    static void onAsyncInputAvailable(AMediaCodec* codec, void* userdata, int32_t index) {
+        VideoTrackTranscoder* transcoder = static_cast<VideoTrackTranscoder*>(userdata);
+        if (codec == transcoder->mDecoder) {
+            transcoder->mCodecMessageQueue.push(
+                    [transcoder, index] { transcoder->enqueueInputSample(index); });
+        }
+    }
+
+    static void onAsyncOutputAvailable(AMediaCodec* codec, void* userdata, int32_t index,
+                                       AMediaCodecBufferInfo* bufferInfoPtr) {
+        VideoTrackTranscoder* transcoder = static_cast<VideoTrackTranscoder*>(userdata);
+        AMediaCodecBufferInfo bufferInfo = *bufferInfoPtr;
+        transcoder->mCodecMessageQueue.push([transcoder, index, codec, bufferInfo] {
+            if (codec == transcoder->mDecoder) {
+                transcoder->transferBuffer(index, bufferInfo);
+            } else if (codec == transcoder->mEncoder) {
+                transcoder->dequeueOutputSample(index, bufferInfo);
+            }
+        });
+    }
+
+    static void onAsyncFormatChanged(AMediaCodec* codec, void* userdata, AMediaFormat* format) {
+        VideoTrackTranscoder* transcoder = static_cast<VideoTrackTranscoder*>(userdata);
+        const char* kCodecName = (codec == transcoder->mDecoder ? "Decoder" : "Encoder");
+        LOG(DEBUG) << kCodecName << " format changed: " << AMediaFormat_toString(format);
+    }
+
+    static void onAsyncError(AMediaCodec* codec, void* userdata, media_status_t error,
+                             int32_t actionCode, const char* detail) {
+        LOG(ERROR) << "Error from codec " << codec << ", userdata " << userdata << ", error "
+                   << error << ", action " << actionCode << ", detail " << detail;
+        VideoTrackTranscoder* transcoder = static_cast<VideoTrackTranscoder*>(userdata);
+        transcoder->mCodecMessageQueue.push(
+                [transcoder, error] {
+                    transcoder->mStatus = error;
+                    transcoder->mStopRequested = true;
+                },
+                true);
+    }
+};
+
+VideoTrackTranscoder::~VideoTrackTranscoder() {
+    if (mDecoder != nullptr) {
+        AMediaCodec_delete(mDecoder);
+    }
+
+    if (mEncoder != nullptr) {
+        AMediaCodec_delete(mEncoder);
+    }
+
+    if (mSurface != nullptr) {
+        ANativeWindow_release(mSurface);
+    }
+}
+
+// Creates and configures the codecs.
+media_status_t VideoTrackTranscoder::configureDestinationFormat(
+        const std::shared_ptr<AMediaFormat>& destinationFormat) {
+    media_status_t status = AMEDIA_OK;
+
+    if (destinationFormat == nullptr) {
+        LOG(ERROR) << "Destination format is null";
+        return AMEDIA_ERROR_INVALID_PARAMETER;
+    }
+
+    mDestinationFormat = destinationFormat;
+
+    // Create and configure the encoder.
+    const char* destinationMime = nullptr;
+    bool ok = AMediaFormat_getString(mDestinationFormat.get(), AMEDIAFORMAT_KEY_MIME,
+                                     &destinationMime);
+    if (!ok) {
+        LOG(ERROR) << "Destination MIME type is required for transcoding.";
+        return AMEDIA_ERROR_INVALID_PARAMETER;
+    }
+
+    mEncoder = AMediaCodec_createEncoderByType(destinationMime);
+    if (mEncoder == nullptr) {
+        LOG(ERROR) << "Unable to create encoder for type " << destinationMime;
+        return AMEDIA_ERROR_UNSUPPORTED;
+    }
+
+    status = AMediaCodec_configure(mEncoder, mDestinationFormat.get(), NULL /* surface */,
+                                   NULL /* crypto */, AMEDIACODEC_CONFIGURE_FLAG_ENCODE);
+    if (status != AMEDIA_OK) {
+        LOG(ERROR) << "Unable to configure video encoder: " << status;
+        return status;
+    }
+
+    status = AMediaCodec_createInputSurface(mEncoder, &mSurface);
+    if (status != AMEDIA_OK) {
+        LOG(ERROR) << "Unable to create an encoder input surface: %d" << status;
+        return status;
+    }
+
+    // Create and configure the decoder.
+    const char* sourceMime = nullptr;
+    ok = AMediaFormat_getString(mSourceFormat.get(), AMEDIAFORMAT_KEY_MIME, &sourceMime);
+    if (!ok) {
+        LOG(ERROR) << "Source MIME type is required for transcoding.";
+        return AMEDIA_ERROR_INVALID_PARAMETER;
+    }
+
+    mDecoder = AMediaCodec_createDecoderByType(sourceMime);
+    if (mDecoder == nullptr) {
+        LOG(ERROR) << "Unable to create decoder for type " << sourceMime;
+        return AMEDIA_ERROR_UNSUPPORTED;
+    }
+
+    status = AMediaCodec_configure(mDecoder, mSourceFormat.get(), mSurface, NULL /* crypto */,
+                                   0 /* flags */);
+    if (status != AMEDIA_OK) {
+        LOG(ERROR) << "Unable to configure video decoder: " << status;
+        return status;
+    }
+
+    // Configure codecs to run in async mode.
