Add start() method in MediaCodecAdapter

PiperOrigin-RevId: 288476415

Add start() method in MediaCodecAdapter
PiperOrigin-RevId: 288476415
fb42f818 · christosts · Oliver Woodman · c5535e82 · fb42f818 · fb42f818
Commit fb42f818 authored Jan 07, 2020 by christosts Committed by Oliver Woodman Jan 08, 2020
Showing with 135 additions and 357 deletions
library/core/src/main/java/com/google/android/exoplayer2/mediacodec/AsynchronousMediaCodecAdapter.java
library/core/src/main/java/com/google/android/exoplayer2/mediacodec/DedicatedThreadAsyncMediaCodecAdapter.java
library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecAdapter.java
library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecRenderer.java
library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MultiLockAsyncMediaCodecAdapter.java
library/core/src/main/java/com/google/android/exoplayer2/mediacodec/SynchronousMediaCodecAdapter.java
library/core/src/test/java/com/google/android/exoplayer2/mediacodec/AsynchronousMediaCodecAdapterTest.java
library/core/src/test/java/com/google/android/exoplayer2/mediacodec/DedicatedThreadAsyncMediaCodecAdapterTest.java
library/core/src/test/java/com/google/android/exoplayer2/mediacodec/MultiLockAsyncMediaCodecAdapterTest.java
--- a/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/AsynchronousMediaCodecAdapter.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/AsynchronousMediaCodecAdapter.java
@@ -38,7 +38,7 @@ import com.google.android.exoplayer2.util.Assertions;
  private final MediaCodec codec;
  @Nullable private IllegalStateException internalException;
  private boolean flushing;
-  private Runnable onCodecStart;
+  private Runnable codecStartRunnable;
  /**
   * Create a new {@code AsynchronousMediaCodecAdapter}.
@@ -55,7 +55,12 @@ import com.google.android.exoplayer2.util.Assertions;
    handler = new Handler(looper);
    this.codec = codec;
    this.codec.setCallback(mediaCodecAsyncCallback);
-    onCodecStart = () -> codec.start();
+    codecStartRunnable = codec::start;
+  }
+  @Override
+  public void start() {
+    codecStartRunnable.run();
  }
  @Override
@@ -105,7 +110,7 @@ import com.google.android.exoplayer2.util.Assertions;
    flushing = false;
    mediaCodecAsyncCallback.flush();
    try {
-      onCodecStart.run();
+      codecStartRunnable.run();
    } catch (IllegalStateException e) {
      // Catch IllegalStateException directly so that we don't have to wrap it.
      internalException = e;
@@ -115,8 +120,8 @@ import com.google.android.exoplayer2.util.Assertions;
  }
  @VisibleForTesting
-  /* package */ void setOnCodecStart(Runnable onCodecStart) {
+  /* package */ void setCodecStartRunnable(Runnable codecStartRunnable) {
-    this.onCodecStart = onCodecStart;
+    this.codecStartRunnable = codecStartRunnable;
  }
  private void maybeThrowException() throws IllegalStateException {

--- a/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/DedicatedThreadAsyncMediaCodecAdapter.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/DedicatedThreadAsyncMediaCodecAdapter.java
@@ -26,7 +26,6 @@ import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
 import androidx.annotation.VisibleForTesting;
 import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
@@ -54,7 +53,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
  @MonotonicNonNull private Handler handler;
  private long pendingFlushCount;
  private @State int state;
-  private Runnable onCodecStart;
+  private Runnable codecStartRunnable;
  @Nullable private IllegalStateException internalException;
  /**
@@ -77,31 +76,20 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
    this.codec = codec;
    this.handlerThread = handlerThread;
    state = STATE_CREATED;
-    onCodecStart = codec::start;
+    codecStartRunnable = codec::start;
  }
-  /**
+  @Override
-   * Starts the operation of the instance.
-   *
-   * <p>After a call to this method, make sure to call {@link #shutdown()} to terminate the internal
-   * Thread. You can only call this method once during the lifetime of this instance; calling this
-   * method again will throw an {@link IllegalStateException}.
-   *
-   * @throws IllegalStateException If this method has been called already.
