Add AudioProcessor.AudioFormat

Issue: #6601
PiperOrigin-RevId: 282515179

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

@@ -18,7 +18,6 @@ package com.google.android.exoplayer2.ext.gvr;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ExoPlayerLibraryInfo;
-import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.audio.AudioProcessor;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.vr.sdk.audio.GvrAudioSurround;
@@ -44,8 +43,7 @@ public final class GvrAudioProcessor implements AudioProcessor {
   private static final int OUTPUT_FRAME_SIZE = OUTPUT_CHANNEL_COUNT * 2; // 16-bit stereo output.
   private static final int NO_SURROUND_FORMAT = GvrAudioSurround.SurroundFormat.INVALID;
 
-  private int sampleRateHz;
-  private int channelCount;
+  private AudioFormat inputAudioFormat;
   private int pendingGvrAudioSurroundFormat;
   @Nullable private GvrAudioSurround gvrAudioSurround;
   private ByteBuffer buffer;
@@ -60,8 +58,7 @@ public final class GvrAudioProcessor implements AudioProcessor {
   public GvrAudioProcessor() {
     // Use the identity for the initial orientation.
     w = 1f;
-    sampleRateHz = Format.NO_VALUE;
-    channelCount = Format.NO_VALUE;
+    inputAudioFormat = AudioFormat.NOT_SET;
     buffer = EMPTY_BUFFER;
     pendingGvrAudioSurroundFormat = NO_SURROUND_FORMAT;
   }
@@ -87,15 +84,13 @@ public final class GvrAudioProcessor implements AudioProcessor {
 
   @SuppressWarnings("ReferenceEquality")
   @Override
-  public synchronized void configure(int sampleRateHz, int channelCount, @C.Encoding int encoding)
-      throws UnhandledFormatException {
-    if (encoding != C.ENCODING_PCM_16BIT) {
+  public synchronized AudioFormat configure(AudioFormat inputAudioFormat)
+      throws UnhandledAudioFormatException {
+    if (inputAudioFormat.encoding != C.ENCODING_PCM_16BIT) {
       maybeReleaseGvrAudioSurround();
-      throw new UnhandledFormatException(sampleRateHz, channelCount, encoding);
+      throw new UnhandledAudioFormatException(inputAudioFormat);
     }
-    this.sampleRateHz = sampleRateHz;
-    this.channelCount = channelCount;
-    switch (channelCount) {
+    switch (inputAudioFormat.channelCount) {
       case 1:
         pendingGvrAudioSurroundFormat = GvrAudioSurround.SurroundFormat.SURROUND_MONO;
         break;
@@ -115,12 +110,14 @@ public final class GvrAudioProcessor implements AudioProcessor {
         pendingGvrAudioSurroundFormat = GvrAudioSurround.SurroundFormat.THIRD_ORDER_AMBISONICS;
         break;
       default:
-        throw new UnhandledFormatException(sampleRateHz, channelCount, encoding);
+        throw new UnhandledAudioFormatException(inputAudioFormat);
     }
     if (buffer == EMPTY_BUFFER) {
       buffer = ByteBuffer.allocateDirect(FRAMES_PER_OUTPUT_BUFFER * OUTPUT_FRAME_SIZE)
           .order(ByteOrder.nativeOrder());
     }
+    this.inputAudioFormat = inputAudioFormat;
+    return new AudioFormat(inputAudioFormat.sampleRate, OUTPUT_CHANNEL_COUNT, C.ENCODING_PCM_16BIT);
   }
 
   @Override
@@ -129,21 +126,6 @@ public final class GvrAudioProcessor implements AudioProcessor {
   }
 
   @Override
-  public int getOutputChannelCount() {
-    return OUTPUT_CHANNEL_COUNT;
-  }
-
-  @Override
-  public int getOutputEncoding() {
-    return C.ENCODING_PCM_16BIT;
-  }
-
-  @Override
-  public int getOutputSampleRateHz() {
-    return sampleRateHz;
-  }
-
-  @Override
   public void queueInput(ByteBuffer input) {
     int position = input.position();
     Assertions.checkNotNull(gvrAudioSurround);
@@ -181,7 +163,10 @@ public final class GvrAudioProcessor implements AudioProcessor {
       maybeReleaseGvrAudioSurround();
       gvrAudioSurround =
           new GvrAudioSurround(
-              pendingGvrAudioSurroundFormat, sampleRateHz, channelCount, FRAMES_PER_OUTPUT_BUFFER);
+              pendingGvrAudioSurroundFormat,
+              inputAudioFormat.sampleRate,
+              inputAudioFormat.channelCount,
+              FRAMES_PER_OUTPUT_BUFFER);
       gvrAudioSurround.updateNativeOrientation(w, x, y, z);
       pendingGvrAudioSurroundFormat = NO_SURROUND_FORMAT;
     } else if (gvrAudioSurround != null) {
@@ -195,8 +180,7 @@ public final class GvrAudioProcessor implements AudioProcessor {
     maybeReleaseGvrAudioSurround();
     updateOrientation(/* w= */ 1f, /* x= */ 0f, /* y= */ 0f, /* z= */ 0f);
     inputEnded = false;
-    sampleRateHz = Format.NO_VALUE;
-    channelCount = Format.NO_VALUE;
+    inputAudioFormat = AudioFormat.NOT_SET;
     buffer = EMPTY_BUFFER;
     pendingGvrAudioSurroundFormat = NO_SURROUND_FORMAT;
   }