+    AMediaCodecOnAsyncNotifyCallback asyncCodecCallbacks = {
+            .onAsyncInputAvailable = AsyncCodecCallbackDispatch::onAsyncInputAvailable,
+            .onAsyncOutputAvailable = AsyncCodecCallbackDispatch::onAsyncOutputAvailable,
+            .onAsyncFormatChanged = AsyncCodecCallbackDispatch::onAsyncFormatChanged,
+            .onAsyncError = AsyncCodecCallbackDispatch::onAsyncError};
+
+    status = AMediaCodec_setAsyncNotifyCallback(mDecoder, asyncCodecCallbacks, this);
+    if (status != AMEDIA_OK) {
+        LOG(ERROR) << "Unable to set decoder to async mode: " << status;
+        return status;
+    }
+
+    status = AMediaCodec_setAsyncNotifyCallback(mEncoder, asyncCodecCallbacks, this);
+    if (status != AMEDIA_OK) {
+        LOG(ERROR) << "Unable to set encoder to async mode: " << status;
+        return status;
+    }
+
+    return AMEDIA_OK;
+}
+
+void VideoTrackTranscoder::enqueueInputSample(int32_t bufferIndex) {
+    media_status_t status = AMEDIA_OK;
+
+    if (mEOSFromSource) {
+        return;
+    }
+
+    status = mMediaSampleReader->getSampleInfoForTrack(mTrackIndex, &mSampleInfo);
+    if (status != AMEDIA_OK && status != AMEDIA_ERROR_END_OF_STREAM) {
+        LOG(ERROR) << "Error getting next sample info: " << status;
+        mStatus = status;
+        return;
+    }
+    const bool endOfStream = (status == AMEDIA_ERROR_END_OF_STREAM);
+
+    if (!endOfStream) {
+        size_t bufferSize = 0;
+        uint8_t* sourceBuffer = AMediaCodec_getInputBuffer(mDecoder, bufferIndex, &bufferSize);
+        if (sourceBuffer == nullptr) {
+            LOG(ERROR) << "Decoder returned a NULL input buffer.";
+            mStatus = AMEDIA_ERROR_UNKNOWN;
+            return;
+        } else if (bufferSize < mSampleInfo.size) {
+            LOG(ERROR) << "Decoder returned an input buffer that is smaller than the sample.";
+            mStatus = AMEDIA_ERROR_UNKNOWN;
+            return;
+        }
+
+        status = mMediaSampleReader->readSampleDataForTrack(mTrackIndex, sourceBuffer,
+                                                            mSampleInfo.size);
+        if (status != AMEDIA_OK) {
+            LOG(ERROR) << "Unable to read next sample data. Aborting transcode.";
+            mStatus = status;
+            return;
+        }
+
+        mMediaSampleReader->advanceTrack(mTrackIndex);
+    } else {
+        LOG(DEBUG) << "EOS from source.";
+        mEOSFromSource = true;
+    }
+
+    status = AMediaCodec_queueInputBuffer(mDecoder, bufferIndex, 0, mSampleInfo.size,
+                                          mSampleInfo.presentationTimeUs, mSampleInfo.flags);
+    if (status != AMEDIA_OK) {
+        LOG(ERROR) << "Unable to queue input buffer for decode: " << status;
+        mStatus = status;
+        return;
+    }
+}
+
+void VideoTrackTranscoder::transferBuffer(int32_t bufferIndex, AMediaCodecBufferInfo bufferInfo) {
+    if (bufferIndex >= 0) {
+        bool needsRender = bufferInfo.size > 0;
+        AMediaCodec_releaseOutputBuffer(mDecoder, bufferIndex, needsRender);
+    }
+
+    if (bufferInfo.flags & AMEDIACODEC_BUFFER_FLAG_END_OF_STREAM) {
+        LOG(DEBUG) << "EOS from decoder.";
+        media_status_t status = AMediaCodec_signalEndOfInputStream(mEncoder);
+        if (status != AMEDIA_OK) {
+            LOG(ERROR) << "SignalEOS on encoder returned error: " << status;
+            mStatus = status;
+        }
+    }
+}
+
+void VideoTrackTranscoder::dequeueOutputSample(int32_t bufferIndex,
+                                               AMediaCodecBufferInfo bufferInfo) {
+    if (bufferIndex >= 0) {
+        size_t sampleSize = 0;
+        uint8_t* buffer = AMediaCodec_getOutputBuffer(mEncoder, bufferIndex, &sampleSize);
+
+        std::shared_ptr<MediaSample> sample = MediaSample::createWithReleaseCallback(
+                buffer, bufferInfo.offset, bufferIndex,
+                std::bind(&VideoTrackTranscoder::releaseOutputSample, this, std::placeholders::_1));
+        sample->info.size = bufferInfo.size;
+        sample->info.flags = bufferInfo.flags;
+        sample->info.presentationTimeUs = bufferInfo.presentationTimeUs;
+
+        const bool aborted = mOutputQueue.enqueue(sample);
+        if (aborted) {
+            LOG(ERROR) << "Output sample queue was aborted. Stopping transcode.";
+            mStatus = AMEDIA_ERROR_IO;  // TODO: Define custom error codes?
+            return;
+        }
+    } else if (bufferIndex == AMEDIACODEC_INFO_OUTPUT_FORMAT_CHANGED) {
+        AMediaFormat* newFormat = AMediaCodec_getOutputFormat(mEncoder);
+        LOG(DEBUG) << "Encoder output format changed: " << AMediaFormat_toString(newFormat);
+    }
+
+    if (bufferInfo.flags & AMEDIACODEC_BUFFER_FLAG_END_OF_STREAM) {
+        LOG(DEBUG) << "EOS from encoder.";
+        mEOSFromEncoder = true;
+    }
+}
+
+void VideoTrackTranscoder::releaseOutputSample(MediaSample* sample) {
+    AMediaCodec_releaseOutputBuffer(mEncoder, sample->bufferId, false /* render */);
+}
+
+media_status_t VideoTrackTranscoder::runTranscodeLoop() {
+    media_status_t status = AMEDIA_OK;
+
+    status = AMediaCodec_start(mDecoder);
+    if (status != AMEDIA_OK) {
+        LOG(ERROR) << "Unable to start video decoder: " << status;
+        return status;
+    }
+
+    status = AMediaCodec_start(mEncoder);
+    if (status != AMEDIA_OK) {
+        LOG(ERROR) << "Unable to start video encoder: " << status;
+        AMediaCodec_stop(mDecoder);
+        return status;
+    }
+
+    // Process codec events until EOS is reached, transcoding is stopped or an error occurs.
