add android-transcoder directly into libs

33 files changed, 3098 insertions, 3 deletions

diff --git a/build.gradle b/build.gradle
index 5b8680813..f75d4fbbf 100644
--- a/build.gradle
+++ b/build.gradle
@@ -31,10 +31,11 @@ dependencies {
     compile project(':libs:MemorizingTrustManager')
     compile project(':libs:audiowife')
     compile project(':libs:emojicon')
+    compile project(':libs:android-transcoder')
     playstoreCompile 'com.google.android.gms:play-services-gcm:10.0.1'
     compile 'org.sufficientlysecure:openpgp-api:10.0'
     compile 'com.soundcloud.android:android-crop:1.0.1@aar'
-    compile 'com.android.support:support-v13:25.1.0'
+    compile 'com.android.support:support-v13:25.1.1'
     compile 'org.bouncycastle:bcprov-jdk15on:1.56'
     compile 'org.bouncycastle:bcmail-jdk15on:1.56'
     compile 'org.jitsi:org.otr4j:0.22'
@@ -50,7 +51,7 @@ dependencies {
     compile 'jetty:javax.servlet:5.1.12'
     compile 'com.google.code.gson:gson:2.4'
     compile 'org.jbundle.util.osgi.wrapped:org.jbundle.util.osgi.wrapped.org.apache.http.client:4.1.2'
-    compile 'com.android.support:appcompat-v7:25.1.0'
+    compile 'com.android.support:appcompat-v7:25.1.1'
     compile 'com.android.support:multidex:1.0.1'
     compile 'com.github.bumptech.glide:glide:3.7.0'
     compile 'com.github.chrisbanes:PhotoView:1.3.1'
@@ -60,7 +61,6 @@ dependencies {
     compile 'pub.devrel:easypermissions:0.2.1'
     compile 'com.wefika:flowlayout:0.4.1'
     compile 'com.googlecode.ez-vcard:ez-vcard:0.10.1'
-    compile 'net.ypresto.androidtranscoder:android-transcoder:0.2.0'
 }
 
 ext {
diff --git a/libs/android-transcoder/.gitignore b/libs/android-transcoder/.gitignore
new file mode 100644
index 000000000..796b96d1c
--- /dev/null
+++ b/libs/android-transcoder/.gitignore
@@ -0,0 +1 @@
+/build
diff --git a/libs/android-transcoder/build.gradle b/libs/android-transcoder/build.gradle
new file mode 100644
index 000000000..1b6e8f17c
--- /dev/null
+++ b/libs/android-transcoder/build.gradle
@@ -0,0 +1,40 @@
+buildscript {
+    repositories {
+        jcenter()
+    }
+    dependencies {
+        classpath 'com.novoda:bintray-release:0.2.4'
+    }
+}
+
+apply plugin: 'com.android.library'
+apply plugin: 'bintray-release'
+
+android {
+    compileSdkVersion 24
+    buildToolsVersion "24.0.1"
+
+    defaultConfig {
+        minSdkVersion 18
+        targetSdkVersion 24
+    }
+
+    buildTypes {
+        release {
+            zipAlignEnabled true
+            minifyEnabled false
+            shrinkResources false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+}
+
+publish {
+    groupId = 'net.ypresto.androidtranscoder'
+    artifactId = 'android-transcoder'
+    version = '0.2.0'
+    licences = ['Apache-2.0']
+    website = 'https://github.com/ypresto/android-transcoder'
+    autoPublish = false
+    dryRun = false
+}
diff --git a/libs/android-transcoder/proguard-rules.pro b/libs/android-transcoder/proguard-rules.pro
new file mode 100644
index 000000000..91dd3543e
--- /dev/null
+++ b/libs/android-transcoder/proguard-rules.pro
@@ -0,0 +1,17 @@
+# Add project specific ProGuard rules here.
+# By default, the flags in this file are appended to flags specified
+# in /Users/yuya.tanaka/devel/android-sdk/tools/proguard/proguard-android.txt
+# You can edit the include path and order by changing the proguardFiles
+# directive in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# Add any project specific keep options here:
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
diff --git a/libs/android-transcoder/src/main/AndroidManifest.xml b/libs/android-transcoder/src/main/AndroidManifest.xml
new file mode 100644
index 000000000..0bfa93402
--- /dev/null
+++ b/libs/android-transcoder/src/main/AndroidManifest.xml
@@ -0,0 +1,6 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="net.ypresto.androidtranscoder">
+
+    <application />
+
+</manifest>
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/MediaTranscoder.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/MediaTranscoder.java
new file mode 100644
index 000000000..7ec32bc97
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/MediaTranscoder.java
@@ -0,0 +1,248 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder;
+
+import android.media.MediaFormat;
+import android.os.Handler;
+import android.os.Looper;
+import android.util.Log;
+
+import net.ypresto.androidtranscoder.engine.MediaTranscoderEngine;
+import net.ypresto.androidtranscoder.format.MediaFormatPresets;
+import net.ypresto.androidtranscoder.format.MediaFormatStrategy;
+
+import java.io.FileDescriptor;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.util.concurrent.Callable;
+import java.util.concurrent.Future;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
+
+public class MediaTranscoder {
+    private static final String TAG = "MediaTranscoder";
+    private static final int MAXIMUM_THREAD = 1; // TODO
+    private static volatile MediaTranscoder sMediaTranscoder;
+    private ThreadPoolExecutor mExecutor;
+
+    private MediaTranscoder() {
+        mExecutor = new ThreadPoolExecutor(
+                0, MAXIMUM_THREAD, 60, TimeUnit.SECONDS,
+                new LinkedBlockingQueue<Runnable>(),
+                new ThreadFactory() {
+                    @Override
+                    public Thread newThread(Runnable r) {
+                        return new Thread(r, "MediaTranscoder-Worker");
+                    }
+                });
+    }
+
+    public static MediaTranscoder getInstance() {
+        if (sMediaTranscoder == null) {
+            synchronized (MediaTranscoder.class) {
+                if (sMediaTranscoder == null) {
+                    sMediaTranscoder = new MediaTranscoder();
+                }
+            }
+        }
+        return sMediaTranscoder;
+    }
+
+    /**
+     * Transcodes video file asynchronously.
+     * Audio track will be kept unchanged.
+     *
+     * @param inFileDescriptor FileDescriptor for input.
+     * @param outPath          File path for output.
+     * @param listener         Listener instance for callback.
+     * @deprecated Use {@link #transcodeVideo(FileDescriptor, String, MediaFormatStrategy, MediaTranscoder.Listener)} which accepts output video format.
+     */
+    @Deprecated
+    public Future<Void> transcodeVideo(final FileDescriptor inFileDescriptor, final String outPath, final Listener listener) {
+        return transcodeVideo(inFileDescriptor, outPath, new MediaFormatStrategy() {
+            @Override
+            public MediaFormat createVideoOutputFormat(MediaFormat inputFormat) {
+                return MediaFormatPresets.getExportPreset960x540();
+            }
+
+            @Override
+            public MediaFormat createAudioOutputFormat(MediaFormat inputFormat) {
+                return null;
+            }
+        }, listener);
+    }
+
+    /**
+     * Transcodes video file asynchronously.
+     * Audio track will be kept unchanged.
+     *
+     * @param inPath            File path for input.
+     * @param outPath           File path for output.
+     * @param outFormatStrategy Strategy for output video format.
+     * @param listener          Listener instance for callback.
+     * @throws IOException if input file could not be read.
+     */
+    public Future<Void> transcodeVideo(final String inPath, final String outPath, final MediaFormatStrategy outFormatStrategy, final Listener listener) throws IOException {
+        FileInputStream fileInputStream = null;
+        FileDescriptor inFileDescriptor;
+        try {
+            fileInputStream = new FileInputStream(inPath);
+            inFileDescriptor = fileInputStream.getFD();
+        } catch (IOException e) {
+            if (fileInputStream != null) {
+                try {
+                    fileInputStream.close();
+                } catch (IOException eClose) {
+                    Log.e(TAG, "Can't close input stream: ", eClose);
+                }
+            }
+            throw e;
+        }
+        final FileInputStream finalFileInputStream = fileInputStream;
+        return transcodeVideo(inFileDescriptor, outPath, outFormatStrategy, new Listener() {
+            @Override
+            public void onTranscodeProgress(double progress) {
+                listener.onTranscodeProgress(progress);
+            }
+
+            @Override
+            public void onTranscodeCompleted() {
+                closeStream();
+                listener.onTranscodeCompleted();
+            }
+
+            @Override
+            public void onTranscodeCanceled() {
+                closeStream();
+                listener.onTranscodeCanceled();
+            }
+
+            @Override
+            public void onTranscodeFailed(Exception exception) {
+                closeStream();
+                listener.onTranscodeFailed(exception);
+            }
+
+            private void closeStream() {
+                try {
+                    finalFileInputStream.close();
+                } catch (IOException e) {
+                    Log.e(TAG, "Can't close input stream: ", e);
+                }
+            }
+        });
+    }
+
+    /**
+     * Transcodes video file asynchronously.
+     * Audio track will be kept unchanged.
+     *
+     * @param inFileDescriptor  FileDescriptor for input.
+     * @param outPath           File path for output.
+     * @param outFormatStrategy Strategy for output video format.
+     * @param listener          Listener instance for callback.
+     */
+    public Future<Void> transcodeVideo(final FileDescriptor inFileDescriptor, final String outPath, final MediaFormatStrategy outFormatStrategy, final Listener listener) {
+        Looper looper = Looper.myLooper();
+        if (looper == null) looper = Looper.getMainLooper();
+        final Handler handler = new Handler(looper);
+        final AtomicReference<Future<Void>> futureReference = new AtomicReference<>();
+        final Future<Void> createdFuture = mExecutor.submit(new Callable<Void>() {
+            @Override
+            public Void call() throws Exception {
+                Exception caughtException = null;
+                try {
+                    MediaTranscoderEngine engine = new MediaTranscoderEngine();
+                    engine.setProgressCallback(new MediaTranscoderEngine.ProgressCallback() {
+                        @Override
+                        public void onProgress(final double progress) {
+                            handler.post(new Runnable() { // TODO: reuse instance
+                                @Override
+                                public void run() {
+                                    listener.onTranscodeProgress(progress);
+                                }
+                            });
+                        }
+                    });
+                    engine.setDataSource(inFileDescriptor);
+                    engine.transcodeVideo(outPath, outFormatStrategy);
+                } catch (IOException e) {
+                    Log.w(TAG, "Transcode failed: input file (fd: " + inFileDescriptor.toString() + ") not found"
+                            + " or could not open output file ('" + outPath + "') .", e);
+                    caughtException = e;
+                } catch (InterruptedException e) {
+                    Log.i(TAG, "Cancel transcode video file.", e);
+                    caughtException = e;
+                } catch (RuntimeException e) {
+                    Log.e(TAG, "Fatal error while transcoding, this might be invalid format or bug in engine or Android.", e);
+                    caughtException = e;
+                }
+
+                final Exception exception = caughtException;
+                handler.post(new Runnable() {
+                    @Override
+                    public void run() {
+                        if (exception == null) {
+                            listener.onTranscodeCompleted();
+                        } else {
+                            Future<Void> future = futureReference.get();
+                            if (future != null && future.isCancelled()) {
+                                listener.onTranscodeCanceled();
+                            } else {
+                                listener.onTranscodeFailed(exception);
+                            }
+                        }
+                    }
+                });
+
+                if (exception != null) throw exception;
+                return null;
+            }
+        });
+        futureReference.set(createdFuture);
+        return createdFuture;
+    }
+
+    public interface Listener {
+        /**
+         * Called to notify progress.
+         *
+         * @param progress Progress in [0.0, 1.0] range, or negative value if progress is unknown.
+         */
+        void onTranscodeProgress(double progress);
+
+        /**
+         * Called when transcode completed.
+         */
+        void onTranscodeCompleted();
+
+        /**
+         * Called when transcode canceled.
+         */
+        void onTranscodeCanceled();
+
+        /**
+         * Called when transcode failed.
+         *
+         * @param exception Exception thrown from {@link MediaTranscoderEngine#transcodeVideo(String, MediaFormatStrategy)}.
+         *                  Note that it IS NOT {@link java.lang.Throwable}. This means {@link java.lang.Error} won't be caught.
+         */
+        void onTranscodeFailed(Exception exception);
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/compat/MediaCodecBufferCompatWrapper.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/compat/MediaCodecBufferCompatWrapper.java
new file mode 100644
index 000000000..e36db4b72
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/compat/MediaCodecBufferCompatWrapper.java
@@ -0,0 +1,42 @@
+package net.ypresto.androidtranscoder.compat;
+
+import android.media.MediaCodec;
+import android.os.Build;
+
+import java.nio.ByteBuffer;
+
+/**
+ * A Wrapper to MediaCodec that facilitates the use of API-dependent get{Input/Output}Buffer methods,
+ * in order to prevent: http://stackoverflow.com/q/30646885
+ */
+public class MediaCodecBufferCompatWrapper {
+
+    final MediaCodec mMediaCodec;
+    final ByteBuffer[] mInputBuffers;
+    final ByteBuffer[] mOutputBuffers;
+
+    public MediaCodecBufferCompatWrapper(MediaCodec mediaCodec) {
+        mMediaCodec = mediaCodec;
+
+        if (Build.VERSION.SDK_INT < 21) {
+            mInputBuffers = mediaCodec.getInputBuffers();
+            mOutputBuffers = mediaCodec.getOutputBuffers();
+        } else {
+            mInputBuffers = mOutputBuffers = null;
+        }
+    }
+
+    public ByteBuffer getInputBuffer(final int index) {
+        if (Build.VERSION.SDK_INT >= 21) {
+            return mMediaCodec.getInputBuffer(index);
+        }
+        return mInputBuffers[index];
+    }
+
+    public ByteBuffer getOutputBuffer(final int index) {
+        if (Build.VERSION.SDK_INT >= 21) {
+            return mMediaCodec.getOutputBuffer(index);
+        }
+        return mOutputBuffers[index];
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/compat/MediaCodecListCompat.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/compat/MediaCodecListCompat.java
new file mode 100644
index 000000000..cc4c7a025
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/compat/MediaCodecListCompat.java
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.compat;
+
+import android.media.MediaCodecInfo;
+import android.media.MediaCodecList;
+import android.media.MediaFormat;
+
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+/**
+ * This class emulates basic behavior of MediaCodecList in API level &gt;= 21.
+ * TODO: implement delegate to MediaCodecList in newer API.