-   */
  public synchronized void start() {
-    Assertions.checkState(state == STATE_CREATED);
    handlerThread.start();
    handler = new Handler(handlerThread.getLooper());
    codec.setCallback(this, handler);
+    codecStartRunnable.run();
    state = STATE_STARTED;
  }
  @Override
  public synchronized int dequeueInputBufferIndex() {
-    Assertions.checkState(state == STATE_STARTED);
    if (isFlushing()) {
      return MediaCodec.INFO_TRY_AGAIN_LATER;
    } else {
@@ -112,8 +100,6 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
  @Override
  public synchronized int dequeueOutputBufferIndex(MediaCodec.BufferInfo bufferInfo) {
-    Assertions.checkState(state == STATE_STARTED);
    if (isFlushing()) {
      return MediaCodec.INFO_TRY_AGAIN_LATER;
    } else {
@@ -124,15 +110,11 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
  @Override
  public synchronized MediaFormat getOutputFormat() {
-    Assertions.checkState(state == STATE_STARTED);
    return mediaCodecAsyncCallback.getOutputFormat();
  }
  @Override
  public synchronized void flush() {
-    Assertions.checkState(state == STATE_STARTED);
    codec.flush();
    ++pendingFlushCount;
    Util.castNonNull(handler).post(this::onFlushCompleted);
@@ -177,8 +159,8 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
  }
  @VisibleForTesting
-  /* package */ void setOnCodecStart(Runnable onCodecStart) {
+  /* package */ void setCodecStartRunnable(Runnable codecStartRunnable) {
-    this.onCodecStart = onCodecStart;
+    this.codecStartRunnable = codecStartRunnable;
  }
  private synchronized void onFlushCompleted() {
@@ -199,7 +181,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
    mediaCodecAsyncCallback.flush();
    try {
-      onCodecStart.run();
+      codecStartRunnable.run();
    } catch (IllegalStateException e) {
      internalException = e;
    } catch (Exception e) {

--- a/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecAdapter.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecAdapter.java
@@ -32,6 +32,13 @@ import android.media.MediaFormat;
 /* package */ interface MediaCodecAdapter {
  /**
+   * Starts this instance.
+   *
+   * @see MediaCodec#start().
+   */
+  void start();
+  /**
   * Returns the next available input buffer index from the underlying {@link MediaCodec} or {@link
   * MediaCodec#INFO_TRY_AGAIN_LATER} if no such buffer exists.
   *

--- a/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecRenderer.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecRenderer.java
@@ -995,11 +995,9 @@ public abstract class MediaCodecRenderer extends BaseRenderer {
      } else if (mediaCodecOperationMode == OPERATION_MODE_ASYNCHRONOUS_DEDICATED_THREAD
          && Util.SDK_INT >= 23) {
        codecAdapter = new DedicatedThreadAsyncMediaCodecAdapter(codec, getTrackType());
-        ((DedicatedThreadAsyncMediaCodecAdapter) codecAdapter).start();
      } else if (mediaCodecOperationMode == OPERATION_MODE_ASYNCHRONOUS_DEDICATED_THREAD_MULTI_LOCK
          && Util.SDK_INT >= 23) {
        codecAdapter = new MultiLockAsyncMediaCodecAdapter(codec, getTrackType());
-        ((MultiLockAsyncMediaCodecAdapter) codecAdapter).start();
      } else {
        codecAdapter = new SynchronousMediaCodecAdapter(codec);
      }
@@ -1009,7 +1007,7 @@ public abstract class MediaCodecRenderer extends BaseRenderer {
      configureCodec(codecInfo, codec, inputFormat, crypto, codecOperatingRate);
      TraceUtil.endSection();
      TraceUtil.beginSection("startCodec");
-      codec.start();
+      codecAdapter.start();
      TraceUtil.endSection();
      codecInitializedTimestamp = SystemClock.elapsedRealtime();
      getCodecBuffers(codec);

--- a/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MultiLockAsyncMediaCodecAdapter.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MultiLockAsyncMediaCodecAdapter.java
@@ -27,7 +27,6 @@ import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
 import androidx.annotation.VisibleForTesting;
 import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.IntArrayQueue;
 import com.google.android.exoplayer2.util.Util;
 import java.util.ArrayDeque;
@@ -94,7 +93,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
  private final HandlerThread handlerThread;
  @MonotonicNonNull private Handler handler;
-  private Runnable onCodecStart;
+  private Runnable codecStartRunnable;
  /** Creates a new instance that wraps the specified {@link MediaCodec}. */
  /* package */ MultiLockAsyncMediaCodecAdapter(MediaCodec codec, int trackType) {
@@ -114,25 +113,16 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
    codecException = null;
    state = STATE_CREATED;
    this.handlerThread = handlerThread;
-    onCodecStart = codec::start;
+    codecStartRunnable = codec::start;
  }
-  /**
+  @Override
-   * Starts the operation of this instance.
-   *
-   * <p>After a call to this method, make sure to call {@link #shutdown()} to terminate the internal
-   * Thread. You can only call this method once during the lifetime of an instance; calling this
-   * method again will throw an {@link IllegalStateException}.
-   *
-   * @throws IllegalStateException If this method has been called already.
