Support tunneling in video renderer

At this point the renderers all have TODOs in enable(),
and turning on tunneling is reduced to the problem of
propagating a tunneling ID to these points.

Issue: #1688

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=144619393

library/src/main/java/com/google/android/exoplayer2/C.java

@@ -15,6 +15,8 @@
  */
 package com.google.android.exoplayer2;
 
+import android.annotation.TargetApi;
+import android.content.Context;
 import android.media.AudioFormat;
 import android.media.AudioManager;
 import android.media.MediaCodec;
@@ -550,4 +552,13 @@ public final class C {
     return timeMs == TIME_UNSET ? TIME_UNSET : (timeMs * 1000);
   }
 
+  /**
+   * Returns a newly generated {@link android.media.AudioTrack} session identifier.
+   */
+  @TargetApi(21)
+  public static int generateAudioSessionIdV21(Context context) {
+    return ((AudioManager) context.getSystemService(Context.AUDIO_SERVICE))
+        .generateAudioSessionId();
+  }
+
 }

library/src/main/java/com/google/android/exoplayer2/video/MediaCodecVideoRenderer.java

@@ -19,6 +19,7 @@ import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 import android.content.Context;
 import android.media.MediaCodec;
+import android.media.MediaCodecInfo.CodecCapabilities;
 import android.media.MediaCrypto;
 import android.media.MediaFormat;
 import android.os.Handler;
@@ -28,6 +29,7 @@ import android.view.Surface;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ExoPlaybackException;
 import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.decoder.DecoderInputBuffer;
 import com.google.android.exoplayer2.drm.DrmInitData;
 import com.google.android.exoplayer2.drm.DrmSessionManager;
 import com.google.android.exoplayer2.drm.FrameworkMediaCrypto;
@@ -83,6 +85,10 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
   private int lastReportedUnappliedRotationDegrees;
   private float lastReportedPixelWidthHeightRatio;
 
+  private boolean tunneling;
+  private int tunnelingAudioSessionId;
+  /* package */ OnFrameRenderedListenerV23 tunnelingOnFrameRenderedListener;
+
   /**
    * @param context A context.
    * @param mediaCodecSelector A decoder selector.
@@ -204,6 +210,9 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
   @Override
   protected void onEnabled(boolean joining) throws ExoPlaybackException {
     super.onEnabled(joining);
+    // TODO: Allow this to be set.
+    tunnelingAudioSessionId = C.AUDIO_SESSION_ID_UNSET;
+    tunneling = tunnelingAudioSessionId != C.AUDIO_SESSION_ID_UNSET;
     eventDispatcher.enabled(decoderCounters);
     frameReleaseTimeHelper.enable();
   }
@@ -217,7 +226,7 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
   @Override
   protected void onPositionReset(long positionUs, boolean joining) throws ExoPlaybackException {
     super.onPositionReset(positionUs, joining);
-    renderedFirstFrame = false;
+    clearRenderedFirstFrame();
     consecutiveDroppedFrameCount = 0;
     joiningDeadlineMs = joining && allowedJoiningTimeMs > 0
         ? (SystemClock.elapsedRealtime() + allowedJoiningTimeMs) : C.TIME_UNSET;
@@ -264,6 +273,7 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
     pendingPixelWidthHeightRatio = Format.NO_VALUE;
     clearLastReportedVideoSize();
     frameReleaseTimeHelper.disable();
+    tunnelingOnFrameRenderedListener = null;
     try {
       super.onDisabled();
     } finally {
@@ -288,11 +298,7 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
   }
 
   private void setSurface(Surface surface) throws ExoPlaybackException {
-    // Clear state so that we always call the event listener with the video size and when a frame
+    // We only need to release and reinitialize the codec if the surface has changed.
-    // is rendered, even if the surface hasn't changed.
-    renderedFirstFrame = false;
-    clearLastReportedVideoSize();
-    // We only need to actually release and reinitialize the codec if the surface has changed.
     if (this.surface != surface) {
       this.surface = surface;
       int state = getState();
@@ -301,6 +307,10 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
         maybeInitCodec();
       }
     }
+    // Clear state so that we always call the event listener with the video size and when a frame
+    // is rendered, even if the surface hasn't changed.
+    clearRenderedFirstFrame();
+    clearLastReportedVideoSize();
   }
 
