Implement acquirePlaceholderSession in DefaultDrmSessionManager

Issue:#4867
PiperOrigin-RevId: 268497377

library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSessionManager.java

@@ -93,11 +93,13 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto>
   @Nullable private final HashMap<String, String> optionalKeyRequestParameters;
   private final EventDispatcher<DefaultDrmSessionEventListener> eventDispatcher;
   private final boolean multiSession;
+  private final boolean allowPlaceholderSessions;
   private final LoadErrorHandlingPolicy loadErrorHandlingPolicy;
 
   private final List<DefaultDrmSession<T>> sessions;
   private final List<DefaultDrmSession<T>> provisioningSessions;
 
+  @Nullable private DefaultDrmSession<T> placeholderDrmSession;
   @Nullable private Looper playbackLooper;
   private int mode;
   @Nullable private byte[] offlineLicenseKeySetId;
@@ -232,6 +234,7 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto>
         callback,
         optionalKeyRequestParameters,
         multiSession,
+        /* allowPlaceholderSessions= */ false,
         new DefaultLoadErrorHandlingPolicy(initialDrmRequestRetryCount));
   }
 
@@ -241,6 +244,7 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto>
       MediaDrmCallback callback,
       @Nullable HashMap<String, String> optionalKeyRequestParameters,
       boolean multiSession,
+      boolean allowPlaceholderSessions,
       LoadErrorHandlingPolicy loadErrorHandlingPolicy) {
     Assertions.checkNotNull(uuid);
     Assertions.checkNotNull(mediaDrm);
@@ -251,6 +255,11 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto>
     this.optionalKeyRequestParameters = optionalKeyRequestParameters;
     this.eventDispatcher = new EventDispatcher<>();
     this.multiSession = multiSession;
+    boolean canAcquirePlaceholderSessions =
+        !FrameworkMediaCrypto.class.equals(mediaDrm.getExoMediaCryptoType())
+            || !FrameworkMediaCrypto.WORKAROUND_DEVICE_NEEDS_KEYS_TO_CONFIGURE_CODEC;
+    // TODO: Allow customization once this class has a Builder.
+    this.allowPlaceholderSessions = canAcquirePlaceholderSessions && allowPlaceholderSessions;
     this.loadErrorHandlingPolicy = loadErrorHandlingPolicy;
     mode = MODE_PLAYBACK;
     sessions = new ArrayList<>();
@@ -398,15 +407,26 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto>
     return true;
   }
 
+  @Override
+  @Nullable
+  public DrmSession<T> acquirePlaceholderSession(Looper playbackLooper) {
+    if (!allowPlaceholderSessions) {
+      return null;
+    }
+    maybeCreateMediaDrmHandler(playbackLooper);
+    if (placeholderDrmSession == null) {
+      DefaultDrmSession<T> placeholderDrmSession =
+          createNewDefaultSession(/* schemeDatas= */ null, /* isPlaceholderSession= */ true);
+      sessions.add(placeholderDrmSession);
+      this.placeholderDrmSession = placeholderDrmSession;
+    }
+    placeholderDrmSession.acquireReference();
+    return placeholderDrmSession;
+  }
+
   @Override
   public DrmSession<T> acquireSession(Looper playbackLooper, DrmInitData drmInitData) {
-    Assertions.checkState(this.playbackLooper == null || this.playbackLooper == playbackLooper);
-    if (sessions.isEmpty()) {
-      this.playbackLooper = playbackLooper;
-      if (mediaDrmHandler == null) {
-        mediaDrmHandler = new MediaDrmHandler(playbackLooper);
-      }
-    }
+    maybeCreateMediaDrmHandler(playbackLooper);
 