+    while (!mStopRequested && !mEOSFromEncoder && mStatus == AMEDIA_OK) {
+        std::function<void()> message = mCodecMessageQueue.pop();
+        message();
+    }
+
+    // Return error if transcoding was stopped before it finished.
+    if (mStopRequested && !mEOSFromEncoder && mStatus == AMEDIA_OK) {
+        mStatus = AMEDIA_ERROR_UNKNOWN;  // TODO: Define custom error codes?
+    }
+
+    AMediaCodec_stop(mDecoder);
+    AMediaCodec_stop(mEncoder);
+    return mStatus;
+}
+
+void VideoTrackTranscoder::abortTranscodeLoop() {
+    // Push abort message to the front of the codec event queue.
+    mCodecMessageQueue.push([this] { mStopRequested = true; }, true /* front */);
+}
+
+}  // namespace android
diff --git a/media/libmediatranscoding/transcoder/include/media/MediaSample.h b/media/libmediatranscoding/transcoder/include/media/MediaSample.h
index e206a3e..c2cef84 100644
--- a/media/libmediatranscoding/transcoder/include/media/MediaSample.h
+++ b/media/libmediatranscoding/transcoder/include/media/MediaSample.h
@@ -38,21 +38,6 @@
     SAMPLE_FLAG_PARTIAL_FRAME = 8,
 };
 
-// Check that the sample flags have the expected NDK meaning.
-namespace {
-#include <media/NdkMediaCodec.h>
-#include <media/NdkMediaExtractor.h>
-
-static_assert(SAMPLE_FLAG_SYNC_SAMPLE == AMEDIAEXTRACTOR_SAMPLE_FLAG_SYNC,
-              "Sample flag mismatch: SYNC_SAMPLE");
-static_assert(SAMPLE_FLAG_CODEC_CONFIG == AMEDIACODEC_BUFFER_FLAG_CODEC_CONFIG,
-              "Sample flag mismatch: CODEC_CONFIG");
-static_assert(SAMPLE_FLAG_END_OF_STREAM == AMEDIACODEC_BUFFER_FLAG_END_OF_STREAM,
-              "Sample flag mismatch: END_OF_STREAM");
-static_assert(SAMPLE_FLAG_PARTIAL_FRAME == AMEDIACODEC_BUFFER_FLAG_PARTIAL_FRAME,
-              "Sample flag mismatch: PARTIAL_FRAME");
-}  // anonymous namespace
-
 /**
  * MediaSampleInfo is an object that carries information about a compressed media sample without
  * holding any sample data.
diff --git a/media/libmediatranscoding/transcoder/include/media/MediaTrackTranscoder.h b/media/libmediatranscoding/transcoder/include/media/MediaTrackTranscoder.h
new file mode 100644
index 0000000..bbdbc1a
--- /dev/null
+++ b/media/libmediatranscoding/transcoder/include/media/MediaTrackTranscoder.h
@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) 2020 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 ANDROID_MEDIA_TRACK_TRANSCODER_H
+#define ANDROID_MEDIA_TRACK_TRANSCODER_H
+
+#include <media/MediaSampleQueue.h>
+#include <media/MediaSampleReader.h>
+#include <media/NdkMediaError.h>
+#include <media/NdkMediaFormat.h>
+#include <utils/Mutex.h>
+
+#include <functional>
+#include <memory>
+#include <thread>
+
+namespace android {
+
+class MediaTrackTranscoder;
+
+/** Callback interface for MediaTrackTranscoder. */
+class MediaTrackTranscoderCallback {
+public:
+    /**
+     * Called when the MediaTrackTranscoder instance have finished transcoding all media samples
+     * successfully.
+     * @param transcoder The MediaTrackTranscoder that finished the transcoding.
+     */
+    virtual void onTrackFinished(MediaTrackTranscoder* transcoder);
+
+    /**
+     * Called when the MediaTrackTranscoder instance encountered an error it could not recover from.
+     * @param transcoder The MediaTrackTranscoder that encountered the error.
+     * @param status The non-zero error code describing the encountered error.
+     */
+    virtual void onTrackError(MediaTrackTranscoder* transcoder, media_status_t status);
+
+protected:
+    virtual ~MediaTrackTranscoderCallback() = default;
+};
+
+/**
+ * Base class for all track transcoders. MediaTrackTranscoder operates asynchronously on an internal
+ * thread and communicates through a MediaTrackTranscoderCallback instance. Transcoded samples are
+ * enqueued on the MediaTrackTranscoder's output queue. Samples need to be dequeued from the output
+ * queue or the transcoder will run out of buffers and stall. Once the consumer is done with a
+ * transcoded sample it is the consumer's responsibility to as soon as possible release all
+ * references to that sample in order to return the buffer to the transcoder. MediaTrackTranscoder
+ * is an abstract class and instances are created through one of the concrete subclasses.
+ *
+ * The base class MediaTrackTranscoder is responsible for thread and state management and guarantees
+ * that operations {configure, start, stop} are sent to the derived class in correct order.
+ * MediaTrackTranscoder is also responsible for delivering callback notifications once the
+ * transcoder has been successfully started.
+ */
+class MediaTrackTranscoder {
+public:
+    /**
+     * Configures the track transcoder with an input MediaSampleReader and a destination format.
+     * A track transcoder have to be configured before it is started.
+     * @param mediaSampleReader The MediaSampleReader to read input samples from.