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

@@ -16,6 +16,8 @@
 package com.google.android.exoplayer2.audio;
 
 import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.util.Util;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 
@@ -23,24 +25,56 @@ import java.nio.ByteOrder;
  * Interface for audio processors, which take audio data as input and transform it, potentially
  * modifying its channel count, encoding and/or sample rate.
  *
- * <p>Call {@link #configure(int, int, int)} to configure the processor to receive input audio, then
- * call {@link #isActive()} to determine whether the processor is active in the new configuration.
- * {@link #queueInput(ByteBuffer)}, {@link #getOutputChannelCount()}, {@link #getOutputEncoding()}
- * and {@link #getOutputSampleRateHz()} may only be called if the processor is active. Call {@link
- * #reset()} to reset the processor to its unconfigured state and release any resources.
- *
  * <p>In addition to being able to modify the format of audio, implementations may allow parameters
  * to be set that affect the output audio and whether the processor is active/inactive.
  */
 public interface AudioProcessor {
 
+  /** PCM audio format that may be handled by an audio processor. */
+  final class AudioFormat {
+    public static final AudioFormat NOT_SET =
+        new AudioFormat(
+            /* sampleRate= */ Format.NO_VALUE,
+            /* channelCount= */ Format.NO_VALUE,
+            /* encoding= */ Format.NO_VALUE);
+
+    /** The sample rate in Hertz. */
+    public final int sampleRate;
+    /** The number of interleaved channels. */
+    public final int channelCount;
+    /** The type of linear PCM encoding. */
+    @C.PcmEncoding public final int encoding;
+    /** The number of bytes used to represent one audio frame. */
+    public final int bytesPerFrame;
+
+    public AudioFormat(int sampleRate, int channelCount, @C.PcmEncoding int encoding) {
+      this.sampleRate = sampleRate;
+      this.channelCount = channelCount;
+      this.encoding = encoding;
+      bytesPerFrame =
+          Util.isEncodingLinearPcm(encoding)
+              ? Util.getPcmFrameSize(encoding, channelCount)
+              : Format.NO_VALUE;
+    }
+
+    @Override
+    public String toString() {
+      return "AudioFormat["
+          + "sampleRate="
+          + sampleRate
+          + ", channelCount="
+          + channelCount
+          + ", encoding="
+          + encoding
+          + ']';
+    }
+  }
+
   /** Exception thrown when a processor can't be configured for a given input audio format. */
-  final class UnhandledFormatException extends Exception {
+  final class UnhandledAudioFormatException extends Exception {
 
-    public UnhandledFormatException(
-        int sampleRateHz, int channelCount, @C.PcmEncoding int encoding) {
-      super("Unhandled format: " + sampleRateHz + " Hz, " + channelCount + " channels in encoding "
-          + encoding);
+    public UnhandledAudioFormatException(AudioFormat inputAudioFormat) {
+      super("Unhandled format: " + inputAudioFormat);
     }
 
   }
@@ -50,46 +84,24 @@ public interface AudioProcessor {
 
   /**
    * Configures the processor to process input audio with the specified format. After calling this
-   * method, call {@link #isActive()} to determine whether the audio processor is active.
-   *
-   * <p>If the audio processor is active after configuration, call {@link #getOutputSampleRateHz()},
-   * {@link #getOutputChannelCount()} and {@link #getOutputEncoding()} to get its new output format.
+   * method, call {@link #isActive()} to determine whether the audio processor is active. Returns
+   * the configured output audio format if this instance is active.
    *
    * <p>After calling this method, it is necessary to {@link #flush()} the processor to apply the
    * new configuration before queueing more data. You can (optionally) first drain output in the
    * previous configuration by calling {@link #queueEndOfStream()} and {@link #getOutput()}.
    *
-   * @param sampleRateHz The sample rate of input audio in Hz.
-   * @param channelCount The number of interleaved channels in input audio.
-   * @param encoding The encoding of input audio.
-   * @throws UnhandledFormatException Thrown if the specified format can't be handled as input.
+   * @param inputAudioFormat The format of audio that will be queued after the next call to {@link
+   *     #flush()}.
+   * @return The configured output audio format if this instance is {@link #isActive() active}.
+   * @throws UnhandledAudioFormatException Thrown if the specified format can't be handled as input.
    */
-  void configure(int sampleRateHz, int channelCount, @C.PcmEncoding int encoding)
-      throws UnhandledFormatException;
+  AudioFormat configure(AudioFormat inputAudioFormat) throws UnhandledAudioFormatException;
 
   /** Returns whether the processor is configured and will process input buffers. */
   boolean isActive();
 
   /**
-   * Returns the number of audio channels in the data output by the processor. The value may change
-   * as a result of calling {@link #configure(int, int, int)}.
-   */
-  int getOutputChannelCount();
-
-  /**
-   * Returns the audio encoding used in the data output by the processor. The value may change as a
-   * result of calling {@link #configure(int, int, int)}.
-   */
-  @C.PcmEncoding
-  int getOutputEncoding();
-
-  /**
-   * Returns the sample rate of audio output by the processor, in hertz. The value may change as a
-   * result of calling {@link #configure(int, int, int)}.
-   */
-  int getOutputSampleRateHz();
-
-  /**
    * Queues audio data between the position and limit of the input {@code buffer} for processing.
    * {@code buffer} must be a direct byte buffer with native byte order. Its contents are treated as
    * read-only. Its position will be advanced by the number of bytes consumed (which may be zero).
@@ -130,6 +142,6 @@ public interface AudioProcessor {
    */
   void flush();
 
-  /** Resets the processor to its unconfigured state. */
+  /** Resets the processor to its unconfigured state, releasing any resources. */
   void reset();
 }

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

@@ -16,24 +16,20 @@
 package com.google.android.exoplayer2.audio;
 
 import androidx.annotation.CallSuper;
-import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.Format;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 
 /**
  * Base class for audio processors that keep an output buffer and an internal buffer that is reused
- * whenever input is queued.
+ * whenever input is queued. Subclasses should override {@link #onConfigure(AudioFormat)} to return
+ * the output audio format for the processor if it's active.
  */
 public abstract class BaseAudioProcessor implements AudioProcessor {
 
