Bump minSdk to 21 and remove resulting simple dead code

All other AndroidX libraries have already increased their min SDK to
21.

This change renames private symbols to remove `V21` suffixes and
similar, but doesn't change public or protected symbols with similar
names, to avoid needless breakages/churn on users of the library.

Some of the dead code removal is more complex, so I've split it out
into follow-up changes to make it easier to review.

PiperOrigin-RevId: 651776556

RELEASENOTES.md

@@ -11,6 +11,8 @@
     *   Add override for `SimpleBasePlayer.State.Builder.setPlaylist()` to
         directly specify a `Timeline` and current `Tracks` and `Metadata`
         instead of building a playlist structure.
+    *   Increase `minSdk` to 21 (Android Lollipop). This is aligned with all
+        other AndroidX libraries.
 *   ExoPlayer:
     *   `MediaCodecRenderer.onProcessedStreamChange()` can now be called for
         every media item. Previously it was not called for the first one. Use

api.txt

@@ -26,7 +26,7 @@ package androidx.media3.common {
   }
 
   public final class AudioAttributes {
-    method @RequiresApi(21) public androidx.media3.common.AudioAttributes.AudioAttributesV21 getAudioAttributesV21();
+    method public androidx.media3.common.AudioAttributes.AudioAttributesV21 getAudioAttributesV21();
     field public static final androidx.media3.common.AudioAttributes DEFAULT;
     field @androidx.media3.common.C.AudioAllowedCapturePolicy public final int allowedCapturePolicy;
     field @androidx.media3.common.C.AudioContentType public final int contentType;
@@ -35,7 +35,7 @@ package androidx.media3.common {
     field @androidx.media3.common.C.AudioUsage public final int usage;
   }
 
-  @RequiresApi(21) public static final class AudioAttributes.AudioAttributesV21 {
+  public static final class AudioAttributes.AudioAttributesV21 {
     field public final android.media.AudioAttributes audioAttributes;
   }
 

constants.gradle

@@ -14,7 +14,7 @@
 project.ext {
     releaseVersion = '1.4.0-rc01'
     releaseVersionCode = 1_004_000_2_01
-    minSdkVersion = 19
+    minSdkVersion = 21
     // See https://developer.android.com/training/cars/media/automotive-os#automotive-module
     automotiveMinSdkVersion = 28
     appTargetSdkVersion = 34

demos/main/src/main/java/androidx/media3/demo/main/DemoDownloadService.java

@@ -63,7 +63,7 @@ public class DemoDownloadService extends DownloadService {
 
   @Override
   protected Scheduler getScheduler() {
-    return Util.SDK_INT >= 21 ? new PlatformScheduler(this, JOB_ID) : null;
+    return new PlatformScheduler(this, JOB_ID);
   }
 
   @Override

libraries/common/src/main/java/androidx/media3/common/AudioAttributes.java

@@ -37,7 +37,6 @@ import com.google.errorprone.annotations.CanIgnoreReturnValue;
 public final class AudioAttributes {
 
   /** A direct wrapper around {@link android.media.AudioAttributes}. */
-  @RequiresApi(21)
   public static final class AudioAttributesV21 {
     public final android.media.AudioAttributes audioAttributes;
 
@@ -165,7 +164,6 @@ public final class AudioAttributes {
    * <p>Some fields are ignored if the corresponding {@link android.media.AudioAttributes.Builder}
    * setter is not available on the current API level.
    */
-  @RequiresApi(21)
   public AudioAttributesV21 getAudioAttributesV21() {
     if (audioAttributesV21 == null) {
       audioAttributesV21 = new AudioAttributesV21(this);

libraries/common/src/main/java/androidx/media3/common/C.java

@@ -32,7 +32,6 @@ import android.media.MediaFormat;
 import android.net.Uri;
 import android.view.Surface;
 import androidx.annotation.IntDef;
-import androidx.annotation.RequiresApi;
 import androidx.media3.common.util.UnstableApi;
 import androidx.media3.common.util.Util;
 import com.google.errorprone.annotations.InlineMe;
@@ -1698,7 +1697,6 @@ public final class C {
       replacement = "Util.generateAudioSessionIdV21(context)",
       imports = {"androidx.media3.common.util.Util"})
   @Deprecated
-  @RequiresApi(21)
   public static int generateAudioSessionIdV21(Context context) {
     return Util.generateAudioSessionIdV21(context);
   }

libraries/common/src/main/java/androidx/media3/common/util/Util.java

@@ -962,16 +962,14 @@ public final class Util {
   /**
    * Returns the language tag for a {@link Locale}.
    *
-   * <p>For API levels &ge; 21, this tag is IETF BCP 47 compliant. Use {@link
+   * <p>This tag is IETF BCP 47 compliant.
-   * #normalizeLanguageCode(String)} to retrieve a normalized IETF BCP 47 language tag for all API
-   * levels if needed.
    *
    * @param locale A {@link Locale}.
    * @return The language tag.
    */
   @UnstableApi
   public static String getLocaleLanguageTag(Locale locale) {
-    return SDK_INT >= 21 ? getLocaleLanguageTagV21(locale) : locale.toString();
+    return locale.toLanguageTag();
   }
 
