Publish the transformer demo app

PiperOrigin-RevId: 424850283

RELEASENOTES.md

@@ -114,6 +114,7 @@
     *   Fix Transformer being stuck when the codec output is partially read.
     *   Fix potential NPE in `Transformer.getProgress` when releasing the muxer
         throws.
+    *   Add a demo app for applying transformations.
 *   MediaSession extension:
     *   Remove deprecated call to `onStop(/* reset= */ true)` and provide an
         opt-out flag for apps that don't want to clear the playlist on stop.

constants.gradle

@@ -37,6 +37,7 @@ project.ext {
     androidxAnnotationVersion = '1.3.0'
     androidxAppCompatVersion = '1.3.1'
     androidxCollectionVersion = '1.1.0'
+    androidxConstraintLayoutVersion = '2.0.4'
     androidxCoreVersion = '1.7.0'
     androidxFuturesVersion = '1.1.0'
     androidxMediaVersion = '1.4.3'

demos/transformer/README.md

+# Transformer demo
+
+This app demonstrates how to use the [Transformer][] API to modify videos, for
+example by removing audio or video.
+
+See the [demos README](../README.md) for instructions on how to build and run
+this demo.
+
+[Transformer]: https://exoplayer.dev/transforming-media.html

demos/transformer/build.gradle

+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+apply from: '../../constants.gradle'
+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion project.ext.compileSdkVersion
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+
+    defaultConfig {
+        versionName project.ext.releaseVersion
+        versionCode project.ext.releaseVersionCode
+        minSdkVersion 21
+        targetSdkVersion project.ext.appTargetSdkVersion
+        multiDexEnabled true
+    }
+
+    buildTypes {
+        release {
+            shrinkResources true
+            minifyEnabled true
+            proguardFiles getDefaultProguardFile('proguard-android.txt')
+            signingConfig signingConfigs.debug
+        }
+    }
+
+    lintOptions {
+        // This demo app isn't indexed and doesn't have translations.
+        disable 'GoogleAppIndexingWarning','MissingTranslation'
+    }
+}
+
+dependencies {
+    compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
+    implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
+    implementation 'androidx.appcompat:appcompat:' + androidxAppCompatVersion
+    implementation 'androidx.constraintlayout:constraintlayout:' + androidxConstraintLayoutVersion
+    implementation 'androidx.multidex:multidex:' + androidxMultidexVersion
+    implementation 'com.google.android.material:material:' + androidxMaterialVersion
+    implementation project(modulePrefix + 'library-core')
+    implementation project(modulePrefix + 'library-transformer')
+    implementation project(modulePrefix + 'library-ui')
+}

demos/transformer/src/main/AndroidManifest.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright 2021 The Android Open Source Project
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    package="com.google.android.exoplayer2.transformerdemo">
+  <uses-sdk />
+
+  <uses-permission android:name="android.permission.INTERNET"/>
+  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
+  <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
+  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
+
+  <application
+      android:allowBackup="false"
+      android:icon="@mipmap/ic_launcher"
+      android:label="@string/app_name"
+      android:theme="@style/Theme.AppCompat"
+      android:taskAffinity=""
+      tools:targetApi="29">
+    <activity android:name=".ConfigurationActivity"
+        android:configChanges="keyboard|keyboardHidden|orientation|screenSize|screenLayout|smallestScreenSize|uiMode"
+        android:launchMode="singleTop"
+        android:label="@string/app_name"
+        android:exported="true"
+        android:theme="@style/Theme.MaterialComponents.DayNight.NoActionBar">
+      <intent-filter>
+        <action android:name="android.intent.action.MAIN"/>
+        <category android:name="android.intent.category.LAUNCHER"/>
+      </intent-filter>
+      <intent-filter>
+        <action android:name="com.google.android.exoplayer2.transformerdemo.action.VIEW"/>
+        <category android:name="android.intent.category.DEFAULT"/>
+        <data android:scheme="http"/>
+        <data android:scheme="https"/>
+        <data android:scheme="content"/>
+        <data android:scheme="asset"/>
+        <data android:scheme="file"/>
+      </intent-filter>
+    </activity>
+    <activity android:name=".TransformerActivity"
+        android:configChanges="keyboard|keyboardHidden|orientation|screenSize|screenLayout|smallestScreenSize|uiMode"
+        android:launchMode="singleTop"
+        android:label="@string/app_name"
+        android:exported="true"
+        android:theme="@style/Theme.MaterialComponents.DayNight.NoActionBar"/>
+  </application>
+</manifest>

demos/transformer/src/main/java/com/google/android/exoplayer2/transformerdemo/ConfigurationActivity.java