-   */
  public void start() {
    synchronized (objectStateLock) {
-      Assertions.checkState(state == STATE_CREATED);
      handlerThread.start();
      handler = new Handler(handlerThread.getLooper());
      codec.setCallback(this, handler);
+      codecStartRunnable.run();
      state = STATE_STARTED;
    }
  }
@@ -140,8 +130,6 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
  @Override
  public int dequeueInputBufferIndex() {
    synchronized (objectStateLock) {
-      Assertions.checkState(state == STATE_STARTED);
      if (isFlushing()) {
        return MediaCodec.INFO_TRY_AGAIN_LATER;
      } else {
@@ -154,8 +142,6 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
  @Override
  public int dequeueOutputBufferIndex(MediaCodec.BufferInfo bufferInfo) {
    synchronized (objectStateLock) {
-      Assertions.checkState(state == STATE_STARTED);
      if (isFlushing()) {
        return MediaCodec.INFO_TRY_AGAIN_LATER;
      } else {
@@ -168,8 +154,6 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
  @Override
  public MediaFormat getOutputFormat() {
    synchronized (objectStateLock) {
-      Assertions.checkState(state == STATE_STARTED);
      if (currentFormat == null) {
        throw new IllegalStateException();
      }
@@ -181,8 +165,6 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
  @Override
  public void flush() {
    synchronized (objectStateLock) {
-      Assertions.checkState(state == STATE_STARTED);
      codec.flush();
      pendingFlush++;
      Util.castNonNull(handler).post(this::onFlushComplete);
@@ -200,8 +182,8 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
  }
  @VisibleForTesting
-  /* package */ void setOnCodecStart(Runnable onCodecStart) {
+  /* package */ void setCodecStartRunnable(Runnable codecStartRunnable) {
-    this.onCodecStart = onCodecStart;
+    this.codecStartRunnable = codecStartRunnable;
  }
  private int dequeueAvailableInputBufferIndex() {
@@ -307,7 +289,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
      clearAvailableOutput();
      codecException = null;
      try {
-        onCodecStart.run();
+        codecStartRunnable.run();
      } catch (IllegalStateException e) {
        codecException = e;
      } catch (Exception e) {

--- a/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/SynchronousMediaCodecAdapter.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/mediacodec/SynchronousMediaCodecAdapter.java
@@ -23,6 +23,7 @@ import android.media.MediaFormat;
 * A {@link MediaCodecAdapter} that operates the underlying {@link MediaCodec} in synchronous mode.
 */
 /* package */ final class SynchronousMediaCodecAdapter implements MediaCodecAdapter {
  private final MediaCodec codec;
  public SynchronousMediaCodecAdapter(MediaCodec mediaCodec) {
@@ -30,6 +31,11 @@ import android.media.MediaFormat;
  }
  @Override
+  public void start() {
+    codec.start();
+  }
+  @Override
  public int dequeueInputBufferIndex() {
    return codec.dequeueInputBuffer(0);
  }

--- a/library/core/src/test/java/com/google/android/exoplayer2/mediacodec/AsynchronousMediaCodecAdapterTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/mediacodec/AsynchronousMediaCodecAdapterTest.java
@@ -19,7 +19,7 @@ package com.google.android.exoplayer2.mediacodec;
 import static com.google.android.exoplayer2.mediacodec.MediaCodecTestUtils.areEqual;
 import static com.google.android.exoplayer2.mediacodec.MediaCodecTestUtils.waitUntilAllEventsAreExecuted;
 import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.fail;
+import static org.junit.Assert.assertThrows;
 import android.media.MediaCodec;
 import android.media.MediaFormat;
@@ -29,7 +29,7 @@ import android.os.Looper;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import java.io.IOException;
 import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -45,27 +45,32 @@ public class AsynchronousMediaCodecAdapterTest {
  private MediaCodec.BufferInfo bufferInfo;
  @Before
-  public void setup() throws IOException {
+  public void setUp() throws IOException {
    handlerThread = new HandlerThread("TestHandlerThread");
    handlerThread.start();
    looper = handlerThread.getLooper();
    codec = MediaCodec.createByCodecName("h264");
    adapter = new AsynchronousMediaCodecAdapter(codec, looper);
+    adapter.setCodecStartRunnable(() -> {});
    bufferInfo = new MediaCodec.BufferInfo();
  }
  @After
  public void tearDown() {
+    adapter.shutdown();
    handlerThread.quit();
  }
  @Test
  public void dequeueInputBufferIndex_withoutInputBuffer_returnsTryAgainLater() {
+    adapter.start();
    assertThat(adapter.dequeueInputBufferIndex()).isEqualTo(MediaCodec.INFO_TRY_AGAIN_LATER);
  }
  @Test
  public void dequeueInputBufferIndex_withInputBuffer_returnsInputBuffer() {
+    adapter.start();
    adapter.getMediaCodecCallback().onInputBufferAvailable(codec, /* index=*/ 0);