+ */
+public class MediaCodecListCompat {
+    public static final int REGULAR_CODECS = 0;
+    public static final int ALL_CODECS = 1;
+
+    public MediaCodecListCompat(int kind) {
+        if (kind != REGULAR_CODECS) {
+            throw new UnsupportedOperationException("kind other than REGULAR_CODECS is not implemented.");
+        }
+    }
+
+    public final String findDecoderForFormat(MediaFormat format) {
+        return findCoderForFormat(format, false);
+    }
+
+    public final String findEncoderForFormat(MediaFormat format) {
+        return findCoderForFormat(format, true);
+    }
+
+    private String findCoderForFormat(MediaFormat format, boolean findEncoder) {
+        String mimeType = format.getString(MediaFormat.KEY_MIME);
+        Iterator<MediaCodecInfo> iterator = new MediaCodecInfoIterator();
+        while (iterator.hasNext()) {
+            MediaCodecInfo codecInfo = iterator.next();
+            if (codecInfo.isEncoder() != findEncoder) continue;
+            if (Arrays.asList(codecInfo.getSupportedTypes()).contains(mimeType)) {
+                return codecInfo.getName();
+            }
+        }
+        return null;
+    }
+
+    public final MediaCodecInfo[] getCodecInfos() {
+        int codecCount = getCodecCount();
+        MediaCodecInfo[] codecInfos = new MediaCodecInfo[codecCount];
+        Iterator<MediaCodecInfo> iterator = new MediaCodecInfoIterator();
+        for (int i = 0; i < codecCount; i++) {
+            codecInfos[i] = getCodecInfoAt(i);
+        }
+        return codecInfos;
+    }
+
+    private static int getCodecCount() {
+        return MediaCodecList.getCodecCount();
+    }
+
+    private static MediaCodecInfo getCodecInfoAt(int index) {
+        return MediaCodecList.getCodecInfoAt(index);
+    }
+
+    private final class MediaCodecInfoIterator implements Iterator<MediaCodecInfo> {
+        private int mCodecCount = getCodecCount();
+        private int mIndex = -1;
+
+        @Override
+        public boolean hasNext() {
+            return mIndex + 1 < mCodecCount;
+        }
+
+        @Override
+        public MediaCodecInfo next() {
+            if (!hasNext()) {
+                throw new NoSuchElementException();
+            }
+            mIndex++;
+            return getCodecInfoAt(mIndex);
+        }
+
+        @Override
+        public void remove() {
+            throw new UnsupportedOperationException();
+        }
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/AudioChannel.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/AudioChannel.java
new file mode 100644
index 000000000..ac3e43efb
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/AudioChannel.java
@@ -0,0 +1,231 @@
+package net.ypresto.androidtranscoder.engine;
+
+import android.media.MediaCodec;
+import android.media.MediaFormat;
+
+import net.ypresto.androidtranscoder.compat.MediaCodecBufferCompatWrapper;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.ShortBuffer;
+import java.util.ArrayDeque;
+import java.util.Queue;
+
+/**
+ * Channel of raw audio from decoder to encoder.
+ * Performs the necessary conversion between different input & output audio formats.
+ *
+ * We currently support upmixing from mono to stereo & downmixing from stereo to mono.
+ * Sample rate conversion is not supported yet.
+ */
+class AudioChannel {
+
+    private static class AudioBuffer {
+        int bufferIndex;
+        long presentationTimeUs;
+        ShortBuffer data;
+    }
+
+    public static final int BUFFER_INDEX_END_OF_STREAM = -1;
+
+    private static final int BYTES_PER_SHORT = 2;
+    private static final long MICROSECS_PER_SEC = 1000000;
+
+    private final Queue<AudioBuffer> mEmptyBuffers = new ArrayDeque<>();
+    private final Queue<AudioBuffer> mFilledBuffers = new ArrayDeque<>();
+
+    private final MediaCodec mDecoder;
+    private final MediaCodec mEncoder;
+    private final MediaFormat mEncodeFormat;
+
+    private int mInputSampleRate;
+    private int mInputChannelCount;
+    private int mOutputChannelCount;
+
+    private AudioRemixer mRemixer;
+
+    private final MediaCodecBufferCompatWrapper mDecoderBuffers;
+    private final MediaCodecBufferCompatWrapper mEncoderBuffers;
+
+    private final AudioBuffer mOverflowBuffer = new AudioBuffer();
+
+    private MediaFormat mActualDecodedFormat;
+
+
+    public AudioChannel(final MediaCodec decoder,
+                        final MediaCodec encoder, final MediaFormat encodeFormat) {
+        mDecoder = decoder;
+        mEncoder = encoder;
+        mEncodeFormat = encodeFormat;
+
+        mDecoderBuffers = new MediaCodecBufferCompatWrapper(mDecoder);
+        mEncoderBuffers = new MediaCodecBufferCompatWrapper(mEncoder);
+    }
+
+    public void setActualDecodedFormat(final MediaFormat decodedFormat) {
+        mActualDecodedFormat = decodedFormat;
+
+        mInputSampleRate = mActualDecodedFormat.getInteger(MediaFormat.KEY_SAMPLE_RATE);
+        if (mInputSampleRate != mEncodeFormat.getInteger(MediaFormat.KEY_SAMPLE_RATE)) {
+            throw new UnsupportedOperationException("Audio sample rate conversion not supported yet.");
+        }
+
+        mInputChannelCount = mActualDecodedFormat.getInteger(MediaFormat.KEY_CHANNEL_COUNT);
+        mOutputChannelCount = mEncodeFormat.getInteger(MediaFormat.KEY_CHANNEL_COUNT);
+
+        if (mInputChannelCount != 1 && mInputChannelCount != 2) {
+            throw new UnsupportedOperationException("Input channel count (" + mInputChannelCount + ") not supported.");
+        }
+
+        if (mOutputChannelCount != 1 && mOutputChannelCount != 2) {
+            throw new UnsupportedOperationException("Output channel count (" + mOutputChannelCount + ") not supported.");
+        }
+
+        if (mInputChannelCount > mOutputChannelCount) {
+            mRemixer = AudioRemixer.DOWNMIX;
+        } else if (mInputChannelCount < mOutputChannelCount) {
+            mRemixer = AudioRemixer.UPMIX;
+        } else {
+            mRemixer = AudioRemixer.PASSTHROUGH;
+        }
+
+        mOverflowBuffer.presentationTimeUs = 0;
+    }
+
+    public void drainDecoderBufferAndQueue(final int bufferIndex, final long presentationTimeUs) {
+        if (mActualDecodedFormat == null) {
+            throw new RuntimeException("Buffer received before format!");
+        }
+
+        final ByteBuffer data =
+                bufferIndex == BUFFER_INDEX_END_OF_STREAM ?
+                        null : mDecoderBuffers.getOutputBuffer(bufferIndex);
+
+        AudioBuffer buffer = mEmptyBuffers.poll();
+        if (buffer == null) {
+            buffer = new AudioBuffer();
+        }
+
+        buffer.bufferIndex = bufferIndex;
+        buffer.presentationTimeUs = presentationTimeUs;
+        buffer.data = data == null ? null : data.asShortBuffer();
+
+        if (mOverflowBuffer.data == null) {
+            mOverflowBuffer.data = ByteBuffer
+                    .allocateDirect(data.capacity())
+                    .order(ByteOrder.nativeOrder())
+                    .asShortBuffer();
+            mOverflowBuffer.data.clear().flip();
+        }
+
+        mFilledBuffers.add(buffer);
+    }
+
+    public boolean feedEncoder(long timeoutUs) {
+        final boolean hasOverflow = mOverflowBuffer.data != null && mOverflowBuffer.data.hasRemaining();
+        if (mFilledBuffers.isEmpty() && !hasOverflow) {
+            // No audio data - Bail out
+            return false;
+        }
+
+        final int encoderInBuffIndex = mEncoder.dequeueInputBuffer(timeoutUs);
+        if (encoderInBuffIndex < 0) {
+            // Encoder is full - Bail out
+            return false;
+        }
+
+        // Drain overflow first
+        final ShortBuffer outBuffer = mEncoderBuffers.getInputBuffer(encoderInBuffIndex).asShortBuffer();
+        if (hasOverflow) {
+            final long presentationTimeUs = drainOverflow(outBuffer);
+            mEncoder.queueInputBuffer(encoderInBuffIndex,
+                    0, outBuffer.position() * BYTES_PER_SHORT,
+                    presentationTimeUs, 0);
+            return true;
+        }
+
+        final AudioBuffer inBuffer = mFilledBuffers.poll();
+        if (inBuffer.bufferIndex == BUFFER_INDEX_END_OF_STREAM) {
+            mEncoder.queueInputBuffer(encoderInBuffIndex, 0, 0, 0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
+            return false;
+        }
+
+        final long presentationTimeUs = remixAndMaybeFillOverflow(inBuffer, outBuffer);
+        mEncoder.queueInputBuffer(encoderInBuffIndex,
+                0, outBuffer.position() * BYTES_PER_SHORT,
+                presentationTimeUs, 0);
+        if (inBuffer != null) {
+            mDecoder.releaseOutputBuffer(inBuffer.bufferIndex, false);
+            mEmptyBuffers.add(inBuffer);
+        }
+
+        return true;
+    }
+
+    private static long sampleCountToDurationUs(final int sampleCount,
+                                                final int sampleRate,
+                                                final int channelCount) {
+        return (sampleCount / (sampleRate * MICROSECS_PER_SEC)) / channelCount;
+    }
+
+    private long drainOverflow(final ShortBuffer outBuff) {
+        final ShortBuffer overflowBuff = mOverflowBuffer.data;
+        final int overflowLimit = overflowBuff.limit();
+        final int overflowSize = overflowBuff.remaining();
+
+        final long beginPresentationTimeUs = mOverflowBuffer.presentationTimeUs +
+                sampleCountToDurationUs(overflowBuff.position(), mInputSampleRate, mOutputChannelCount);
+
+        outBuff.clear();
+        // Limit overflowBuff to outBuff's capacity
+        overflowBuff.limit(outBuff.capacity());
+        // Load overflowBuff onto outBuff
+        outBuff.put(overflowBuff);
+
+        if (overflowSize >= outBuff.capacity()) {
+            // Overflow fully consumed - Reset
+            overflowBuff.clear().limit(0);
+        } else {
+            // Only partially consumed - Keep position & restore previous limit
+            overflowBuff.limit(overflowLimit);
+        }
+
+        return beginPresentationTimeUs;
+    }
+
+    private long remixAndMaybeFillOverflow(final AudioBuffer input,
+                                           final ShortBuffer outBuff) {
+        final ShortBuffer inBuff = input.data;
+        final ShortBuffer overflowBuff = mOverflowBuffer.data;
+
+        outBuff.clear();
+
+        // Reset position to 0, and set limit to capacity (Since MediaCodec doesn't do that for us)
+        inBuff.clear();
+
+        if (inBuff.remaining() > outBuff.remaining()) {
+            // Overflow
+            // Limit inBuff to outBuff's capacity
+            inBuff.limit(outBuff.capacity());
+            mRemixer.remix(inBuff, outBuff);
+
+            // Reset limit to its own capacity & Keep position
+            inBuff.limit(inBuff.capacity());
+
+            // Remix the rest onto overflowBuffer
+            // NOTE: We should only reach this point when overflow buffer is empty
+            final long consumedDurationUs =
+                    sampleCountToDurationUs(inBuff.position(), mInputSampleRate, mInputChannelCount);
+            mRemixer.remix(inBuff, overflowBuff);
+
+            // Seal off overflowBuff & mark limit
+            overflowBuff.flip();
+            mOverflowBuffer.presentationTimeUs = input.presentationTimeUs + consumedDurationUs;
+        } else {
+            // No overflow
+            mRemixer.remix(inBuff, outBuff);
+        }
+
+        return input.presentationTimeUs;
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/AudioRemixer.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/AudioRemixer.java
new file mode 100644
index 000000000..5255a2219
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/AudioRemixer.java
@@ -0,0 +1,66 @@
+package net.ypresto.androidtranscoder.engine;
+
+import java.nio.ShortBuffer;
+
+public interface AudioRemixer {
+    void remix(final ShortBuffer inSBuff, final ShortBuffer outSBuff);
+
+    AudioRemixer DOWNMIX = new AudioRemixer() {
+        private static final int SIGNED_SHORT_LIMIT = 32768;
+        private static final int UNSIGNED_SHORT_MAX = 65535;
+
+        @Override
+        public void remix(final ShortBuffer inSBuff, final ShortBuffer outSBuff) {
+            // Down-mix stereo to mono
+            // Viktor Toth's algorithm -
+            // See: http://www.vttoth.com/CMS/index.php/technical-notes/68
+            //      http://stackoverflow.com/a/25102339
+            final int inRemaining = inSBuff.remaining() / 2;
+            final int outSpace = outSBuff.remaining();
+
+            final int samplesToBeProcessed = Math.min(inRemaining, outSpace);
+            for (int i = 0; i < samplesToBeProcessed; ++i) {
+                // Convert to unsigned
+                final int a = inSBuff.get() + SIGNED_SHORT_LIMIT;
+                final int b = inSBuff.get() + SIGNED_SHORT_LIMIT;
+                int m;
+                // Pick the equation
+                if ((a < SIGNED_SHORT_LIMIT) || (b < SIGNED_SHORT_LIMIT)) {
+                    // Viktor's first equation when both sources are "quiet"
+                    // (i.e. less than middle of the dynamic range)
+                    m = a * b / SIGNED_SHORT_LIMIT;
+                } else {
+                    // Viktor's second equation when one or both sources are loud
+                    m = 2 * (a + b) - (a * b) / SIGNED_SHORT_LIMIT - UNSIGNED_SHORT_MAX;
+                }
+                // Convert output back to signed short
+                if (m == UNSIGNED_SHORT_MAX + 1) m = UNSIGNED_SHORT_MAX;
+                outSBuff.put((short) (m - SIGNED_SHORT_LIMIT));
+            }
+        }
+    };
+
+    AudioRemixer UPMIX = new AudioRemixer() {
+        @Override
+        public void remix(final ShortBuffer inSBuff, final ShortBuffer outSBuff) {
+            // Up-mix mono to stereo
+            final int inRemaining = inSBuff.remaining();
+            final int outSpace = outSBuff.remaining() / 2;
+
+            final int samplesToBeProcessed = Math.min(inRemaining, outSpace);
+            for (int i = 0; i < samplesToBeProcessed; ++i) {
+                final short inSample = inSBuff.get();
+                outSBuff.put(inSample);
+                outSBuff.put(inSample);
+            }
+        }
+    };
+
+    AudioRemixer PASSTHROUGH = new AudioRemixer() {
+        @Override
+        public void remix(final ShortBuffer inSBuff, final ShortBuffer outSBuff) {
+            // Passthrough
+            outSBuff.put(inSBuff);
+        }
+    };
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/AudioTrackTranscoder.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/AudioTrackTranscoder.java
new file mode 100644
index 000000000..47e0a61d9
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/AudioTrackTranscoder.java
@@ -0,0 +1,209 @@
+package net.ypresto.androidtranscoder.engine;
+
+import android.media.MediaCodec;
+import android.media.MediaExtractor;
+import android.media.MediaFormat;
+
+import net.ypresto.androidtranscoder.compat.MediaCodecBufferCompatWrapper;
+
+import java.io.IOException;
+
+public class AudioTrackTranscoder implements TrackTranscoder {
+
+    private static final QueuedMuxer.SampleType SAMPLE_TYPE = QueuedMuxer.SampleType.AUDIO;
+
+    private static final int DRAIN_STATE_NONE = 0;
+    private static final int DRAIN_STATE_SHOULD_RETRY_IMMEDIATELY = 1;
+    private static final int DRAIN_STATE_CONSUMED = 2;
+
+    private final MediaExtractor mExtractor;
+    private final QueuedMuxer mMuxer;
+    private long mWrittenPresentationTimeUs;
+
+    private final int mTrackIndex;
+    private final MediaFormat mInputFormat;
+    private final MediaFormat mOutputFormat;
+
+    private final MediaCodec.BufferInfo mBufferInfo = new MediaCodec.BufferInfo();
+    private MediaCodec mDecoder;
+    private MediaCodec mEncoder;
+    private MediaFormat mActualOutputFormat;
+
+    private MediaCodecBufferCompatWrapper mDecoderBuffers;
+    private MediaCodecBufferCompatWrapper mEncoderBuffers;
+
+    private boolean mIsExtractorEOS;
+    private boolean mIsDecoderEOS;
+    private boolean mIsEncoderEOS;
+    private boolean mDecoderStarted;
+    private boolean mEncoderStarted;
+
+    private AudioChannel mAudioChannel;
+
+    public AudioTrackTranscoder(MediaExtractor extractor, int trackIndex,
+                                MediaFormat outputFormat, QueuedMuxer muxer) {
+        mExtractor = extractor;
+        mTrackIndex = trackIndex;
+        mOutputFormat = outputFormat;
+        mMuxer = muxer;
+
+        mInputFormat = mExtractor.getTrackFormat(mTrackIndex);
+    }
+
+    @Override
+    public void setup() {
+        mExtractor.selectTrack(mTrackIndex);
+        try {
+            mEncoder = MediaCodec.createEncoderByType(mOutputFormat.getString(MediaFormat.KEY_MIME));
+        } catch (IOException e) {
+            throw new IllegalStateException(e);
+        }
+        mEncoder.configure(mOutputFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
+        mEncoder.start();
+        mEncoderStarted = true;
+        mEncoderBuffers = new MediaCodecBufferCompatWrapper(mEncoder);
+
+        final MediaFormat inputFormat = mExtractor.getTrackFormat(mTrackIndex);
+        try {
+            mDecoder = MediaCodec.createDecoderByType(inputFormat.getString(MediaFormat.KEY_MIME));
+        } catch (IOException e) {
+            throw new IllegalStateException(e);
+        }
+        mDecoder.configure(inputFormat, null, null, 0);
+        mDecoder.start();
+        mDecoderStarted = true;
+        mDecoderBuffers = new MediaCodecBufferCompatWrapper(mDecoder);
+
+        mAudioChannel = new AudioChannel(mDecoder, mEncoder, mOutputFormat);
+    }
+
+    @Override
+    public MediaFormat getDeterminedFormat() {
+        return mInputFormat;
+    }
+
+    @Override
+    public boolean stepPipeline() {
+        boolean busy = false;
+
+        int status;
+        while (drainEncoder(0) != DRAIN_STATE_NONE) busy = true;
+        do {
+            status = drainDecoder(0);
+            if (status != DRAIN_STATE_NONE) busy = true;
+            // NOTE: not repeating to keep from deadlock when encoder is full.