+     * @param trackIndex The index of the track to transcode in mediaSampleReader.
+     * @param destinationFormat The destination format.
+     * @return AMEDIA_OK if the track transcoder was successfully configured.
+     */
+    media_status_t configure(const std::shared_ptr<MediaSampleReader>& mediaSampleReader,
+                             int trackIndex,
+                             const std::shared_ptr<AMediaFormat>& destinationFormat);
+
+    /**
+     * Starts the track transcoder. Once started the track transcoder have to be stopped by calling
+     * {@link #stop}, even after completing successfully. Start should only be called once.
+     * @return True if the track transcoder started, or false if it had already been started.
+     */
+    bool start();
+
+    /**
+     * Stops the track transcoder. Once the transcoding has been stopped it cannot be restarted
+     * again. It is safe to call stop multiple times.
+     * @return True if the track transcoder stopped, or false if it was already stopped.
+     */
+    bool stop();
+
+    /** Sample output queue. */
+    MediaSampleQueue mOutputQueue = {};
+
+protected:
+    MediaTrackTranscoder(const std::weak_ptr<MediaTrackTranscoderCallback>& transcoderCallback)
+          : mTranscoderCallback(transcoderCallback){};
+    virtual ~MediaTrackTranscoder() = default;
+
+    // configureDestinationFormat needs to be implemented by subclasses, and gets called on an
+    // external thread before start.
+    virtual media_status_t configureDestinationFormat(
+            const std::shared_ptr<AMediaFormat>& destinationFormat) = 0;
+
+    // runTranscodeLoop needs to be implemented by subclasses, and gets called on
+    // MediaTrackTranscoder's internal thread when the track transcoder is started.
+    virtual media_status_t runTranscodeLoop() = 0;
+
+    // abortTranscodeLoop needs to be implemented by subclasses, and should request transcoding to
+    // be aborted as soon as possible. It should be safe to call abortTranscodeLoop multiple times.
+    virtual void abortTranscodeLoop() = 0;
+
+    std::shared_ptr<MediaSampleReader> mMediaSampleReader;
+    int mTrackIndex;
+    std::shared_ptr<AMediaFormat> mSourceFormat;
+
+private:
+    const std::weak_ptr<MediaTrackTranscoderCallback> mTranscoderCallback;
+    std::mutex mStateMutex;
+    std::thread mTranscodingThread GUARDED_BY(mStateMutex);
+    enum {
+        UNINITIALIZED,
+        CONFIGURED,
+        STARTED,
+        STOPPED,
+    } mState GUARDED_BY(mStateMutex) = UNINITIALIZED;
+};
+
+}  // namespace android
+#endif  // ANDROID_MEDIA_TRACK_TRANSCODER_H
diff --git a/media/libmediatranscoding/transcoder/include/media/VideoTrackTranscoder.h b/media/libmediatranscoding/transcoder/include/media/VideoTrackTranscoder.h
new file mode 100644
index 0000000..7607c12
--- /dev/null
+++ b/media/libmediatranscoding/transcoder/include/media/VideoTrackTranscoder.h
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2020 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 ANDROID_VIDEO_TRACK_TRANSCODER_H
+#define ANDROID_VIDEO_TRACK_TRANSCODER_H
+
+#include <android/native_window.h>
+#include <media/MediaTrackTranscoder.h>
+#include <media/NdkMediaCodec.h>
+#include <media/NdkMediaFormat.h>
+
+#include <condition_variable>
+#include <deque>
+#include <mutex>
+
+namespace android {
+
+/**
+ * Track transcoder for video tracks. VideoTrackTranscoder uses AMediaCodec from the Media NDK
+ * internally. The two media codecs are run in asynchronous mode and shares uncompressed buffers
+ * using a native surface (ANativeWindow). Codec callback events are placed on a message queue and
+ * serviced in order on the transcoding thread managed by MediaTrackTranscoder.
+ */
+class VideoTrackTranscoder : public MediaTrackTranscoder {
+public:
+    VideoTrackTranscoder(const std::weak_ptr<MediaTrackTranscoderCallback>& transcoderCallback)
+          : MediaTrackTranscoder(transcoderCallback){};
+    virtual ~VideoTrackTranscoder() override;
+
+private:
+    friend struct AsyncCodecCallbackDispatch;
+
+    // Minimal blocking queue used as a message queue by VideoTrackTranscoder.
+    template <typename T>
+    class BlockingQueue {
+    public:
+        void push(T const& value, bool front = false);
+        T pop();
+
+    private:
+        std::mutex mMutex;
+        std::condition_variable mCondition;
+        std::deque<T> mQueue;
+    };
+
+    // MediaTrackTranscoder
+    media_status_t runTranscodeLoop() override;
+    void abortTranscodeLoop() override;
+    media_status_t configureDestinationFormat(
+            const std::shared_ptr<AMediaFormat>& destinationFormat) override;
+    // ~MediaTrackTranscoder
+
+    // Enqueues an input sample with the decoder.
+    void enqueueInputSample(int32_t bufferIndex);
+
+    // Moves a decoded buffer from the decoder's output to the encoder's input.
+    void transferBuffer(int32_t bufferIndex, AMediaCodecBufferInfo bufferInfo);
+
+    // Dequeues an encoded buffer from the encoder and adds it to the output queue.
+    void dequeueOutputSample(int32_t bufferIndex, AMediaCodecBufferInfo bufferInfo);
+
+    // MediaSample release callback to return a buffer to the codec.