-  /** The configured input sample rate, in Hertz, or {@link Format#NO_VALUE} if not configured. */
-  protected int sampleRateHz;
-  /** The configured input channel count, or {@link Format#NO_VALUE} if not configured. */
-  protected int channelCount;
-  /** The configured input encoding, or {@link Format#NO_VALUE} if not configured. */
-  @C.PcmEncoding protected int encoding;
+  /** The configured input audio format. */
+  protected AudioFormat inputAudioFormat;
 
+  private AudioFormat outputAudioFormat;
   private ByteBuffer buffer;
   private ByteBuffer outputBuffer;
   private boolean inputEnded;
@@ -41,29 +37,21 @@ public abstract class BaseAudioProcessor implements AudioProcessor {
   public BaseAudioProcessor() {
     buffer = EMPTY_BUFFER;
     outputBuffer = EMPTY_BUFFER;
-    channelCount = Format.NO_VALUE;
-    sampleRateHz = Format.NO_VALUE;
-    encoding = Format.NO_VALUE;
+    inputAudioFormat = AudioFormat.NOT_SET;
+    outputAudioFormat = AudioFormat.NOT_SET;
   }
 
   @Override
-  public boolean isActive() {
-    return sampleRateHz != Format.NO_VALUE;
-  }
-
-  @Override
-  public int getOutputChannelCount() {
-    return channelCount;
-  }
-
-  @Override
-  public int getOutputEncoding() {
-    return encoding;
+  public final AudioFormat configure(AudioFormat inputAudioFormat)
+      throws UnhandledAudioFormatException {
+    this.inputAudioFormat = inputAudioFormat;
+    outputAudioFormat = onConfigure(inputAudioFormat);
+    return isActive() ? outputAudioFormat : AudioFormat.NOT_SET;
   }
 
   @Override
-  public int getOutputSampleRateHz() {
-    return sampleRateHz;
+  public boolean isActive() {
+    return outputAudioFormat != AudioFormat.NOT_SET;
   }
 
   @Override
@@ -98,20 +86,11 @@ public abstract class BaseAudioProcessor implements AudioProcessor {
   public final void reset() {
     flush();
     buffer = EMPTY_BUFFER;
-    sampleRateHz = Format.NO_VALUE;
-    channelCount = Format.NO_VALUE;
-    encoding = Format.NO_VALUE;
+    inputAudioFormat = AudioFormat.NOT_SET;
+    outputAudioFormat = AudioFormat.NOT_SET;
     onReset();
   }
 
-  /** Sets the input format of this processor. */
-  protected final void setInputFormat(
-      int sampleRateHz, int channelCount, @C.PcmEncoding int encoding) {
-    this.sampleRateHz = sampleRateHz;
-    this.channelCount = channelCount;
-    this.encoding = encoding;
-  }
-
   /**
    * Replaces the current output buffer with a buffer of at least {@code count} bytes and returns
    * it. Callers should write to the returned buffer then {@link ByteBuffer#flip()} it so it can be
@@ -132,6 +111,12 @@ public abstract class BaseAudioProcessor implements AudioProcessor {
     return outputBuffer.hasRemaining();
   }
 
+  /** Called when the processor is configured for a new input format. */
+  protected AudioFormat onConfigure(AudioFormat inputAudioFormat)
+      throws UnhandledAudioFormatException {
+    return AudioFormat.NOT_SET;
+  }
+
   /** Called when the end-of-stream is queued to the processor. */
   protected void onQueueEndOfStream() {
     // Do nothing.

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

@@ -24,19 +24,17 @@ import java.nio.ByteBuffer;
  * An {@link AudioProcessor} that applies a mapping from input channels onto specified output
  * channels. This can be used to reorder, duplicate or discard channels.
  */
-/* package */
 // the constructor does not initialize fields: pendingOutputChannels, outputChannels
 @SuppressWarnings("nullness:initialization.fields.uninitialized")
-final class ChannelMappingAudioProcessor extends BaseAudioProcessor {
+/* package */ final class ChannelMappingAudioProcessor extends BaseAudioProcessor {
 
   @Nullable private int[] pendingOutputChannels;
 
-  private boolean active;
   @Nullable private int[] outputChannels;
 
   /**
-   * Resets the channel mapping. After calling this method, call {@link #configure(int, int, int)}
-   * to start using the new channel map.
+   * Resets the channel mapping. After calling this method, call {@link #configure(AudioFormat)} to
+   * start using the new channel map.
    *
    * @param outputChannels The mapping from input to output channel indices, or {@code null} to
    *     leave the input unchanged.
@@ -47,38 +45,30 @@ final class ChannelMappingAudioProcessor extends BaseAudioProcessor {
   }
 
   @Override
-  public void configure(int sampleRateHz, int channelCount, @C.PcmEncoding int encoding)
-      throws UnhandledFormatException {
+  public AudioFormat onConfigure(AudioFormat inputAudioFormat)
+      throws UnhandledAudioFormatException {
     outputChannels = pendingOutputChannels;
 
     int[] outputChannels = this.outputChannels;
     if (outputChannels == null) {
-      active = false;
-      return;
+      return AudioFormat.NOT_SET;
     }
-    if (encoding != C.ENCODING_PCM_16BIT) {
-      throw new UnhandledFormatException(sampleRateHz, channelCount, encoding);
+
+    if (inputAudioFormat.encoding != C.ENCODING_PCM_16BIT) {
+      throw new UnhandledAudioFormatException(inputAudioFormat);
     }
 
-    setInputFormat(sampleRateHz, channelCount, encoding);
-    active = channelCount != outputChannels.length;
+    boolean active = inputAudioFormat.channelCount != outputChannels.length;
     for (int i = 0; i < outputChannels.length; i++) {
       int channelIndex = outputChannels[i];
-      if (channelIndex >= channelCount) {
-        throw new UnhandledFormatException(sampleRateHz, channelCount, encoding);
+      if (channelIndex >= inputAudioFormat.channelCount) {
+        throw new UnhandledAudioFormatException(inputAudioFormat);
       }
       active |= (channelIndex != i);
     }
-  }
-
-  @Override
-  public boolean isActive() {
-    return active;
-  }
-
-  @Override
-  public int getOutputChannelCount() {
-    return outputChannels == null ? channelCount : outputChannels.length;
+    return active
+        ? new AudioFormat(inputAudioFormat.sampleRate, outputChannels.length, C.ENCODING_PCM_16BIT)
+        : AudioFormat.NOT_SET;
   }
 