+        } while (status == DRAIN_STATE_SHOULD_RETRY_IMMEDIATELY);
+
+        while (mAudioChannel.feedEncoder(0)) busy = true;
+        while (drainExtractor(0) != DRAIN_STATE_NONE) busy = true;
+
+        return busy;
+    }
+
+    private int drainExtractor(long timeoutUs) {
+        if (mIsExtractorEOS) return DRAIN_STATE_NONE;
+        int trackIndex = mExtractor.getSampleTrackIndex();
+        if (trackIndex >= 0 && trackIndex != mTrackIndex) {
+            return DRAIN_STATE_NONE;
+        }
+
+        final int result = mDecoder.dequeueInputBuffer(timeoutUs);
+        if (result < 0) return DRAIN_STATE_NONE;
+        if (trackIndex < 0) {
+            mIsExtractorEOS = true;
+            mDecoder.queueInputBuffer(result, 0, 0, 0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
+            return DRAIN_STATE_NONE;
+        }
+
+        final int sampleSize = mExtractor.readSampleData(mDecoderBuffers.getInputBuffer(result), 0);
+        final boolean isKeyFrame = (mExtractor.getSampleFlags() & MediaExtractor.SAMPLE_FLAG_SYNC) != 0;
+        mDecoder.queueInputBuffer(result, 0, sampleSize, mExtractor.getSampleTime(), isKeyFrame ? MediaCodec.BUFFER_FLAG_SYNC_FRAME : 0);
+        mExtractor.advance();
+        return DRAIN_STATE_CONSUMED;
+    }
+
+    private int drainDecoder(long timeoutUs) {
+        if (mIsDecoderEOS) return DRAIN_STATE_NONE;
+
+        int result = mDecoder.dequeueOutputBuffer(mBufferInfo, timeoutUs);
+        switch (result) {
+            case MediaCodec.INFO_TRY_AGAIN_LATER:
+                return DRAIN_STATE_NONE;
+            case MediaCodec.INFO_OUTPUT_FORMAT_CHANGED:
+                mAudioChannel.setActualDecodedFormat(mDecoder.getOutputFormat());
+            case MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED:
+                return DRAIN_STATE_SHOULD_RETRY_IMMEDIATELY;
+        }
+
+        if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
+            mIsDecoderEOS = true;
+            mAudioChannel.drainDecoderBufferAndQueue(AudioChannel.BUFFER_INDEX_END_OF_STREAM, 0);
+        } else if (mBufferInfo.size > 0) {
+            mAudioChannel.drainDecoderBufferAndQueue(result, mBufferInfo.presentationTimeUs);
+        }
+
+        return DRAIN_STATE_CONSUMED;
+    }
+
+    private int drainEncoder(long timeoutUs) {
+        if (mIsEncoderEOS) return DRAIN_STATE_NONE;
+
+        int result = mEncoder.dequeueOutputBuffer(mBufferInfo, timeoutUs);
+        switch (result) {
+            case MediaCodec.INFO_TRY_AGAIN_LATER:
+                return DRAIN_STATE_NONE;
+            case MediaCodec.INFO_OUTPUT_FORMAT_CHANGED:
+                if (mActualOutputFormat != null) {
+                    throw new RuntimeException("Audio output format changed twice.");
+                }
+                mActualOutputFormat = mEncoder.getOutputFormat();
+                mMuxer.setOutputFormat(SAMPLE_TYPE, mActualOutputFormat);
+                return DRAIN_STATE_SHOULD_RETRY_IMMEDIATELY;
+            case MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED:
+                mEncoderBuffers = new MediaCodecBufferCompatWrapper(mEncoder);
+                return DRAIN_STATE_SHOULD_RETRY_IMMEDIATELY;
+        }
+
+        if (mActualOutputFormat == null) {
+            throw new RuntimeException("Could not determine actual output format.");
+        }
+
+        if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
+            mIsEncoderEOS = true;
+            mBufferInfo.set(0, 0, 0, mBufferInfo.flags);
+        }
+        if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0) {
+            // SPS or PPS, which should be passed by MediaFormat.
+            mEncoder.releaseOutputBuffer(result, false);
+            return DRAIN_STATE_SHOULD_RETRY_IMMEDIATELY;
+        }
+        mMuxer.writeSampleData(SAMPLE_TYPE, mEncoderBuffers.getOutputBuffer(result), mBufferInfo);
+        mWrittenPresentationTimeUs = mBufferInfo.presentationTimeUs;
+        mEncoder.releaseOutputBuffer(result, false);
+        return DRAIN_STATE_CONSUMED;
+    }
+
+    @Override
+    public long getWrittenPresentationTimeUs() {
+        return mWrittenPresentationTimeUs;
+    }
+
+    @Override
+    public boolean isFinished() {
+        return mIsEncoderEOS;
+    }
+
+    @Override
+    public void release() {
+        if (mDecoder != null) {
+            if (mDecoderStarted) mDecoder.stop();
+            mDecoder.release();
+            mDecoder = null;
+        }
+        if (mEncoder != null) {
+            if (mEncoderStarted) mEncoder.stop();
+            mEncoder.release();
+            mEncoder = null;
+        }
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/InputSurface.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/InputSurface.java
new file mode 100644
index 000000000..9793c8911
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/InputSurface.java
@@ -0,0 +1,175 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+// from: https://android.googlesource.com/platform/cts/+/lollipop-release/tests/tests/media/src/android/media/cts/InputSurface.java
+// blob: 157ed88d143229e4edb6889daf18fb73aa2fc5a5
+package net.ypresto.androidtranscoder.engine;
+import android.opengl.EGL14;
+import android.opengl.EGLConfig;
+import android.opengl.EGLContext;
+import android.opengl.EGLDisplay;
+import android.opengl.EGLExt;
+import android.opengl.EGLSurface;
+import android.view.Surface;
+/**
+ * Holds state associated with a Surface used for MediaCodec encoder input.
+ * <p>
+ * The constructor takes a Surface obtained from MediaCodec.createInputSurface(), and uses that
+ * to create an EGL window surface.  Calls to eglSwapBuffers() cause a frame of data to be sent
+ * to the video encoder.
+ */
+class InputSurface {
+    private static final String TAG = "InputSurface";
+    private static final int EGL_RECORDABLE_ANDROID = 0x3142;
+    private EGLDisplay mEGLDisplay = EGL14.EGL_NO_DISPLAY;
+    private EGLContext mEGLContext = EGL14.EGL_NO_CONTEXT;
+    private EGLSurface mEGLSurface = EGL14.EGL_NO_SURFACE;
+    private Surface mSurface;
+    /**
+     * Creates an InputSurface from a Surface.
+     */
+    public InputSurface(Surface surface) {
+        if (surface == null) {
+            throw new NullPointerException();
+        }
+        mSurface = surface;
+        eglSetup();
+    }
+    /**
+     * Prepares EGL.  We want a GLES 2.0 context and a surface that supports recording.
+     */
+    private void eglSetup() {
+        mEGLDisplay = EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY);
+        if (mEGLDisplay == EGL14.EGL_NO_DISPLAY) {
+            throw new RuntimeException("unable to get EGL14 display");
+        }
+        int[] version = new int[2];
+        if (!EGL14.eglInitialize(mEGLDisplay, version, 0, version, 1)) {
+            mEGLDisplay = null;
+            throw new RuntimeException("unable to initialize EGL14");
+        }
+        // Configure EGL for recordable and OpenGL ES 2.0.  We want enough RGB bits
+        // to minimize artifacts from possible YUV conversion.
+        int[] attribList = {
+                EGL14.EGL_RED_SIZE, 8,
+                EGL14.EGL_GREEN_SIZE, 8,
+                EGL14.EGL_BLUE_SIZE, 8,
+                EGL14.EGL_RENDERABLE_TYPE, EGL14.EGL_OPENGL_ES2_BIT,
+                EGL_RECORDABLE_ANDROID, 1,
+                EGL14.EGL_NONE
+        };
+        EGLConfig[] configs = new EGLConfig[1];
+        int[] numConfigs = new int[1];
+        if (!EGL14.eglChooseConfig(mEGLDisplay, attribList, 0, configs, 0, configs.length,
+                numConfigs, 0)) {
+            throw new RuntimeException("unable to find RGB888+recordable ES2 EGL config");
+        }
+        // Configure context for OpenGL ES 2.0.
+        int[] attrib_list = {
+                EGL14.EGL_CONTEXT_CLIENT_VERSION, 2,
+                EGL14.EGL_NONE
+        };
+        mEGLContext = EGL14.eglCreateContext(mEGLDisplay, configs[0], EGL14.EGL_NO_CONTEXT,
+                attrib_list, 0);
+        checkEglError("eglCreateContext");
+        if (mEGLContext == null) {
+            throw new RuntimeException("null context");
+        }
+        // Create a window surface, and attach it to the Surface we received.
+        int[] surfaceAttribs = {
+                EGL14.EGL_NONE
+        };
+        mEGLSurface = EGL14.eglCreateWindowSurface(mEGLDisplay, configs[0], mSurface,
+                surfaceAttribs, 0);
+        checkEglError("eglCreateWindowSurface");
+        if (mEGLSurface == null) {
+            throw new RuntimeException("surface was null");
+        }
+    }
+    /**
+     * Discard all resources held by this class, notably the EGL context.  Also releases the
+     * Surface that was passed to our constructor.
+     */
+    public void release() {
+        if (mEGLDisplay != EGL14.EGL_NO_DISPLAY) {
+            EGL14.eglDestroySurface(mEGLDisplay, mEGLSurface);
+            EGL14.eglDestroyContext(mEGLDisplay, mEGLContext);
+            EGL14.eglReleaseThread();
+            EGL14.eglTerminate(mEGLDisplay);
+        }
+        mSurface.release();
+        mEGLDisplay = EGL14.EGL_NO_DISPLAY;
+        mEGLContext = EGL14.EGL_NO_CONTEXT;
+        mEGLSurface = EGL14.EGL_NO_SURFACE;
+        mSurface = null;
+    }
+    /**
+     * Makes our EGL context and surface current.
+     */
+    public void makeCurrent() {
+        if (!EGL14.eglMakeCurrent(mEGLDisplay, mEGLSurface, mEGLSurface, mEGLContext)) {
+            throw new RuntimeException("eglMakeCurrent failed");
+        }
+    }
+    public void makeUnCurrent() {
+        if (!EGL14.eglMakeCurrent(mEGLDisplay, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_SURFACE,
+                EGL14.EGL_NO_CONTEXT)) {
+            throw new RuntimeException("eglMakeCurrent failed");
+        }
+    }
+    /**
+     * Calls eglSwapBuffers.  Use this to "publish" the current frame.
+     */
+    public boolean swapBuffers() {
+        return EGL14.eglSwapBuffers(mEGLDisplay, mEGLSurface);
+    }
+    /**
+     * Returns the Surface that the MediaCodec receives buffers from.
+     */
+    public Surface getSurface() {
+        return mSurface;
+    }
+    /**
+     * Queries the surface's width.
+     */
+    public int getWidth() {
+        int[] value = new int[1];
+        EGL14.eglQuerySurface(mEGLDisplay, mEGLSurface, EGL14.EGL_WIDTH, value, 0);
+        return value[0];
+    }
+    /**
+     * Queries the surface's height.
+     */
+    public int getHeight() {
+        int[] value = new int[1];
+        EGL14.eglQuerySurface(mEGLDisplay, mEGLSurface, EGL14.EGL_HEIGHT, value, 0);
+        return value[0];
+    }
+    /**
+     * Sends the presentation time stamp to EGL.  Time is expressed in nanoseconds.
+     */
+    public void setPresentationTime(long nsecs) {
+        EGLExt.eglPresentationTimeANDROID(mEGLDisplay, mEGLSurface, nsecs);
+    }
+    /**
+     * Checks for EGL errors.