   /**
@@ -2253,7 +2251,6 @@ public final class Util {
 
   /** Creates {@link AudioFormat} with given sampleRate, channelConfig, and encoding. */
   @UnstableApi
-  @RequiresApi(21)
   public static AudioFormat getAudioFormat(int sampleRate, int channelConfig, int encoding) {
     return new AudioFormat.Builder()
         .setSampleRate(sampleRate)
@@ -2417,7 +2414,6 @@ public final class Util {
    * @see AudioManager#generateAudioSessionId()
    */
   @UnstableApi
-  @RequiresApi(21)
   public static int generateAudioSessionIdV21(Context context) {
     @Nullable
     AudioManager audioManager = ((AudioManager) context.getSystemService(Context.AUDIO_SERVICE));
@@ -3065,8 +3061,7 @@ public final class Util {
    */
   @UnstableApi
   public static boolean isWear(Context context) {
-    return SDK_INT >= 20
+    return context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_WATCH);
-        && context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_WATCH);
   }
 
   /**
@@ -3502,9 +3497,7 @@ public final class Util {
   @UnstableApi
   public static Drawable getDrawable(
       Context context, Resources resources, @DrawableRes int drawableRes) {
-    return SDK_INT >= 21
+    return resources.getDrawable(drawableRes, context.getTheme());
-        ? Api21.getDrawable(context, resources, drawableRes)
-        : resources.getDrawable(drawableRes);
   }
 
   /**
@@ -3666,11 +3659,6 @@ public final class Util {
     return split(config.getLocales().toLanguageTags(), ",");
   }
 
-  @RequiresApi(21)
-  private static String getLocaleLanguageTagV21(Locale locale) {
-    return locale.toLanguageTag();
-  }
-
   private static HashMap<String, String> createIsoLanguageReplacementMap() {
     String[] iso2Languages = Locale.getISOLanguages();
     HashMap<String, String> replacedLanguages =
@@ -3890,14 +3878,6 @@ public final class Util {
     0xF3
   };
 
-  @RequiresApi(21)
-  private static final class Api21 {
-    @DoNotInline
-    public static Drawable getDrawable(Context context, Resources resources, @DrawableRes int res) {
-      return resources.getDrawable(res, context.getTheme());
-    }
-  }
-
   @RequiresApi(29)
   private static class Api29 {
 

libraries/datasource/src/main/java/androidx/media3/datasource/DefaultHttpDataSource.java

@@ -40,7 +40,6 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.InterruptedIOException;
 import java.io.OutputStream;
-import java.lang.reflect.Method;
 import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
 import java.net.NoRouteToHostException;
@@ -248,7 +247,6 @@ public class DefaultHttpDataSource extends BaseDataSource implements HttpDataSou
   private static final int MAX_REDIRECTS = 20; // Same limit as okhttp.
   private static final int HTTP_STATUS_TEMPORARY_REDIRECT = 307;
   private static final int HTTP_STATUS_PERMANENT_REDIRECT = 308;
-  private static final long MAX_BYTES_TO_DRAIN = 2048;
 
   private final boolean allowCrossProtocolRedirects;
   private final boolean crossProtocolRedirectsForceOriginal;
@@ -482,9 +480,6 @@ public class DefaultHttpDataSource extends BaseDataSource implements HttpDataSou
     try {
       @Nullable InputStream inputStream = this.inputStream;
       if (inputStream != null) {
-        long bytesRemaining =
-            bytesToRead == C.LENGTH_UNSET ? C.LENGTH_UNSET : bytesToRead - bytesRead;
-        maybeTerminateInputStream(connection, bytesRemaining);
         try {
           inputStream.close();
         } catch (IOException e) {
@@ -784,52 +779,6 @@ public class DefaultHttpDataSource extends BaseDataSource implements HttpDataSou
     return read;
   }
 
