Fix some AudioProcessor nits

- Fix nullness warnings
- Fix annotations
- Make TeeAudioProcessor flush its sink for every format change

PiperOrigin-RevId: 234017068

extensions/gvr/src/main/java/com/google/android/exoplayer2/ext/gvr/GvrAudioProcessor.java

@@ -194,10 +194,9 @@ public final class GvrAudioProcessor implements AudioProcessor {
   }
 
   private void maybeReleaseGvrAudioSurround() {
-    if (this.gvrAudioSurround != null) {
-      GvrAudioSurround gvrAudioSurround = this.gvrAudioSurround;
-      this.gvrAudioSurround = null;
+    if (gvrAudioSurround != null) {
       gvrAudioSurround.release();
+      gvrAudioSurround = null;
     }
   }
 

library/core/src/main/java/com/google/android/exoplayer2/audio/ChannelMappingAudioProcessor.java

@@ -32,10 +32,10 @@ import java.util.Arrays;
 
   private int channelCount;
   private int sampleRateHz;
-  private @Nullable int[] pendingOutputChannels;
+  @Nullable private int[] pendingOutputChannels;
 
   private boolean active;
-  private @Nullable int[] outputChannels;
+  @Nullable private int[] outputChannels;
   private ByteBuffer buffer;
   private ByteBuffer outputBuffer;
   private boolean inputEnded;
@@ -112,7 +112,7 @@ import java.util.Arrays;
 
   @Override
   public void queueInput(ByteBuffer inputBuffer) {
-    Assertions.checkState(outputChannels != null);
+    int[] outputChannels = Assertions.checkNotNull(this.outputChannels);
     int position = inputBuffer.position();
     int limit = inputBuffer.limit();
     int frameCount = (limit - position) / (2 * channelCount);

library/core/src/main/java/com/google/android/exoplayer2/audio/FloatResamplingAudioProcessor.java

@@ -32,7 +32,7 @@ import java.nio.ByteOrder;
 
   private int sampleRateHz;
   private int channelCount;
-  private @C.PcmEncoding int sourceEncoding;
+  @C.PcmEncoding private int sourceEncoding;
   private ByteBuffer buffer;
   private ByteBuffer outputBuffer;
   private boolean inputEnded;

library/core/src/main/java/com/google/android/exoplayer2/audio/ResamplingAudioProcessor.java

@@ -28,7 +28,7 @@ import java.nio.ByteOrder;
 
   private int sampleRateHz;
   private int channelCount;
-  private @C.PcmEncoding int encoding;
+  @C.PcmEncoding private int encoding;
   private ByteBuffer buffer;
   private ByteBuffer outputBuffer;
   private boolean inputEnded;

library/core/src/main/java/com/google/android/exoplayer2/audio/SilenceSkippingAudioProcessor.java

@@ -93,7 +93,7 @@ public final class SilenceSkippingAudioProcessor implements AudioProcessor {
    */
   private byte[] paddingBuffer;
 
-  private @State int state;
+  @State private int state;
   private int maybeSilenceBufferSize;
   private int paddingSize;
   private boolean hasOutputNoise;

library/core/src/main/java/com/google/android/exoplayer2/audio/SonicAudioProcessor.java

@@ -69,7 +69,7 @@ public final class SonicAudioProcessor implements AudioProcessor {
   private int outputSampleRateHz;
   private int pendingOutputSampleRateHz;
 
-  private @Nullable Sonic sonic;
+  @Nullable private Sonic sonic;
   private ByteBuffer buffer;
   private ShortBuffer shortBuffer;
   private ByteBuffer outputBuffer;
@@ -201,7 +201,7 @@ public final class SonicAudioProcessor implements AudioProcessor {
 
   @Override
   public void queueInput(ByteBuffer inputBuffer) {
-    Assertions.checkState(sonic != null);
+    Sonic sonic = Assertions.checkNotNull(this.sonic);
     if (inputBuffer.hasRemaining()) {
       ShortBuffer shortBuffer = inputBuffer.asShortBuffer();
       int inputSize = inputBuffer.remaining();
@@ -227,8 +227,7 @@ public final class SonicAudioProcessor implements AudioProcessor {
 
   @Override
   public void queueEndOfStream() {
-    Assertions.checkState(sonic != null);
-    sonic.queueEndOfStream();
+    Assertions.checkNotNull(sonic).queueEndOfStream();
     inputEnded = true;
   }
 

library/core/src/main/java/com/google/android/exoplayer2/audio/TeeAudioProcessor.java

@@ -56,8 +56,7 @@ public final class TeeAudioProcessor implements AudioProcessor {
 
   private int sampleRateHz;
   private int channelCount;
-  private @C.Encoding int encoding;
-  private boolean isActive;
+  @C.Encoding private int encoding;
 
   private ByteBuffer buffer;
   private ByteBuffer outputBuffer;
@@ -79,19 +78,21 @@ public final class TeeAudioProcessor implements AudioProcessor {
   }
 
   @Override
-  public boolean configure(int sampleRateHz, int channelCount, @C.Encoding int encoding)
-      throws UnhandledFormatException {
+  public boolean configure(int sampleRateHz, int channelCount, @C.Encoding int encoding) {
+    boolean formatChanged =
+        sampleRateHz != this.sampleRateHz
+            || channelCount != this.channelCount
+            || encoding != this.encoding;
     this.sampleRateHz = sampleRateHz;
     this.channelCount = channelCount;
     this.encoding = encoding;
-    boolean wasActive = isActive;
-    isActive = true;
-    return !wasActive;
+    // The sink always needs to be flushed if the format is changing.
+    return formatChanged;
   }
 
   @Override
   public boolean isActive() {
-    return isActive;
+    return sampleRateHz != Format.NO_VALUE;
   }
 
   @Override
@@ -145,7 +146,7 @@ public final class TeeAudioProcessor implements AudioProcessor {
   @SuppressWarnings("ReferenceEquality")
   @Override
   public boolean isEnded() {
-    return inputEnded && buffer == EMPTY_BUFFER;
+    return inputEnded && outputBuffer == EMPTY_BUFFER;
   }
 
   @Override

library/core/src/main/java/com/google/android/exoplayer2/audio/TrimmingAudioProcessor.java

@@ -25,7 +25,7 @@ import java.nio.ByteOrder;
 /** Audio processor for trimming samples from the start/end of data. */
 /* package */ final class TrimmingAudioProcessor implements AudioProcessor {
 
-  private static final int OUTPUT_ENCODING = C.ENCODING_PCM_16BIT;
+  @C.Encoding private static final int OUTPUT_ENCODING = C.ENCODING_PCM_16BIT;
 
   private boolean isActive;
   private int trimStartFrames;