   @Override
@@ -86,14 +76,14 @@ final class ChannelMappingAudioProcessor extends BaseAudioProcessor {
     int[] outputChannels = Assertions.checkNotNull(this.outputChannels);
     int position = inputBuffer.position();
     int limit = inputBuffer.limit();
-    int frameCount = (limit - position) / (2 * channelCount);
+    int frameCount = (limit - position) / (2 * inputAudioFormat.channelCount);
     int outputSize = frameCount * outputChannels.length * 2;
     ByteBuffer buffer = replaceOutputBuffer(outputSize);
     while (position < limit) {
       for (int channelIndex : outputChannels) {
         buffer.putShort(inputBuffer.getShort(position + 2 * channelIndex));
       }
-      position += channelCount * 2;
+      position += inputAudioFormat.channelCount * 2;
     }
     inputBuffer.position(limit);
     buffer.flip();
@@ -103,7 +93,6 @@ final class ChannelMappingAudioProcessor extends BaseAudioProcessor {
   protected void onReset() {
     outputChannels = null;
     pendingOutputChannels = null;
-    active = false;
   }
 
 }

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

@@ -27,6 +27,7 @@ import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.PlaybackParameters;
+import com.google.android.exoplayer2.audio.AudioProcessor.UnhandledAudioFormatException;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.Util;
@@ -435,18 +436,22 @@ public final class DefaultAudioSink implements AudioSink {
     if (processingEnabled) {
       trimmingAudioProcessor.setTrimFrameCount(trimStartFrames, trimEndFrames);
       channelMappingAudioProcessor.setChannelMap(outputChannels);
+      AudioProcessor.AudioFormat inputAudioFormat =
+          new AudioProcessor.AudioFormat(sampleRate, channelCount, encoding);
+      AudioProcessor.AudioFormat outputAudioFormat = inputAudioFormat;
       for (AudioProcessor audioProcessor : availableAudioProcessors) {
         try {
-          audioProcessor.configure(sampleRate, channelCount, encoding);
-        } catch (AudioProcessor.UnhandledFormatException e) {
+          outputAudioFormat = audioProcessor.configure(inputAudioFormat);
+        } catch (UnhandledAudioFormatException e) {
           throw new ConfigurationException(e);
         }
         if (audioProcessor.isActive()) {
-          channelCount = audioProcessor.getOutputChannelCount();
-          sampleRate = audioProcessor.getOutputSampleRateHz();
-          encoding = audioProcessor.getOutputEncoding();
+          inputAudioFormat = outputAudioFormat;
         }
       }
+      sampleRate = outputAudioFormat.sampleRate;
+      channelCount = outputAudioFormat.channelCount;
+      encoding = outputAudioFormat.encoding;
     }
 
     int outputChannelConfig = getChannelConfig(channelCount, isInputPcm);

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

@@ -16,6 +16,7 @@
 package com.google.android.exoplayer2.audio;
 
 import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import java.nio.ByteBuffer;
 
@@ -29,27 +30,21 @@ import java.nio.ByteBuffer;
   private static final double PCM_32_BIT_INT_TO_PCM_32_BIT_FLOAT_FACTOR = 1.0 / 0x7FFFFFFF;
 
   @Override
-  public void configure(int sampleRateHz, int channelCount, @C.PcmEncoding int encoding)
-      throws UnhandledFormatException {
-    if (!Util.isEncodingHighResolutionIntegerPcm(encoding)) {
-      throw new UnhandledFormatException(sampleRateHz, channelCount, encoding);
+  public AudioFormat onConfigure(AudioFormat inputAudioFormat)
+      throws UnhandledAudioFormatException {
+    if (!Util.isEncodingHighResolutionIntegerPcm(inputAudioFormat.encoding)) {
+      throw new UnhandledAudioFormatException(inputAudioFormat);
     }
-    setInputFormat(sampleRateHz, channelCount, encoding);
-  }
-
-  @Override
-  public boolean isActive() {
-    return Util.isEncodingHighResolutionIntegerPcm(encoding);
-  }
-
-  @Override
-  public int getOutputEncoding() {
-    return C.ENCODING_PCM_FLOAT;
+    return Util.isEncodingHighResolutionIntegerPcm(inputAudioFormat.encoding)
+        ? new AudioFormat(
+            inputAudioFormat.sampleRate, inputAudioFormat.channelCount, C.ENCODING_PCM_FLOAT)
+        : AudioFormat.NOT_SET;
   }
 
   @Override
   public void queueInput(ByteBuffer inputBuffer) {
-    boolean isInput32Bit = encoding == C.ENCODING_PCM_32BIT;
+    Assertions.checkState(Util.isEncodingHighResolutionIntegerPcm(inputAudioFormat.encoding));
+    boolean isInput32Bit = inputAudioFormat.encoding == C.ENCODING_PCM_32BIT;
     int position = inputBuffer.position();
     int limit = inputBuffer.limit();
     int size = limit - position;
@@ -65,7 +60,7 @@ import java.nio.ByteBuffer;
                 | ((inputBuffer.get(i + 3) & 0xFF) << 24);
         writePcm32BitFloat(pcm32BitInteger, buffer);
       }
-    } else {
+    } else { // Input is 24-bit PCM.
       for (int i = position; i < limit; i += 3) {
         int pcm32BitInteger =
             ((inputBuffer.get(i) & 0xFF) << 8)

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

@@ -26,23 +26,17 @@ import java.nio.ByteBuffer;
 /* package */ final class ResamplingAudioProcessor extends BaseAudioProcessor {
 