-  /**
-   * On platform API levels 19 and 20, okhttp's implementation of {@link InputStream#close} can
-   * block for a long time if the stream has a lot of data remaining. Call this method before
-   * closing the input stream to make a best effort to cause the input stream to encounter an
-   * unexpected end of input, working around this issue. On other platform API levels, the method
-   * does nothing.
-   *
-   * @param connection The connection whose {@link InputStream} should be terminated.
-   * @param bytesRemaining The number of bytes remaining to be read from the input stream if its
-   *     length is known. {@link C#LENGTH_UNSET} otherwise.
-   */
-  private static void maybeTerminateInputStream(
-      @Nullable HttpURLConnection connection, long bytesRemaining) {
-    if (connection == null || Util.SDK_INT > 20) {
-      return;
-    }
-
-    try {
-      InputStream inputStream = connection.getInputStream();
-      if (bytesRemaining == C.LENGTH_UNSET) {
-        // If the input stream has already ended, do nothing. The socket may be re-used.
-        if (inputStream.read() == -1) {
-          return;
-        }
-      } else if (bytesRemaining <= MAX_BYTES_TO_DRAIN) {
-        // There isn't much data left. Prefer to allow it to drain, which may allow the socket to be
-        // re-used.
-        return;
-      }
-      String className = inputStream.getClass().getName();
-      if ("com.android.okhttp.internal.http.HttpTransport$ChunkedInputStream".equals(className)
-          || "com.android.okhttp.internal.http.HttpTransport$FixedLengthInputStream"
-              .equals(className)) {
-        Class<?> superclass = inputStream.getClass().getSuperclass();
-        Method unexpectedEndOfInput =
-            checkNotNull(superclass).getDeclaredMethod("unexpectedEndOfInput");
-        unexpectedEndOfInput.setAccessible(true);
-        unexpectedEndOfInput.invoke(inputStream);
-      }
-    } catch (Exception e) {
-      // If an IOException then the connection didn't ever have an input stream, or it was closed
-      // already. If another type of exception then something went wrong, most likely the device
-      // isn't using okhttp.
-    }
-  }
-
   /** Closes the current connection quietly, if there is one. */
   private void closeConnectionQuietly() {
     if (connection != null) {

libraries/datasource/src/main/java/androidx/media3/datasource/FileDataSource.java

@@ -22,14 +22,11 @@ import android.net.Uri;
 import android.system.ErrnoException;
 import android.system.OsConstants;
 import android.text.TextUtils;
-import androidx.annotation.DoNotInline;
 import androidx.annotation.Nullable;
-import androidx.annotation.RequiresApi;
 import androidx.media3.common.C;
 import androidx.media3.common.PlaybackException;
 import androidx.media3.common.util.Assertions;
 import androidx.media3.common.util.UnstableApi;
-import androidx.media3.common.util.Util;
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.FileNotFoundException;
 import java.io.IOException;
@@ -200,7 +197,8 @@ public final class FileDataSource extends BaseDataSource {
       // different SDK versions.
       throw new FileDataSourceException(
           e,
-          Util.SDK_INT >= 21 && Api21.isPermissionError(e.getCause())
+          e.getCause() instanceof ErrnoException
+                  && ((ErrnoException) e.getCause()).errno == OsConstants.EACCES
               ? PlaybackException.ERROR_CODE_IO_NO_PERMISSION
               : PlaybackException.ERROR_CODE_IO_FILE_NOT_FOUND);
     } catch (SecurityException e) {
@@ -209,12 +207,4 @@ public final class FileDataSource extends BaseDataSource {
       throw new FileDataSourceException(e, PlaybackException.ERROR_CODE_IO_UNSPECIFIED);
     }
   }
-
-  @RequiresApi(21)
-  private static final class Api21 {
-    @DoNotInline
-    private static boolean isPermissionError(@Nullable Throwable e) {
-      return e instanceof ErrnoException && ((ErrnoException) e).errno == OsConstants.EACCES;
-    }
-  }
 }

libraries/datasource/src/main/java/androidx/media3/datasource/FileDescriptorDataSource.java

@@ -24,7 +24,6 @@ import android.system.ErrnoException;
 import android.system.Os;
 import android.system.OsConstants;
 import androidx.annotation.Nullable;
-import androidx.annotation.RequiresApi;
 import androidx.media3.common.C;
 import androidx.media3.common.PlaybackException;
 import androidx.media3.common.util.UnstableApi;
@@ -48,7 +47,6 @@ import java.util.Set;
  * #open(DataSpec)} is not actually used for reading data. Instead, the underlying {@link
  * FileDescriptor} is used for all read operations.
  */
-@RequiresApi(21)
 @UnstableApi
 public class FileDescriptorDataSource extends BaseDataSource {
 

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/analytics/MediaMetricsListener.java

@@ -748,7 +748,7 @@ public final class MediaMetricsListener
       } else if (cause instanceof DrmSession.DrmSessionException) {
         // Unpack DrmSessionException.
         cause = checkNotNull(cause.getCause());
-        if (Util.SDK_INT >= 21 && cause instanceof MediaDrm.MediaDrmStateException) {
+        if (cause instanceof MediaDrm.MediaDrmStateException) {
           String diagnosticsInfo = ((MediaDrm.MediaDrmStateException) cause).getDiagnosticInfo();
           int subErrorCode = Util.getErrorCodeFromPlatformDiagnosticsInfo(diagnosticsInfo);
           int errorCode = getDrmErrorCode(subErrorCode);
@@ -771,8 +771,7 @@ public final class MediaMetricsListener
       } else if (cause instanceof FileDataSource.FileDataSourceException
           && cause.getCause() instanceof FileNotFoundException) {
         @Nullable Throwable notFoundCause = checkNotNull(cause.getCause()).getCause();
-        if (Util.SDK_INT >= 21
+        if (notFoundCause instanceof ErrnoException
-            && notFoundCause instanceof ErrnoException
             && ((ErrnoException) notFoundCause).errno == OsConstants.EACCES) {
           return new ErrorInfo(PlaybackErrorEvent.ERROR_IO_NO_PERMISSION, /* subErrorCode= */ 0);
         } else {