    assertThat(adapter.dequeueInputBufferIndex()).isEqualTo(0);
@@ -73,6 +78,7 @@ public class AsynchronousMediaCodecAdapterTest {
  @Test
  public void dequeueInputBufferIndex_whileFlushing_returnsTryAgainLater() {
+    adapter.start();
    adapter.getMediaCodecCallback().onInputBufferAvailable(codec, /* index=*/ 0);
    adapter.flush();
    adapter.getMediaCodecCallback().onInputBufferAvailable(codec, /* index=*/ 1);
@@ -83,9 +89,7 @@ public class AsynchronousMediaCodecAdapterTest {
  @Test
  public void dequeueInputBufferIndex_afterFlushCompletes_returnsNextInputBuffer()
      throws InterruptedException {
-    // Disable calling codec.start() after flush() completes to avoid receiving buffers from the
+    adapter.start();
-    // shadow codec impl
-    adapter.setOnCodecStart(() -> {});
    Handler handler = new Handler(looper);
    handler.post(
        () -> adapter.getMediaCodecCallback().onInputBufferAvailable(codec, /* index=*/ 0));
@@ -100,28 +104,35 @@ public class AsynchronousMediaCodecAdapterTest {
  @Test
  public void dequeueInputBufferIndex_afterFlushCompletesWithError_throwsException()
      throws InterruptedException {
-    adapter.setOnCodecStart(
+    AtomicInteger calls = new AtomicInteger(0);
+    adapter.setCodecStartRunnable(
        () -> {
-          throw new IllegalStateException("codec#start() exception");
+          if (calls.incrementAndGet() == 2) {
+            throw new IllegalStateException();
+          }
        });
+    adapter.start();
    adapter.flush();
    assertThat(waitUntilAllEventsAreExecuted(looper, /* time= */ 5, TimeUnit.SECONDS)).isTrue();
-    try {
+    assertThrows(
-      adapter.dequeueInputBufferIndex();
+        IllegalStateException.class,
-      fail();
+        () -> {
-    } catch (IllegalStateException expected) {
+          adapter.dequeueInputBufferIndex();
-    }
+        });
  }
  @Test
  public void dequeueOutputBufferIndex_withoutOutputBuffer_returnsTryAgainLater() {
+    adapter.start();
    assertThat(adapter.dequeueOutputBufferIndex(bufferInfo))
        .isEqualTo(MediaCodec.INFO_TRY_AGAIN_LATER);
  }
  @Test
  public void dequeueOutputBufferIndex_withOutputBuffer_returnsOutputBuffer() {
+    adapter.start();
    MediaCodec.BufferInfo outBufferInfo = new MediaCodec.BufferInfo();
    outBufferInfo.presentationTimeUs = 10;
    adapter.getMediaCodecCallback().onOutputBufferAvailable(codec, /* index=*/ 0, outBufferInfo);
@@ -132,6 +143,7 @@ public class AsynchronousMediaCodecAdapterTest {
  @Test
  public void dequeueOutputBufferIndex_whileFlushing_returnsTryAgainLater() {
+    adapter.start();
    adapter.getMediaCodecCallback().onOutputBufferAvailable(codec, /* index=*/ 0, bufferInfo);
    adapter.flush();
    adapter.getMediaCodecCallback().onOutputBufferAvailable(codec, /* index=*/ 1, bufferInfo);
@@ -143,9 +155,7 @@ public class AsynchronousMediaCodecAdapterTest {
  @Test
  public void dequeueOutputBufferIndex_afterFlushCompletes_returnsNextOutputBuffer()
      throws InterruptedException {
-    // Disable calling codec.start() after flush() completes to avoid receiving buffers from the
+    adapter.start();
-    // shadow codec impl
-    adapter.setOnCodecStart(() -> {});
    Handler handler = new Handler(looper);
    MediaCodec.BufferInfo info0 = new MediaCodec.BufferInfo();
    handler.post(
@@ -164,31 +174,23 @@ public class AsynchronousMediaCodecAdapterTest {
  @Test
  public void dequeueOutputBufferIndex_afterFlushCompletesWithError_throwsException()
      throws InterruptedException {
-    adapter.setOnCodecStart(
+    AtomicInteger calls = new AtomicInteger(0);
+    adapter.setCodecStartRunnable(
        () -> {
-          throw new RuntimeException("codec#start() exception");
+          if (calls.incrementAndGet() == 2) {
+            throw new RuntimeException("codec#start() exception");
+          }
        });
+    adapter.start();
    adapter.flush();
    assertThat(waitUntilAllEventsAreExecuted(looper, /* time= */ 5, TimeUnit.SECONDS)).isTrue();
-    try {
+    assertThrows(IllegalStateException.class, () -> adapter.dequeueOutputBufferIndex(bufferInfo));
-      adapter.dequeueOutputBufferIndex(bufferInfo);
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
-  public void getOutputFormat_withoutFormat_throwsException() {
-    try {
-      adapter.getOutputFormat();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
  }
  @Test
  public void getOutputFormat_withMultipleFormats_returnsFormatsInCorrectOrder() {
+    adapter.start();
    MediaFormat[] formats = new MediaFormat[10];
    MediaCodec.Callback mediaCodecCallback = adapter.getMediaCodecCallback();
    for (int i = 0; i < formats.length; i++) {
@@ -212,6 +214,7 @@ public class AsynchronousMediaCodecAdapterTest {
  @Test
  public void getOutputFormat_afterFlush_returnsPreviousFormat() throws InterruptedException {
+    adapter.start();
    MediaFormat format = new MediaFormat();