+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.transformerdemo;
+
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+import static com.google.android.exoplayer2.util.Assertions.checkState;
+
+import android.app.Activity;
+import android.content.DialogInterface;
+import android.content.Intent;
+import android.net.Uri;
+import android.os.Bundle;
+import android.view.View;
+import android.widget.ArrayAdapter;
+import android.widget.Button;
+import android.widget.CheckBox;
+import android.widget.Spinner;
+import android.widget.TextView;
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.AlertDialog;
+import androidx.appcompat.app.AppCompatActivity;
+import com.google.android.exoplayer2.util.MimeTypes;
+import java.util.Arrays;
+import java.util.List;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+import org.checkerframework.checker.nullness.qual.RequiresNonNull;
+
+/**
+ * An {@link Activity} that sets the configuration to use for transforming and playing media, using
+ * {@link TransformerActivity}.
+ */
+public final class ConfigurationActivity extends AppCompatActivity {
+  public static final String SHOULD_REMOVE_AUDIO = "should_remove_audio";
+  public static final String SHOULD_REMOVE_VIDEO = "should_remove_video";
+  public static final String SHOULD_FLATTEN_FOR_SLOW_MOTION = "should_flatten_for_slow_motion";
+  public static final String AUDIO_MIME_TYPE = "audio_mime_type";
+  public static final String VIDEO_MIME_TYPE = "video_mime_type";
+  public static final String RESOLUTION_HEIGHT = "resolution_height";
+  public static final String TRANSLATE_X = "translate_x";
+  public static final String TRANSLATE_Y = "translate_y";
+  public static final String SCALE_X = "scale_x";
+  public static final String SCALE_Y = "scale_y";
+  public static final String ROTATE_DEGREES = "rotate_degrees";
+  private static final String[] INPUT_URIS = {
+    "https://html5demos.com/assets/dizzy.mp4",
+    "https://storage.googleapis.com/exoplayer-test-media-0/android-block-1080-hevc.mp4",
+    "https://storage.googleapis.com/exoplayer-test-media-0/BigBuckBunny_320x180.mp4",
+    "https://html5demos.com/assets/dizzy.webm",
+  };
+  private static final String[] URI_DESCRIPTIONS = { // same order as INPUT_URIS
+    "MP4 with H264 video and AAC audio",
+    "MP4 with H265 video and AAC audio",
+    "Long MP4 with H264 video and AAC audio",
+    "WebM with VP8 video and Vorbis audio",
+  };
+  private static final String SAME_AS_INPUT_OPTION = "same as input";
+
+  private @MonotonicNonNull Button chooseFileButton;
+  private @MonotonicNonNull CheckBox removeAudioCheckbox;
+  private @MonotonicNonNull CheckBox removeVideoCheckbox;
+  private @MonotonicNonNull CheckBox flattenForSlowMotionCheckbox;
+  private @MonotonicNonNull Spinner audioMimeSpinner;
+  private @MonotonicNonNull Spinner videoMimeSpinner;
+  private @MonotonicNonNull Spinner resolutionHeightSpinner;
+  private @MonotonicNonNull Spinner translateSpinner;
+  private @MonotonicNonNull Spinner scaleSpinner;
+  private @MonotonicNonNull Spinner rotateSpinner;
+  private @MonotonicNonNull TextView chosenFileTextView;
+  private int inputUriPosition;
+
+  @Override
+  protected void onCreate(@Nullable Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    setContentView(R.layout.configuration_activity);
+
+    findViewById(R.id.transform_button).setOnClickListener(this::startTransformation);
+
+    chooseFileButton = findViewById(R.id.choose_file_button);
+    chooseFileButton.setOnClickListener(this::chooseFile);
+
+    chosenFileTextView = findViewById(R.id.chosen_file_text_view);
+    chosenFileTextView.setText(URI_DESCRIPTIONS[inputUriPosition]);
+
+    removeAudioCheckbox = findViewById(R.id.remove_audio_checkbox);
+    removeAudioCheckbox.setOnClickListener(this::onRemoveAudio);
+
+    removeVideoCheckbox = findViewById(R.id.remove_video_checkbox);
+    removeVideoCheckbox.setOnClickListener(this::onRemoveVideo);
+
+    flattenForSlowMotionCheckbox = findViewById(R.id.flatten_for_slow_motion_checkbox);
+
+    ArrayAdapter<String> audioMimeAdapter =
