Propagate DRM config when creating ad media sources

The `DrmConfiguration.sessionForClearTypes` property is often used
to ensure a secure decoder is used for clear ads played in encrypted
content. This is because some devices show black frames when switching
decoders.

Before this change the DRM config isn't propagated down when
constructing the ad media source, meaning
`DrmSessionManager.DRM_UNSUPPORTED` is always used, which will
cause playback to switch from secure to clear decoder when transitioning
to an ad break (ignoring the MediaItem `sessionForClearTypes` option.

Issue: #8568

PiperOrigin-RevId: 356951124

RELEASENOTES.md

@@ -21,6 +21,8 @@
     *   Re-use the previous `DrmSessionManager` instance when playing a playlist
         (if possible)
         ([#8523](https://github.com/google/ExoPlayer/issues/8523)).
+    *   Propagate DRM configuration when creating media sources for ad content
+        ([#8568](https://github.com/google/ExoPlayer/issues/8568)).
 
 ### 2.13.0 (2021-02-04)
 

library/core/src/main/java/com/google/android/exoplayer2/source/ads/AdsMediaSource.java

@@ -318,8 +318,28 @@ public final class AdsMediaSource extends CompositeMediaSource<MediaPeriodId> {
             && adIndexInAdGroup < adPlaybackState.adGroups[adGroupIndex].uris.length) {
           @Nullable Uri adUri = adPlaybackState.adGroups[adGroupIndex].uris[adIndexInAdGroup];
           if (adUri != null) {
-            MediaSource adMediaSource =
-                adMediaSourceFactory.createMediaSource(MediaItem.fromUri(adUri));
+            MediaItem.Builder adMediaItem = new MediaItem.Builder().setUri(adUri);
+            // Propagate the content's DRM config into the ad media source.
+            @Nullable
+            MediaItem.PlaybackProperties contentPlaybackProperties =
+                contentMediaSource.getMediaItem().playbackProperties;
+            if (contentPlaybackProperties != null
+                && contentPlaybackProperties.drmConfiguration != null) {
+              MediaItem.DrmConfiguration drmConfiguration =
+                  contentPlaybackProperties.drmConfiguration;
+              // TODO(internal b/179984779): Use MediaItem.Builder#setDrmConfiguration() when it's
+              // available.
+              adMediaItem.setDrmUuid(drmConfiguration.uuid);
+              adMediaItem.setDrmKeySetId(drmConfiguration.getKeySetId());
+              adMediaItem.setDrmLicenseUri(drmConfiguration.licenseUri);
+              adMediaItem.setDrmForceDefaultLicenseUri(drmConfiguration.forceDefaultLicenseUri);
+              adMediaItem.setDrmLicenseRequestHeaders(drmConfiguration.requestHeaders);
+              adMediaItem.setDrmMultiSession(drmConfiguration.multiSession);
+              adMediaItem.setDrmPlayClearContentWithoutKey(
+                  drmConfiguration.playClearContentWithoutKey);
+              adMediaItem.setDrmSessionForClearTypes(drmConfiguration.sessionForClearTypes);
+            }
+            MediaSource adMediaSource = adMediaSourceFactory.createMediaSource(adMediaItem.build());
             adMediaSourceHolder.initializeWithMediaSource(adMediaSource, adUri);
           }
         }