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/AudioCapabilitiesReceiver.java

@@ -57,7 +57,7 @@ public final class AudioCapabilitiesReceiver {
   private final Listener listener;
   private final Handler handler;
   @Nullable private final AudioDeviceCallbackV23 audioDeviceCallback;
-  @Nullable private final BroadcastReceiver hdmiAudioPlugBroadcastReceiver;
+  private final BroadcastReceiver hdmiAudioPlugBroadcastReceiver;
   @Nullable private final ExternalSurroundSoundSettingObserver externalSurroundSoundSettingObserver;
 
   @Nullable private AudioCapabilities audioCapabilities;
@@ -105,8 +105,7 @@ public final class AudioCapabilitiesReceiver {
     this.routedDevice = routedDevice;
     handler = Util.createHandlerForCurrentOrMainLooper();
     audioDeviceCallback = Util.SDK_INT >= 23 ? new AudioDeviceCallbackV23() : null;
-    hdmiAudioPlugBroadcastReceiver =
+    hdmiAudioPlugBroadcastReceiver = new HdmiAudioPlugBroadcastReceiver();
-        Util.SDK_INT >= 21 ? new HdmiAudioPlugBroadcastReceiver() : null;
     Uri externalSurroundSoundUri = AudioCapabilities.getExternalSurroundSoundGlobalSettingUri();
     externalSurroundSoundSettingObserver =
         externalSurroundSoundUri != null
@@ -162,16 +161,12 @@ public final class AudioCapabilitiesReceiver {
     if (Util.SDK_INT >= 23 && audioDeviceCallback != null) {
       Api23.registerAudioDeviceCallback(context, audioDeviceCallback, handler);
     }
-    @Nullable Intent stickyIntent = null;
+    Intent stickyIntent =
-    if (hdmiAudioPlugBroadcastReceiver != null) {
+        context.registerReceiver(
-      IntentFilter intentFilter = new IntentFilter(AudioManager.ACTION_HDMI_AUDIO_PLUG);
+            hdmiAudioPlugBroadcastReceiver,
-      stickyIntent =
+            new IntentFilter(AudioManager.ACTION_HDMI_AUDIO_PLUG),
-          context.registerReceiver(
+            /* broadcastPermission= */ null,
-              hdmiAudioPlugBroadcastReceiver,
+            handler);
-              intentFilter,
-              /* broadcastPermission= */ null,
-              handler);
-    }
     audioCapabilities =
         AudioCapabilities.getCapabilitiesInternal(
             context, stickyIntent, audioAttributes, routedDevice);
@@ -190,9 +185,7 @@ public final class AudioCapabilitiesReceiver {
     if (Util.SDK_INT >= 23 && audioDeviceCallback != null) {
       Api23.unregisterAudioDeviceCallback(context, audioDeviceCallback);
     }
-    if (hdmiAudioPlugBroadcastReceiver != null) {
+    context.unregisterReceiver(hdmiAudioPlugBroadcastReceiver);
-      context.unregisterReceiver(hdmiAudioPlugBroadcastReceiver);
-    }
     if (externalSurroundSoundSettingObserver != null) {
       externalSurroundSoundSettingObserver.unregister();
     }

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/DecoderAudioRenderer.java

@@ -244,9 +244,7 @@ public abstract class DecoderAudioRenderer<
     if (formatSupport <= C.FORMAT_UNSUPPORTED_DRM) {
       return RendererCapabilities.create(formatSupport);
     }
-    @TunnelingSupport
+    return RendererCapabilities.create(formatSupport, ADAPTIVE_NOT_SEAMLESS, TUNNELING_SUPPORTED);
-    int tunnelingSupport = Util.SDK_INT >= 21 ? TUNNELING_SUPPORTED : TUNNELING_NOT_SUPPORTED;
-    return RendererCapabilities.create(formatSupport, ADAPTIVE_NOT_SEAMLESS, tunnelingSupport);
   }
 