+     */
+    private void checkEglError(String msg) {
+        int error;
+        if ((error = EGL14.eglGetError()) != EGL14.EGL_SUCCESS) {
+            throw new RuntimeException(msg + ": EGL error: 0x" + Integer.toHexString(error));
+        }
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/InvalidOutputFormatException.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/InvalidOutputFormatException.java
new file mode 100644
index 000000000..4c6bbd9a4
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/InvalidOutputFormatException.java
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2015 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.engine;
+
+public class InvalidOutputFormatException extends RuntimeException {
+    public InvalidOutputFormatException(String detailMessage) {
+        super(detailMessage);
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/MediaFormatValidator.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/MediaFormatValidator.java
new file mode 100644
index 000000000..67ea5ba85
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/MediaFormatValidator.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2015 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.engine;
+
+import android.media.MediaFormat;
+
+import net.ypresto.androidtranscoder.format.MediaFormatExtraConstants;
+import net.ypresto.androidtranscoder.utils.AvcCsdUtils;
+import net.ypresto.androidtranscoder.utils.AvcSpsUtils;
+
+import java.nio.ByteBuffer;
+
+class MediaFormatValidator {
+    // Refer: http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC#Profiles
+    private static final byte PROFILE_IDC_BASELINE = 66;
+
+    public static void validateVideoOutputFormat(MediaFormat format) {
+        String mime = format.getString(MediaFormat.KEY_MIME);
+        // Refer: http://developer.android.com/guide/appendix/media-formats.html#core
+        // Refer: http://en.wikipedia.org/wiki/MPEG-4_Part_14#Data_streams
+        if (!MediaFormatExtraConstants.MIMETYPE_VIDEO_AVC.equals(mime)) {
+            throw new InvalidOutputFormatException("Video codecs other than AVC is not supported, actual mime type: " + mime);
+        }
+        ByteBuffer spsBuffer = AvcCsdUtils.getSpsBuffer(format);
+        byte profileIdc = AvcSpsUtils.getProfileIdc(spsBuffer);
+        if (profileIdc != PROFILE_IDC_BASELINE) {
+            throw new InvalidOutputFormatException("Non-baseline AVC video profile is not supported by Android OS, actual profile_idc: " + profileIdc);
+        }
+    }
+
+    public static void validateAudioOutputFormat(MediaFormat format) {
+        String mime = format.getString(MediaFormat.KEY_MIME);
+        if (!MediaFormatExtraConstants.MIMETYPE_AUDIO_AAC.equals(mime)) {
+            throw new InvalidOutputFormatException("Audio codecs other than AAC is not supported, actual mime type: " + mime);
+        }
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/MediaTranscoderEngine.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/MediaTranscoderEngine.java
new file mode 100644
index 000000000..64a1edef4
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/MediaTranscoderEngine.java
@@ -0,0 +1,219 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.engine;
+
+import android.media.MediaExtractor;
+import android.media.MediaFormat;
+import android.media.MediaMetadataRetriever;
+import android.media.MediaMuxer;
+import android.util.Log;
+
+import net.ypresto.androidtranscoder.format.MediaFormatStrategy;
+import net.ypresto.androidtranscoder.utils.MediaExtractorUtils;
+
+import java.io.FileDescriptor;
+import java.io.IOException;
+
+/**
+ * Internal engine, do not use this directly.
+ */
+// TODO: treat encrypted data
+public class MediaTranscoderEngine {
+    private static final String TAG = "MediaTranscoderEngine";
+    private static final double PROGRESS_UNKNOWN = -1.0;
+    private static final long SLEEP_TO_WAIT_TRACK_TRANSCODERS = 10;
+    private static final long PROGRESS_INTERVAL_STEPS = 10;
+    private FileDescriptor mInputFileDescriptor;
+    private TrackTranscoder mVideoTrackTranscoder;
+    private TrackTranscoder mAudioTrackTranscoder;
+    private MediaExtractor mExtractor;
+    private MediaMuxer mMuxer;
+    private volatile double mProgress;
+    private ProgressCallback mProgressCallback;
+    private long mDurationUs;
+
+    /**
+     * Do not use this constructor unless you know what you are doing.
+     */
+    public MediaTranscoderEngine() {
+    }
+
+    public void setDataSource(FileDescriptor fileDescriptor) {
+        mInputFileDescriptor = fileDescriptor;
+    }
+
+    public ProgressCallback getProgressCallback() {
+        return mProgressCallback;
+    }
+
+    public void setProgressCallback(ProgressCallback progressCallback) {
+        mProgressCallback = progressCallback;
+    }
+
+    /**
+     * NOTE: This method is thread safe.
+     */
+    public double getProgress() {
+        return mProgress;
+    }
+
+    /**
+     * Run video transcoding. Blocks current thread.
+     * Audio data will not be transcoded; original stream will be wrote to output file.
+     *
+     * @param outputPath     File path to output transcoded video file.
+     * @param formatStrategy Output format strategy.
+     * @throws IOException                  when input or output file could not be opened.
+     * @throws InvalidOutputFormatException when output format is not supported.
+     * @throws InterruptedException         when cancel to transcode.
+     */
+    public void transcodeVideo(String outputPath, MediaFormatStrategy formatStrategy) throws IOException, InterruptedException {
+        if (outputPath == null) {
+            throw new NullPointerException("Output path cannot be null.");
+        }
+        if (mInputFileDescriptor == null) {
+            throw new IllegalStateException("Data source is not set.");
+        }
+        try {
+            // NOTE: use single extractor to keep from running out audio track fast.
+            mExtractor = new MediaExtractor();
+            mExtractor.setDataSource(mInputFileDescriptor);
+            mMuxer = new MediaMuxer(outputPath, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
+            setupMetadata();
+            setupTrackTranscoders(formatStrategy);
+            runPipelines();
+            mMuxer.stop();
+        } finally {
+            try {
+                if (mVideoTrackTranscoder != null) {
+                    mVideoTrackTranscoder.release();
+                    mVideoTrackTranscoder = null;
+                }
+                if (mAudioTrackTranscoder != null) {
+                    mAudioTrackTranscoder.release();
+                    mAudioTrackTranscoder = null;
+                }
+                if (mExtractor != null) {
+                    mExtractor.release();
+                    mExtractor = null;
+                }
+            } catch (RuntimeException e) {
+                // Too fatal to make alive the app, because it may leak native resources.
+                //noinspection ThrowFromFinallyBlock
+                throw new Error("Could not shutdown extractor, codecs and muxer pipeline.", e);
+            }
+            try {
+                if (mMuxer != null) {
+                    mMuxer.release();
+                    mMuxer = null;
+                }
+            } catch (RuntimeException e) {
+                Log.e(TAG, "Failed to release muxer.", e);
+            }
+        }
+    }
+
+    private void setupMetadata() throws IOException {
+        MediaMetadataRetriever mediaMetadataRetriever = new MediaMetadataRetriever();
+        mediaMetadataRetriever.setDataSource(mInputFileDescriptor);
+
+        String rotationString = mediaMetadataRetriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_ROTATION);
+        try {
+            mMuxer.setOrientationHint(Integer.parseInt(rotationString));
+        } catch (NumberFormatException e) {
+            // skip
+        }
+
+        // TODO: parse ISO 6709
+        // String locationString = mediaMetadataRetriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_LOCATION);
+        // mMuxer.setLocation(Integer.getInteger(rotationString, 0));
+
+        try {
+            mDurationUs = Long.parseLong(mediaMetadataRetriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION)) * 1000;
+        } catch (NumberFormatException e) {
+            mDurationUs = -1;
+        }
+        Log.d(TAG, "Duration (us): " + mDurationUs);
+    }
+
+    private void setupTrackTranscoders(MediaFormatStrategy formatStrategy) {
+        MediaExtractorUtils.TrackResult trackResult = MediaExtractorUtils.getFirstVideoAndAudioTrack(mExtractor);
+        MediaFormat videoOutputFormat = formatStrategy.createVideoOutputFormat(trackResult.mVideoTrackFormat);
+        MediaFormat audioOutputFormat = formatStrategy.createAudioOutputFormat(trackResult.mAudioTrackFormat);
+        if (videoOutputFormat == null && audioOutputFormat == null) {
+            throw new InvalidOutputFormatException("MediaFormatStrategy returned pass-through for both video and audio. No transcoding is necessary.");
+        }
+        QueuedMuxer queuedMuxer = new QueuedMuxer(mMuxer, new QueuedMuxer.Listener() {
+            @Override
+            public void onDetermineOutputFormat() {
+                MediaFormatValidator.validateVideoOutputFormat(mVideoTrackTranscoder.getDeterminedFormat());
+                MediaFormatValidator.validateAudioOutputFormat(mAudioTrackTranscoder.getDeterminedFormat());
+            }
+        });
+
+        if (videoOutputFormat == null) {
+            mVideoTrackTranscoder = new PassThroughTrackTranscoder(mExtractor, trackResult.mVideoTrackIndex, queuedMuxer, QueuedMuxer.SampleType.VIDEO);
+        } else {
+            mVideoTrackTranscoder = new VideoTrackTranscoder(mExtractor, trackResult.mVideoTrackIndex, videoOutputFormat, queuedMuxer);
+        }
+        mVideoTrackTranscoder.setup();
+        if (audioOutputFormat == null) {
+            mAudioTrackTranscoder = new PassThroughTrackTranscoder(mExtractor, trackResult.mAudioTrackIndex, queuedMuxer, QueuedMuxer.SampleType.AUDIO);
+        } else {
+            mAudioTrackTranscoder = new AudioTrackTranscoder(mExtractor, trackResult.mAudioTrackIndex, audioOutputFormat, queuedMuxer);
+        }
+        mAudioTrackTranscoder.setup();
+        mExtractor.selectTrack(trackResult.mVideoTrackIndex);
+        mExtractor.selectTrack(trackResult.mAudioTrackIndex);
+    }
+
+    private void runPipelines() {
+        long loopCount = 0;
+        if (mDurationUs <= 0) {
+            double progress = PROGRESS_UNKNOWN;
+            mProgress = progress;
+            if (mProgressCallback != null) mProgressCallback.onProgress(progress); // unknown
+        }
+        while (!(mVideoTrackTranscoder.isFinished() && mAudioTrackTranscoder.isFinished())) {
+            boolean stepped = mVideoTrackTranscoder.stepPipeline()
+                    || mAudioTrackTranscoder.stepPipeline();
+            loopCount++;
+            if (mDurationUs > 0 && loopCount % PROGRESS_INTERVAL_STEPS == 0) {
+                double videoProgress = mVideoTrackTranscoder.isFinished() ? 1.0 : Math.min(1.0, (double) mVideoTrackTranscoder.getWrittenPresentationTimeUs() / mDurationUs);
+                double audioProgress = mAudioTrackTranscoder.isFinished() ? 1.0 : Math.min(1.0, (double) mAudioTrackTranscoder.getWrittenPresentationTimeUs() / mDurationUs);
+                double progress = (videoProgress + audioProgress) / 2.0;
+                mProgress = progress;
+                if (mProgressCallback != null) mProgressCallback.onProgress(progress);
+            }
+            if (!stepped) {
+                try {
+                    Thread.sleep(SLEEP_TO_WAIT_TRACK_TRANSCODERS);
+                } catch (InterruptedException e) {
+                    // nothing to do
+                }
+            }
+        }
+    }
+
+    public interface ProgressCallback {
+        /**
+         * Called to notify progress. Same thread which initiated transcode is used.
+         *
+         * @param progress Progress in [0.0, 1.0] range, or negative value if progress is unknown.
+         */
+        void onProgress(double progress);
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/OutputSurface.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/OutputSurface.java
new file mode 100644
index 000000000..e52ba0217
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/OutputSurface.java
@@ -0,0 +1,276 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+// from: https://android.googlesource.com/platform/cts/+/lollipop-release/tests/tests/media/src/android/media/cts/OutputSurface.java
+// blob: fc8ad9cd390c5c311f015d3b7c1359e4d295bc52
+// modified: change TIMEOUT_MS from 500 to 10000
+package net.ypresto.androidtranscoder.engine;
+import android.graphics.SurfaceTexture;
+import android.opengl.EGL14;
+import android.opengl.EGLConfig;
+import android.opengl.EGLContext;
+import android.opengl.EGLDisplay;
+import android.opengl.EGLSurface;
+import android.util.Log;
+import android.view.Surface;
+/**
+ * Holds state associated with a Surface used for MediaCodec decoder output.
+ * <p>
+ * The (width,height) constructor for this class will prepare GL, create a SurfaceTexture,
+ * and then create a Surface for that SurfaceTexture.  The Surface can be passed to
+ * MediaCodec.configure() to receive decoder output.  When a frame arrives, we latch the
+ * texture with updateTexImage, then render the texture with GL to a pbuffer.
+ * <p>
+ * The no-arg constructor skips the GL preparation step and doesn't allocate a pbuffer.
+ * Instead, it just creates the Surface and SurfaceTexture, and when a frame arrives
+ * we just draw it on whatever surface is current.
+ * <p>
+ * By default, the Surface will be using a BufferQueue in asynchronous mode, so we
+ * can potentially drop frames.
+ */
+class OutputSurface implements SurfaceTexture.OnFrameAvailableListener {
+    private static final String TAG = "OutputSurface";
+    private static final boolean VERBOSE = false;
+    private EGLDisplay mEGLDisplay = EGL14.EGL_NO_DISPLAY;
+    private EGLContext mEGLContext = EGL14.EGL_NO_CONTEXT;
+    private EGLSurface mEGLSurface = EGL14.EGL_NO_SURFACE;
+    private SurfaceTexture mSurfaceTexture;
+    private Surface mSurface;
+    private Object mFrameSyncObject = new Object();     // guards mFrameAvailable
+    private boolean mFrameAvailable;
+    private TextureRender mTextureRender;
+    /**
+     * Creates an OutputSurface backed by a pbuffer with the specifed dimensions.  The new
+     * EGL context and surface will be made current.  Creates a Surface that can be passed
+     * to MediaCodec.configure().
+     */
+    public OutputSurface(int width, int height) {
+        if (width <= 0 || height <= 0) {
+            throw new IllegalArgumentException();
+        }
+        eglSetup(width, height);
+        makeCurrent();
+        setup();
+    }
+    /**
+     * Creates an OutputSurface using the current EGL context (rather than establishing a
+     * new one).  Creates a Surface that can be passed to MediaCodec.configure().
+     */
+    public OutputSurface() {
+        setup();
+    }
+    /**
+     * Creates instances of TextureRender and SurfaceTexture, and a Surface associated
+     * with the SurfaceTexture.
+     */
+    private void setup() {
+        mTextureRender = new TextureRender();
+        mTextureRender.surfaceCreated();
+        // Even if we don't access the SurfaceTexture after the constructor returns, we
+        // still need to keep a reference to it.  The Surface doesn't retain a reference
+        // at the Java level, so if we don't either then the object can get GCed, which
+        // causes the native finalizer to run.
+        if (VERBOSE) Log.d(TAG, "textureID=" + mTextureRender.getTextureId());
+        mSurfaceTexture = new SurfaceTexture(mTextureRender.getTextureId());
+        // This doesn't work if OutputSurface is created on the thread that CTS started for
+        // these test cases.
+        //
+        // The CTS-created thread has a Looper, and the SurfaceTexture constructor will
+        // create a Handler that uses it.  The "frame available" message is delivered
+        // there, but since we're not a Looper-based thread we'll never see it.  For
+        // this to do anything useful, OutputSurface must be created on a thread without
+        // a Looper, so that SurfaceTexture uses the main application Looper instead.