+        new ArrayAdapter<>(/* context= */ this, R.layout.spinner_item);
+    audioMimeAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
+    audioMimeSpinner = findViewById(R.id.audio_mime_spinner);
+    audioMimeSpinner.setAdapter(audioMimeAdapter);
+    audioMimeAdapter.addAll(
+        SAME_AS_INPUT_OPTION, MimeTypes.AUDIO_AAC, MimeTypes.AUDIO_AMR_NB, MimeTypes.AUDIO_AMR_WB);
+
+    ArrayAdapter<String> videoMimeAdapter =
+        new ArrayAdapter<>(/* context= */ this, R.layout.spinner_item);
+    videoMimeAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
+    videoMimeSpinner = findViewById(R.id.video_mime_spinner);
+    videoMimeSpinner.setAdapter(videoMimeAdapter);
+    videoMimeAdapter.addAll(
+        SAME_AS_INPUT_OPTION,
+        MimeTypes.VIDEO_H263,
+        MimeTypes.VIDEO_H264,
+        MimeTypes.VIDEO_H265,
+        MimeTypes.VIDEO_MP4V);
+
+    ArrayAdapter<String> resolutionHeightAdapter =
+        new ArrayAdapter<>(/* context= */ this, R.layout.spinner_item);
+    resolutionHeightAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
+    resolutionHeightSpinner = findViewById(R.id.resolution_height_spinner);
+    resolutionHeightSpinner.setAdapter(resolutionHeightAdapter);
+    resolutionHeightAdapter.addAll(
+        SAME_AS_INPUT_OPTION, "144", "240", "360", "480", "720", "1080", "1440", "2160");
+
+    ArrayAdapter<String> translateAdapter =
+        new ArrayAdapter<>(/* context= */ this, R.layout.spinner_item);
+    translateAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
+    translateSpinner = findViewById(R.id.translate_spinner);
+    translateSpinner.setAdapter(translateAdapter);
+    translateAdapter.addAll(
+        SAME_AS_INPUT_OPTION, "-.1, -.1", "0, 0", ".5, 0", "0, .5", "1, 1", "1.9, 0", "0, 1.9");
+
+    ArrayAdapter<String> scaleAdapter =
+        new ArrayAdapter<>(/* context= */ this, R.layout.spinner_item);
+    scaleAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
+    scaleSpinner = findViewById(R.id.scale_spinner);
+    scaleSpinner.setAdapter(scaleAdapter);
+    scaleAdapter.addAll(SAME_AS_INPUT_OPTION, "-1, -1", "-1, 1", "1, 1", ".5, 1", ".5, .5", "2, 2");
+
+    ArrayAdapter<String> rotateAdapter =
+        new ArrayAdapter<>(/* context= */ this, R.layout.spinner_item);
+    rotateAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
+    rotateSpinner = findViewById(R.id.rotate_spinner);
+    rotateSpinner.setAdapter(rotateAdapter);
+    rotateAdapter.addAll(SAME_AS_INPUT_OPTION, "0", "10", "45", "90", "180");
+  }
+
+  @Override
+  protected void onResume() {
+    super.onResume();
+    @Nullable Uri intentUri = getIntent().getData();
+    if (intentUri != null) {
+      checkNotNull(chooseFileButton).setEnabled(false);
+      checkNotNull(chosenFileTextView).setText(intentUri.toString());
+    }
+  }
+
+  @Override
+  protected void onNewIntent(Intent intent) {
+    super.onNewIntent(intent);
+    setIntent(intent);
+  }
+
+  @RequiresNonNull({
+    "removeAudioCheckbox",
+    "removeVideoCheckbox",
+    "flattenForSlowMotionCheckbox",
+    "audioMimeSpinner",
+    "videoMimeSpinner",
+    "resolutionHeightSpinner",
+    "translateSpinner",
+    "scaleSpinner",
+    "rotateSpinner"
+  })
+  private void startTransformation(View view) {
+    Intent transformerIntent = new Intent(this, TransformerActivity.class);
+    Bundle bundle = new Bundle();
+    bundle.putBoolean(SHOULD_REMOVE_AUDIO, removeAudioCheckbox.isChecked());
+    bundle.putBoolean(SHOULD_REMOVE_VIDEO, removeVideoCheckbox.isChecked());
+    bundle.putBoolean(SHOULD_FLATTEN_FOR_SLOW_MOTION, flattenForSlowMotionCheckbox.isChecked());
+    String selectedAudioMimeType = String.valueOf(audioMimeSpinner.getSelectedItem());
+    if (!SAME_AS_INPUT_OPTION.equals(selectedAudioMimeType)) {
+      bundle.putString(AUDIO_MIME_TYPE, selectedAudioMimeType);
+    }
+    String selectedVideoMimeType = String.valueOf(videoMimeSpinner.getSelectedItem());
+    if (!SAME_AS_INPUT_OPTION.equals(selectedVideoMimeType)) {
+      bundle.putString(VIDEO_MIME_TYPE, selectedVideoMimeType);
+    }
+    String selectedResolutionHeight = String.valueOf(resolutionHeightSpinner.getSelectedItem());