+    void releaseOutputSample(MediaSample* sample);
+
+    AMediaCodec* mDecoder = nullptr;
+    AMediaCodec* mEncoder = nullptr;
+    ANativeWindow* mSurface = nullptr;
+    bool mEOSFromSource = false;
+    bool mEOSFromEncoder = false;
+    bool mStopRequested = false;
+    media_status_t mStatus = AMEDIA_OK;
+    MediaSampleInfo mSampleInfo;
+    BlockingQueue<std::function<void()>> mCodecMessageQueue;
+    std::shared_ptr<AMediaFormat> mDestinationFormat;
+};
+
+}  // namespace android
+#endif  // ANDROID_VIDEO_TRACK_TRANSCODER_H
diff --git a/media/libmediatranscoding/transcoder/tests/Android.bp b/media/libmediatranscoding/transcoder/tests/Android.bp
index a9937d7..48449f8 100644
--- a/media/libmediatranscoding/transcoder/tests/Android.bp
+++ b/media/libmediatranscoding/transcoder/tests/Android.bp
@@ -44,3 +44,17 @@
     defaults: ["testdefaults"],
     srcs: ["MediaSampleQueueTests.cpp"],
 }
+
+// MediaTrackTranscoder unit test
+cc_test {
+    name: "MediaTrackTranscoderTests",
+    defaults: ["testdefaults"],
+    srcs: ["MediaTrackTranscoderTests.cpp"],
+}
+
+// VideoTrackTranscoder unit test
+cc_test {
+    name: "VideoTrackTranscoderTests",
+    defaults: ["testdefaults"],
+    srcs: ["VideoTrackTranscoderTests.cpp"],
+}
diff --git a/media/libmediatranscoding/transcoder/tests/MediaTrackTranscoderTests.cpp b/media/libmediatranscoding/transcoder/tests/MediaTrackTranscoderTests.cpp
new file mode 100644
index 0000000..d1f3fee
--- /dev/null
+++ b/media/libmediatranscoding/transcoder/tests/MediaTrackTranscoderTests.cpp
@@ -0,0 +1,264 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+// Unit Test for MediaTrackTranscoder
+
+// #define LOG_NDEBUG 0
+#define LOG_TAG "MediaTrackTranscoderTests"
+
+#include <android-base/logging.h>
+#include <fcntl.h>
+#include <gtest/gtest.h>
+#include <media/MediaSampleReaderNDK.h>
+#include <media/MediaTrackTranscoder.h>
+#include <media/VideoTrackTranscoder.h>
+
+#include "TrackTranscoderTestUtils.h"
+
+namespace android {
+
+/** TrackTranscoder types to test. */
+enum TrackTranscoderType {
+    VIDEO,
+};
+
+class MediaTrackTranscoderTests : public ::testing::TestWithParam<TrackTranscoderType> {
+public:
+    MediaTrackTranscoderTests() { LOG(DEBUG) << "MediaTrackTranscoderTests created"; }
+
+    void SetUp() override {
+        LOG(DEBUG) << "MediaTrackTranscoderTests set up";
+
+        mCallback = std::make_shared<TestCallback>();
+
+        switch (GetParam()) {
+        case VIDEO:
+            mTranscoder = std::make_shared<VideoTrackTranscoder>(mCallback);
+            ASSERT_NE(mTranscoder, nullptr);
+            break;
+        }
+        ASSERT_NE(mTranscoder, nullptr);
+
+        initSampleReader();
+    }
+
+    void initSampleReader() {
+        const char* sourcePath =
+                "/data/local/tmp/TranscoderTestAssets/cubicle_avc_480x240_aac_24KHz.mp4";
+
+        const int sourceFd = open(sourcePath, O_RDONLY);
+        ASSERT_GT(sourceFd, 0);
+
+        const size_t fileSize = lseek(sourceFd, 0, SEEK_END);
+        lseek(sourceFd, 0, SEEK_SET);
+
+        mMediaSampleReader = MediaSampleReaderNDK::createFromFd(sourceFd, 0 /* offset */, fileSize);
+        ASSERT_NE(mMediaSampleReader, nullptr);
+        close(sourceFd);
+
+        for (size_t trackIndex = 0; trackIndex < mMediaSampleReader->getTrackCount();
+             ++trackIndex) {
+            AMediaFormat* trackFormat = mMediaSampleReader->getTrackFormat(trackIndex);
+            ASSERT_NE(trackFormat, nullptr);
+
+            const char* mime = nullptr;
+            AMediaFormat_getString(trackFormat, AMEDIAFORMAT_KEY_MIME, &mime);
+            ASSERT_NE(mime, nullptr);
+
+            if (GetParam() == VIDEO && strncmp(mime, "video/", 6) == 0) {
+                mTrackIndex = trackIndex;
+
+                mSourceFormat = std::shared_ptr<AMediaFormat>(
+                        trackFormat, std::bind(AMediaFormat_delete, std::placeholders::_1));
+                ASSERT_NE(mSourceFormat, nullptr);
+
+                mDestinationFormat =
+                        TrackTranscoderTestUtils::getDefaultVideoDestinationFormat(trackFormat);
+                ASSERT_NE(mDestinationFormat, nullptr);
+                break;
+            }
+
+            AMediaFormat_delete(trackFormat);
+        }
+
+        ASSERT_NE(mSourceFormat, nullptr);
+    }
+
+    // Drains the transcoder's output queue in a loop.