    adapter.getMediaCodecCallback().onOutputFormatChanged(codec, format);
    adapter.dequeueOutputBufferIndex(bufferInfo);
@@ -223,13 +226,13 @@ public class AsynchronousMediaCodecAdapterTest {
  @Test
  public void shutdown_withPendingFlush_cancelsFlush() throws InterruptedException {
-    AtomicBoolean onCodecStartCalled = new AtomicBoolean(false);
+    AtomicInteger onCodecStartCalled = new AtomicInteger(0);
-    Runnable onCodecStart = () -> onCodecStartCalled.set(true);
+    adapter.setCodecStartRunnable(() -> onCodecStartCalled.incrementAndGet());
-    adapter.setOnCodecStart(onCodecStart);
+    adapter.start();
    adapter.flush();
    adapter.shutdown();
    assertThat(waitUntilAllEventsAreExecuted(looper, /* time= */ 5, TimeUnit.SECONDS)).isTrue();
-    assertThat(onCodecStartCalled.get()).isFalse();
+    assertThat(onCodecStartCalled.get()).isEqualTo(1);
  }
 }
--- a/library/core/src/test/java/com/google/android/exoplayer2/mediacodec/DedicatedThreadAsyncMediaCodecAdapterTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/mediacodec/DedicatedThreadAsyncMediaCodecAdapterTest.java
@@ -19,7 +19,7 @@ package com.google.android.exoplayer2.mediacodec;
 import static com.google.android.exoplayer2.mediacodec.MediaCodecTestUtils.areEqual;
 import static com.google.android.exoplayer2.mediacodec.MediaCodecTestUtils.waitUntilAllEventsAreExecuted;
 import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.fail;
+import static org.junit.Assert.assertThrows;
 import static org.robolectric.Shadows.shadowOf;
 import android.media.MediaCodec;
@@ -47,16 +47,18 @@ public class DedicatedThreadAsyncMediaCodecAdapterTest {
  private MediaCodec.BufferInfo bufferInfo = null;
  @Before
-  public void setup() throws IOException {
+  public void setUp() throws IOException {
    codec = MediaCodec.createByCodecName("h264");
    handlerThread = new TestHandlerThread("TestHandlerThread");
    adapter = new DedicatedThreadAsyncMediaCodecAdapter(codec, handlerThread);
+    adapter.setCodecStartRunnable(() -> {});
    bufferInfo = new MediaCodec.BufferInfo();
  }
  @After
  public void tearDown() {
    adapter.shutdown();
    assertThat(TestHandlerThread.INSTANCES_STARTED.get()).isEqualTo(0);
  }
@@ -67,41 +69,14 @@ public class DedicatedThreadAsyncMediaCodecAdapterTest {
  }
  @Test
-  public void start_calledTwice_throwsException() {
-    adapter.start();
-    try {
-      adapter.start();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
-  public void dequeueInputBufferIndex_withoutStart_throwsException() {
-    try {
-      adapter.dequeueInputBufferIndex();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
-  public void dequeueInputBufferIndex_afterShutdown_throwsException() {
-    adapter.start();
-    adapter.shutdown();
-    try {
-      adapter.dequeueInputBufferIndex();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
  public void dequeueInputBufferIndex_withAfterFlushFailed_throwsException()
      throws InterruptedException {
-    adapter.setOnCodecStart(
+    AtomicInteger codecStartCalls = new AtomicInteger(0);
+    adapter.setCodecStartRunnable(
        () -> {
-          throw new IllegalStateException("codec#start() exception");
+          if (codecStartCalls.incrementAndGet() == 2) {
+            throw new IllegalStateException("codec#start() exception");
+          }
        });
    adapter.start();
    adapter.flush();
@@ -110,11 +85,8 @@ public class DedicatedThreadAsyncMediaCodecAdapterTest {
            waitUntilAllEventsAreExecuted(
                handlerThread.getLooper(), /* time= */ 5, TimeUnit.SECONDS))
        .isTrue();
-    try {
-      adapter.dequeueInputBufferIndex();
+    assertThrows(IllegalStateException.class, () -> adapter.dequeueInputBufferIndex());
-      fail();
-    } catch (IllegalStateException expected) {
-    }
  }
  @Test
@@ -144,9 +116,6 @@ public class DedicatedThreadAsyncMediaCodecAdapterTest {
  @Test
  public void dequeueInputBufferIndex_withFlushCompletedAndInputBuffer_returnsInputBuffer()
      throws InterruptedException {
-    // Disable calling codec.start() after flush to avoid receiving buffers from the
-    // shadow codec impl
-    adapter.setOnCodecStart(() -> {});
    adapter.start();
    Looper looper = handlerThread.getLooper();
    Handler handler = new Handler(looper);
@@ -169,39 +138,18 @@ public class DedicatedThreadAsyncMediaCodecAdapterTest {
    adapter.start();
    adapter.onMediaCodecError(new IllegalStateException("error from codec"));
-    try {
+    assertThrows(IllegalStateException.class, () -> adapter.dequeueInputBufferIndex());
-      adapter.dequeueInputBufferIndex();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
-  public void dequeueOutputBufferIndex_withoutStart_throwsException() {
-    try {
-      adapter.dequeueOutputBufferIndex(bufferInfo);
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