   @Override
-  public void configure(int sampleRateHz, int channelCount, @C.PcmEncoding int encoding)
-      throws UnhandledFormatException {
+  public AudioFormat onConfigure(AudioFormat inputAudioFormat)
+      throws UnhandledAudioFormatException {
+    @C.PcmEncoding int encoding = inputAudioFormat.encoding;
     if (encoding != C.ENCODING_PCM_8BIT && encoding != C.ENCODING_PCM_16BIT
         && encoding != C.ENCODING_PCM_24BIT && encoding != C.ENCODING_PCM_32BIT) {
-      throw new UnhandledFormatException(sampleRateHz, channelCount, encoding);
+      throw new UnhandledAudioFormatException(inputAudioFormat);
     }
-    setInputFormat(sampleRateHz, channelCount, encoding);
-  }
-
-  @Override
-  public boolean isActive() {
-    return encoding != C.ENCODING_INVALID && encoding != C.ENCODING_PCM_16BIT;
-  }
-
-  @Override
-  public int getOutputEncoding() {
-    return C.ENCODING_PCM_16BIT;
+    return encoding != C.ENCODING_PCM_16BIT
+        ? new AudioFormat(
+            inputAudioFormat.sampleRate, inputAudioFormat.channelCount, C.ENCODING_PCM_16BIT)
+        : AudioFormat.NOT_SET;
   }
 
   @Override
@@ -52,7 +46,7 @@ import java.nio.ByteBuffer;
     int limit = inputBuffer.limit();
     int size = limit - position;
     int resampledSize;
-    switch (encoding) {
+    switch (inputAudioFormat.encoding) {
       case C.ENCODING_PCM_8BIT:
         resampledSize = size * 2;
         break;
@@ -74,7 +68,7 @@ import java.nio.ByteBuffer;
 
     // Resample the little endian input and update the input/output buffers.
     ByteBuffer buffer = replaceOutputBuffer(resampledSize);
-    switch (encoding) {
+    switch (inputAudioFormat.encoding) {
       case C.ENCODING_PCM_8BIT:
         // 8->16 bit resampling. Shift each byte from [0, 256) to [-128, 128) and scale up.
         for (int i = position; i < limit; i++) {

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

@@ -119,18 +119,17 @@ public final class SilenceSkippingAudioProcessor extends BaseAudioProcessor {
   // AudioProcessor implementation.
 
   @Override
-  public void configure(int sampleRateHz, int channelCount, @C.PcmEncoding int encoding)
-      throws UnhandledFormatException {
-    if (encoding != C.ENCODING_PCM_16BIT) {
-      throw new UnhandledFormatException(sampleRateHz, channelCount, encoding);
+  public AudioFormat onConfigure(AudioFormat inputAudioFormat)
+      throws UnhandledAudioFormatException {
+    if (inputAudioFormat.encoding != C.ENCODING_PCM_16BIT) {
+      throw new UnhandledAudioFormatException(inputAudioFormat);
     }
-    bytesPerFrame = channelCount * 2;
-    setInputFormat(sampleRateHz, channelCount, encoding);
+    return enabled ? inputAudioFormat : AudioFormat.NOT_SET;
   }
 
   @Override
   public boolean isActive() {
-    return super.isActive() && enabled;
+    return enabled;
   }
 
   @Override
@@ -165,7 +164,8 @@ public final class SilenceSkippingAudioProcessor extends BaseAudioProcessor {
 
   @Override
   protected void onFlush() {
-    if (isActive()) {
+    if (enabled) {
+      bytesPerFrame = inputAudioFormat.bytesPerFrame;
       int maybeSilenceBufferSize = durationUsToFrames(MINIMUM_SILENCE_DURATION_US) * bytesPerFrame;
       if (maybeSilenceBuffer.length != maybeSilenceBufferSize) {
         maybeSilenceBuffer = new byte[maybeSilenceBufferSize];
@@ -317,7 +317,7 @@ public final class SilenceSkippingAudioProcessor extends BaseAudioProcessor {
    * Returns the number of input frames corresponding to {@code durationUs} microseconds of audio.
    */
   private int durationUsToFrames(long durationUs) {
-    return (int) ((durationUs * sampleRateHz) / C.MICROS_PER_SECOND);
+    return (int) ((durationUs * inputAudioFormat.sampleRate) / C.MICROS_PER_SECOND);
   }
 
   /**

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

@@ -17,7 +17,6 @@ package com.google.android.exoplayer2.audio;
 
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.C.Encoding;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
@@ -62,12 +61,12 @@ public final class SonicAudioProcessor implements AudioProcessor {
    */
   private static final int MIN_BYTES_FOR_SPEEDUP_CALCULATION = 1024;
 
-  private int channelCount;
-  private int sampleRateHz;
+  private int pendingOutputSampleRate;
   private float speed;
   private float pitch;
-  private int outputSampleRateHz;
-  private int pendingOutputSampleRateHz;
+
+  private AudioFormat inputAudioFormat;
+  private AudioFormat outputAudioFormat;
 
   private boolean pendingSonicRecreation;
   @Nullable private Sonic sonic;
@@ -84,13 +83,12 @@ public final class SonicAudioProcessor implements AudioProcessor {
   public SonicAudioProcessor() {
     speed = 1f;
     pitch = 1f;
-    channelCount = Format.NO_VALUE;
-    sampleRateHz = Format.NO_VALUE;
-    outputSampleRateHz = Format.NO_VALUE;
+    inputAudioFormat = AudioFormat.NOT_SET;
+    outputAudioFormat = AudioFormat.NOT_SET;
     buffer = EMPTY_BUFFER;
     shortBuffer = buffer.asShortBuffer();
     outputBuffer = EMPTY_BUFFER;
-    pendingOutputSampleRateHz = SAMPLE_RATE_NO_CHANGE;
+    pendingOutputSampleRate = SAMPLE_RATE_NO_CHANGE;
   }
 