+    void drainOutputSampleQueue() {
+        mSampleQueueDrainThread = std::thread{[this] {
+            std::shared_ptr<MediaSample> sample;
+            bool aborted = false;
+            do {
+                aborted = mTranscoder->mOutputQueue.dequeue(&sample);
+            } while (!aborted && !(sample->info.flags & SAMPLE_FLAG_END_OF_STREAM));
+            mQueueWasAborted = aborted;
+            mGotEndOfStream =
+                    sample != nullptr && (sample->info.flags & SAMPLE_FLAG_END_OF_STREAM) != 0;
+        }};
+    }
+
+    void joinDrainThread() {
+        if (mSampleQueueDrainThread.joinable()) {
+            mSampleQueueDrainThread.join();
+        }
+    }
+    void TearDown() override {
+        LOG(DEBUG) << "MediaTrackTranscoderTests tear down";
+        joinDrainThread();
+    }
+
+    ~MediaTrackTranscoderTests() { LOG(DEBUG) << "MediaTrackTranscoderTests destroyed"; }
+
+protected:
+    std::shared_ptr<MediaTrackTranscoder> mTranscoder;
+    std::shared_ptr<TestCallback> mCallback;
+
+    std::shared_ptr<MediaSampleReader> mMediaSampleReader;
+    int mTrackIndex;
+
+    std::shared_ptr<AMediaFormat> mSourceFormat;
+    std::shared_ptr<AMediaFormat> mDestinationFormat;
+
+    std::thread mSampleQueueDrainThread;
+    bool mQueueWasAborted = false;
+    bool mGotEndOfStream = false;
+};
+
+TEST_P(MediaTrackTranscoderTests, WaitNormalOperation) {
+    LOG(DEBUG) << "Testing WaitNormalOperation";
+    EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
+              AMEDIA_OK);
+    ASSERT_TRUE(mTranscoder->start());
+    drainOutputSampleQueue();
+    EXPECT_EQ(mCallback->waitUntilFinished(), AMEDIA_OK);
+    EXPECT_TRUE(mTranscoder->stop());
+    joinDrainThread();
+    EXPECT_FALSE(mQueueWasAborted);
+    EXPECT_TRUE(mGotEndOfStream);
+}
+
+TEST_P(MediaTrackTranscoderTests, StopNormalOperation) {
+    LOG(DEBUG) << "Testing StopNormalOperation";
+    EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
+              AMEDIA_OK);
+    EXPECT_TRUE(mTranscoder->start());
+    EXPECT_TRUE(mTranscoder->stop());
+}
+
+TEST_P(MediaTrackTranscoderTests, StartWithoutConfigure) {
+    LOG(DEBUG) << "Testing StartWithoutConfigure";
+    EXPECT_FALSE(mTranscoder->start());
+}
+
+TEST_P(MediaTrackTranscoderTests, StopWithoutStart) {
+    LOG(DEBUG) << "Testing StopWithoutStart";
+    EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
+              AMEDIA_OK);
+    EXPECT_FALSE(mTranscoder->stop());
+}
+
+TEST_P(MediaTrackTranscoderTests, DoubleStartStop) {
+    LOG(DEBUG) << "Testing DoubleStartStop";
+    EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
+              AMEDIA_OK);
+    EXPECT_TRUE(mTranscoder->start());
+    EXPECT_FALSE(mTranscoder->start());
+    EXPECT_TRUE(mTranscoder->stop());
+    EXPECT_FALSE(mTranscoder->stop());
+}
+
+TEST_P(MediaTrackTranscoderTests, DoubleConfigure) {
+    LOG(DEBUG) << "Testing DoubleConfigure";
+    EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
+              AMEDIA_OK);
+    EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
+              AMEDIA_ERROR_UNSUPPORTED);
+}
+
+TEST_P(MediaTrackTranscoderTests, ConfigureAfterFail) {
+    LOG(DEBUG) << "Testing ConfigureAfterFail";
+    EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, -1, mDestinationFormat),
+              AMEDIA_ERROR_INVALID_PARAMETER);
+    EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
+              AMEDIA_OK);
+}
+
+TEST_P(MediaTrackTranscoderTests, RestartAfterStop) {
+    LOG(DEBUG) << "Testing RestartAfterStop";
+    EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
+              AMEDIA_OK);
+    EXPECT_TRUE(mTranscoder->start());
+    EXPECT_TRUE(mTranscoder->stop());
+    EXPECT_FALSE(mTranscoder->start());
+}
+
+TEST_P(MediaTrackTranscoderTests, RestartAfterFinish) {
+    LOG(DEBUG) << "Testing RestartAfterFinish";
+    EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
+              AMEDIA_OK);
+    ASSERT_TRUE(mTranscoder->start());
+    drainOutputSampleQueue();
+    EXPECT_EQ(mCallback->waitUntilFinished(), AMEDIA_OK);
+    EXPECT_TRUE(mTranscoder->stop());
+    EXPECT_FALSE(mTranscoder->start());
+
+    joinDrainThread();
+    EXPECT_FALSE(mQueueWasAborted);
+    EXPECT_TRUE(mGotEndOfStream);
+}
+
+TEST_P(MediaTrackTranscoderTests, AbortOutputQueue) {
+    LOG(DEBUG) << "Testing AbortOutputQueue";
+    EXPECT_EQ(mTranscoder->configure(mMediaSampleReader, mTrackIndex, mDestinationFormat),
+              AMEDIA_OK);
+    ASSERT_TRUE(mTranscoder->start());
+    mTranscoder->mOutputQueue.abort();
+    drainOutputSampleQueue();
+    EXPECT_EQ(mCallback->waitUntilFinished(), AMEDIA_ERROR_IO);
+    EXPECT_TRUE(mTranscoder->stop());
+
+    joinDrainThread();
+    EXPECT_TRUE(mQueueWasAborted);
+    EXPECT_FALSE(mGotEndOfStream);
+}
+
+TEST_P(MediaTrackTranscoderTests, NullSampleReader) {
+    LOG(DEBUG) << "Testing NullSampleReader";
+    std::shared_ptr<MediaSampleReader> nullSampleReader;
+    EXPECT_NE(mTranscoder->configure(nullSampleReader, mTrackIndex, mDestinationFormat), AMEDIA_OK);
+    EXPECT_FALSE(mTranscoder->start());
+}
+
+TEST_P(MediaTrackTranscoderTests, InvalidTrackIndex) {
+    LOG(DEBUG) << "Testing InvalidTrackIndex";
+    EXPECT_NE(mTranscoder->configure(mMediaSampleReader, -1, mDestinationFormat), AMEDIA_OK);
+    EXPECT_NE(mTranscoder->configure(mMediaSampleReader, mMediaSampleReader->getTrackCount(),
+                                     mDestinationFormat),
+              AMEDIA_OK);
+}
+
+};  // namespace android
+
+using namespace android;
+
+INSTANTIATE_TEST_SUITE_P(MediaTrackTranscoderTestsAll, MediaTrackTranscoderTests,
+                         ::testing::Values(VIDEO));
+
+int main(int argc, char** argv) {
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}
diff --git a/media/libmediatranscoding/transcoder/tests/TrackTranscoderTestUtils.h b/media/libmediatranscoding/transcoder/tests/TrackTranscoderTestUtils.h
new file mode 100644
index 0000000..6b9131c
--- /dev/null
+++ b/media/libmediatranscoding/transcoder/tests/TrackTranscoderTestUtils.h
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2020 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 <media/MediaTrackTranscoder.h>
+
+#include <condition_variable>
+#include <memory>
+#include <mutex>
+
+namespace android {
+
+//
+// This file contains test utilities used by more than one track transcoder test.