   /**

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/DefaultAudioSink.java

@@ -337,8 +337,8 @@ public final class DefaultAudioSink implements AudioSink {
     /**
      * Sets whether to enable 32-bit float output or integer output. Where possible, 32-bit float
      * output will be used if the input is 32-bit float, and also if the input is high resolution
-     * (24-bit or 32-bit) integer PCM. Float output is supported from API level 21. Audio processing
+     * (24-bit or 32-bit) integer PCM. Audio processing (for example, speed adjustment) will not be
-     * (for example, speed adjustment) will not be available when float output is in use.
+     * available when float output is in use.
      *
      * <p>The default value is {@code false}.
      */
@@ -541,8 +541,6 @@ public final class DefaultAudioSink implements AudioSink {
   @Nullable private ByteBuffer inputBuffer;
   private int inputBufferAccessUnitCount;
   @Nullable private ByteBuffer outputBuffer;
-  private byte @MonotonicNonNull [] preV21OutputBuffer;
-  private int preV21OutputBufferOffset;
   private boolean handledEndOfStream;
   private boolean stoppedAudioTrack;
   private boolean handledOffloadOnPresentationEnded;
@@ -571,7 +569,7 @@ public final class DefaultAudioSink implements AudioSink {
             ? getCapabilities(context, audioAttributes, /* routedDevice= */ null)
             : builder.audioCapabilities;
     audioProcessorChain = builder.audioProcessorChain;
-    enableFloatOutput = Util.SDK_INT >= 21 && builder.enableFloatOutput;
+    enableFloatOutput = builder.enableFloatOutput;
     preferAudioTrackPlaybackParams = Util.SDK_INT >= 23 && builder.enableAudioTrackPlaybackParams;
     offloadMode = OFFLOAD_MODE_DISABLED;
     audioTrackBufferSizeProvider = builder.audioTrackBufferSizeProvider;
@@ -700,14 +698,6 @@ public final class DefaultAudioSink implements AudioSink {
       trimmingAudioProcessor.setTrimFrameCount(
           inputFormat.encoderDelay, inputFormat.encoderPadding);
 
-      if (Util.SDK_INT < 21 && inputFormat.channelCount == 8 && outputChannels == null) {
-        // AudioTrack doesn't support 8 channel output before Android L. Discard the last two (side)
-        // channels to give a 6 channel stream that is supported.
-        outputChannels = new int[6];
-        for (int i = 0; i < outputChannels.length; i++) {
-          outputChannels[i] = i;
-        }
-      }
       channelMappingAudioProcessor.setChannelMap(outputChannels);
 
       AudioProcessor.AudioFormat outputFormat = new AudioProcessor.AudioFormat(inputFormat);
@@ -1160,32 +1150,10 @@ public final class DefaultAudioSink implements AudioSink {
       Assertions.checkArgument(outputBuffer == buffer);
     } else {
       outputBuffer = buffer;
-      if (Util.SDK_INT < 21) {
-        int bytesRemaining = buffer.remaining();
-        if (preV21OutputBuffer == null || preV21OutputBuffer.length < bytesRemaining) {
-          preV21OutputBuffer = new byte[bytesRemaining];
-        }
-        int originalPosition = buffer.position();
-        buffer.get(preV21OutputBuffer, 0, bytesRemaining);
-        buffer.position(originalPosition);
-        preV21OutputBufferOffset = 0;
-      }
     }
     int bytesRemaining = buffer.remaining();
     int bytesWrittenOrError = 0; // Error if negative
-    if (Util.SDK_INT < 21) { // outputMode == OUTPUT_MODE_PCM.
+    if (tunneling) {
-      // Work out how many bytes we can write without the risk of blocking.
-      int bytesToWrite = audioTrackPositionTracker.getAvailableBufferSize(writtenPcmBytes);
-      if (bytesToWrite > 0) {
-        bytesToWrite = min(bytesRemaining, bytesToWrite);
-        bytesWrittenOrError =
-            audioTrack.write(preV21OutputBuffer, preV21OutputBufferOffset, bytesToWrite);
-        if (bytesWrittenOrError > 0) { // No error
-          preV21OutputBufferOffset += bytesWrittenOrError;
-          buffer.position(buffer.position() + bytesWrittenOrError);
-        }
-      }
-    } else if (tunneling) {
       Assertions.checkState(avSyncPresentationTimeUs != C.TIME_UNSET);
       if (avSyncPresentationTimeUs == C.TIME_END_OF_SOURCE) {
         // Audio processors during tunneling are required to produce buffers immediately when
@@ -1196,10 +1164,9 @@ public final class DefaultAudioSink implements AudioSink {
         lastTunnelingAvSyncPresentationTimeUs = avSyncPresentationTimeUs;
       }
       bytesWrittenOrError =
-          writeNonBlockingWithAvSyncV21(
+          writeNonBlockingWithAvSync(audioTrack, buffer, bytesRemaining, avSyncPresentationTimeUs);
-              audioTrack, buffer, bytesRemaining, avSyncPresentationTimeUs);
     } else {
-      bytesWrittenOrError = writeNonBlockingV21(audioTrack, buffer, bytesRemaining);
+      bytesWrittenOrError = writeNonBlocking(audioTrack, buffer, bytesRemaining);
     }
 
     lastFeedElapsedRealtimeMs = SystemClock.elapsedRealtime();
@@ -1402,7 +1369,6 @@ public final class DefaultAudioSink implements AudioSink {
 