-  public void dequeueOutputBufferIndex_afterShutdown_throwsException() {
-    adapter.start();
-    adapter.shutdown();
-    try {
-      adapter.dequeueOutputBufferIndex(bufferInfo);
-      fail();
-    } catch (IllegalStateException expected) {
-    }
  }
  @Test
  public void dequeueOutputBufferIndex_withInternalException_throwsException()
      throws InterruptedException {
-    adapter.setOnCodecStart(
+    AtomicInteger codecStartCalls = new AtomicInteger(0);
+    adapter.setCodecStartRunnable(
        () -> {
-          throw new RuntimeException("codec#start() exception");
+          if (codecStartCalls.incrementAndGet() == 2) {
+            throw new RuntimeException("codec#start() exception");
+          }
        });
    adapter.start();
    adapter.flush();
@@ -210,11 +158,7 @@ public class DedicatedThreadAsyncMediaCodecAdapterTest {
            waitUntilAllEventsAreExecuted(
                handlerThread.getLooper(), /* time= */ 5, TimeUnit.SECONDS))
        .isTrue();
-    try {
+    assertThrows(IllegalStateException.class, () -> adapter.dequeueOutputBufferIndex(bufferInfo));
-      adapter.dequeueOutputBufferIndex(bufferInfo);
-      fail();
-    } catch (IllegalStateException expected) {
-    }
  }
  @Test
@@ -275,42 +219,14 @@ public class DedicatedThreadAsyncMediaCodecAdapterTest {
    adapter.start();
    adapter.onMediaCodecError(new IllegalStateException("error from codec"));
-    try {
+    assertThrows(IllegalStateException.class, () -> adapter.dequeueOutputBufferIndex(bufferInfo));
-      adapter.dequeueOutputBufferIndex(bufferInfo);
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
-  public void getOutputFormat_withoutStart_throwsException() {
-    try {
-      adapter.getOutputFormat();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
-  public void getOutputFormat_afterShutdown_throwsException() {
-    adapter.start();
-    adapter.shutdown();
-    try {
-      adapter.getOutputFormat();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
  }
  @Test
  public void getOutputFormat_withoutFormatReceived_throwsException() {
    adapter.start();
-    try {
+    assertThrows(IllegalStateException.class, () -> adapter.getOutputFormat());
-      adapter.getOutputFormat();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
  }
  @Test
@@ -352,27 +268,9 @@ public class DedicatedThreadAsyncMediaCodecAdapterTest {
  }
  @Test
-  public void flush_withoutStarted_throwsException() {
-    try {
-      adapter.flush();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
-  public void flush_afterShutdown_throwsException() {
-    adapter.start();
-    adapter.shutdown();
-    try {
-      adapter.flush();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
  public void flush_multipleTimes_onlyLastFlushExecutes() throws InterruptedException {
-    AtomicInteger onCodecStartCount = new AtomicInteger(0);
+    AtomicInteger codecStartCalls = new AtomicInteger(0);
-    adapter.setOnCodecStart(() -> onCodecStartCount.incrementAndGet());
+    adapter.setCodecStartRunnable(() -> codecStartCalls.incrementAndGet());
    adapter.start();
    Looper looper = handlerThread.getLooper();
    Handler handler = new Handler(looper);
@@ -384,23 +282,23 @@ public class DedicatedThreadAsyncMediaCodecAdapterTest {
    adapter.flush(); // Enqueues a second flush event
    handler.post(() -> adapter.onInputBufferAvailable(codec, 3));
-    // Progress the looper until the milestoneCount is increased - first flush event
+    // Progress the looper until the milestoneCount is increased.
-    // should have been a no-op
+    // adapter.start() will call codec.start(). First flush event should not call codec.start().
    ShadowLooper shadowLooper = shadowOf(looper);
    while (milestoneCount.get() < 1) {
      shadowLooper.runOneTask();
    }
-    assertThat(onCodecStartCount.get()).isEqualTo(0);
+    assertThat(codecStartCalls.get()).isEqualTo(1);
    assertThat(waitUntilAllEventsAreExecuted(looper, /* time= */ 5, TimeUnit.SECONDS)).isTrue();
    assertThat(adapter.dequeueInputBufferIndex()).isEqualTo(3);
-    assertThat(onCodecStartCount.get()).isEqualTo(1);
+    assertThat(codecStartCalls.get()).isEqualTo(2);
  }
  @Test
  public void flush_andImmediatelyShutdown_flushIsNoOp() throws InterruptedException {
    AtomicInteger onCodecStartCount = new AtomicInteger(0);
-    adapter.setOnCodecStart(() -> onCodecStartCount.incrementAndGet());
+    adapter.setCodecStartRunnable(() -> onCodecStartCount.incrementAndGet());
    adapter.start();
    // Obtain looper when adapter is started
    Looper looper = handlerThread.getLooper();
@@ -408,8 +306,8 @@ public class DedicatedThreadAsyncMediaCodecAdapterTest {
    adapter.shutdown();
    assertThat(waitUntilAllEventsAreExecuted(looper, 5, TimeUnit.SECONDS)).isTrue();
-    // only shutdown flushes the MediaCodecAsync handler
+    // Only adapter.start() calls onCodecStart.