+        //
+        // Java language note: passing "this" out of a constructor is generally unwise,
+        // but we should be able to get away with it here.
+        mSurfaceTexture.setOnFrameAvailableListener(this);
+        mSurface = new Surface(mSurfaceTexture);
+    }
+    /**
+     * Prepares EGL.  We want a GLES 2.0 context and a surface that supports pbuffer.
+     */
+    private void eglSetup(int width, int height) {
+        mEGLDisplay = EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY);
+        if (mEGLDisplay == EGL14.EGL_NO_DISPLAY) {
+            throw new RuntimeException("unable to get EGL14 display");
+        }
+        int[] version = new int[2];
+        if (!EGL14.eglInitialize(mEGLDisplay, version, 0, version, 1)) {
+            mEGLDisplay = null;
+            throw new RuntimeException("unable to initialize EGL14");
+        }
+        // Configure EGL for pbuffer and OpenGL ES 2.0.  We want enough RGB bits
+        // to be able to tell if the frame is reasonable.
+        int[] attribList = {
+                EGL14.EGL_RED_SIZE, 8,
+                EGL14.EGL_GREEN_SIZE, 8,
+                EGL14.EGL_BLUE_SIZE, 8,
+                EGL14.EGL_RENDERABLE_TYPE, EGL14.EGL_OPENGL_ES2_BIT,
+                EGL14.EGL_SURFACE_TYPE, EGL14.EGL_PBUFFER_BIT,
+                EGL14.EGL_NONE
+        };
+        EGLConfig[] configs = new EGLConfig[1];
+        int[] numConfigs = new int[1];
+        if (!EGL14.eglChooseConfig(mEGLDisplay, attribList, 0, configs, 0, configs.length,
+                numConfigs, 0)) {
+            throw new RuntimeException("unable to find RGB888+recordable ES2 EGL config");
+        }
+        // Configure context for OpenGL ES 2.0.
+        int[] attrib_list = {
+                EGL14.EGL_CONTEXT_CLIENT_VERSION, 2,
+                EGL14.EGL_NONE
+        };
+        mEGLContext = EGL14.eglCreateContext(mEGLDisplay, configs[0], EGL14.EGL_NO_CONTEXT,
+                attrib_list, 0);
+        checkEglError("eglCreateContext");
+        if (mEGLContext == null) {
+            throw new RuntimeException("null context");
+        }
+        // Create a pbuffer surface.  By using this for output, we can use glReadPixels
+        // to test values in the output.
+        int[] surfaceAttribs = {
+                EGL14.EGL_WIDTH, width,
+                EGL14.EGL_HEIGHT, height,
+                EGL14.EGL_NONE
+        };
+        mEGLSurface = EGL14.eglCreatePbufferSurface(mEGLDisplay, configs[0], surfaceAttribs, 0);
+        checkEglError("eglCreatePbufferSurface");
+        if (mEGLSurface == null) {
+            throw new RuntimeException("surface was null");
+        }
+    }
+    /**
+     * Discard all resources held by this class, notably the EGL context.
+     */
+    public void release() {
+        if (mEGLDisplay != EGL14.EGL_NO_DISPLAY) {
+            EGL14.eglDestroySurface(mEGLDisplay, mEGLSurface);
+            EGL14.eglDestroyContext(mEGLDisplay, mEGLContext);
+            EGL14.eglReleaseThread();
+            EGL14.eglTerminate(mEGLDisplay);
+        }
+        mSurface.release();
+        // this causes a bunch of warnings that appear harmless but might confuse someone:
+        //  W BufferQueue: [unnamed-3997-2] cancelBuffer: BufferQueue has been abandoned!
+        //mSurfaceTexture.release();
+        mEGLDisplay = EGL14.EGL_NO_DISPLAY;
+        mEGLContext = EGL14.EGL_NO_CONTEXT;
+        mEGLSurface = EGL14.EGL_NO_SURFACE;
+        mTextureRender = null;
+        mSurface = null;
+        mSurfaceTexture = null;
+    }
+    /**
+     * Makes our EGL context and surface current.
+     */
+    public void makeCurrent() {
+        if (!EGL14.eglMakeCurrent(mEGLDisplay, mEGLSurface, mEGLSurface, mEGLContext)) {
+            throw new RuntimeException("eglMakeCurrent failed");
+        }
+    }
+    /**
+     * Returns the Surface that we draw onto.
+     */
+    public Surface getSurface() {
+        return mSurface;
+    }
+    /**
+     * Replaces the fragment shader.
+     */
+    public void changeFragmentShader(String fragmentShader) {
+        mTextureRender.changeFragmentShader(fragmentShader);
+    }
+    /**
+     * Latches the next buffer into the texture.  Must be called from the thread that created
+     * the OutputSurface object, after the onFrameAvailable callback has signaled that new
+     * data is available.
+     */
+    public void awaitNewImage() {
+        final int TIMEOUT_MS = 10000;
+        synchronized (mFrameSyncObject) {
+            while (!mFrameAvailable) {
+                try {
+                    // Wait for onFrameAvailable() to signal us.  Use a timeout to avoid
+                    // stalling the test if it doesn't arrive.
+                    mFrameSyncObject.wait(TIMEOUT_MS);
+                    if (!mFrameAvailable) {
+                        // TODO: if "spurious wakeup", continue while loop
+                        throw new RuntimeException("Surface frame wait timed out");
+                    }
+                } catch (InterruptedException ie) {
+                    // shouldn't happen
+                    throw new RuntimeException(ie);
+                }
+            }
+            mFrameAvailable = false;
+        }
+        // Latch the data.
+        mTextureRender.checkGlError("before updateTexImage");
+        mSurfaceTexture.updateTexImage();
+    }
+    /**
+     * Wait up to given timeout until new image become available.
+     * @param timeoutMs
+     * @return true if new image is available. false for no new image until timeout.
+     */
+    public boolean checkForNewImage(int timeoutMs) {
+        synchronized (mFrameSyncObject) {
+            while (!mFrameAvailable) {
+                try {
+                    // Wait for onFrameAvailable() to signal us.  Use a timeout to avoid
+                    // stalling the test if it doesn't arrive.
+                    mFrameSyncObject.wait(timeoutMs);
+                    if (!mFrameAvailable) {
+                        return false;
+                    }
+                } catch (InterruptedException ie) {
+                    // shouldn't happen
+                    throw new RuntimeException(ie);
+                }
+            }
+            mFrameAvailable = false;
+        }
+        // Latch the data.
+        mTextureRender.checkGlError("before updateTexImage");
+        mSurfaceTexture.updateTexImage();
+        return true;
+    }
+    /**
+     * Draws the data from SurfaceTexture onto the current EGL surface.
+     */
+    public void drawImage() {
+        mTextureRender.drawFrame(mSurfaceTexture);
+    }
+    @Override
+    public void onFrameAvailable(SurfaceTexture st) {
+        if (VERBOSE) Log.d(TAG, "new frame available");
+        synchronized (mFrameSyncObject) {
+            if (mFrameAvailable) {
+                throw new RuntimeException("mFrameAvailable already set, frame could be dropped");
+            }
+            mFrameAvailable = true;
+            mFrameSyncObject.notifyAll();
+        }
+    }
+    /**
+     * Checks for EGL errors.
+     */
+    private void checkEglError(String msg) {
+        int error;
+        if ((error = EGL14.eglGetError()) != EGL14.EGL_SUCCESS) {
+            throw new RuntimeException(msg + ": EGL error: 0x" + Integer.toHexString(error));
+        }
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/PassThroughTrackTranscoder.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/PassThroughTrackTranscoder.java
new file mode 100644
index 000000000..7608dac86
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/PassThroughTrackTranscoder.java
@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.engine;
+
+import android.annotation.SuppressLint;
+import android.media.MediaCodec;
+import android.media.MediaExtractor;
+import android.media.MediaFormat;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
+public class PassThroughTrackTranscoder implements TrackTranscoder {
+    private final MediaExtractor mExtractor;
+    private final int mTrackIndex;
+    private final QueuedMuxer mMuxer;
+    private final QueuedMuxer.SampleType mSampleType;
+    private final MediaCodec.BufferInfo mBufferInfo = new MediaCodec.BufferInfo();
+    private int mBufferSize;
+    private ByteBuffer mBuffer;
+    private boolean mIsEOS;
+    private MediaFormat mActualOutputFormat;
+    private long mWrittenPresentationTimeUs;
+
+    public PassThroughTrackTranscoder(MediaExtractor extractor, int trackIndex,
+                                      QueuedMuxer muxer, QueuedMuxer.SampleType sampleType) {
+        mExtractor = extractor;
+        mTrackIndex = trackIndex;
+        mMuxer = muxer;
+        mSampleType = sampleType;
+
+        mActualOutputFormat = mExtractor.getTrackFormat(mTrackIndex);
+        mMuxer.setOutputFormat(mSampleType, mActualOutputFormat);
+        mBufferSize = mActualOutputFormat.getInteger(MediaFormat.KEY_MAX_INPUT_SIZE);
+        mBuffer = ByteBuffer.allocateDirect(mBufferSize).order(ByteOrder.nativeOrder());
+    }
+
+    @Override
+    public void setup() {
+    }
+
+    @Override
+    public MediaFormat getDeterminedFormat() {
+        return mActualOutputFormat;
+    }
+
+    @SuppressLint("Assert")
+    @Override
+    public boolean stepPipeline() {
+        if (mIsEOS) return false;
+        int trackIndex = mExtractor.getSampleTrackIndex();
+        if (trackIndex < 0) {
+            mBuffer.clear();
+            mBufferInfo.set(0, 0, 0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
+            mMuxer.writeSampleData(mSampleType, mBuffer, mBufferInfo);
+            mIsEOS = true;
+            return true;
+        }
+        if (trackIndex != mTrackIndex) return false;
+
+        mBuffer.clear();
+        int sampleSize = mExtractor.readSampleData(mBuffer, 0);
+        assert sampleSize <= mBufferSize;
+        boolean isKeyFrame = (mExtractor.getSampleFlags() & MediaExtractor.SAMPLE_FLAG_SYNC) != 0;
+        int flags = isKeyFrame ? MediaCodec.BUFFER_FLAG_SYNC_FRAME : 0;
+        mBufferInfo.set(0, sampleSize, mExtractor.getSampleTime(), flags);
+        mMuxer.writeSampleData(mSampleType, mBuffer, mBufferInfo);
+        mWrittenPresentationTimeUs = mBufferInfo.presentationTimeUs;
+
+        mExtractor.advance();
+        return true;
+    }
+
+    @Override
+    public long getWrittenPresentationTimeUs() {
+        return mWrittenPresentationTimeUs;
+    }
+
+    @Override
+    public boolean isFinished() {
+        return mIsEOS;
+    }
+
+    @Override
+    public void release() {
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/QueuedMuxer.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/QueuedMuxer.java
new file mode 100644
index 000000000..df58e9923
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/QueuedMuxer.java
@@ -0,0 +1,140 @@
+/*
+ * Copyright (C) 2015 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.engine;
+
+import android.media.MediaCodec;
+import android.media.MediaFormat;
+import android.media.MediaMuxer;
+import android.util.Log;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * This class queues until all output track formats are determined.
+ */
+public class QueuedMuxer {
+    private static final String TAG = "QueuedMuxer";
+    private static final int BUFFER_SIZE = 64 * 1024; // I have no idea whether this value is appropriate or not...
+    private final MediaMuxer mMuxer;
+    private final Listener mListener;
+    private MediaFormat mVideoFormat;
+    private MediaFormat mAudioFormat;
+    private int mVideoTrackIndex;
+    private int mAudioTrackIndex;
+    private ByteBuffer mByteBuffer;
+    private final List<SampleInfo> mSampleInfoList;
+    private boolean mStarted;
+
+    public QueuedMuxer(MediaMuxer muxer, Listener listener) {
+        mMuxer = muxer;
+        mListener = listener;
+        mSampleInfoList = new ArrayList<>();
+    }
+
+    public void setOutputFormat(SampleType sampleType, MediaFormat format) {
+        switch (sampleType) {
+            case VIDEO:
+                mVideoFormat = format;
+                break;
+            case AUDIO:
+                mAudioFormat = format;
+                break;
+            default:
+                throw new AssertionError();
+        }
+        onSetOutputFormat();
+    }
+
+    private void onSetOutputFormat() {
+        if (mVideoFormat == null || mAudioFormat == null) return;
+        mListener.onDetermineOutputFormat();
+
+        mVideoTrackIndex = mMuxer.addTrack(mVideoFormat);
+        Log.v(TAG, "Added track #" + mVideoTrackIndex + " with " + mVideoFormat.getString(MediaFormat.KEY_MIME) + " to muxer");
+        mAudioTrackIndex = mMuxer.addTrack(mAudioFormat);
+        Log.v(TAG, "Added track #" + mAudioTrackIndex + " with " + mAudioFormat.getString(MediaFormat.KEY_MIME) + " to muxer");
+        mMuxer.start();
+        mStarted = true;
+
+        if (mByteBuffer == null) {
+            mByteBuffer = ByteBuffer.allocate(0);
+        }
+        mByteBuffer.flip();
+        Log.v(TAG, "Output format determined, writing " + mSampleInfoList.size() +
+                " samples / " + mByteBuffer.limit() + " bytes to muxer.");
+        MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
+        int offset = 0;
+        for (SampleInfo sampleInfo : mSampleInfoList) {
+            sampleInfo.writeToBufferInfo(bufferInfo, offset);
+            mMuxer.writeSampleData(getTrackIndexForSampleType(sampleInfo.mSampleType), mByteBuffer, bufferInfo);
+            offset += sampleInfo.mSize;
+        }
+        mSampleInfoList.clear();
+        mByteBuffer = null;
+    }
+
+    public void writeSampleData(SampleType sampleType, ByteBuffer byteBuf, MediaCodec.BufferInfo bufferInfo) {
+        if (mStarted) {
+            mMuxer.writeSampleData(getTrackIndexForSampleType(sampleType), byteBuf, bufferInfo);
+            return;
+        }
+        byteBuf.limit(bufferInfo.offset + bufferInfo.size);
+        byteBuf.position(bufferInfo.offset);
+        if (mByteBuffer == null) {
+            mByteBuffer = ByteBuffer.allocateDirect(BUFFER_SIZE).order(ByteOrder.nativeOrder());
+        }
+        mByteBuffer.put(byteBuf);
+        mSampleInfoList.add(new SampleInfo(sampleType, bufferInfo.size, bufferInfo));
+    }
+
+    private int getTrackIndexForSampleType(SampleType sampleType) {
+        switch (sampleType) {
+            case VIDEO:
+                return mVideoTrackIndex;
+            case AUDIO:
+                return mAudioTrackIndex;
+            default:
+                throw new AssertionError();
+        }
+    }
+
+    public enum SampleType {VIDEO, AUDIO}
+
+    private static class SampleInfo {
+        private final SampleType mSampleType;
+        private final int mSize;
+        private final long mPresentationTimeUs;
+        private final int mFlags;
+
+        private SampleInfo(SampleType sampleType, int size, MediaCodec.BufferInfo bufferInfo) {
+            mSampleType = sampleType;
+            mSize = size;
+            mPresentationTimeUs = bufferInfo.presentationTimeUs;
+            mFlags = bufferInfo.flags;
+        }
+
+        private void writeToBufferInfo(MediaCodec.BufferInfo bufferInfo, int offset) {
+            bufferInfo.set(offset, mSize, mPresentationTimeUs, mFlags);
+        }
+    }
+
+    public interface Listener {
+        void onDetermineOutputFormat();
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/TextureRender.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/TextureRender.java
new file mode 100644
index 000000000..571427d30
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/TextureRender.java
@@ -0,0 +1,219 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+// from: https://android.googlesource.com/platform/cts/+/lollipop-release/tests/tests/media/src/android/media/cts/TextureRender.java
+// blob: 4125dcfcfed6ed7fddba5b71d657dec0d433da6a
+// modified: removed unused method bodies
+// modified: use GL_LINEAR for GL_TEXTURE_MIN_FILTER to improve quality.