   @Override
   public void enableTunnelingV21() {
-    Assertions.checkState(Util.SDK_INT >= 21);
     Assertions.checkState(externalAudioSessionIdProvided);
     if (!tunneling) {
       tunneling = true;
@@ -1445,12 +1411,8 @@ public final class DefaultAudioSink implements AudioSink {
   }
 
   private void setVolumeInternal() {
-    if (!isAudioTrackInitialized()) {
+    if (isAudioTrackInitialized()) {
-      // Do nothing.
+      audioTrack.setVolume(volume);
-    } else if (Util.SDK_INT >= 21) {
-      setVolumeInternalV21(audioTrack, volume);
-    } else {
-      setVolumeInternalV3(audioTrack, volume);
     }
   }
 
@@ -1474,14 +1436,6 @@ public final class DefaultAudioSink implements AudioSink {
       if (isOffloadedPlayback(audioTrack)) {
         checkNotNull(offloadStreamEventCallbackV29).unregister(audioTrack);
       }
-      if (Util.SDK_INT < 21 && !externalAudioSessionIdProvided) {
-        // Prior to API level 21, audio sessions are not kept alive once there are no components
-        // associated with them. If we generated the session ID internally, the only component
-        // associated with the session is the audio track that's being released, and therefore
-        // the session will not be kept alive. As a result, we need to generate a new session when
-        // we next create an audio track.
-        audioSessionId = C.AUDIO_SESSION_ID_UNSET;
-      }
       AudioTrackConfig oldAudioTrackConfig = configuration.buildAudioTrackConfig();
       if (pendingConfiguration != null) {
         configuration = pendingConfiguration;
@@ -1822,13 +1776,11 @@ public final class DefaultAudioSink implements AudioSink {
     }
   }
 
-  @RequiresApi(21)
+  private static int writeNonBlocking(AudioTrack audioTrack, ByteBuffer buffer, int size) {
-  private static int writeNonBlockingV21(AudioTrack audioTrack, ByteBuffer buffer, int size) {
     return audioTrack.write(buffer, size, AudioTrack.WRITE_NON_BLOCKING);
   }
 
-  @RequiresApi(21)
+  private int writeNonBlockingWithAvSync(
-  private int writeNonBlockingWithAvSyncV21(
       AudioTrack audioTrack, ByteBuffer buffer, int size, long presentationTimeUs) {
     if (Util.SDK_INT >= 26) {
       // The underlying platform AudioTrack writes AV sync headers directly.
@@ -1858,7 +1810,7 @@ public final class DefaultAudioSink implements AudioSink {
         return 0;
       }
     }
-    int result = writeNonBlockingV21(audioTrack, buffer, size);
+    int result = writeNonBlocking(audioTrack, buffer, size);
     if (result < 0) {
       bytesUntilNextAvSync = 0;
       return result;
@@ -1867,15 +1819,6 @@ public final class DefaultAudioSink implements AudioSink {
     return result;
   }
 
-  @RequiresApi(21)
-  private static void setVolumeInternalV21(AudioTrack audioTrack, float volume) {
-    audioTrack.setVolume(volume);
-  }
-
-  private static void setVolumeInternalV3(AudioTrack audioTrack, float volume) {
-    audioTrack.setStereoVolume(volume, volume);
-  }
-
   private void playPendingData() {
     if (!stoppedAudioTrack) {
       stoppedAudioTrack = true;
@@ -2253,10 +2196,8 @@ public final class DefaultAudioSink implements AudioSink {
     private AudioTrack createAudioTrack(AudioAttributes audioAttributes, int audioSessionId) {
       if (Util.SDK_INT >= 29) {
         return createAudioTrackV29(audioAttributes, audioSessionId);
-      } else if (Util.SDK_INT >= 21) {
-        return createAudioTrackV21(audioAttributes, audioSessionId);
       } else {
-        return createAudioTrackV9(audioAttributes, audioSessionId);
+        return createAudioTrackV21(audioAttributes, audioSessionId);
       }
     }
 
@@ -2265,7 +2206,7 @@ public final class DefaultAudioSink implements AudioSink {
       AudioFormat audioFormat =
           Util.getAudioFormat(outputSampleRate, outputChannelConfig, outputEncoding);
       android.media.AudioAttributes audioTrackAttributes =
-          getAudioTrackAttributesV21(audioAttributes, tunneling);
+          getAudioTrackAttributes(audioAttributes, tunneling);
       return new AudioTrack.Builder()
           .setAudioAttributes(audioTrackAttributes)
           .setAudioFormat(audioFormat)
@@ -2276,59 +2217,28 @@ public final class DefaultAudioSink implements AudioSink {
           .build();
     }
 