+//
+
+class TrackTranscoderTestUtils {
+public:
+    static std::shared_ptr<AMediaFormat> getDefaultVideoDestinationFormat(
+            AMediaFormat* sourceFormat) {
+        // Default video destination format setup.
+        static constexpr float kFrameRate = 30.0f;
+        static constexpr float kIFrameInterval = 30.0f;
+        static constexpr int32_t kBitRate = 2 * 1000 * 1000;
+        static constexpr int32_t kColorFormatSurface = 0x7f000789;
+
+        AMediaFormat* destinationFormat = AMediaFormat_new();
+        AMediaFormat_copy(destinationFormat, sourceFormat);
+        AMediaFormat_setFloat(destinationFormat, AMEDIAFORMAT_KEY_FRAME_RATE, kFrameRate);
+        AMediaFormat_setFloat(destinationFormat, AMEDIAFORMAT_KEY_I_FRAME_INTERVAL,
+                              kIFrameInterval);
+        AMediaFormat_setInt32(destinationFormat, AMEDIAFORMAT_KEY_BIT_RATE, kBitRate);
+        AMediaFormat_setInt32(destinationFormat, AMEDIAFORMAT_KEY_COLOR_FORMAT,
+                              kColorFormatSurface);
+
+        return std::shared_ptr<AMediaFormat>(destinationFormat,
+                                             std::bind(AMediaFormat_delete, std::placeholders::_1));
+    }
+};
+
+class TestCallback : public MediaTrackTranscoderCallback {
+public:
+    TestCallback() = default;
+    ~TestCallback() = default;
+
+    // MediaTrackTranscoderCallback
+    void onTrackFinished(MediaTrackTranscoder* transcoder __unused) {
+        std::unique_lock<std::mutex> lock(mMutex);
+        mTranscodingFinished = true;
+        mCv.notify_all();
+    }
+
+    void onTrackError(MediaTrackTranscoder* transcoder __unused, media_status_t status) {
+        std::unique_lock<std::mutex> lock(mMutex);
+        mTranscodingFinished = true;
+        mStatus = status;
+        mCv.notify_all();
+    }
+    // ~MediaTrackTranscoderCallback
+
+    media_status_t waitUntilFinished() {
+        std::unique_lock<std::mutex> lock(mMutex);
+        while (!mTranscodingFinished) {
+            mCv.wait(lock);
+        }
+        return mStatus;
+    }
+
+private:
+    media_status_t mStatus = AMEDIA_OK;
+    std::mutex mMutex;
+    std::condition_variable mCv;
+    bool mTranscodingFinished = false;
+};
+
+};  // namespace android
diff --git a/media/libmediatranscoding/transcoder/tests/VideoTrackTranscoderTests.cpp b/media/libmediatranscoding/transcoder/tests/VideoTrackTranscoderTests.cpp
new file mode 100644
index 0000000..3cec1a1
--- /dev/null
+++ b/media/libmediatranscoding/transcoder/tests/VideoTrackTranscoderTests.cpp
@@ -0,0 +1,160 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+// Unit Test for VideoTrackTranscoder
+
+// #define LOG_NDEBUG 0
+#define LOG_TAG "VideoTrackTranscoderTests"
+
+#include <android-base/logging.h>
+#include <fcntl.h>
+#include <gtest/gtest.h>
+#include <media/MediaSampleReaderNDK.h>
+#include <media/VideoTrackTranscoder.h>
+#include <utils/Timers.h>
+
+#include "TrackTranscoderTestUtils.h"
+
+namespace android {
+
+// TODO(b/155304421): Implement more advanced video specific tests:
+//  - Codec conversions (HEVC -> AVC).
+//  - Bitrate validation.
+//  - Output frame validation through PSNR.