+    if (!SAME_AS_INPUT_OPTION.equals(selectedResolutionHeight)) {
+      bundle.putInt(RESOLUTION_HEIGHT, Integer.valueOf(selectedResolutionHeight));
+    }
+    String selectedTranslate = String.valueOf(translateSpinner.getSelectedItem());
+    if (!SAME_AS_INPUT_OPTION.equals(selectedTranslate)) {
+      List<String> translateXY = Arrays.asList(selectedTranslate.split(", "));
+      checkState(translateXY.size() == 2);
+      bundle.putFloat(TRANSLATE_X, Float.valueOf(translateXY.get(0)));
+      bundle.putFloat(TRANSLATE_Y, Float.valueOf(translateXY.get(1)));
+    }
+    String selectedScale = String.valueOf(scaleSpinner.getSelectedItem());
+    if (!SAME_AS_INPUT_OPTION.equals(selectedScale)) {
+      List<String> scaleXY = Arrays.asList(selectedScale.split(", "));
+      checkState(scaleXY.size() == 2);
+      bundle.putFloat(SCALE_X, Float.valueOf(scaleXY.get(0)));
+      bundle.putFloat(SCALE_Y, Float.valueOf(scaleXY.get(1)));
+    }
+    String selectedRotate = String.valueOf(rotateSpinner.getSelectedItem());
+    if (!SAME_AS_INPUT_OPTION.equals(selectedRotate)) {
+      bundle.putFloat(ROTATE_DEGREES, Float.valueOf(selectedRotate));
+    }
+    transformerIntent.putExtras(bundle);
+
+    @Nullable Uri intentUri = getIntent().getData();
+    transformerIntent.setData(
+        intentUri != null ? intentUri : Uri.parse(INPUT_URIS[inputUriPosition]));
+
+    startActivity(transformerIntent);
+  }
+
+  private void chooseFile(View view) {
+    new AlertDialog.Builder(/* context= */ this)
+        .setTitle(R.string.choose_file_title)
+        .setSingleChoiceItems(URI_DESCRIPTIONS, inputUriPosition, this::selectFileInDialog)
+        .setPositiveButton(android.R.string.ok, /* listener= */ null)
+        .create()
+        .show();
+  }
+
+  @RequiresNonNull("chosenFileTextView")
+  private void selectFileInDialog(DialogInterface dialog, int which) {
+    inputUriPosition = which;
+    chosenFileTextView.setText(URI_DESCRIPTIONS[inputUriPosition]);
+  }
+
+  @RequiresNonNull({
+    "removeVideoCheckbox",
+    "audioMimeSpinner",
+    "videoMimeSpinner",
+    "resolutionHeightSpinner",
+    "translateSpinner",
+    "scaleSpinner",
+    "rotateSpinner"
+  })
+  private void onRemoveAudio(View view) {
+    if (((CheckBox) view).isChecked()) {
+      removeVideoCheckbox.setChecked(false);
+      enableTrackSpecificOptions(/* isAudioEnabled= */ false, /* isVideoEnabled= */ true);
+    } else {
+      enableTrackSpecificOptions(/* isAudioEnabled= */ true, /* isVideoEnabled= */ true);
+    }
+  }
+
+  @RequiresNonNull({
+    "removeAudioCheckbox",
+    "audioMimeSpinner",
+    "videoMimeSpinner",
+    "resolutionHeightSpinner",
+    "translateSpinner",
+    "scaleSpinner",
+    "rotateSpinner"
+  })
+  private void onRemoveVideo(View view) {
+    if (((CheckBox) view).isChecked()) {
+      removeAudioCheckbox.setChecked(false);
+      enableTrackSpecificOptions(/* isAudioEnabled= */ true, /* isVideoEnabled= */ false);
+    } else {
+      enableTrackSpecificOptions(/* isAudioEnabled= */ true, /* isVideoEnabled= */ true);
+    }
+  }
+
+  @RequiresNonNull({
+    "audioMimeSpinner",
+    "videoMimeSpinner",
+    "resolutionHeightSpinner",
+    "translateSpinner",
+    "scaleSpinner",
+    "rotateSpinner"
+  })
+  private void enableTrackSpecificOptions(boolean isAudioEnabled, boolean isVideoEnabled) {
+    audioMimeSpinner.setEnabled(isAudioEnabled);
+    videoMimeSpinner.setEnabled(isVideoEnabled);
+    resolutionHeightSpinner.setEnabled(isVideoEnabled);
+    translateSpinner.setEnabled(isVideoEnabled);
+    scaleSpinner.setEnabled(isVideoEnabled);
+    rotateSpinner.setEnabled(isVideoEnabled);
+
+    findViewById(R.id.audio_mime_text_view).setEnabled(isAudioEnabled);
+    findViewById(R.id.video_mime_text_view).setEnabled(isVideoEnabled);
+    findViewById(R.id.resolution_height_text_view).setEnabled(isVideoEnabled);
+    findViewById(R.id.translate).setEnabled(isVideoEnabled);
+    findViewById(R.id.scale).setEnabled(isVideoEnabled);
+    findViewById(R.id.rotate).setEnabled(isVideoEnabled);
+  }
+}