   /**
@@ -129,14 +127,14 @@ public final class SonicAudioProcessor implements AudioProcessor {
 
   /**
    * Sets the sample rate for output audio, in hertz. Pass {@link #SAMPLE_RATE_NO_CHANGE} to output
-   * audio at the same sample rate as the input. After calling this method, call
-   * {@link #configure(int, int, int)} to start using the new sample rate.
+   * audio at the same sample rate as the input. After calling this method, call {@link
+   * #configure(AudioFormat)} to start using the new sample rate.
    *
    * @param sampleRateHz The sample rate for output audio, in hertz.
-   * @see #configure(int, int, int)
+   * @see #configure(AudioFormat)
    */
   public void setOutputSampleRateHz(int sampleRateHz) {
-    pendingOutputSampleRateHz = sampleRateHz;
+    pendingOutputSampleRate = sampleRateHz;
   }
 
   /**
@@ -149,50 +147,39 @@ public final class SonicAudioProcessor implements AudioProcessor {
    */
   public long scaleDurationForSpeedup(long duration) {
     if (outputBytes >= MIN_BYTES_FOR_SPEEDUP_CALCULATION) {
-      return outputSampleRateHz == sampleRateHz
+      return outputAudioFormat.sampleRate == inputAudioFormat.sampleRate
           ? Util.scaleLargeTimestamp(duration, inputBytes, outputBytes)
-          : Util.scaleLargeTimestamp(duration, inputBytes * outputSampleRateHz,
-              outputBytes * sampleRateHz);
+          : Util.scaleLargeTimestamp(
+              duration,
+              inputBytes * outputAudioFormat.sampleRate,
+              outputBytes * inputAudioFormat.sampleRate);
     } else {
       return (long) ((double) speed * duration);
     }
   }
 
   @Override
-  public void configure(int sampleRateHz, int channelCount, @Encoding int encoding)
-      throws UnhandledFormatException {
-    if (encoding != C.ENCODING_PCM_16BIT) {
-      throw new UnhandledFormatException(sampleRateHz, channelCount, encoding);
+  public AudioFormat configure(AudioFormat inputAudioFormat) throws UnhandledAudioFormatException {
+    if (inputAudioFormat.encoding != C.ENCODING_PCM_16BIT) {
+      throw new UnhandledAudioFormatException(inputAudioFormat);
     }
-    int outputSampleRateHz = pendingOutputSampleRateHz == SAMPLE_RATE_NO_CHANGE
-        ? sampleRateHz : pendingOutputSampleRateHz;
-    this.sampleRateHz = sampleRateHz;
-    this.channelCount = channelCount;
-    this.outputSampleRateHz = outputSampleRateHz;
+    int outputSampleRateHz =
+        pendingOutputSampleRate == SAMPLE_RATE_NO_CHANGE
+            ? inputAudioFormat.sampleRate
+            : pendingOutputSampleRate;
+    this.inputAudioFormat = inputAudioFormat;
+    this.outputAudioFormat =
+        new AudioFormat(outputSampleRateHz, inputAudioFormat.channelCount, C.ENCODING_PCM_16BIT);
     pendingSonicRecreation = true;
+    return outputAudioFormat;
   }
 
   @Override
   public boolean isActive() {
-    return sampleRateHz != Format.NO_VALUE
+    return outputAudioFormat.sampleRate != Format.NO_VALUE
         && (Math.abs(speed - 1f) >= CLOSE_THRESHOLD
             || Math.abs(pitch - 1f) >= CLOSE_THRESHOLD
-            || outputSampleRateHz != sampleRateHz);
-  }
-
-  @Override
-  public int getOutputChannelCount() {
-    return channelCount;
-  }
-
-  @Override
-  public int getOutputEncoding() {
-    return C.ENCODING_PCM_16BIT;
-  }
-
-  @Override
-  public int getOutputSampleRateHz() {
-    return outputSampleRateHz;
+            || outputAudioFormat.sampleRate != inputAudioFormat.sampleRate);
   }
 
   @Override
@@ -245,7 +232,13 @@ public final class SonicAudioProcessor implements AudioProcessor {
   public void flush() {
     if (isActive()) {
       if (pendingSonicRecreation) {
-        sonic = new Sonic(sampleRateHz, channelCount, speed, pitch, outputSampleRateHz);
+        sonic =
+            new Sonic(
+                inputAudioFormat.sampleRate,
+                inputAudioFormat.channelCount,
+                speed,
+                pitch,
+                outputAudioFormat.sampleRate);
       } else if (sonic != null) {
         sonic.flush();
       }
@@ -260,13 +253,12 @@ public final class SonicAudioProcessor implements AudioProcessor {
   public void reset() {
     speed = 1f;
     pitch = 1f;
-    channelCount = Format.NO_VALUE;
-    sampleRateHz = Format.NO_VALUE;
-    outputSampleRateHz = Format.NO_VALUE;
+    inputAudioFormat = AudioFormat.NOT_SET;
+    outputAudioFormat = AudioFormat.NOT_SET;
     buffer = EMPTY_BUFFER;
     shortBuffer = buffer.asShortBuffer();
     outputBuffer = EMPTY_BUFFER;
-    pendingOutputSampleRateHz = SAMPLE_RATE_NO_CHANGE;
+    pendingOutputSampleRate = SAMPLE_RATE_NO_CHANGE;
     pendingSonicRecreation = false;
     sonic = null;
     inputBytes = 0;

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

@@ -64,8 +64,9 @@ public final class TeeAudioProcessor extends BaseAudioProcessor {
   }
 
   @Override
-  public void configure(int sampleRateHz, int channelCount, @C.PcmEncoding int encoding) {
-    setInputFormat(sampleRateHz, channelCount, encoding);
+  public AudioFormat onConfigure(AudioFormat inputAudioFormat) {
+    // This processor is always active (if passed to the sink) and outputs its input.
+    return inputAudioFormat;
   }
 