-    @RequiresApi(21)
     private AudioTrack createAudioTrackV21(AudioAttributes audioAttributes, int audioSessionId) {
       return new AudioTrack(
-          getAudioTrackAttributesV21(audioAttributes, tunneling),
+          getAudioTrackAttributes(audioAttributes, tunneling),
           Util.getAudioFormat(outputSampleRate, outputChannelConfig, outputEncoding),
           bufferSize,
           AudioTrack.MODE_STREAM,
           audioSessionId);
     }
 
-    @SuppressWarnings("deprecation") // Using deprecated AudioTrack constructor.
+    private static android.media.AudioAttributes getAudioTrackAttributes(
-    private AudioTrack createAudioTrackV9(AudioAttributes audioAttributes, int audioSessionId) {
-      int streamType = Util.getStreamTypeForAudioUsage(audioAttributes.usage);
-      if (audioSessionId == C.AUDIO_SESSION_ID_UNSET) {
-        return new AudioTrack(
-            streamType,
-            outputSampleRate,
-            outputChannelConfig,
-            outputEncoding,
-            bufferSize,
-            AudioTrack.MODE_STREAM);
-      } else {
-        // Re-attach to the same audio session.
-        return new AudioTrack(
-            streamType,
-            outputSampleRate,
-            outputChannelConfig,
-            outputEncoding,
-            bufferSize,
-            AudioTrack.MODE_STREAM,
-            audioSessionId);
-      }
-    }
-
-    @RequiresApi(21)
-    private static android.media.AudioAttributes getAudioTrackAttributesV21(
         AudioAttributes audioAttributes, boolean tunneling) {
       if (tunneling) {
-        return getAudioTrackTunnelingAttributesV21();
+        return new android.media.AudioAttributes.Builder()
+            .setContentType(android.media.AudioAttributes.CONTENT_TYPE_MOVIE)
+            .setFlags(android.media.AudioAttributes.FLAG_HW_AV_SYNC)
+            .setUsage(android.media.AudioAttributes.USAGE_MEDIA)
+            .build();
       } else {
         return audioAttributes.getAudioAttributesV21().audioAttributes;
       }
     }
 
-    @RequiresApi(21)
-    private static android.media.AudioAttributes getAudioTrackTunnelingAttributesV21() {
-      return new android.media.AudioAttributes.Builder()
-          .setContentType(android.media.AudioAttributes.CONTENT_TYPE_MOVIE)
-          .setFlags(android.media.AudioAttributes.FLAG_HW_AV_SYNC)
-          .setUsage(android.media.AudioAttributes.USAGE_MEDIA)
-          .build();
-    }
-
     public boolean outputModeIsOffload() {
       return outputMode == OUTPUT_MODE_OFFLOAD;
     }

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/MediaCodecAudioRenderer.java

@@ -278,8 +278,6 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
     if (!MimeTypes.isAudio(format.sampleMimeType)) {
       return RendererCapabilities.create(C.FORMAT_UNSUPPORTED_TYPE);
     }
-    @TunnelingSupport
-    int tunnelingSupport = Util.SDK_INT >= 21 ? TUNNELING_SUPPORTED : TUNNELING_NOT_SUPPORTED;
     boolean formatHasDrm = format.cryptoType != C.CRYPTO_TYPE_NONE;
     boolean supportsFormatDrm = supportsFormatDrm(format);
 
@@ -291,7 +289,7 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
       audioOffloadSupport = getAudioOffloadSupport(format);
       if (audioSink.supportsFormat(format)) {
         return RendererCapabilities.create(
-            C.FORMAT_HANDLED, ADAPTIVE_NOT_SEAMLESS, tunnelingSupport, audioOffloadSupport);
+            C.FORMAT_HANDLED, ADAPTIVE_NOT_SEAMLESS, TUNNELING_SUPPORTED, audioOffloadSupport);
       }
     }
     // If the input is PCM then it will be passed directly to the sink. Hence the sink must support
@@ -346,7 +344,7 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
     return RendererCapabilities.create(
         formatSupport,
         adaptiveSupport,
-        tunnelingSupport,
+        TUNNELING_SUPPORTED,
         hardwareAccelerationSupport,
         decoderSupport,
         audioOffloadSupport);

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/drm/DrmUtil.java

@@ -77,8 +77,11 @@ public final class DrmUtil {
    */
   public static @PlaybackException.ErrorCode int getErrorCodeForMediaDrmException(
       Throwable exception, @ErrorSource int errorSource) {
-    if (Util.SDK_INT >= 21 && Api21.isMediaDrmStateException(exception)) {
+    if (exception instanceof MediaDrm.MediaDrmStateException) {
-      return Api21.mediaDrmStateExceptionToErrorCode(exception);
+      @Nullable
+      String diagnosticsInfo = ((MediaDrm.MediaDrmStateException) exception).getDiagnosticInfo();
+      int drmErrorCode = Util.getErrorCodeFromPlatformDiagnosticsInfo(diagnosticsInfo);
+      return Util.getErrorCodeForMediaDrmErrorCode(drmErrorCode);
     } else if (Util.SDK_INT >= 23 && Api23.isMediaDrmResetException(exception)) {
       return PlaybackException.ERROR_CODE_DRM_SYSTEM_ERROR;
     } else if (exception instanceof NotProvisionedException
@@ -128,26 +131,6 @@ public final class DrmUtil {
         && e.getMessage().contains("Landroid/media/ResourceBusyException;.<init>(");
   }
 