demos/transformer/src/main/java/com/google/android/exoplayer2/transformerdemo/TransformerActivity.java

+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.transformerdemo;
+
+import static android.Manifest.permission.READ_EXTERNAL_STORAGE;
+import static android.Manifest.permission.WRITE_EXTERNAL_STORAGE;
+import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.graphics.Matrix;
+import android.net.Uri;
+import android.os.Bundle;
+import android.os.Handler;
+import android.view.SurfaceHolder;
+import android.view.SurfaceView;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+import android.widget.Toast;
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.AppCompatActivity;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ExoPlayer;
+import com.google.android.exoplayer2.MediaItem;
+import com.google.android.exoplayer2.transformer.ProgressHolder;
+import com.google.android.exoplayer2.transformer.TransformationException;
+import com.google.android.exoplayer2.transformer.TransformationRequest;
+import com.google.android.exoplayer2.transformer.Transformer;
+import com.google.android.exoplayer2.ui.AspectRatioFrameLayout;
+import com.google.android.exoplayer2.ui.StyledPlayerView;
+import com.google.android.exoplayer2.util.DebugTextViewHelper;
+import com.google.android.exoplayer2.util.Log;
+import com.google.android.exoplayer2.util.Util;
+import com.google.android.material.progressindicator.LinearProgressIndicator;
+import com.google.common.base.Stopwatch;
+import com.google.common.base.Ticker;
+import java.io.File;
+import java.io.IOException;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+import org.checkerframework.checker.nullness.qual.RequiresNonNull;
+
+/** An {@link Activity} that transforms and plays media using {@link Transformer}. */
+public final class TransformerActivity extends AppCompatActivity {
+  private static final String TAG = "TransformerActivity";
+
+  private @MonotonicNonNull StyledPlayerView playerView;
+  private @MonotonicNonNull TextView debugTextView;
+  private @MonotonicNonNull TextView informationTextView;
+  private @MonotonicNonNull ViewGroup progressViewGroup;
+  private @MonotonicNonNull LinearProgressIndicator progressIndicator;
+  private @MonotonicNonNull Stopwatch transformationStopwatch;
+  private @MonotonicNonNull AspectRatioFrameLayout debugFrame;
+
+  @Nullable private DebugTextViewHelper debugTextViewHelper;
+  @Nullable private ExoPlayer player;
+  @Nullable private Transformer transformer;
+  @Nullable private File externalCacheFile;
+
+  @Override
+  protected void onCreate(@Nullable Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    setContentView(R.layout.transformer_activity);
+
+    playerView = findViewById(R.id.player_view);
+    debugTextView = findViewById(R.id.debug_text_view);
+    informationTextView = findViewById(R.id.information_text_view);
+    progressViewGroup = findViewById(R.id.progress_view_group);
+    progressIndicator = findViewById(R.id.progress_indicator);
+    debugFrame = findViewById(R.id.debug_aspect_ratio_frame_layout);
+
+    transformationStopwatch =
+        Stopwatch.createUnstarted(
+            new Ticker() {
+              public long read() {
+                return android.os.SystemClock.elapsedRealtimeNanos();
+              }
+            });
+  }
+
+  @Override
+  protected void onStart() {
+    super.onStart();
+
+    checkNotNull(progressIndicator);
+    checkNotNull(informationTextView);
+    checkNotNull(transformationStopwatch);
+    checkNotNull(playerView);
+    checkNotNull(debugTextView);
+    checkNotNull(progressViewGroup);
+    startTransformation();
+
+    playerView.onResume();
+  }
+
+  @Override
+  protected void onStop() {
+    super.onStop();
+
+    checkNotNull(transformationStopwatch).reset();
+
+    checkNotNull(transformer).cancel();
+    transformer = null;
+
+    checkNotNull(playerView).onPause();
+    releasePlayer();
+
+    checkNotNull(externalCacheFile).delete();
+    externalCacheFile = null;
+  }
+
+  @RequiresNonNull({
+    "playerView",
+    "debugTextView",
+    "informationTextView",
+    "progressIndicator",
+    "transformationStopwatch",
+    "progressViewGroup",
+  })
+  private void startTransformation() {
+    requestTransformerPermissions();
+
+    Intent intent = getIntent();
+    Uri uri = checkNotNull(intent.getData());
+    try {
+      externalCacheFile = createExternalCacheFile("transformer-output.mp4");
+      String filePath = externalCacheFile.getAbsolutePath();
+      @Nullable Bundle bundle = intent.getExtras();
+      Transformer transformer = createTransformer(bundle, filePath);
+      transformationStopwatch.start();
+      transformer.startTransformation(MediaItem.fromUri(uri), filePath);
+      this.transformer = transformer;
+    } catch (IOException e) {
+      throw new IllegalStateException(e);
+    }
+    informationTextView.setText(R.string.transformation_started);
+    Handler mainHandler = new Handler(getMainLooper());
+    ProgressHolder progressHolder = new ProgressHolder();
+    mainHandler.post(
+        new Runnable() {
+          @Override
+          public void run() {
+            if (transformer != null
+                && transformer.getProgress(progressHolder)
+                    != Transformer.PROGRESS_STATE_NO_TRANSFORMATION) {
+              progressIndicator.setProgress(progressHolder.progress);
+              informationTextView.setText(
+                  getString(
+                      R.string.transformation_timer,
+                      transformationStopwatch.elapsed(TimeUnit.SECONDS)));
+              mainHandler.postDelayed(/* r= */ this, /* delayMillis= */ 500);
+            }
+          }
+        });
+  }
+
+  // Create a cache file, resetting it if it already exists.
+  private File createExternalCacheFile(String fileName) throws IOException {
+    File file = new File(getExternalCacheDir(), fileName);
+    if (file.exists() && !file.delete()) {
+      throw new IllegalStateException("Could not delete the previous transformer output file");
+    }
+    if (!file.createNewFile()) {
+      throw new IllegalStateException("Could not create the transformer output file");
+    }
+    return file;
+  }
+
+  @RequiresNonNull({
+    "playerView",
+    "debugTextView",
+    "informationTextView",
+    "transformationStopwatch",
+    "progressViewGroup",
+  })
+  private Transformer createTransformer(@Nullable Bundle bundle, String filePath) {
+    Transformer.Builder transformerBuilder = new Transformer.Builder(/* context= */ this);
+    if (bundle != null) {
+      TransformationRequest.Builder requestBuilder = new TransformationRequest.Builder();
+      requestBuilder.setFlattenForSlowMotion(
+          bundle.getBoolean(ConfigurationActivity.SHOULD_FLATTEN_FOR_SLOW_MOTION));
