Cast: Add JSON serialization/deserialization for MediaItem

This will allow the Cast extension to reconstruct MediaItems from MediaQueueItems
obtained from the receiver's queue.

PiperOrigin-RevId: 260554381

extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/DefaultMediaItemConverter.java

@@ -15,41 +15,132 @@
  */
 package com.google.android.exoplayer2.ext.cast;
 
+import android.net.Uri;
+import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ext.cast.MediaItem.DrmConfiguration;
 import com.google.android.gms.cast.MediaInfo;
 import com.google.android.gms.cast.MediaMetadata;
 import com.google.android.gms.cast.MediaQueueItem;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.UUID;
 import org.json.JSONException;
 import org.json.JSONObject;
 
 /** Default {@link MediaItemConverter} implementation. */
 public final class DefaultMediaItemConverter implements MediaItemConverter {
 
+  private static final String KEY_MEDIA_ITEM = "mediaItem";
+  private static final String KEY_PLAYER_CONFIG = "exoPlayerConfig";
+  private static final String KEY_URI = "uri";
+  private static final String KEY_TITLE = "title";
+  private static final String KEY_MIME_TYPE = "mimeType";
+  private static final String KEY_DRM_CONFIGURATION = "drmConfiguration";
+  private static final String KEY_UUID = "uuid";
+  private static final String KEY_LICENSE_URI = "licenseUri";
+  private static final String KEY_REQUEST_HEADERS = "requestHeaders";
+
+  @Override
+  public MediaItem toMediaItem(MediaQueueItem item) {
+    return getMediaItem(item.getMedia().getCustomData());
+  }
+
   @Override
   public MediaQueueItem toMediaQueueItem(MediaItem item) {
     if (item.mimeType == null) {
       throw new IllegalArgumentException("The item must specify its mimeType");
     }
-    MediaMetadata movieMetadata = new MediaMetadata(MediaMetadata.MEDIA_TYPE_MOVIE);
+    MediaMetadata metadata = new MediaMetadata(MediaMetadata.MEDIA_TYPE_MOVIE);
     if (item.title != null) {
-      movieMetadata.putString(MediaMetadata.KEY_TITLE, item.title);
+      metadata.putString(MediaMetadata.KEY_TITLE, item.title);
     }
     MediaInfo mediaInfo =
         new MediaInfo.Builder(item.uri.toString())
             .setStreamType(MediaInfo.STREAM_TYPE_BUFFERED)
             .setContentType(item.mimeType)
-            .setMetadata(movieMetadata)
+            .setMetadata(metadata)
             .setCustomData(getCustomData(item))
             .build();
     return new MediaQueueItem.Builder(mediaInfo).build();
   }
 
-  private static JSONObject getCustomData(MediaItem item) {
-    JSONObject customData = new JSONObject();
+  // Deserialization.
 
-    MediaItem.DrmConfiguration drmConfiguration = item.drmConfiguration;
+  private static MediaItem getMediaItem(JSONObject customData) {
+    try {
+      JSONObject mediaItemJson = customData.getJSONObject(KEY_MEDIA_ITEM);
+      MediaItem.Builder builder = new MediaItem.Builder();
+      builder.setUri(Uri.parse(mediaItemJson.getString(KEY_URI)));
+      if (mediaItemJson.has(KEY_TITLE)) {
+        builder.setTitle(mediaItemJson.getString(KEY_TITLE));
+      }
+      if (mediaItemJson.has(KEY_MIME_TYPE)) {
+        builder.setMimeType(mediaItemJson.getString(KEY_MIME_TYPE));
+      }
+      if (mediaItemJson.has(KEY_DRM_CONFIGURATION)) {
+        builder.setDrmConfiguration(
+            getDrmConfiguration(mediaItemJson.getJSONObject(KEY_DRM_CONFIGURATION)));
+      }
+      return builder.build();
+    } catch (JSONException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  private static DrmConfiguration getDrmConfiguration(JSONObject json) throws JSONException {
+    UUID uuid = UUID.fromString(json.getString(KEY_UUID));
+    Uri licenseUri = Uri.parse(json.getString(KEY_LICENSE_URI));
+    JSONObject requestHeadersJson = json.getJSONObject(KEY_REQUEST_HEADERS);
+    HashMap<String, String> requestHeaders = new HashMap<>();
+    for (Iterator<String> iterator = requestHeadersJson.keys(); iterator.hasNext(); ) {
+      String key = iterator.next();
+      requestHeaders.put(key, requestHeadersJson.getString(key));
+    }
+    return new DrmConfiguration(uuid, licenseUri, requestHeaders);
+  }
+
+  // Serialization.
+
+  private static JSONObject getCustomData(MediaItem item) {
+    JSONObject json = new JSONObject();
+    try {
+      json.put(KEY_MEDIA_ITEM, getMediaItemJson(item));
+      JSONObject playerConfigJson = getPlayerConfigJson(item);
+      if (playerConfigJson != null) {
+        json.put(KEY_PLAYER_CONFIG, playerConfigJson);
+      }
+    } catch (JSONException e) {
+      throw new RuntimeException(e);
+    }
+    return json;
+  }
+
+  private static JSONObject getMediaItemJson(MediaItem item) throws JSONException {
+    JSONObject json = new JSONObject();
+    json.put(KEY_URI, item.uri.toString());
+    json.put(KEY_TITLE, item.title);
+    json.put(KEY_MIME_TYPE, item.mimeType);
+    if (item.drmConfiguration != null) {
+      json.put(KEY_DRM_CONFIGURATION, getDrmConfigurationJson(item.drmConfiguration));
+    }
+    return json;
+  }
+
+  private static JSONObject getDrmConfigurationJson(DrmConfiguration drmConfiguration)
+      throws JSONException {
+    JSONObject json = new JSONObject();
+    json.put(KEY_UUID, drmConfiguration.uuid);
+    json.put(KEY_LICENSE_URI, drmConfiguration.licenseUri);
+    json.put(KEY_REQUEST_HEADERS, new JSONObject(drmConfiguration.requestHeaders));
+    return json;
+  }
+
+  @Nullable
+  private static JSONObject getPlayerConfigJson(MediaItem item) throws JSONException {
+    DrmConfiguration drmConfiguration = item.drmConfiguration;
     if (drmConfiguration == null) {
-      return customData;
+      return null;
     }
 