   @Override
@@ -311,8 +321,12 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
   @Override
   protected void configureCodec(MediaCodec codec, Format format, MediaCrypto crypto) {
     codecMaxValues = getCodecMaxValues(format, streamFormats);
-    MediaFormat mediaFormat = getMediaFormat(format, codecMaxValues, deviceNeedsAutoFrcWorkaround);
+    MediaFormat mediaFormat = getMediaFormat(format, codecMaxValues, deviceNeedsAutoFrcWorkaround,
+        tunnelingAudioSessionId);
     codec.configure(mediaFormat, surface, crypto, 0);
+    if (Util.SDK_INT >= 23 && tunneling) {
+      tunnelingOnFrameRenderedListener = new OnFrameRenderedListenerV23(codec);
+    }
   }
 
   @Override
@@ -329,6 +343,13 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
     pendingRotationDegrees = getRotationDegrees(newFormat);
   }
 
+  @Override
+  protected void onQueueInputBuffer(DecoderInputBuffer buffer) {
+    if (Util.SDK_INT < 23 && tunneling) {
+      maybeNotifyRenderedFirstFrame();
+    }
+  }
+
   @Override
   protected void onOutputFormatChanged(MediaCodec codec, android.media.MediaFormat outputFormat) {
     boolean hasCrop = outputFormat.containsKey(KEY_CROP_RIGHT)
@@ -479,10 +500,7 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
     TraceUtil.endSection();
     decoderCounters.renderedOutputBufferCount++;
     consecutiveDroppedFrameCount = 0;
-    if (!renderedFirstFrame) {
+    maybeNotifyRenderedFirstFrame();
-      renderedFirstFrame = true;
-      eventDispatcher.renderedFirstFrame(surface);
-    }
   }
 
   @TargetApi(21)
@@ -493,6 +511,25 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
     TraceUtil.endSection();
     decoderCounters.renderedOutputBufferCount++;
     consecutiveDroppedFrameCount = 0;
+    maybeNotifyRenderedFirstFrame();
+  }
+
+  private void clearRenderedFirstFrame() {
+    renderedFirstFrame = false;
+    // The first frame notification is triggered by renderOutputBuffer or renderOutputBufferV21 for
+    // non-tunneled playback, onQueueInputBuffer for tunneled playback prior to API level 23, and
+    // OnFrameRenderedListenerV23.onFrameRenderedListener for tunneled playback on API level 23 and
+    // above.
+    if (Util.SDK_INT >= 23 && tunneling) {
+      MediaCodec codec = getCodec();
+      // If codec is null then the listener will be instantiated in configureCodec.
+      if (codec != null) {
+        tunnelingOnFrameRenderedListener = new OnFrameRenderedListenerV23(codec);
+      }
+    }
+  }
+
+  /* package */ void maybeNotifyRenderedFirstFrame() {
     if (!renderedFirstFrame) {
       renderedFirstFrame = true;
       eventDispatcher.renderedFirstFrame(surface);
@@ -531,7 +568,7 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
 
   @SuppressLint("InlinedApi")
   private static MediaFormat getMediaFormat(Format format, CodecMaxValues codecMaxValues,
-      boolean deviceNeedsAutoFrcWorkaround) {
+      boolean deviceNeedsAutoFrcWorkaround, int tunnelingAudioSessionId) {
     MediaFormat frameworkMediaFormat = format.getFrameworkMediaFormatV16();
     // Set the maximum adaptive video dimensions.
     frameworkMediaFormat.setInteger(MediaFormat.KEY_MAX_WIDTH, codecMaxValues.width);
@@ -544,6 +581,11 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
     if (deviceNeedsAutoFrcWorkaround) {
       frameworkMediaFormat.setInteger("auto-frc", 0);
     }
+    // Configure tunneling if enabled.
+    if (tunnelingAudioSessionId != C.AUDIO_SESSION_ID_UNSET) {
+      frameworkMediaFormat.setFeatureEnabled(CodecCapabilities.FEATURE_TunneledPlayback, true);
+      frameworkMediaFormat.setInteger(MediaFormat.KEY_AUDIO_SESSION_ID, tunnelingAudioSessionId);
+    }
     return frameworkMediaFormat;
   }
 
@@ -682,4 +724,22 @@ public class MediaCodecVideoRenderer extends MediaCodecRenderer {
 
   }
 
+  @TargetApi(23)
+  private final class OnFrameRenderedListenerV23 implements MediaCodec.OnFrameRenderedListener {
+
+    private OnFrameRenderedListenerV23(MediaCodec codec) {
+      codec.setOnFrameRenderedListener(this, new Handler());
+    }
+
+    @Override
+    public void onFrameRendered(MediaCodec codec, long presentationTimeUs, long nanoTime) {
+      if (this != tunnelingOnFrameRenderedListener) {
+        // Stale event.
+        return;
+      }
+      maybeNotifyRenderedFirstFrame();
+    }
+
+  }
+
 }