+      @Nullable String audioMimeType = bundle.getString(ConfigurationActivity.AUDIO_MIME_TYPE);
+      if (audioMimeType != null) {
+        requestBuilder.setAudioMimeType(audioMimeType);
+      }
+      @Nullable String videoMimeType = bundle.getString(ConfigurationActivity.VIDEO_MIME_TYPE);
+      if (videoMimeType != null) {
+        requestBuilder.setVideoMimeType(videoMimeType);
+      }
+      int resolutionHeight =
+          bundle.getInt(
+              ConfigurationActivity.RESOLUTION_HEIGHT, /* defaultValue= */ C.LENGTH_UNSET);
+      if (resolutionHeight != C.LENGTH_UNSET) {
+        requestBuilder.setResolution(resolutionHeight);
+      }
+      Matrix transformationMatrix = getTransformationMatrix(bundle);
+      if (!transformationMatrix.isIdentity()) {
+        requestBuilder.setTransformationMatrix(transformationMatrix);
+      }
+      transformerBuilder
+          .setTransformationRequest(requestBuilder.build())
+          .setRemoveAudio(bundle.getBoolean(ConfigurationActivity.SHOULD_REMOVE_AUDIO))
+          .setRemoveVideo(bundle.getBoolean(ConfigurationActivity.SHOULD_REMOVE_VIDEO));
+    }
+    return transformerBuilder
+        .addListener(
+            new Transformer.Listener() {
+              @Override
+              public void onTransformationCompleted(MediaItem mediaItem) {
+                TransformerActivity.this.onTransformationCompleted(filePath);
+              }
+
+              @Override
+              public void onTransformationError(
+                  MediaItem mediaItem, TransformationException exception) {
+                TransformerActivity.this.onTransformationError(exception);
+              }
+            })
+        .setDebugViewProvider(new DemoDebugViewProvider())
+        .build();
+  }
+
+  private static Matrix getTransformationMatrix(Bundle bundle) {
+    Matrix transformationMatrix = new Matrix();
+
+    float translateX = bundle.getFloat(ConfigurationActivity.TRANSLATE_X, /* defaultValue= */ 0);
+    float translateY = bundle.getFloat(ConfigurationActivity.TRANSLATE_Y, /* defaultValue= */ 0);
+    // TODO(b/213198690): Get resolution for aspect ratio and scale all translations' translateX
+    // by this aspect ratio.
+    transformationMatrix.postTranslate(translateX, translateY);
+
+    float scaleX = bundle.getFloat(ConfigurationActivity.SCALE_X, /* defaultValue= */ 1);
+    float scaleY = bundle.getFloat(ConfigurationActivity.SCALE_Y, /* defaultValue= */ 1);
+    transformationMatrix.postScale(scaleX, scaleY);
+
+    float rotateDegrees =
+        bundle.getFloat(ConfigurationActivity.ROTATE_DEGREES, /* defaultValue= */ 0);
+    transformationMatrix.postRotate(rotateDegrees);
+
+    return transformationMatrix;
+  }
+
+  @RequiresNonNull({
+    "informationTextView",
+    "progressViewGroup",
+    "transformationStopwatch",
+  })
+  private void onTransformationError(TransformationException exception) {
+    transformationStopwatch.stop();
+    informationTextView.setText(R.string.transformation_error);
+    progressViewGroup.setVisibility(View.GONE);
+    Toast.makeText(
+            TransformerActivity.this, "Transformation error: " + exception, Toast.LENGTH_LONG)
+        .show();
+    Log.e(TAG, "Transformation error", exception);
+  }
+
+  @RequiresNonNull({
+    "playerView",
+    "debugTextView",
+    "informationTextView",
+    "progressViewGroup",
+    "transformationStopwatch",
+  })
+  private void onTransformationCompleted(String filePath) {
+    transformationStopwatch.stop();
+    informationTextView.setText(
+        getString(
+            R.string.transformation_completed, transformationStopwatch.elapsed(TimeUnit.SECONDS)));
+    progressViewGroup.setVisibility(View.GONE);
+    playMediaItem(MediaItem.fromUri("file://" + filePath));
+    Log.d(TAG, "Output file path: file://" + filePath);
+  }
+
+  @RequiresNonNull({"playerView", "debugTextView"})
+  private void playMediaItem(MediaItem mediaItem) {
+    playerView.setPlayer(null);
+    releasePlayer();
+
+    ExoPlayer player = new ExoPlayer.Builder(/* context= */ this).build();
+    playerView.setPlayer(player);
+    player.setMediaItem(mediaItem);
+    player.play();
+    player.prepare();
+    this.player = player;
+    debugTextViewHelper = new DebugTextViewHelper(player, debugTextView);
+    debugTextViewHelper.start();
+  }
+
+  private void releasePlayer() {
+    if (debugTextViewHelper != null) {
+      debugTextViewHelper.stop();
+      debugTextViewHelper = null;
+    }
+    if (player != null) {
+      player.release();
+      player = null;
+    }
+  }
+
+  private void requestTransformerPermissions() {
+    if (Util.SDK_INT < 23) {
+      return;
+    }
+    if (checkSelfPermission(READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED
+        || checkSelfPermission(WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
+      requestPermissions(
+          new String[] {READ_EXTERNAL_STORAGE, WRITE_EXTERNAL_STORAGE}, /* requestCode= */ 0);
+    }
+  }
+
+  private final class DemoDebugViewProvider implements Transformer.DebugViewProvider {
+
+    @Nullable
+    @Override
+    public SurfaceView getDebugPreviewSurfaceView(int width, int height) {
+      // Update the UI on the main thread and wait for the output surface to be available.
+      CountDownLatch surfaceCreatedCountDownLatch = new CountDownLatch(1);
+      SurfaceView surfaceView = new SurfaceView(/* context= */ TransformerActivity.this);
+      runOnUiThread(
+          () -> {
+            AspectRatioFrameLayout debugFrame = checkNotNull(TransformerActivity.this.debugFrame);
+            debugFrame.addView(surfaceView);
+            debugFrame.setAspectRatio((float) width / height);
+            surfaceView
+                .getHolder()
+                .addCallback(
+                    new SurfaceHolder.Callback() {
+                      @Override
+                      public void surfaceCreated(SurfaceHolder surfaceHolder) {
+                        surfaceCreatedCountDownLatch.countDown();
+                      }
+
+                      @Override
+                      public void surfaceChanged(
+                          SurfaceHolder surfaceHolder, int format, int width, int height) {
+                        // Do nothing.
+                      }
+
+                      @Override
+                      public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
+                        // Do nothing.
+                      }
+                    });
+          });
+      try {
+        surfaceCreatedCountDownLatch.await();
+      } catch (InterruptedException e) {
+        Log.w(TAG, "Interrupted waiting for debug surface.");
+        Thread.currentThread().interrupt();
+        return null;
+      }
+      return surfaceView;
+    }
+  }
+}