     List<SchemeData> schemeDatas = null;
     if (offlineLicenseKeySetId == null) {
@@ -434,25 +454,39 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto>
 
     if (session == null) {
       // Create a new session.
-      session =
-          new DefaultDrmSession<>(
+      session = createNewDefaultSession(schemeDatas, /* isPlaceholderSession= */ false);
+      sessions.add(session);
+    }
+    session.acquireReference();
+    return session;
+  }
+
+  private DefaultDrmSession<T> createNewDefaultSession(
+      @Nullable List<SchemeData> schemeDatas, boolean isPlaceholderSession) {
+    return new DefaultDrmSession<>(
         uuid,
         mediaDrm,
         /* provisioningManager= */ this,
         /* releaseCallback= */ this::onSessionReleased,
         schemeDatas,
         mode,
-              /* isPlaceholderSession= */ false,
+        isPlaceholderSession,
         offlineLicenseKeySetId,
         optionalKeyRequestParameters,
         callback,
-              playbackLooper,
+        Assertions.checkNotNull(playbackLooper),
         eventDispatcher,
         loadErrorHandlingPolicy);
-      sessions.add(session);
   }
-    session.acquireReference();
-    return session;
+
+  private void maybeCreateMediaDrmHandler(Looper playbackLooper) {
+    Assertions.checkState(this.playbackLooper == null || this.playbackLooper == playbackLooper);
+    if (sessions.isEmpty()) {
+      this.playbackLooper = playbackLooper;
+      if (mediaDrmHandler == null) {
+        mediaDrmHandler = new MediaDrmHandler(playbackLooper);
+      }
+    }
   }
 
   @Override
@@ -496,6 +530,9 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto>
 
   private void onSessionReleased(DefaultDrmSession<T> drmSession) {
     sessions.remove(drmSession);
+    if (placeholderDrmSession == drmSession) {
+      placeholderDrmSession = null;
+    }
     if (provisioningSessions.size() > 1 && provisioningSessions.get(0) == drmSession) {
       // Other sessions were waiting for the released session to complete a provision operation.
       // We need to have one of those sessions perform the provision operation instead.

library/core/src/main/java/com/google/android/exoplayer2/drm/FrameworkMediaCrypto.java

@@ -16,6 +16,7 @@
 package com.google.android.exoplayer2.drm;
 
 import android.media.MediaCrypto;
+import com.google.android.exoplayer2.util.Util;
 import java.util.UUID;
 
 /**
@@ -24,6 +25,15 @@ import java.util.UUID;
  */
 public final class FrameworkMediaCrypto implements ExoMediaCrypto {
 
+  /**
+   * Whether the device needs keys to have been loaded into the {@link DrmSession} before codec
+   * configuration.
+   */
+  public static final boolean WORKAROUND_DEVICE_NEEDS_KEYS_TO_CONFIGURE_CODEC =
+      "Amazon".equals(Util.MANUFACTURER)
+          && ("AFTM".equals(Util.MODEL) // Fire TV Stick Gen 1
+              || "AFTB".equals(Util.MODEL)); // Fire TV Gen 1
+
   /** The DRM scheme UUID. */
   public final UUID uuid;
   /** The DRM session id. */

library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecRenderer.java

@@ -521,7 +521,7 @@ public abstract class MediaCodecRenderer extends BaseRenderer {
                   && mediaCrypto.requiresSecureDecoderComponent(mimeType);
         }
       }
-      if (deviceNeedsDrmKeysToConfigureCodecWorkaround()) {
+      if (FrameworkMediaCrypto.WORKAROUND_DEVICE_NEEDS_KEYS_TO_CONFIGURE_CODEC) {
         @DrmSession.State int drmSessionState = codecDrmSession.getState();
         if (drmSessionState == DrmSession.STATE_ERROR) {
           throw ExoPlaybackException.createForRenderer(codecDrmSession.getError(), getIndex());
@@ -1754,16 +1754,6 @@ public abstract class MediaCodecRenderer extends BaseRenderer {
     return error instanceof MediaCodec.CodecException;
   }
 
-  /**
-   * Returns whether the device needs keys to have been loaded into the {@link DrmSession} before
-   * codec configuration.
-   */
-  private boolean deviceNeedsDrmKeysToConfigureCodecWorkaround() {
-    return "Amazon".equals(Util.MANUFACTURER)
-        && ("AFTM".equals(Util.MODEL) // Fire TV Stick Gen 1
-            || "AFTB".equals(Util.MODEL)); // Fire TV Gen 1
-  }
-
   /**
    * Returns whether the decoder is known to fail when flushed.
    * <p>