     String drmScheme;
@@ -58,24 +149,19 @@ public final class DefaultMediaItemConverter implements MediaItemConverter {
     } else if (C.PLAYREADY_UUID.equals(drmConfiguration.uuid)) {
       drmScheme = "playready";
     } else {
-      return customData;
+      return null;
     }
 
-    JSONObject exoPlayerConfig = new JSONObject();
-    try {
-      exoPlayerConfig.put("withCredentials", false);
-      exoPlayerConfig.put("protectionSystem", drmScheme);
-      if (drmConfiguration.licenseUri != null) {
-        exoPlayerConfig.put("licenseUrl", drmConfiguration.licenseUri);
-      }
-      if (!drmConfiguration.requestHeaders.isEmpty()) {
-        exoPlayerConfig.put("headers", new JSONObject(drmConfiguration.requestHeaders));
-      }
-      customData.put("exoPlayerConfig", exoPlayerConfig);
-    } catch (JSONException e) {
-      throw new RuntimeException(e);
+    JSONObject exoPlayerConfigJson = new JSONObject();
+    exoPlayerConfigJson.put("withCredentials", false);
+    exoPlayerConfigJson.put("protectionSystem", drmScheme);
+    if (drmConfiguration.licenseUri != null) {
+      exoPlayerConfigJson.put("licenseUrl", drmConfiguration.licenseUri);
+    }
+    if (!drmConfiguration.requestHeaders.isEmpty()) {
+      exoPlayerConfigJson.put("headers", new JSONObject(drmConfiguration.requestHeaders));
     }
 
-    return customData;
+    return exoPlayerConfigJson;
   }
 }

extensions/cast/src/main/java/com/google/android/exoplayer2/ext/cast/MediaItemConverter.java

@@ -28,5 +28,11 @@ public interface MediaItemConverter {
    */
   MediaQueueItem toMediaQueueItem(MediaItem mediaItem);
 
-  // TODO: Add toMediaItem to convert in the opposite direction.
+  /**
+   * Converts a {@link MediaQueueItem} to a {@link MediaItem}.
+   *
+   * @param mediaQueueItem The {@link MediaQueueItem}.
+   * @return The equivalent {@link MediaItem}.
+   */
+  MediaItem toMediaItem(MediaQueueItem mediaQueueItem);
 }

extensions/cast/src/test/java/com/google/android/exoplayer2/ext/cast/DefaultMediaItemConverterTest.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.ext.cast;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.net.Uri;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.ext.cast.MediaItem.DrmConfiguration;
+import com.google.android.gms.cast.MediaQueueItem;
+import java.util.Collections;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Test for {@link DefaultMediaItemConverter}. */
+@RunWith(AndroidJUnit4.class)
+public class DefaultMediaItemConverterTest {
+
+  @Test
+  public void serialize_deserialize_minimal() {
+    MediaItem.Builder builder = new MediaItem.Builder();
+    MediaItem item = builder.setUri(Uri.parse("http://example.com")).setMimeType("mime").build();
+
+    DefaultMediaItemConverter converter = new DefaultMediaItemConverter();
+    MediaQueueItem queueItem = converter.toMediaQueueItem(item);
+    MediaItem reconstructedItem = converter.toMediaItem(queueItem);
+
+    assertThat(reconstructedItem).isEqualTo(item);
+  }
+
+  @Test
+  public void serialize_deserialize_complete() {
+    MediaItem.Builder builder = new MediaItem.Builder();
+    MediaItem item =
+        builder
+            .setUri(Uri.parse("http://example.com"))
+            .setTitle("title")
+            .setMimeType("mime")
+            .setDrmConfiguration(
+                new DrmConfiguration(
+                    C.WIDEVINE_UUID,
+                    Uri.parse("http://license.com"),
+                    Collections.singletonMap("key", "value")))
+            .build();
+
+    DefaultMediaItemConverter converter = new DefaultMediaItemConverter();
+    MediaQueueItem queueItem = converter.toMediaQueueItem(item);
+    MediaItem reconstructedItem = converter.toMediaItem(queueItem);
+
+    assertThat(reconstructedItem).isEqualTo(item);
+  }
+}