+package net.ypresto.androidtranscoder.engine;
+import android.graphics.SurfaceTexture;
+import android.opengl.GLES11Ext;
+import android.opengl.GLES20;
+import android.opengl.Matrix;
+import android.util.Log;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.FloatBuffer;
+/**
+ * Code for rendering a texture onto a surface using OpenGL ES 2.0.
+ */
+class TextureRender {
+    private static final String TAG = "TextureRender";
+    private static final int FLOAT_SIZE_BYTES = 4;
+    private static final int TRIANGLE_VERTICES_DATA_STRIDE_BYTES = 5 * FLOAT_SIZE_BYTES;
+    private static final int TRIANGLE_VERTICES_DATA_POS_OFFSET = 0;
+    private static final int TRIANGLE_VERTICES_DATA_UV_OFFSET = 3;
+    private final float[] mTriangleVerticesData = {
+            // X, Y, Z, U, V
+            -1.0f, -1.0f, 0, 0.f, 0.f,
+            1.0f, -1.0f, 0, 1.f, 0.f,
+            -1.0f,  1.0f, 0, 0.f, 1.f,
+            1.0f,  1.0f, 0, 1.f, 1.f,
+    };
+    private FloatBuffer mTriangleVertices;
+    private static final String VERTEX_SHADER =
+            "uniform mat4 uMVPMatrix;\n" +
+                    "uniform mat4 uSTMatrix;\n" +
+                    "attribute vec4 aPosition;\n" +
+                    "attribute vec4 aTextureCoord;\n" +
+                    "varying vec2 vTextureCoord;\n" +
+                    "void main() {\n" +
+                    "  gl_Position = uMVPMatrix * aPosition;\n" +
+                    "  vTextureCoord = (uSTMatrix * aTextureCoord).xy;\n" +
+                    "}\n";
+    private static final String FRAGMENT_SHADER =
+            "#extension GL_OES_EGL_image_external : require\n" +
+                    "precision mediump float;\n" +      // highp here doesn't seem to matter
+                    "varying vec2 vTextureCoord;\n" +
+                    "uniform samplerExternalOES sTexture;\n" +
+                    "void main() {\n" +
+                    "  gl_FragColor = texture2D(sTexture, vTextureCoord);\n" +
+                    "}\n";
+    private float[] mMVPMatrix = new float[16];
+    private float[] mSTMatrix = new float[16];
+    private int mProgram;
+    private int mTextureID = -12345;
+    private int muMVPMatrixHandle;
+    private int muSTMatrixHandle;
+    private int maPositionHandle;
+    private int maTextureHandle;
+    public TextureRender() {
+        mTriangleVertices = ByteBuffer.allocateDirect(
+                mTriangleVerticesData.length * FLOAT_SIZE_BYTES)
+                .order(ByteOrder.nativeOrder()).asFloatBuffer();
+        mTriangleVertices.put(mTriangleVerticesData).position(0);
+        Matrix.setIdentityM(mSTMatrix, 0);
+    }
+    public int getTextureId() {
+        return mTextureID;
+    }
+    public void drawFrame(SurfaceTexture st) {
+        checkGlError("onDrawFrame start");
+        st.getTransformMatrix(mSTMatrix);
+        GLES20.glClearColor(0.0f, 1.0f, 0.0f, 1.0f);
+        GLES20.glClear(GLES20.GL_DEPTH_BUFFER_BIT | GLES20.GL_COLOR_BUFFER_BIT);
+        GLES20.glUseProgram(mProgram);
+        checkGlError("glUseProgram");
+        GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
+        GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, mTextureID);
+        mTriangleVertices.position(TRIANGLE_VERTICES_DATA_POS_OFFSET);
+        GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false,
+                TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);
+        checkGlError("glVertexAttribPointer maPosition");
+        GLES20.glEnableVertexAttribArray(maPositionHandle);
+        checkGlError("glEnableVertexAttribArray maPositionHandle");
+        mTriangleVertices.position(TRIANGLE_VERTICES_DATA_UV_OFFSET);
+        GLES20.glVertexAttribPointer(maTextureHandle, 2, GLES20.GL_FLOAT, false,
+                TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);
+        checkGlError("glVertexAttribPointer maTextureHandle");
+        GLES20.glEnableVertexAttribArray(maTextureHandle);
+        checkGlError("glEnableVertexAttribArray maTextureHandle");
+        Matrix.setIdentityM(mMVPMatrix, 0);
+        GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, mMVPMatrix, 0);
+        GLES20.glUniformMatrix4fv(muSTMatrixHandle, 1, false, mSTMatrix, 0);
+        GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
+        checkGlError("glDrawArrays");
+        GLES20.glFinish();
+    }
+    /**
+     * Initializes GL state.  Call this after the EGL surface has been created and made current.
+     */
+    public void surfaceCreated() {
+        mProgram = createProgram(VERTEX_SHADER, FRAGMENT_SHADER);
+        if (mProgram == 0) {
+            throw new RuntimeException("failed creating program");
+        }
+        maPositionHandle = GLES20.glGetAttribLocation(mProgram, "aPosition");
+        checkGlError("glGetAttribLocation aPosition");
+        if (maPositionHandle == -1) {
+            throw new RuntimeException("Could not get attrib location for aPosition");
+        }
+        maTextureHandle = GLES20.glGetAttribLocation(mProgram, "aTextureCoord");
+        checkGlError("glGetAttribLocation aTextureCoord");
+        if (maTextureHandle == -1) {
+            throw new RuntimeException("Could not get attrib location for aTextureCoord");
+        }
+        muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
+        checkGlError("glGetUniformLocation uMVPMatrix");
+        if (muMVPMatrixHandle == -1) {
+            throw new RuntimeException("Could not get attrib location for uMVPMatrix");
+        }
+        muSTMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uSTMatrix");
+        checkGlError("glGetUniformLocation uSTMatrix");
+        if (muSTMatrixHandle == -1) {
+            throw new RuntimeException("Could not get attrib location for uSTMatrix");
+        }
+        int[] textures = new int[1];
+        GLES20.glGenTextures(1, textures, 0);
+        mTextureID = textures[0];
+        GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, mTextureID);
+        checkGlError("glBindTexture mTextureID");
+        GLES20.glTexParameterf(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MIN_FILTER,
+                GLES20.GL_LINEAR);
+        GLES20.glTexParameterf(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MAG_FILTER,
+                GLES20.GL_LINEAR);
+        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_S,
+                GLES20.GL_CLAMP_TO_EDGE);
+        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_T,
+                GLES20.GL_CLAMP_TO_EDGE);
+        checkGlError("glTexParameter");
+    }
+    /**
+     * Replaces the fragment shader.
+     */
+    public void changeFragmentShader(String fragmentShader) {
+        throw new UnsupportedOperationException("Not implemented");
+    }
+    private int loadShader(int shaderType, String source) {
+        int shader = GLES20.glCreateShader(shaderType);
+        checkGlError("glCreateShader type=" + shaderType);
+        GLES20.glShaderSource(shader, source);
+        GLES20.glCompileShader(shader);
+        int[] compiled = new int[1];
+        GLES20.glGetShaderiv(shader, GLES20.GL_COMPILE_STATUS, compiled, 0);
+        if (compiled[0] == 0) {
+            Log.e(TAG, "Could not compile shader " + shaderType + ":");
+            Log.e(TAG, " " + GLES20.glGetShaderInfoLog(shader));
+            GLES20.glDeleteShader(shader);
+            shader = 0;
+        }
+        return shader;
+    }
+    private int createProgram(String vertexSource, String fragmentSource) {
+        int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexSource);
+        if (vertexShader == 0) {
+            return 0;
+        }
+        int pixelShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentSource);
+        if (pixelShader == 0) {
+            return 0;
+        }
+        int program = GLES20.glCreateProgram();
+        checkGlError("glCreateProgram");
+        if (program == 0) {
+            Log.e(TAG, "Could not create program");
+        }
+        GLES20.glAttachShader(program, vertexShader);
+        checkGlError("glAttachShader");
+        GLES20.glAttachShader(program, pixelShader);
+        checkGlError("glAttachShader");
+        GLES20.glLinkProgram(program);
+        int[] linkStatus = new int[1];
+        GLES20.glGetProgramiv(program, GLES20.GL_LINK_STATUS, linkStatus, 0);
+        if (linkStatus[0] != GLES20.GL_TRUE) {
+            Log.e(TAG, "Could not link program: ");
+            Log.e(TAG, GLES20.glGetProgramInfoLog(program));
+            GLES20.glDeleteProgram(program);
+            program = 0;
+        }
+        return program;
+    }
+    public void checkGlError(String op) {
+        int error;
+        while ((error = GLES20.glGetError()) != GLES20.GL_NO_ERROR) {
+            Log.e(TAG, op + ": glError " + error);
+            throw new RuntimeException(op + ": glError " + error);
+        }
+    }
+    /**
+     * Saves the current frame to disk as a PNG image.  Frame starts from (0,0).
+     * <p>
+     * Useful for debugging.
+     */
+    public static void saveFrame(String filename, int width, int height) {
+        throw new UnsupportedOperationException("Not implemented.");
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/TrackTranscoder.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/TrackTranscoder.java
new file mode 100644
index 000000000..04bff2a40
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/TrackTranscoder.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.engine;
+
+import android.media.MediaFormat;
+
+public interface TrackTranscoder {
+
+    void setup();
+
+    /**
+     * Get actual MediaFormat which is used to write to muxer.
+     * To determine you should call {@link #stepPipeline()} several times.
+     *
+     * @return Actual output format determined by coder, or {@code null} if not yet determined.
+     */
+    MediaFormat getDeterminedFormat();
+
+    /**
+     * Step pipeline if output is available in any step of it.
+     * It assumes muxer has been started, so you should call muxer.start() first.
+     *
+     * @return true if data moved in pipeline.
+     */
+    boolean stepPipeline();
+
+    /**
+     * Get presentation time of last sample written to muxer.
+     *
+     * @return Presentation time in micro-second. Return value is undefined if finished writing.
+     */
+    long getWrittenPresentationTimeUs();
+
+    boolean isFinished();
+
+    void release();
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/VideoTrackTranscoder.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/VideoTrackTranscoder.java
new file mode 100644
index 000000000..a5640dd99
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/engine/VideoTrackTranscoder.java
@@ -0,0 +1,231 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.engine;
+
+import android.media.MediaCodec;
+import android.media.MediaExtractor;
+import android.media.MediaFormat;
+
+import net.ypresto.androidtranscoder.format.MediaFormatExtraConstants;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+// Refer: https://android.googlesource.com/platform/cts/+/lollipop-release/tests/tests/media/src/android/media/cts/ExtractDecodeEditEncodeMuxTest.java
+public class VideoTrackTranscoder implements TrackTranscoder {
+    private static final String TAG = "VideoTrackTranscoder";
+    private static final int DRAIN_STATE_NONE = 0;
+    private static final int DRAIN_STATE_SHOULD_RETRY_IMMEDIATELY = 1;
+    private static final int DRAIN_STATE_CONSUMED = 2;
+
+    private final MediaExtractor mExtractor;
+    private final int mTrackIndex;
+    private final MediaFormat mOutputFormat;
+    private final QueuedMuxer mMuxer;
+    private final MediaCodec.BufferInfo mBufferInfo = new MediaCodec.BufferInfo();
+    private MediaCodec mDecoder;
+    private MediaCodec mEncoder;
+    private ByteBuffer[] mDecoderInputBuffers;
+    private ByteBuffer[] mEncoderOutputBuffers;
+    private MediaFormat mActualOutputFormat;
+    private OutputSurface mDecoderOutputSurfaceWrapper;
+    private InputSurface mEncoderInputSurfaceWrapper;
+    private boolean mIsExtractorEOS;
+    private boolean mIsDecoderEOS;
+    private boolean mIsEncoderEOS;
+    private boolean mDecoderStarted;
+    private boolean mEncoderStarted;
+    private long mWrittenPresentationTimeUs;
+
+    public VideoTrackTranscoder(MediaExtractor extractor, int trackIndex,
+                                MediaFormat outputFormat, QueuedMuxer muxer) {
+        mExtractor = extractor;
+        mTrackIndex = trackIndex;
+        mOutputFormat = outputFormat;
+        mMuxer = muxer;
+    }
+
+    @Override
+    public void setup() {
+        mExtractor.selectTrack(mTrackIndex);
+        try {
+            mEncoder = MediaCodec.createEncoderByType(mOutputFormat.getString(MediaFormat.KEY_MIME));
+        } catch (IOException e) {
+            throw new IllegalStateException(e);
+        }
+        mEncoder.configure(mOutputFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
+        mEncoderInputSurfaceWrapper = new InputSurface(mEncoder.createInputSurface());
+        mEncoderInputSurfaceWrapper.makeCurrent();
+        mEncoder.start();
+        mEncoderStarted = true;
+        mEncoderOutputBuffers = mEncoder.getOutputBuffers();
+
+        MediaFormat inputFormat = mExtractor.getTrackFormat(mTrackIndex);
+        if (inputFormat.containsKey(MediaFormatExtraConstants.KEY_ROTATION_DEGREES)) {
+            // Decoded video is rotated automatically in Android 5.0 lollipop.
+            // Turn off here because we don't want to encode rotated one.
+            // refer: https://android.googlesource.com/platform/frameworks/av/+blame/lollipop-release/media/libstagefright/Utils.cpp
+            inputFormat.setInteger(MediaFormatExtraConstants.KEY_ROTATION_DEGREES, 0);
+        }
+        mDecoderOutputSurfaceWrapper = new OutputSurface();
+        try {
+            mDecoder = MediaCodec.createDecoderByType(inputFormat.getString(MediaFormat.KEY_MIME));
+        } catch (IOException e) {
+            throw new IllegalStateException(e);
+        }
+        mDecoder.configure(inputFormat, mDecoderOutputSurfaceWrapper.getSurface(), null, 0);
+        mDecoder.start();
+        mDecoderStarted = true;
+        mDecoderInputBuffers = mDecoder.getInputBuffers();
+    }
+
+    @Override
+    public MediaFormat getDeterminedFormat() {
+        return mActualOutputFormat;
+    }
+
+    @Override
+    public boolean stepPipeline() {
+        boolean busy = false;
+
+        int status;
+        while (drainEncoder(0) != DRAIN_STATE_NONE) busy = true;
+        do {
+            status = drainDecoder(0);
+            if (status != DRAIN_STATE_NONE) busy = true;
+            // NOTE: not repeating to keep from deadlock when encoder is full.