   @Override
@@ -81,7 +82,8 @@ public final class TeeAudioProcessor extends BaseAudioProcessor {
   @Override
   protected void onFlush() {
     if (isActive()) {
-      audioBufferSink.flush(sampleRateHz, channelCount, encoding);
+      audioBufferSink.flush(
+          inputAudioFormat.sampleRate, inputAudioFormat.channelCount, inputAudioFormat.encoding);
     }
   }
 

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

@@ -24,7 +24,6 @@ import java.nio.ByteBuffer;
 
   @C.PcmEncoding private static final int OUTPUT_ENCODING = C.ENCODING_PCM_16BIT;
 
-  private boolean isActive;
   private int trimStartFrames;
   private int trimEndFrames;
   private int bytesPerFrame;
@@ -42,7 +41,7 @@ import java.nio.ByteBuffer;
 
   /**
    * Sets the number of audio frames to trim from the start and end of audio passed to this
-   * processor. After calling this method, call {@link #configure(int, int, int)} to apply the new
+   * processor. After calling this method, call {@link #configure(AudioFormat)} to apply the new
    * trimming frame counts.
    *
    * @param trimStartFrames The number of audio frames to trim from the start of audio.
@@ -68,26 +67,20 @@ import java.nio.ByteBuffer;
   }
 
   @Override
-  public void configure(int sampleRateHz, int channelCount, @C.PcmEncoding int encoding)
-      throws UnhandledFormatException {
-    if (encoding != OUTPUT_ENCODING) {
-      throw new UnhandledFormatException(sampleRateHz, channelCount, encoding);
+  public AudioFormat onConfigure(AudioFormat inputAudioFormat)
+      throws UnhandledAudioFormatException {
+    if (inputAudioFormat.encoding != OUTPUT_ENCODING) {
+      throw new UnhandledAudioFormatException(inputAudioFormat);
     }
     if (endBufferSize > 0) {
       trimmedFrameCount += endBufferSize / bytesPerFrame;
     }
-    bytesPerFrame = Util.getPcmFrameSize(OUTPUT_ENCODING, channelCount);
+    bytesPerFrame = inputAudioFormat.bytesPerFrame;
     endBuffer = new byte[trimEndFrames * bytesPerFrame];
     endBufferSize = 0;
     pendingTrimStartBytes = trimStartFrames * bytesPerFrame;
-    isActive = trimStartFrames != 0 || trimEndFrames != 0;
     receivedInputSinceConfigure = false;
-    setInputFormat(sampleRateHz, channelCount, encoding);
-  }
-
-  @Override
-  public boolean isActive() {
-    return isActive;
+    return trimStartFrames != 0 || trimEndFrames != 0 ? inputAudioFormat : AudioFormat.NOT_SET;
   }
 
   @Override
@@ -140,7 +133,6 @@ import java.nio.ByteBuffer;
     buffer.flip();
   }
 
-  @SuppressWarnings("ReferenceEquality")
   @Override
   public ByteBuffer getOutput() {
     if (super.isEnded() && endBufferSize > 0) {
@@ -155,7 +147,6 @@ import java.nio.ByteBuffer;
     return super.getOutput();
   }
 
-  @SuppressWarnings("ReferenceEquality")
   @Override
   public boolean isEnded() {
     return super.isEnded() && endBufferSize == 0;

library/core/src/test/java/com/google/android/exoplayer2/audio/SonicAudioProcessorTest.java

@@ -20,6 +20,8 @@ import static org.junit.Assert.fail;
 
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.audio.AudioProcessor.AudioFormat;
+import com.google.android.exoplayer2.audio.AudioProcessor.UnhandledAudioFormatException;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -28,6 +30,16 @@ import org.junit.runner.RunWith;
 @RunWith(AndroidJUnit4.class)
 public final class SonicAudioProcessorTest {
 
+  private static final AudioFormat AUDIO_FORMAT_22050_HZ =
+      new AudioFormat(
+          /* sampleRate= */ 22050, /* channelCount= */ 2, /* encoding= */ C.ENCODING_PCM_16BIT);
+  private static final AudioFormat AUDIO_FORMAT_44100_HZ =
+      new AudioFormat(
+          /* sampleRate= */ 44100, /* channelCount= */ 2, /* encoding= */ C.ENCODING_PCM_16BIT);
+  private static final AudioFormat AUDIO_FORMAT_48000_HZ =
+      new AudioFormat(
+          /* sampleRate= */ 48000, /* channelCount= */ 2, /* encoding= */ C.ENCODING_PCM_16BIT);
+
   private SonicAudioProcessor sonicAudioProcessor;
 
   @Before
@@ -39,59 +51,36 @@ public final class SonicAudioProcessorTest {
   public void testReconfigureWithSameSampleRate() throws Exception {
     // When configured for resampling from 44.1 kHz to 48 kHz, the output sample rate is correct.
     sonicAudioProcessor.setOutputSampleRateHz(48000);
-    sonicAudioProcessor.configure(44100, 2, C.ENCODING_PCM_16BIT);
-    assertThat(sonicAudioProcessor.getOutputSampleRateHz()).isEqualTo(48000);
+    AudioFormat outputAudioFormat = sonicAudioProcessor.configure(AUDIO_FORMAT_44100_HZ);
     assertThat(sonicAudioProcessor.isActive()).isTrue();
+    assertThat(outputAudioFormat.sampleRate).isEqualTo(48000);
     // When reconfigured with 48 kHz input, there is no resampling.
-    sonicAudioProcessor.configure(48000, 2, C.ENCODING_PCM_16BIT);
-    assertThat(sonicAudioProcessor.getOutputSampleRateHz()).isEqualTo(48000);
+    outputAudioFormat = sonicAudioProcessor.configure(AUDIO_FORMAT_48000_HZ);
     assertThat(sonicAudioProcessor.isActive()).isFalse();
+    assertThat(outputAudioFormat.sampleRate).isEqualTo(48000);
     // When reconfigure with 44.1 kHz input, resampling is enabled again.
-    sonicAudioProcessor.configure(44100, 2, C.ENCODING_PCM_16BIT);
-    assertThat(sonicAudioProcessor.getOutputSampleRateHz()).isEqualTo(48000);
+    outputAudioFormat = sonicAudioProcessor.configure(AUDIO_FORMAT_44100_HZ);
     assertThat(sonicAudioProcessor.isActive()).isTrue();
+    assertThat(outputAudioFormat.sampleRate).isEqualTo(48000);
   }
 