-    assertThat(onCodecStartCount.get()).isEqualTo(0);
+    assertThat(onCodecStartCount.get()).isEqualTo(1);
  }
  private static class TestHandlerThread extends HandlerThread {

--- a/library/core/src/test/java/com/google/android/exoplayer2/mediacodec/MultiLockAsyncMediaCodecAdapterTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/mediacodec/MultiLockAsyncMediaCodecAdapterTest.java
@@ -19,7 +19,7 @@ package com.google.android.exoplayer2.mediacodec;
 import static com.google.android.exoplayer2.mediacodec.MediaCodecTestUtils.areEqual;
 import static com.google.android.exoplayer2.mediacodec.MediaCodecTestUtils.waitUntilAllEventsAreExecuted;
 import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.fail;
+import static org.junit.Assert.assertThrows;
 import static org.robolectric.Shadows.shadowOf;
 import android.media.MediaCodec;
@@ -44,20 +44,21 @@ public class MultiLockAsyncMediaCodecAdapterTest {
  private MultiLockAsyncMediaCodecAdapter adapter;
  private MediaCodec codec;
  private MediaCodec.BufferInfo bufferInfo = null;
-  private MediaCodecAsyncCallback mediaCodecAsyncCallbackSpy;
  private TestHandlerThread handlerThread;
  @Before
-  public void setup() throws IOException {
+  public void setUp() throws IOException {
    codec = MediaCodec.createByCodecName("h264");
    handlerThread = new TestHandlerThread("TestHandlerThread");
    adapter = new MultiLockAsyncMediaCodecAdapter(codec, handlerThread);
+    adapter.setCodecStartRunnable(() -> {});
    bufferInfo = new MediaCodec.BufferInfo();
  }
  @After
  public void tearDown() {
    adapter.shutdown();
    assertThat(TestHandlerThread.INSTANCES_STARTED.get()).isEqualTo(0);
  }
@@ -68,41 +69,14 @@ public class MultiLockAsyncMediaCodecAdapterTest {
  }
  @Test
-  public void start_calledTwice_throwsException() {
-    adapter.start();
-    try {
-      adapter.start();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
-  public void dequeueInputBufferIndex_withoutStart_throwsException() {
-    try {
-      adapter.dequeueInputBufferIndex();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
-  public void dequeueInputBufferIndex_afterShutdown_throwsException() {
-    adapter.start();
-    adapter.shutdown();
-    try {
-      adapter.dequeueInputBufferIndex();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
  public void dequeueInputBufferIndex_withAfterFlushFailed_throwsException()
      throws InterruptedException {
-    adapter.setOnCodecStart(
+    AtomicInteger codecStartCalls = new AtomicInteger(0);
+    adapter.setCodecStartRunnable(
        () -> {
-          throw new IllegalStateException("codec#start() exception");
+          if (codecStartCalls.incrementAndGet() == 2) {
+            throw new IllegalStateException("codec#start() exception");
+          }
        });
    adapter.start();
    adapter.flush();
@@ -111,11 +85,7 @@ public class MultiLockAsyncMediaCodecAdapterTest {
            waitUntilAllEventsAreExecuted(
                handlerThread.getLooper(), /* time= */ 5, TimeUnit.SECONDS))
        .isTrue();
-    try {
+    assertThrows(IllegalStateException.class, () -> adapter.dequeueInputBufferIndex());
-      adapter.dequeueInputBufferIndex();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
  }
  @Test
@@ -145,9 +115,6 @@ public class MultiLockAsyncMediaCodecAdapterTest {
  @Test
  public void dequeueInputBufferIndex_withFlushCompletedAndInputBuffer_returnsInputBuffer()
      throws InterruptedException {
-    // Disable calling codec.start() after flush to avoid receiving buffers from the
-    // shadow codec impl
-    adapter.setOnCodecStart(() -> {});
    adapter.start();
    Looper looper = handlerThread.getLooper();
    Handler handler = new Handler(looper);
@@ -170,39 +137,19 @@ public class MultiLockAsyncMediaCodecAdapterTest {
    adapter.start();
    adapter.onMediaCodecError(new IllegalStateException("error from codec"));
-    try {
+    assertThrows(IllegalStateException.class, () -> adapter.dequeueInputBufferIndex());
-      adapter.dequeueInputBufferIndex();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
-  public void dequeueOutputBufferIndex_withoutStart_throwsException() {
-    try {
-      adapter.dequeueOutputBufferIndex(bufferInfo);
-      fail();
-    } catch (IllegalStateException expected) {
-    }
  }
-  @Test
-  public void dequeueOutputBufferIndex_afterShutdown_throwsException() {
-    adapter.start();
-    adapter.shutdown();
-    try {
-      adapter.dequeueOutputBufferIndex(bufferInfo);
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
  @Test
  public void dequeueOutputBufferIndex_withInternalException_throwsException()
      throws InterruptedException {
-    adapter.setOnCodecStart(