+
+class VideoTrackTranscoderTests : public ::testing::Test {
+public:
+    VideoTrackTranscoderTests() { LOG(DEBUG) << "VideoTrackTranscoderTests created"; }
+
+    void SetUp() override {
+        LOG(DEBUG) << "VideoTrackTranscoderTests set up";
+        const char* sourcePath =
+                "/data/local/tmp/TranscoderTestAssets/cubicle_avc_480x240_aac_24KHz.mp4";
+
+        const int sourceFd = open(sourcePath, O_RDONLY);
+        ASSERT_GT(sourceFd, 0);
+
+        const off_t fileSize = lseek(sourceFd, 0, SEEK_END);
+        lseek(sourceFd, 0, SEEK_SET);
+
+        mMediaSampleReader = MediaSampleReaderNDK::createFromFd(sourceFd, 0, fileSize);
+        ASSERT_NE(mMediaSampleReader, nullptr);
+        close(sourceFd);
+
+        for (size_t trackIndex = 0; trackIndex < mMediaSampleReader->getTrackCount();
+             ++trackIndex) {
+            AMediaFormat* trackFormat = mMediaSampleReader->getTrackFormat(trackIndex);
+            ASSERT_NE(trackFormat, nullptr);
+
+            const char* mime = nullptr;
+            AMediaFormat_getString(trackFormat, AMEDIAFORMAT_KEY_MIME, &mime);
+            ASSERT_NE(mime, nullptr);
+
+            if (strncmp(mime, "video/", 6) == 0) {
+                mTrackIndex = trackIndex;
+
+                mSourceFormat = std::shared_ptr<AMediaFormat>(
+                        trackFormat, std::bind(AMediaFormat_delete, std::placeholders::_1));
+                ASSERT_NE(mSourceFormat, nullptr);
+
+                mDestinationFormat =
+                        TrackTranscoderTestUtils::getDefaultVideoDestinationFormat(trackFormat);
+                ASSERT_NE(mDestinationFormat, nullptr);
+                break;
+            }
+
+            AMediaFormat_delete(trackFormat);
+        }
+
+        ASSERT_NE(mSourceFormat, nullptr);
+    }
+
+    void TearDown() override { LOG(DEBUG) << "VideoTrackTranscoderTests tear down"; }
+
+    ~VideoTrackTranscoderTests() { LOG(DEBUG) << "VideoTrackTranscoderTests destroyed"; }
+
+    std::shared_ptr<MediaSampleReader> mMediaSampleReader;
+    int mTrackIndex;
+    std::shared_ptr<AMediaFormat> mSourceFormat;
+    std::shared_ptr<AMediaFormat> mDestinationFormat;
+};
+
+TEST_F(VideoTrackTranscoderTests, SampleSanity) {
+    LOG(DEBUG) << "Testing SampleSanity";
+    std::shared_ptr<TestCallback> callback = std::make_shared<TestCallback>();
+    VideoTrackTranscoder transcoder{callback};
+
+    EXPECT_EQ(transcoder.configure(mMediaSampleReader, mTrackIndex, mDestinationFormat), AMEDIA_OK);
+    ASSERT_TRUE(transcoder.start());
+
+    std::thread sampleConsumerThread{[&transcoder] {
+        uint64_t sampleCount = 0;
+        std::shared_ptr<MediaSample> sample;
+        while (!transcoder.mOutputQueue.dequeue(&sample)) {
+            ASSERT_NE(sample, nullptr);
+            const uint32_t flags = sample->info.flags;
+
+            if (sampleCount == 0) {
+                // Expect first sample to be a codec config.
+                EXPECT_TRUE((flags & SAMPLE_FLAG_CODEC_CONFIG) != 0);
+                EXPECT_TRUE((flags & SAMPLE_FLAG_SYNC_SAMPLE) == 0);
+                EXPECT_TRUE((flags & SAMPLE_FLAG_END_OF_STREAM) == 0);
+                EXPECT_TRUE((flags & SAMPLE_FLAG_PARTIAL_FRAME) == 0);
+            } else if (sampleCount == 1) {
+                // Expect second sample to be a sync sample.
+                EXPECT_TRUE((flags & SAMPLE_FLAG_CODEC_CONFIG) == 0);
+                EXPECT_TRUE((flags & SAMPLE_FLAG_SYNC_SAMPLE) != 0);
+                EXPECT_TRUE((flags & SAMPLE_FLAG_END_OF_STREAM) == 0);
+            }
+
+            if (!(flags & SAMPLE_FLAG_END_OF_STREAM)) {
+                // Expect a valid buffer unless it is EOS.
+                EXPECT_NE(sample->buffer, nullptr);
+                EXPECT_NE(sample->bufferId, 0xBAADF00D);
+                EXPECT_GT(sample->info.size, 0);
+            }
+
+            ++sampleCount;
+            if (sample->info.flags & SAMPLE_FLAG_END_OF_STREAM) {
+                break;
+            }
+            sample.reset();
+        }
+    }};
+
+    EXPECT_EQ(callback->waitUntilFinished(), AMEDIA_OK);
+    EXPECT_TRUE(transcoder.stop());
+
+    sampleConsumerThread.join();
+}
+
+// VideoTrackTranscoder needs a valid destination format.
+TEST_F(VideoTrackTranscoderTests, NullDestinationFormat) {
+    LOG(DEBUG) << "Testing NullDestinationFormat";
+    std::shared_ptr<TestCallback> callback = std::make_shared<TestCallback>();
+    std::shared_ptr<AMediaFormat> nullFormat;
+
+    VideoTrackTranscoder transcoder{callback};
+    EXPECT_EQ(transcoder.configure(mMediaSampleReader, 0 /* trackIndex */, nullFormat),
+              AMEDIA_ERROR_INVALID_PARAMETER);
+}
+
+}  // namespace android
+
+int main(int argc, char** argv) {
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}
diff --git a/media/libmediatranscoding/transcoder/tests/build_and_run_all_unit_tests.sh b/media/libmediatranscoding/transcoder/tests/build_and_run_all_unit_tests.sh
index dbee604..3c30e46 100755
--- a/media/libmediatranscoding/transcoder/tests/build_and_run_all_unit_tests.sh
+++ b/media/libmediatranscoding/transcoder/tests/build_and_run_all_unit_tests.sh
@@ -27,3 +27,9 @@
 
 echo "testing MediaSampleQueue"
 adb shell /data/nativetest64/MediaSampleQueueTests/MediaSampleQueueTests
+
+echo "testing MediaTrackTranscoder"
+adb shell /data/nativetest64/MediaTrackTranscoderTests/MediaTrackTranscoderTests
+
+echo "testing VideoTrackTranscoder"
+adb shell /data/nativetest64/VideoTrackTranscoderTests/VideoTrackTranscoderTests