demos/transformer/src/main/java/com/google/android/exoplayer2/transformerdemo/package-info.java

+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+@NonNullApi
+package com.google.android.exoplayer2.transformerdemo;
+
+import com.google.android.exoplayer2.util.NonNullApi;

demos/transformer/src/main/res/layout/configuration_activity.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright 2021 The Android Open Source Project
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+  xmlns:app="http://schemas.android.com/apk/res-auto"
+  xmlns:tools="http://schemas.android.com/tools"
+  android:layout_width="match_parent"
+  android:layout_height="match_parent"
+  tools:context=".ConfigurationActivity">
+
+  <TextView
+    android:id="@+id/configuration_text_view"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:layout_marginTop="24dp"
+    android:layout_marginStart="32dp"
+    android:layout_marginEnd="32dp"
+    android:text="@string/configuration"
+    android:textSize="24sp"
+    app:layout_constraintEnd_toEndOf="parent"
+    app:layout_constraintStart_toStartOf="parent"
+    app:layout_constraintTop_toTopOf="parent" />
+  <Button
+    android:id="@+id/choose_file_button"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:layout_marginTop="32dp"
+    android:layout_marginStart="32dp"
+    android:layout_marginEnd="32dp"
+    android:text="@string/choose_file_title"
+    app:layout_constraintTop_toBottomOf="@+id/configuration_text_view"
+    app:layout_constraintEnd_toEndOf="parent"
+    app:layout_constraintStart_toStartOf="parent" />
+  <TextView
+    android:id="@+id/chosen_file_text_view"
+    android:layout_width="0dp"
+    android:layout_height="wrap_content"
+    android:layout_marginTop="12dp"
+    android:layout_marginStart="32dp"
+    android:layout_marginEnd="32dp"
+    android:paddingLeft="24dp"
+    android:paddingRight="24dp"
+    android:textSize="12sp"
+    android:gravity="center"
+    app:layout_constraintEnd_toEndOf="parent"
+    app:layout_constraintStart_toStartOf="parent"
+    app:layout_constraintTop_toBottomOf="@+id/choose_file_button" />
+  <TableLayout
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:stretchColumns="1"
+    android:layout_marginTop="32dp"
+    android:layout_marginStart="32dp"
+    android:layout_marginEnd="32dp"
+    android:measureWithLargestChild="true"
+    android:paddingLeft="24dp"
+    android:paddingRight="12dp"
+    app:layout_constraintEnd_toEndOf="parent"
+    app:layout_constraintStart_toStartOf="parent"
+    app:layout_constraintTop_toBottomOf="@+id/chosen_file_text_view" >
+    <TableRow
+      android:layout_weight="1"
+      android:gravity="center_vertical" >
+      <TextView
+        android:text="@string/remove_audio" />
+      <CheckBox
+        android:id="@+id/remove_audio_checkbox"
+        android:layout_gravity="right"/>
+    </TableRow>
+    <TableRow
+      android:layout_weight="1"
+      android:gravity="center_vertical" >
+      <TextView
+        android:text="@string/remove_video"/>
+      <CheckBox
+        android:id="@+id/remove_video_checkbox"
+        android:layout_gravity="right" />
+    </TableRow>
+    <TableRow
+      android:layout_weight="1"
+      android:gravity="center_vertical" >
+      <TextView
+        android:text="@string/flatten_for_slow_motion"/>
+      <CheckBox
+        android:id="@+id/flatten_for_slow_motion_checkbox"
+        android:layout_gravity="right" />
+    </TableRow>
+    <TableRow
+      android:layout_weight="1"
+      android:gravity="center_vertical" >
+      <TextView
+        android:id="@+id/audio_mime_text_view"
+        android:text="@string/audio_mime"/>
+      <Spinner
+        android:id="@+id/audio_mime_spinner"
+        android:layout_gravity="right|center_vertical"
+        android:gravity="right" />
+    </TableRow>
+    <TableRow
+      android:layout_weight="1"
+      android:gravity="center_vertical" >
+      <TextView
+        android:id="@+id/video_mime_text_view"
+        android:text="@string/video_mime"/>
+      <Spinner
+        android:id="@+id/video_mime_spinner"
+        android:layout_gravity="right|center_vertical"
+        android:gravity="right" />
+    </TableRow>
+    <TableRow
+      android:layout_weight="1"
+      android:gravity="center_vertical" >
+      <TextView
+        android:id="@+id/resolution_height_text_view"
+        android:text="@string/resolution_height"/>
+      <Spinner
+        android:id="@+id/resolution_height_spinner"
+        android:layout_gravity="right|center_vertical"
+        android:gravity="right" />
+    </TableRow>
+    <TableRow
+      android:layout_weight="1"
+      android:gravity="center_vertical" >
+      <TextView
+        android:id="@+id/translate"
+        android:text="@string/translate"/>
+      <Spinner
+        android:id="@+id/translate_spinner"
+        android:layout_gravity="right|center_vertical"
+        android:gravity="right" />
+    </TableRow>
+    <TableRow
+      android:layout_weight="1"
+      android:gravity="center_vertical" >
+      <TextView
+        android:id="@+id/scale"
+        android:text="@string/scale"/>
+      <Spinner
+        android:id="@+id/scale_spinner"
+        android:layout_gravity="right|center_vertical"
+        android:gravity="right" />
+    </TableRow>
+    <TableRow
+      android:layout_weight="1"
+      android:gravity="center_vertical" >
+      <TextView
+        android:id="@+id/rotate"
+        android:text="@string/rotate"/>
+      <Spinner
+        android:id="@+id/rotate_spinner"
+        android:layout_gravity="right|center_vertical"
+        android:gravity="right" />
+    </TableRow>
+  </TableLayout>
+  <Button
+    android:id="@+id/transform_button"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:layout_marginBottom="28dp"
+    android:layout_marginStart="32dp"
+    android:layout_marginEnd="32dp"
+    android:text="@string/transform"
+    app:layout_constraintBottom_toBottomOf="parent"
+    app:layout_constraintEnd_toEndOf="parent"
+    app:layout_constraintStart_toStartOf="parent" />
+</androidx.constraintlayout.widget.ConstraintLayout>