+    AtomicInteger codecStartCalls = new AtomicInteger(0);
+    adapter.setCodecStartRunnable(
        () -> {
-          throw new RuntimeException("codec#start() exception");
+          if (codecStartCalls.incrementAndGet() == 2) {
+            throw new RuntimeException("codec#start() exception");
+          }
        });
    adapter.start();
    adapter.flush();
@@ -211,11 +158,7 @@ public class MultiLockAsyncMediaCodecAdapterTest {
            waitUntilAllEventsAreExecuted(
                handlerThread.getLooper(), /* time= */ 5, TimeUnit.SECONDS))
        .isTrue();
-    try {
+    assertThrows(IllegalStateException.class, () -> adapter.dequeueOutputBufferIndex(bufferInfo));
-      adapter.dequeueOutputBufferIndex(bufferInfo);
-      fail();
-    } catch (IllegalStateException expected) {
-    }
  }
  @Test
@@ -276,42 +219,14 @@ public class MultiLockAsyncMediaCodecAdapterTest {
    adapter.start();
    adapter.onMediaCodecError(new IllegalStateException("error from codec"));
-    try {
+    assertThrows(IllegalStateException.class, () -> adapter.dequeueOutputBufferIndex(bufferInfo));
-      adapter.dequeueOutputBufferIndex(bufferInfo);
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
-  public void getOutputFormat_withoutStart_throwsException() {
-    try {
-      adapter.getOutputFormat();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
-  public void getOutputFormat_afterShutdown_throwsException() {
-    adapter.start();
-    adapter.shutdown();
-    try {
-      adapter.getOutputFormat();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
  }
  @Test
  public void getOutputFormat_withoutFormatReceived_throwsException() {
    adapter.start();
-    try {
+    assertThrows(IllegalStateException.class, () -> adapter.getOutputFormat());
-      adapter.getOutputFormat();
-      fail();
-    } catch (IllegalStateException expected) {
-    }
  }
  @Test
@@ -353,27 +268,9 @@ public class MultiLockAsyncMediaCodecAdapterTest {
  }
  @Test
-  public void flush_withoutStarted_throwsException() {
-    try {
-      adapter.flush();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
-  public void flush_afterShutdown_throwsException() {
-    adapter.start();
-    adapter.shutdown();
-    try {
-      adapter.flush();
-    } catch (IllegalStateException expected) {
-    }
-  }
-  @Test
  public void flush_multipleTimes_onlyLastFlushExecutes() throws InterruptedException {
-    AtomicInteger onCodecStartCount = new AtomicInteger(0);
+    AtomicInteger codecStartCalls = new AtomicInteger(0);
-    adapter.setOnCodecStart(() -> onCodecStartCount.incrementAndGet());
+    adapter.setCodecStartRunnable(() -> codecStartCalls.incrementAndGet());
    adapter.start();
    Looper looper = handlerThread.getLooper();
    Handler handler = new Handler(looper);
@@ -385,23 +282,23 @@ public class MultiLockAsyncMediaCodecAdapterTest {
    adapter.flush(); // Enqueues a second flush event
    handler.post(() -> adapter.onInputBufferAvailable(codec, 3));
-    // Progress the looper until the milestoneCount is increased - first flush event
+    // Progress the looper until the milestoneCount is increased:
-    // should have been a no-op
+    // adapter.start() called codec.start() but first flush event should have been a no-op
    ShadowLooper shadowLooper = shadowOf(looper);
    while (milestoneCount.get() < 1) {
      shadowLooper.runOneTask();
    }
-    assertThat(onCodecStartCount.get()).isEqualTo(0);
+    assertThat(codecStartCalls.get()).isEqualTo(1);
    assertThat(waitUntilAllEventsAreExecuted(looper, /* time= */ 5, TimeUnit.SECONDS)).isTrue();
    assertThat(adapter.dequeueInputBufferIndex()).isEqualTo(3);
-    assertThat(onCodecStartCount.get()).isEqualTo(1);
+    assertThat(codecStartCalls.get()).isEqualTo(2);
  }
  @Test
  public void flush_andImmediatelyShutdown_flushIsNoOp() throws InterruptedException {
-    AtomicInteger onCodecStartCount = new AtomicInteger(0);
+    AtomicInteger codecStartCalls = new AtomicInteger(0);
-    adapter.setOnCodecStart(() -> onCodecStartCount.incrementAndGet());
+    adapter.setCodecStartRunnable(() -> codecStartCalls.incrementAndGet());
    adapter.start();
    // Obtain looper when adapter is started.
    Looper looper = handlerThread.getLooper();
@@ -409,8 +306,8 @@ public class MultiLockAsyncMediaCodecAdapterTest {
    adapter.shutdown();
    assertThat(waitUntilAllEventsAreExecuted(looper, 5, TimeUnit.SECONDS)).isTrue();
-    // Only shutdown flushes the MediaCodecAsync handler.
+    // Only adapter.start() called codec#start()
-    assertThat(onCodecStartCount.get()).isEqualTo(0);
+    assertThat(codecStartCalls.get()).isEqualTo(1);
  }
  private static class TestHandlerThread extends HandlerThread {