   @Test
   public void testNoSampleRateChange() throws Exception {
     // Configure for resampling 44.1 kHz to 48 kHz.
     sonicAudioProcessor.setOutputSampleRateHz(48000);
-    sonicAudioProcessor.configure(44100, 2, C.ENCODING_PCM_16BIT);
+    sonicAudioProcessor.configure(AUDIO_FORMAT_44100_HZ);
+    assertThat(sonicAudioProcessor.isActive()).isTrue();
     // Reconfigure to not modify the sample rate.
     sonicAudioProcessor.setOutputSampleRateHz(SonicAudioProcessor.SAMPLE_RATE_NO_CHANGE);
-    sonicAudioProcessor.configure(22050, 2, C.ENCODING_PCM_16BIT);
+    sonicAudioProcessor.configure(AUDIO_FORMAT_22050_HZ);
     // The sample rate is unmodified, and the audio processor is not active.
-    assertThat(sonicAudioProcessor.getOutputSampleRateHz()).isEqualTo(22050);
-    assertThat(sonicAudioProcessor.isActive()).isFalse();
-  }
-
-  @Test
-  public void testBecomesActiveAfterConfigure() throws Exception {
-    sonicAudioProcessor.configure(44100, 2, C.ENCODING_PCM_16BIT);
-    // Set a new sample rate.
-    sonicAudioProcessor.setOutputSampleRateHz(22050);
-    // The new sample rate is not active yet.
     assertThat(sonicAudioProcessor.isActive()).isFalse();
-    assertThat(sonicAudioProcessor.getOutputSampleRateHz()).isEqualTo(44100);
-  }
-
-  @Test
-  public void testSampleRateChangeBecomesActiveAfterConfigure() throws Exception {
-    // Configure for resampling 44.1 kHz to 48 kHz.
-    sonicAudioProcessor.setOutputSampleRateHz(48000);
-    sonicAudioProcessor.configure(44100, 2, C.ENCODING_PCM_16BIT);
-    // Set a new sample rate, which isn't active yet.
-    sonicAudioProcessor.setOutputSampleRateHz(22050);
-    assertThat(sonicAudioProcessor.getOutputSampleRateHz()).isEqualTo(48000);
-    // The new sample rate takes effect on reconfiguration.
-    sonicAudioProcessor.configure(44100, 2, C.ENCODING_PCM_16BIT);
-    assertThat(sonicAudioProcessor.getOutputSampleRateHz()).isEqualTo(22050);
   }
 
   @Test
   public void testIsActiveWithSpeedChange() throws Exception {
     sonicAudioProcessor.setSpeed(1.5f);
-    sonicAudioProcessor.configure(44100, 2, C.ENCODING_PCM_16BIT);
+    sonicAudioProcessor.configure(AUDIO_FORMAT_44100_HZ);
     sonicAudioProcessor.flush();
     assertThat(sonicAudioProcessor.isActive()).isTrue();
   }
@@ -99,35 +88,45 @@ public final class SonicAudioProcessorTest {
   @Test
   public void testIsActiveWithPitchChange() throws Exception {
     sonicAudioProcessor.setPitch(1.5f);
-    sonicAudioProcessor.configure(44100, 2, C.ENCODING_PCM_16BIT);
+    sonicAudioProcessor.configure(AUDIO_FORMAT_44100_HZ);
     sonicAudioProcessor.flush();
     assertThat(sonicAudioProcessor.isActive()).isTrue();
   }
 
   @Test
   public void testIsNotActiveWithNoChange() throws Exception {
-    sonicAudioProcessor.configure(44100, 2, C.ENCODING_PCM_16BIT);
+    sonicAudioProcessor.configure(AUDIO_FORMAT_44100_HZ);
     assertThat(sonicAudioProcessor.isActive()).isFalse();
   }
 
   @Test
   public void testDoesNotSupportNon16BitInput() throws Exception {
     try {
-      sonicAudioProcessor.configure(44100, 2, C.ENCODING_PCM_8BIT);
+      sonicAudioProcessor.configure(
+          new AudioFormat(
+              /* sampleRate= */ 44100, /* channelCount= */ 2, /* encoding= */ C.ENCODING_PCM_8BIT));
       fail();
-    } catch (AudioProcessor.UnhandledFormatException e) {
+    } catch (UnhandledAudioFormatException e) {
       // Expected.
     }
     try {
-      sonicAudioProcessor.configure(44100, 2, C.ENCODING_PCM_24BIT);
+      sonicAudioProcessor.configure(
+          new AudioFormat(
+              /* sampleRate= */ 44100,
+              /* channelCount= */ 2,
+              /* encoding= */ C.ENCODING_PCM_24BIT));
       fail();
-    } catch (AudioProcessor.UnhandledFormatException e) {
+    } catch (UnhandledAudioFormatException e) {
       // Expected.
     }
     try {
-      sonicAudioProcessor.configure(44100, 2, C.ENCODING_PCM_32BIT);
+      sonicAudioProcessor.configure(
+          new AudioFormat(
+              /* sampleRate= */ 44100,
+              /* channelCount= */ 2,
+              /* encoding= */ C.ENCODING_PCM_32BIT));
       fail();
-    } catch (AudioProcessor.UnhandledFormatException e) {
+    } catch (UnhandledAudioFormatException e) {
       // Expected.
     }
   }