demos/transformer/src/main/res/layout/spinner_item.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright 2021 The Android Open Source Project
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+<TextView
+  xmlns:android="http://schemas.android.com/apk/res/android"
+  android:layout_width="wrap_content"
+  android:layout_height="32dp"
+  android:gravity="left|center_vertical"
+  android:paddingLeft="4dp"
+  android:paddingRight="4dp"
+  android:layout_marginLeft="4dp"
+  android:layout_marginRight="4dp"
+  android:textIsSelectable="false" />

demos/transformer/src/main/res/layout/transformer_activity.xml

+<?xml version="1.0" encoding="utf-8"?><!--
+  ~ Copyright 2021 The Android Open Source Project
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+  android:layout_width="match_parent"
+  android:layout_height="match_parent"
+  xmlns:app="http://schemas.android.com/apk/res-auto"
+  xmlns:tools="http://schemas.android.com/tools"
+  android:keepScreenOn="true"
+  android:orientation="vertical">
+
+  <com.google.android.material.card.MaterialCardView
+    android:layout_margin="8dp"
+    android:layout_height="wrap_content"
+    android:layout_width="match_parent"
+    app:cardCornerRadius="4dp"
+    app:cardElevation="2dp"
+    android:gravity="center_vertical" >
+
+    <TextView
+      android:id="@+id/information_text_view"
+      android:layout_width="wrap_content"
+      android:layout_height="match_parent"
+      android:orientation="vertical"
+      android:paddingLeft="8dp"
+      android:paddingRight="8dp"
+      android:paddingTop="8dp"
+      android:paddingBottom="8dp" />
+
+  </com.google.android.material.card.MaterialCardView>
+
+  <com.google.android.material.card.MaterialCardView
+    android:layout_width="match_parent"
+    android:layout_height="0dp"
+    android:layout_weight="1"
+    android:layout_margin="16dp"
+    app:cardCornerRadius="4dp"
+    app:cardElevation="2dp">
+      <FrameLayout
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <com.google.android.exoplayer2.ui.StyledPlayerView
+          android:id="@+id/player_view"
+          android:layout_width="match_parent"
+          android:layout_height="match_parent" />
+
+        <TextView
+          android:id="@+id/debug_text_view"
+          android:layout_width="match_parent"
+          android:layout_height="wrap_content"
+          android:paddingLeft="4dp"
+          android:paddingRight="4dp"
+          android:textSize="10sp"
+          tools:ignore="SmallSp"/>
+
+        <LinearLayout
+          android:id="@+id/progress_view_group"
+          android:layout_height="match_parent"
+          android:layout_width="match_parent"
+          android:orientation="vertical">
+
+          <com.google.android.material.progressindicator.LinearProgressIndicator
+            android:id="@+id/progress_indicator"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:paddingLeft="16dp"
+            android:paddingRight="16dp"
+            android:paddingTop="16dp"
+            android:paddingBottom="16dp"
+            android:layout_gravity="center" />
+
+          <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="@string/debug_preview" />
+
+          <com.google.android.exoplayer2.ui.AspectRatioFrameLayout
+            android:id="@+id/debug_aspect_ratio_frame_layout"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:paddingTop="16dp">
+
+            <TextView
+              android:layout_width="match_parent"
+              android:layout_height="wrap_content"
+              android:text="@string/debug_preview_not_available" />
+
+          </com.google.android.exoplayer2.ui.AspectRatioFrameLayout>
+
+        </LinearLayout>
+
+      </FrameLayout>
+  </com.google.android.material.card.MaterialCardView>
+</LinearLayout>

demos/transformer/src/main/res/values/strings.xml

+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright 2021 The Android Open Source Project
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
+  <string name="app_name" translatable="false">Transformer Demo</string>
+  <string name="configuration" translatable="false">Configuration</string>
+  <string name="choose_file_title" translatable="false">Choose File</string>
+  <string name="remove_audio" translatable="false">Remove audio</string>
+  <string name="remove_video" translatable="false">Remove video</string>
+  <string name="flatten_for_slow_motion" translatable="false">Flatten for slow motion</string>
+  <string name="audio_mime" translatable="false">Output audio MIME type</string>
+  <string name="video_mime" translatable="false">Output video MIME type</string>
+  <string name="resolution_height" translatable="false">Output video resolution</string>
+  <string name="translate" translatable="false">Translate video</string>
+  <string name="scale" translatable="false">Scale video</string>
+  <string name="rotate" translatable="false">Rotate video (degrees)</string>
+  <string name="transform" translatable="false">Transform</string>
+  <string name="debug_preview" translatable="false">Debug preview:</string>
+  <string name="debug_preview_not_available" translatable="false">No debug preview available</string>
+  <string name="transformation_started" translatable="false">Transformation started</string>
+  <string name="transformation_timer" translatable="false">Transformation started %d seconds ago.</string>
+  <string name="transformation_completed" translatable="false">Transformation completed in %d seconds.</string>
+  <string name="transformation_error" translatable="false">Transformation error</string>
+</resources>

settings.gradle

@@ -26,6 +26,8 @@ include modulePrefix + 'demo-gl'
 project(modulePrefix + 'demo-gl').projectDir = new File(rootDir, 'demos/gl')
 include modulePrefix + 'demo-surface'
 project(modulePrefix + 'demo-surface').projectDir = new File(rootDir, 'demos/surface')
+include modulePrefix + 'demo-transformer'
+project(modulePrefix + 'demo-transformer').projectDir = new File(rootDir, 'demos/transformer')
 
 include modulePrefix + 'playbacktests'
 project(modulePrefix + 'playbacktests').projectDir = new File(rootDir, 'playbacktests')