+        } while (status == DRAIN_STATE_SHOULD_RETRY_IMMEDIATELY);
+        while (drainExtractor(0) != DRAIN_STATE_NONE) busy = true;
+
+        return busy;
+    }
+
+    @Override
+    public long getWrittenPresentationTimeUs() {
+        return mWrittenPresentationTimeUs;
+    }
+
+    @Override
+    public boolean isFinished() {
+        return mIsEncoderEOS;
+    }
+
+    // TODO: CloseGuard
+    @Override
+    public void release() {
+        if (mDecoderOutputSurfaceWrapper != null) {
+            mDecoderOutputSurfaceWrapper.release();
+            mDecoderOutputSurfaceWrapper = null;
+        }
+        if (mEncoderInputSurfaceWrapper != null) {
+            mEncoderInputSurfaceWrapper.release();
+            mEncoderInputSurfaceWrapper = null;
+        }
+        if (mDecoder != null) {
+            if (mDecoderStarted) mDecoder.stop();
+            mDecoder.release();
+            mDecoder = null;
+        }
+        if (mEncoder != null) {
+            if (mEncoderStarted) mEncoder.stop();
+            mEncoder.release();
+            mEncoder = null;
+        }
+    }
+
+    private int drainExtractor(long timeoutUs) {
+        if (mIsExtractorEOS) return DRAIN_STATE_NONE;
+        int trackIndex = mExtractor.getSampleTrackIndex();
+        if (trackIndex >= 0 && trackIndex != mTrackIndex) {
+            return DRAIN_STATE_NONE;
+        }
+        int result = mDecoder.dequeueInputBuffer(timeoutUs);
+        if (result < 0) return DRAIN_STATE_NONE;
+        if (trackIndex < 0) {
+            mIsExtractorEOS = true;
+            mDecoder.queueInputBuffer(result, 0, 0, 0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
+            return DRAIN_STATE_NONE;
+        }
+        int sampleSize = mExtractor.readSampleData(mDecoderInputBuffers[result], 0);
+        boolean isKeyFrame = (mExtractor.getSampleFlags() & MediaExtractor.SAMPLE_FLAG_SYNC) != 0;
+        mDecoder.queueInputBuffer(result, 0, sampleSize, mExtractor.getSampleTime(), isKeyFrame ? MediaCodec.BUFFER_FLAG_SYNC_FRAME : 0);
+        mExtractor.advance();
+        return DRAIN_STATE_CONSUMED;
+    }
+
+    private int drainDecoder(long timeoutUs) {
+        if (mIsDecoderEOS) return DRAIN_STATE_NONE;
+        int result = mDecoder.dequeueOutputBuffer(mBufferInfo, timeoutUs);
+        switch (result) {
+            case MediaCodec.INFO_TRY_AGAIN_LATER:
+                return DRAIN_STATE_NONE;
+            case MediaCodec.INFO_OUTPUT_FORMAT_CHANGED:
+            case MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED:
+                return DRAIN_STATE_SHOULD_RETRY_IMMEDIATELY;
+        }
+        if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
+            mEncoder.signalEndOfInputStream();
+            mIsDecoderEOS = true;
+            mBufferInfo.size = 0;
+        }
+        boolean doRender = (mBufferInfo.size > 0);
+        // NOTE: doRender will block if buffer (of encoder) is full.
+        // Refer: http://bigflake.com/mediacodec/CameraToMpegTest.java.txt
+        mDecoder.releaseOutputBuffer(result, doRender);
+        if (doRender) {
+            mDecoderOutputSurfaceWrapper.awaitNewImage();
+            mDecoderOutputSurfaceWrapper.drawImage();
+            mEncoderInputSurfaceWrapper.setPresentationTime(mBufferInfo.presentationTimeUs * 1000);
+            mEncoderInputSurfaceWrapper.swapBuffers();
+        }
+        return DRAIN_STATE_CONSUMED;
+    }
+
+    private int drainEncoder(long timeoutUs) {
+        if (mIsEncoderEOS) return DRAIN_STATE_NONE;
+        int result = mEncoder.dequeueOutputBuffer(mBufferInfo, timeoutUs);
+        switch (result) {
+            case MediaCodec.INFO_TRY_AGAIN_LATER:
+                return DRAIN_STATE_NONE;
+            case MediaCodec.INFO_OUTPUT_FORMAT_CHANGED:
+                if (mActualOutputFormat != null)
+                    throw new RuntimeException("Video output format changed twice.");
+                mActualOutputFormat = mEncoder.getOutputFormat();
+                mMuxer.setOutputFormat(QueuedMuxer.SampleType.VIDEO, mActualOutputFormat);
+                return DRAIN_STATE_SHOULD_RETRY_IMMEDIATELY;
+            case MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED:
+                mEncoderOutputBuffers = mEncoder.getOutputBuffers();
+                return DRAIN_STATE_SHOULD_RETRY_IMMEDIATELY;
+        }
+        if (mActualOutputFormat == null) {
+            throw new RuntimeException("Could not determine actual output format.");
+        }
+
+        if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
+            mIsEncoderEOS = true;
+            mBufferInfo.set(0, 0, 0, mBufferInfo.flags);
+        }
+        if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0) {
+            // SPS or PPS, which should be passed by MediaFormat.
+            mEncoder.releaseOutputBuffer(result, false);
+            return DRAIN_STATE_SHOULD_RETRY_IMMEDIATELY;
+        }
+        mMuxer.writeSampleData(QueuedMuxer.SampleType.VIDEO, mEncoderOutputBuffers[result], mBufferInfo);
+        mWrittenPresentationTimeUs = mBufferInfo.presentationTimeUs;
+        mEncoder.releaseOutputBuffer(result, false);
+        return DRAIN_STATE_CONSUMED;
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/Android16By9FormatStrategy.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/Android16By9FormatStrategy.java
new file mode 100644
index 000000000..faf303127
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/Android16By9FormatStrategy.java
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.format;
+
+import android.media.MediaCodecInfo;
+import android.media.MediaFormat;
+import android.util.Log;
+
+class Android16By9FormatStrategy implements MediaFormatStrategy {
+    public static final int AUDIO_BITRATE_AS_IS = -1;
+    public static final int AUDIO_CHANNELS_AS_IS = -1;
+    public static final int SCALE_720P = 5;
+    private static final String TAG = "Android16By9FormatStrategy";
+    private final int mScale;
+    private final int mVideoBitrate;
+    private final int mAudioBitrate;
+    private final int mAudioChannels;
+
+    public Android16By9FormatStrategy(int scale, int videoBitrate) {
+        this(scale, videoBitrate, AUDIO_BITRATE_AS_IS, AUDIO_CHANNELS_AS_IS);
+    }
+
+    public Android16By9FormatStrategy(int scale, int videoBitrate, int audioBitrate, int audioChannels) {
+        mScale = scale;
+        mVideoBitrate = videoBitrate;
+        mAudioBitrate = audioBitrate;
+        mAudioChannels = audioChannels;
+    }
+
+    @Override
+    public MediaFormat createVideoOutputFormat(MediaFormat inputFormat) {
+        int width = inputFormat.getInteger(MediaFormat.KEY_WIDTH);
+        int height = inputFormat.getInteger(MediaFormat.KEY_HEIGHT);
+        int targetLonger = mScale * 16 * 16;
+        int targetShorter = mScale * 16 * 9;
+        int longer, shorter, outWidth, outHeight;
+        if (width >= height) {
+            longer = width;
+            shorter = height;
+            outWidth = targetLonger;
+            outHeight = targetShorter;
+        } else {
+            shorter = width;
+            longer = height;
+            outWidth = targetShorter;
+            outHeight = targetLonger;
+        }
+        if (longer * 9 != shorter * 16) {
+            throw new OutputFormatUnavailableException("This video is not 16:9, and is not able to transcode. (" + width + "x" + height + ")");
+        }
+        if (shorter <= targetShorter) {
+            Log.d(TAG, "This video's height is less or equal to " + targetShorter + ", pass-through. (" + width + "x" + height + ")");
+            return null;
+        }
+        MediaFormat format = MediaFormat.createVideoFormat("video/avc", outWidth, outHeight);
+        // From Nexus 4 Camera in 720p
+        format.setInteger(MediaFormat.KEY_BIT_RATE, mVideoBitrate);
+        format.setInteger(MediaFormat.KEY_FRAME_RATE, 30);
+        format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 3);
+        format.setInteger(MediaFormat.KEY_COLOR_FORMAT, MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface);
+        return format;
+    }
+
+    @Override
+    public MediaFormat createAudioOutputFormat(MediaFormat inputFormat) {
+        if (mAudioBitrate == AUDIO_BITRATE_AS_IS || mAudioChannels == AUDIO_CHANNELS_AS_IS) return null;
+
+        // Use original sample rate, as resampling is not supported yet.
+        final MediaFormat format = MediaFormat.createAudioFormat(MediaFormatExtraConstants.MIMETYPE_AUDIO_AAC,
+                inputFormat.getInteger(MediaFormat.KEY_SAMPLE_RATE), mAudioChannels);
+        format.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
+        format.setInteger(MediaFormat.KEY_BIT_RATE, mAudioBitrate);
+        return format;
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/Android720pFormatStrategy.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/Android720pFormatStrategy.java
new file mode 100644
index 000000000..dc59caa1d
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/Android720pFormatStrategy.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.format;
+
+import android.media.MediaCodecInfo;
+import android.media.MediaFormat;
+import android.util.Log;
+
+class Android720pFormatStrategy implements MediaFormatStrategy {
+    public static final int AUDIO_BITRATE_AS_IS = -1;
+    public static final int AUDIO_CHANNELS_AS_IS = -1;
+    private static final String TAG = "720pFormatStrategy";
+    private static final int LONGER_LENGTH = 1280;
+    private static final int SHORTER_LENGTH = 720;
+    private static final int DEFAULT_VIDEO_BITRATE = 8000 * 1000; // From Nexus 4 Camera in 720p
+    private final int mVideoBitrate;
+    private final int mAudioBitrate;
+    private final int mAudioChannels;
+
+    public Android720pFormatStrategy() {
+        this(DEFAULT_VIDEO_BITRATE);
+    }
+
+    public Android720pFormatStrategy(int videoBitrate) {
+        this(videoBitrate, AUDIO_BITRATE_AS_IS, AUDIO_CHANNELS_AS_IS);
+    }
+
+    public Android720pFormatStrategy(int videoBitrate, int audioBitrate, int audioChannels) {
+        mVideoBitrate = videoBitrate;
+        mAudioBitrate = audioBitrate;
+        mAudioChannels = audioChannels;
+    }
+
+    @Override
+    public MediaFormat createVideoOutputFormat(MediaFormat inputFormat) {
+        int width = inputFormat.getInteger(MediaFormat.KEY_WIDTH);
+        int height = inputFormat.getInteger(MediaFormat.KEY_HEIGHT);
+        int longer, shorter, outWidth, outHeight;
+        if (width >= height) {
+            longer = width;
+            shorter = height;
+            outWidth = LONGER_LENGTH;
+            outHeight = SHORTER_LENGTH;
+        } else {
+            shorter = width;
+            longer = height;
+            outWidth = SHORTER_LENGTH;
+            outHeight = LONGER_LENGTH;
+        }
+        if (longer * 9 != shorter * 16) {
+            throw new OutputFormatUnavailableException("This video is not 16:9, and is not able to transcode. (" + width + "x" + height + ")");
+        }
+        if (shorter <= SHORTER_LENGTH) {
+            Log.d(TAG, "This video is less or equal to 720p, pass-through. (" + width + "x" + height + ")");
+            return null;
+        }
+        MediaFormat format = MediaFormat.createVideoFormat("video/avc", outWidth, outHeight);
+        // From Nexus 4 Camera in 720p
+        format.setInteger(MediaFormat.KEY_BIT_RATE, mVideoBitrate);
+        format.setInteger(MediaFormat.KEY_FRAME_RATE, 30);
+        format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 3);
+        format.setInteger(MediaFormat.KEY_COLOR_FORMAT, MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface);
+        return format;
+    }
+
+    @Override
+    public MediaFormat createAudioOutputFormat(MediaFormat inputFormat) {
+        if (mAudioBitrate == AUDIO_BITRATE_AS_IS || mAudioChannels == AUDIO_CHANNELS_AS_IS) return null;
+
+        // Use original sample rate, as resampling is not supported yet.
+        final MediaFormat format = MediaFormat.createAudioFormat(MediaFormatExtraConstants.MIMETYPE_AUDIO_AAC,
+                inputFormat.getInteger(MediaFormat.KEY_SAMPLE_RATE), mAudioChannels);
+        format.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
+        format.setInteger(MediaFormat.KEY_BIT_RATE, mAudioBitrate);
+        return format;
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/ExportPreset960x540Strategy.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/ExportPreset960x540Strategy.java
new file mode 100644
index 000000000..56d9a7d34
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/ExportPreset960x540Strategy.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.format;
+
+import android.media.MediaFormat;
+import android.util.Log;
+
+/**
+* Created by yuya.tanaka on 2014/11/20.
+*/
+class ExportPreset960x540Strategy implements MediaFormatStrategy {
+    private static final String TAG = "ExportPreset960x540Strategy";
+
+    @Override
+    public MediaFormat createVideoOutputFormat(MediaFormat inputFormat) {
+        // TODO: detect non-baseline profile and throw exception
+        int width = inputFormat.getInteger(MediaFormat.KEY_WIDTH);
+        int height = inputFormat.getInteger(MediaFormat.KEY_HEIGHT);
+        MediaFormat outputFormat = MediaFormatPresets.getExportPreset960x540(width, height);
+        int outWidth = outputFormat.getInteger(MediaFormat.KEY_WIDTH);
+        int outHeight = outputFormat.getInteger(MediaFormat.KEY_HEIGHT);
+        Log.d(TAG, String.format("inputFormat: %dx%d => outputFormat: %dx%d", width, height, outWidth, outHeight));
+        return outputFormat;
+    }
+
+    @Override
+    public MediaFormat createAudioOutputFormat(MediaFormat inputFormat) {
+        // TODO
+        return null;
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/MediaFormatExtraConstants.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/MediaFormatExtraConstants.java
new file mode 100644
index 000000000..7f34adc97
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/MediaFormatExtraConstants.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.format;
+
+public class MediaFormatExtraConstants {
+    // from MediaFormat of API level >= 21, but might be usable in older APIs as native code implementation exists.
+    // https://android.googlesource.com/platform/frameworks/av/+/lollipop-release/media/libstagefright/ACodec.cpp#2621
+    // NOTE: native code enforces baseline profile.
