Do not drop decoder input buffers close to a reset position

This is a workaround for a bug where the positionUs seen by
MCVR jumps when audio pre-roll samples are discarded.

PiperOrigin-RevId: 743538208
(cherry picked from commit 036bed36326130294f50264659913bdcecb4c9bc)

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/video/MediaCodecVideoRenderer.java

@@ -149,6 +149,17 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer
    */
   private static final long OFFSET_FROM_PERIOD_END_TO_TREAT_AS_LAST_US = 100_000L;
 
+  /**
+   * The offset from {@link #getLastResetPositionUs()} in microseconds, before which input buffers
+   * are not allowed to be dropped.
+   *
+   * <p>This value must be greater than the pre-roll distance used by common audio codecs, such as
+   * 80ms used by Opus <a
+   * href="https://opus-codec.org/docs/opus_in_isobmff.html#4.3.6.2">Encapsulation of Opus in ISO
+   * Base Media File Format</a>
+   */
+  private static final long OFFSET_FROM_RESET_POSITION_TO_ALLOW_INPUT_BUFFER_DROPPING_US = 200_000L;
+
   /**
    * The maximum number of consecutive dropped input buffers that allow discarding frame headers.
    *
@@ -616,7 +627,16 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer
       boolean treatDroppedBuffersAsSkipped)
       throws ExoPlaybackException {
     if (minEarlyUsToDropDecoderInput != C.TIME_UNSET) {
-      shouldDropDecoderInputBuffers = earlyUs < minEarlyUsToDropDecoderInput;
+      // TODO: b/161996553 - Remove the isAwayFromLastResetPosition check when audio pre-rolling
+      // is implemented correctly. Audio codecs such as Opus require pre-roll samples to be decoded
+      // and discarded on a seek. Depending on the audio decoder, the positionUs may jump forward
+      // by the pre-roll duration. Do not drop more frames than necessary when this happens.
+      boolean isAwayFromLastResetPosition =
+          positionUs
+              > getLastResetPositionUs()
+                  + OFFSET_FROM_RESET_POSITION_TO_ALLOW_INPUT_BUFFER_DROPPING_US;
+      shouldDropDecoderInputBuffers =
+          isAwayFromLastResetPosition && earlyUs < minEarlyUsToDropDecoderInput;
     }
     return shouldDropBuffersToKeyframe(earlyUs, elapsedRealtimeUs, isLastFrame)
         && maybeDropBuffersToKeyframe(positionUs, treatDroppedBuffersAsSkipped);

libraries/exoplayer/src/test/java/androidx/media3/exoplayer/e2etest/ParseAv1SampleDependenciesPlaybackTest.java

@@ -29,6 +29,7 @@ import androidx.media3.exoplayer.DecoderCounters;
 import androidx.media3.exoplayer.DefaultRenderersFactory;
 import androidx.media3.exoplayer.ExoPlayer;
 import androidx.media3.exoplayer.Renderer;
+import androidx.media3.exoplayer.analytics.AnalyticsListener;
 import androidx.media3.exoplayer.audio.AudioRendererEventListener;
 import androidx.media3.exoplayer.mediacodec.MediaCodecAdapter;
 import androidx.media3.exoplayer.mediacodec.MediaCodecSelector;
@@ -103,6 +104,14 @@ public class ParseAv1SampleDependenciesPlaybackTest {
         new ExoPlayer.Builder(applicationContext, renderersFactory)
             .setClock(new FakeClock(/* isAutoAdvancing= */ true))
             .build();
+    player.addAnalyticsListener(
+        new AnalyticsListener() {
+          @Override
+          public void onDroppedVideoFrames(EventTime eventTime, int droppedFrames, long elapsedMs) {
+            // Input buffers near the reset position should not be dropped.
+            assertThat(eventTime.currentPlaybackPositionMs).isAtLeast(200);
+          }
+        });
     Surface surface = new Surface(new SurfaceTexture(/* texName= */ 1));
     player.setVideoSurface(surface);
     player.setMediaItem(MediaItem.fromUri(TEST_MP4_URI));
@@ -121,7 +130,7 @@ public class ParseAv1SampleDependenciesPlaybackTest {
     // Which input buffer is dropped first depends on the number of MediaCodec buffer slots.
     // This means the asserts cannot be isEqualTo.
     assertThat(decoderCounters.maxConsecutiveDroppedBufferCount).isAtMost(2);
-    assertThat(decoderCounters.droppedInputBufferCount).isAtLeast(8);
+    assertThat(decoderCounters.droppedInputBufferCount).isAtLeast(4);
   }
 
   private static final class CapturingRenderersFactoryWithLateThresholdToDropDecoderInputUs
@@ -155,7 +164,6 @@ public class ParseAv1SampleDependenciesPlaybackTest {
             /* enableDecoderFallback= */ false,
             eventHandler,
             videoRendererEventListener,
-            DefaultRenderersFactory.MAX_DROPPED_VIDEO_FRAME_COUNT_TO_NOTIFY,
             /* parseAv1SampleDependencies= */ true,
             /* lateThresholdToDropDecoderInputUs= */ -100_000_000L)
       };
@@ -173,7 +181,6 @@ public class ParseAv1SampleDependenciesPlaybackTest {
           boolean enableDecoderFallback,
           @Nullable Handler eventHandler,
           @Nullable VideoRendererEventListener eventListener,
-          int maxDroppedFramesToNotify,
           boolean parseAv1SampleDependencies,
           long lateThresholdToDropDecoderInputUs) {
         super(
@@ -184,7 +191,7 @@ public class ParseAv1SampleDependenciesPlaybackTest {
                 .setEnableDecoderFallback(enableDecoderFallback)
                 .setEventHandler(eventHandler)
                 .setEventListener(eventListener)
-                .setMaxDroppedFramesToNotify(maxDroppedFramesToNotify)
+                .setMaxDroppedFramesToNotify(1)
                 .experimentalSetParseAv1SampleDependencies(parseAv1SampleDependencies)
                 .experimentalSetLateThresholdToDropDecoderInputUs(
                     lateThresholdToDropDecoderInputUs));