+    // https://android.googlesource.com/platform/frameworks/av/+/lollipop-release/media/libstagefright/ACodec.cpp#2638
+    /** For encoder parameter. Use value of MediaCodecInfo.CodecProfileLevel.AVCProfile* . */
+    public static final String KEY_PROFILE = "profile";
+
+    // from https://android.googlesource.com/platform/frameworks/av/+/lollipop-release/media/libstagefright/ACodec.cpp#2623
+    /** For encoder parameter. Use value of MediaCodecInfo.CodecProfileLevel.AVCLevel* . */
+    public static final String KEY_LEVEL = "level";
+
+    // from https://android.googlesource.com/platform/frameworks/av/+/lollipop-release/media/libstagefright/MediaCodec.cpp#2197
+    /** Included in MediaFormat from {@link android.media.MediaExtractor#getTrackFormat(int)}. Value is {@link java.nio.ByteBuffer}. */
+    public static final String KEY_AVC_SPS = "csd-0";
+    /** Included in MediaFormat from {@link android.media.MediaExtractor#getTrackFormat(int)}. Value is {@link java.nio.ByteBuffer}. */
+    public static final String KEY_AVC_PPS = "csd-1";
+
+    /**
+     * For decoder parameter and included in MediaFormat from {@link android.media.MediaExtractor#getTrackFormat(int)}.
+     * Decoder rotates specified degrees before rendering video to surface.
+     * NOTE: Only included in track format of API &gt;= 21.
+     */
+    public static final String KEY_ROTATION_DEGREES = "rotation-degrees";
+
+    // Video formats
+    // from MediaFormat of API level >= 21
+    public static final String MIMETYPE_VIDEO_AVC = "video/avc";
+    public static final String MIMETYPE_VIDEO_H263 = "video/3gpp";
+    public static final String MIMETYPE_VIDEO_VP8 = "video/x-vnd.on2.vp8";
+
+    // Audio formats
+    // from MediaFormat of API level >= 21
+    public static final String MIMETYPE_AUDIO_AAC = "audio/mp4a-latm";
+
+    private MediaFormatExtraConstants() {
+        throw new RuntimeException();
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/MediaFormatPresets.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/MediaFormatPresets.java
new file mode 100644
index 000000000..086bcd3f3
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/MediaFormatPresets.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.format;
+
+import android.media.MediaCodecInfo;
+import android.media.MediaFormat;
+
+// Refer for example: https://gist.github.com/wobbals/3990442
+// Refer for preferred parameters: https://developer.apple.com/library/ios/documentation/networkinginternet/conceptual/streamingmediaguide/UsingHTTPLiveStreaming/UsingHTTPLiveStreaming.html#//apple_ref/doc/uid/TP40008332-CH102-SW8
+// Refer for available keys: (ANDROID ROOT)/media/libstagefright/ACodec.cpp
+public class MediaFormatPresets {
+    private static final int LONGER_LENGTH_960x540 = 960;
+
+    private MediaFormatPresets() {
+    }
+
+    // preset similar to iOS SDK's AVAssetExportPreset960x540
+    @Deprecated
+    public static MediaFormat getExportPreset960x540() {
+        MediaFormat format = MediaFormat.createVideoFormat("video/avc", 960, 540);
+        format.setInteger(MediaFormat.KEY_BIT_RATE, 5500 * 1000);
+        format.setInteger(MediaFormat.KEY_COLOR_FORMAT, MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface);
+        format.setInteger(MediaFormat.KEY_FRAME_RATE, 30);
+        format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 1);
+        return format;
+    }
+
+    /**
+     * Preset similar to iOS SDK's AVAssetExportPreset960x540.
+     * Note that encoding resolutions of this preset are not supported in all devices e.g. Nexus 4.
+     * On unsupported device encoded video stream will be broken without any exception.
+     * @param originalWidth Input video width.
+     * @param originalHeight Input video height.
+     * @return MediaFormat instance, or null if pass through.
+     */
+    public static MediaFormat getExportPreset960x540(int originalWidth, int originalHeight) {
+        int longerLength = Math.max(originalWidth, originalHeight);
+        int shorterLength = Math.min(originalWidth, originalHeight);
+
+        if (longerLength <= LONGER_LENGTH_960x540) return null; // don't upscale
+
+        int residue = LONGER_LENGTH_960x540 * shorterLength % longerLength;
+        if (residue != 0) {
+            double ambiguousShorter = (double) LONGER_LENGTH_960x540 * shorterLength / longerLength;
+            throw new OutputFormatUnavailableException(String.format(
+                    "Could not fit to integer, original: (%d, %d), scaled: (%d, %f)",
+                    longerLength, shorterLength, LONGER_LENGTH_960x540, ambiguousShorter));
+        }
+
+        int scaledShorter = LONGER_LENGTH_960x540 * shorterLength / longerLength;
+        int width, height;
+        if (originalWidth >= originalHeight) {
+            width = LONGER_LENGTH_960x540;
+            height = scaledShorter;
+        } else {
+            width = scaledShorter;
+            height = LONGER_LENGTH_960x540;
+        }
+
+        MediaFormat format = MediaFormat.createVideoFormat("video/avc", width, height);
+        format.setInteger(MediaFormat.KEY_BIT_RATE, 5500 * 1000);
+        format.setInteger(MediaFormat.KEY_COLOR_FORMAT, MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface);
+        format.setInteger(MediaFormat.KEY_FRAME_RATE, 30);
+        format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 1);
+        return format;
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/MediaFormatStrategy.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/MediaFormatStrategy.java
new file mode 100644
index 000000000..1aa8f6dc9
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/MediaFormatStrategy.java
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.format;
+
+import android.media.MediaFormat;
+
+public interface MediaFormatStrategy {
+
+    /**
+     * Returns preferred video format for encoding.
+     *
+     * @param inputFormat MediaFormat from MediaExtractor, contains csd-0/csd-1.
+     * @return null for passthrough.
+     * @throws OutputFormatUnavailableException if input could not be transcoded because of restrictions.
+     */
+    public MediaFormat createVideoOutputFormat(MediaFormat inputFormat);
+
+    /**
+     * Caution: this method should return null currently.
+     *
+     * @return null for passthrough.
+     * @throws OutputFormatUnavailableException if input could not be transcoded because of restrictions.
+     */
+    public MediaFormat createAudioOutputFormat(MediaFormat inputFormat);
+
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/MediaFormatStrategyPresets.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/MediaFormatStrategyPresets.java
new file mode 100644
index 000000000..30802586b
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/MediaFormatStrategyPresets.java
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.format;
+
+public class MediaFormatStrategyPresets {
+    public static final int AUDIO_BITRATE_AS_IS = -1;
+    public static final int AUDIO_CHANNELS_AS_IS = -1;
+
+    /**
+     * @deprecated Use {@link #createExportPreset960x540Strategy()}.
+     */
+    @Deprecated
+    public static final MediaFormatStrategy EXPORT_PRESET_960x540 = new ExportPreset960x540Strategy();
+
+    /**
+     * Preset based on Nexus 4 camera recording with 720p quality.
+     * This preset is ensured to work on any Android &gt;=4.3 devices by Android CTS (if codec is available).
+     * Default bitrate is 8Mbps. {@link #createAndroid720pStrategy(int)} to specify bitrate.
+     */
+    public static MediaFormatStrategy createAndroid720pStrategy() {
+        return new Android720pFormatStrategy();
+    }
+
+    /**
+     * Preset based on Nexus 4 camera recording with 720p quality.
+     * This preset is ensured to work on any Android &gt;=4.3 devices by Android CTS (if codec is available).
+     * Audio track will be copied as-is.
+     *
+     * @param bitrate Preferred bitrate for video encoding.
+     */
+    public static MediaFormatStrategy createAndroid720pStrategy(int bitrate) {
+        return new Android720pFormatStrategy(bitrate);
+    }
+
+    /**
+     * Preset based on Nexus 4 camera recording with 720p quality.
+     * This preset is ensured to work on any Android &gt;=4.3 devices by Android CTS (if codec is available).
+     * <br>
+     * Note: audio transcoding is experimental feature.
+     *
+     * @param bitrate       Preferred bitrate for video encoding.
+     * @param audioBitrate  Preferred bitrate for audio encoding.
+     * @param audioChannels Output audio channels.
+     */
+    public static MediaFormatStrategy createAndroid720pStrategy(int bitrate, int audioBitrate, int audioChannels) {
+        return new Android720pFormatStrategy(bitrate, audioBitrate, audioChannels);
+    }
+
+    /**
+     * Preset similar to iOS SDK's AVAssetExportPreset960x540.
+     * Note that encoding resolutions of this preset are not supported in all devices e.g. Nexus 4.
+     * On unsupported device encoded video stream will be broken without any exception.
+     */
+    public static MediaFormatStrategy createExportPreset960x540Strategy() {
+        return new ExportPreset960x540Strategy();
+    }
+
+    private MediaFormatStrategyPresets() {
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/OutputFormatUnavailableException.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/OutputFormatUnavailableException.java
new file mode 100644
index 000000000..4fb9b33c9
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/format/OutputFormatUnavailableException.java
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.format;
+
+public class OutputFormatUnavailableException extends RuntimeException {
+    public OutputFormatUnavailableException(String detailMessage) {
+        super(detailMessage);
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/utils/AvcCsdUtils.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/utils/AvcCsdUtils.java
new file mode 100644
index 000000000..049296b9b
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/utils/AvcCsdUtils.java
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2015 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.utils;
+
+import android.media.MediaFormat;
+
+import net.ypresto.androidtranscoder.format.MediaFormatExtraConstants;
+
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+
+public class AvcCsdUtils {
+    // Refer: https://android.googlesource.com/platform/frameworks/av/+/lollipop-release/media/libstagefright/MediaCodec.cpp#2198
+    // Refer: http://stackoverflow.com/a/2861340
+    private static final byte[] AVC_START_CODE_3 = {0x00, 0x00, 0x01};
+    private static final byte[] AVC_START_CODE_4 = {0x00, 0x00, 0x00, 0x01};
+    // Refer: http://www.cardinalpeak.com/blog/the-h-264-sequence-parameter-set/
+    private static final byte AVC_SPS_NAL = 103; // 0<<7 + 3<<5 + 7<<0
+    // https://tools.ietf.org/html/rfc6184
+    private static final byte AVC_SPS_NAL_2 = 39; // 0<<7 + 1<<5 + 7<<0
+    private static final byte AVC_SPS_NAL_3 = 71; // 0<<7 + 2<<5 + 7<<0
+
+    /**
+     * @return ByteBuffer contains SPS without NAL header.
+     */
+    public static ByteBuffer getSpsBuffer(MediaFormat format) {
+        ByteBuffer sourceBuffer = format.getByteBuffer(MediaFormatExtraConstants.KEY_AVC_SPS).asReadOnlyBuffer(); // might be direct buffer
+        ByteBuffer prefixedSpsBuffer = ByteBuffer.allocate(sourceBuffer.limit()).order(sourceBuffer.order());
+        prefixedSpsBuffer.put(sourceBuffer);
+        prefixedSpsBuffer.flip();
+
+        skipStartCode(prefixedSpsBuffer);
+
+        byte spsNalData = prefixedSpsBuffer.get();
+        if (spsNalData != AVC_SPS_NAL && spsNalData != AVC_SPS_NAL_2 && spsNalData != AVC_SPS_NAL_3) {
+            throw new IllegalStateException("Got non SPS NAL data.");
+        }
+
+        return prefixedSpsBuffer.slice();
+    }
+
+    private static void skipStartCode(ByteBuffer prefixedSpsBuffer) {
+        byte[] prefix3 = new byte[3];
+        prefixedSpsBuffer.get(prefix3);
+        if (Arrays.equals(prefix3, AVC_START_CODE_3)) return;
+
+        byte[] prefix4 = Arrays.copyOf(prefix3, 4);
+        prefix4[3] = prefixedSpsBuffer.get();
+        if (Arrays.equals(prefix4, AVC_START_CODE_4)) return;
+        throw new IllegalStateException("AVC NAL start code does not found in csd.");
+    }
+
+    private AvcCsdUtils() {
+        throw new RuntimeException();
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/utils/AvcSpsUtils.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/utils/AvcSpsUtils.java
new file mode 100644
index 000000000..3eafbed64
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/utils/AvcSpsUtils.java
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2016 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.utils;
+
+import java.nio.ByteBuffer;
+
+public class AvcSpsUtils {
+    public static byte getProfileIdc(ByteBuffer spsBuffer) {
+        // Refer: http://www.cardinalpeak.com/blog/the-h-264-sequence-parameter-set/
+        // First byte after NAL.
+        return spsBuffer.get(0);
+    }
+}
diff --git a/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/utils/MediaExtractorUtils.java b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/utils/MediaExtractorUtils.java
new file mode 100644
index 000000000..b973d2f16
--- /dev/null
+++ b/libs/android-transcoder/src/main/java/net/ypresto/androidtranscoder/utils/MediaExtractorUtils.java
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2014 Yuya Tanaka
+ *
+ * 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 net.ypresto.androidtranscoder.utils;
+
+import android.media.MediaExtractor;
+import android.media.MediaFormat;
+
+public class MediaExtractorUtils {
+
+    private MediaExtractorUtils() {
+    }
+
+    public static class TrackResult {
+
+        private TrackResult() {
+        }
+
+        public int mVideoTrackIndex;
+        public String mVideoTrackMime;
+        public MediaFormat mVideoTrackFormat;
+        public int mAudioTrackIndex;
+        public String mAudioTrackMime;
+        public MediaFormat mAudioTrackFormat;
+    }
+
+    public static TrackResult getFirstVideoAndAudioTrack(MediaExtractor extractor) {
+        TrackResult trackResult = new TrackResult();
+        trackResult.mVideoTrackIndex = -1;
+        trackResult.mAudioTrackIndex = -1;
+        int trackCount = extractor.getTrackCount();
+        for (int i = 0; i < trackCount; i++) {
+            MediaFormat format = extractor.getTrackFormat(i);
+            String mime = format.getString(MediaFormat.KEY_MIME);
+            if (trackResult.mVideoTrackIndex < 0 && mime.startsWith("video/")) {
+                trackResult.mVideoTrackIndex = i;
+                trackResult.mVideoTrackMime = mime;
+                trackResult.mVideoTrackFormat = format;
+            } else if (trackResult.mAudioTrackIndex < 0 && mime.startsWith("audio/")) {
+                trackResult.mAudioTrackIndex = i;
+                trackResult.mAudioTrackMime = mime;
+                trackResult.mAudioTrackFormat = format;
+            }
+            if (trackResult.mVideoTrackIndex >= 0 && trackResult.mAudioTrackIndex >= 0) break;
+        }
+        if (trackResult.mVideoTrackIndex < 0 || trackResult.mAudioTrackIndex < 0) {
+            throw new IllegalArgumentException("extractor does not contain video and/or audio tracks.");
+        }
+        return trackResult;
+    }
+}
diff --git a/settings.gradle b/settings.gradle
index 4e4fe924e..a9746a41b 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -1,4 +1,5 @@
 include ':libs:MemorizingTrustManager'
 include ':libs:audiowife'
 include ':libs:emojicon'
+include ':libs:android-transcoder'
 rootProject.name = 'Pix-Art Messenger'