-  // Internal classes.
-
-  @RequiresApi(21)
-  private static final class Api21 {
-
-    @DoNotInline
-    public static boolean isMediaDrmStateException(@Nullable Throwable throwable) {
-      return throwable instanceof MediaDrm.MediaDrmStateException;
-    }
-
-    @DoNotInline
-    public static @PlaybackException.ErrorCode int mediaDrmStateExceptionToErrorCode(
-        Throwable throwable) {
-      @Nullable
-      String diagnosticsInfo = ((MediaDrm.MediaDrmStateException) throwable).getDiagnosticInfo();
-      int drmErrorCode = Util.getErrorCodeFromPlatformDiagnosticsInfo(diagnosticsInfo);
-      return Util.getErrorCodeForMediaDrmErrorCode(drmErrorCode);
-    }
-  }
-
   @RequiresApi(23)
   private static final class Api23 {
 

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/drm/FrameworkCryptoConfig.java

@@ -53,12 +53,22 @@ public final class FrameworkCryptoConfig implements CryptoConfig {
   @Deprecated public final boolean forceAllowInsecureDecoderComponents;
 
   /**
+   * Constructs an instance.
+   *
    * @param uuid The DRM scheme UUID.
    * @param sessionId The DRM session id.
-   * @param forceAllowInsecureDecoderComponents Whether to allow use of insecure decoder components
+   */
-   *     even if the underlying platform says otherwise.
+  @SuppressWarnings("deprecation") // Delegating to deprecated constructor
+  public FrameworkCryptoConfig(UUID uuid, byte[] sessionId) {
+    this(uuid, sessionId, /* forceAllowInsecureDecoderComponents= */ false);
+  }
+
+  /**
+   * @deprecated Use {@link FrameworkCryptoConfig#FrameworkCryptoConfig(UUID, byte[])} instead, and
+   *     {@link ExoMediaDrm#requiresSecureDecoder} for the secure decoder handling logic.
    */
   @SuppressWarnings("deprecation") // Setting deprecated field
+  @Deprecated
   public FrameworkCryptoConfig(
       UUID uuid, byte[] sessionId, boolean forceAllowInsecureDecoderComponents) {
     this.uuid = uuid;

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/drm/FrameworkMediaDrm.java

@@ -308,7 +308,7 @@ public final class FrameworkMediaDrm implements ExoMediaDrm {
         }
       }
     }
-    return result && !shouldForceAllowInsecureDecoderComponents();
+    return result;
   }
 
   @UnstableApi
@@ -389,17 +389,7 @@ public final class FrameworkMediaDrm implements ExoMediaDrm {
   @UnstableApi
   @Override
   public FrameworkCryptoConfig createCryptoConfig(byte[] sessionId) throws MediaCryptoException {
-    boolean forceAllowInsecureDecoderComponents = shouldForceAllowInsecureDecoderComponents();
+    return new FrameworkCryptoConfig(adjustUuid(uuid), sessionId);
-    return new FrameworkCryptoConfig(
-        adjustUuid(uuid), sessionId, forceAllowInsecureDecoderComponents);
-  }
-
-  // Work around a bug prior to Lollipop where L1 Widevine forced into L3 mode would still
-  // indicate that it required secure video decoders [Internal ref: b/11428937].
-  private boolean shouldForceAllowInsecureDecoderComponents() {
-    return Util.SDK_INT < 21
-        && C.WIDEVINE_UUID.equals(uuid)
-        && "L3".equals(getPropertyString("securityLevel"));
   }
 
   @UnstableApi

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/mediacodec/MediaCodecAdapter.java

@@ -252,7 +252,6 @@ public interface MediaCodecAdapter {
    *
    * @see MediaCodec#releaseOutputBuffer(int, long)
    */
-  @RequiresApi(21)
   void releaseOutputBuffer(int index, long renderTimeStampNs);
 
   /** Flushes the adapter and the underlying {@link MediaCodec}. */
@@ -278,7 +277,6 @@ public interface MediaCodecAdapter {
    * @see MediaCodec.Callback#onOutputBufferAvailable
    * @return Whether listener was successfully registered.
    */
-  @RequiresApi(21)
   default boolean registerOnBufferAvailableListener(
       MediaCodecAdapter.OnBufferAvailableListener listener) {
     return false;

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/mediacodec/MediaCodecDecoderException.java

@@ -38,22 +38,16 @@ public class MediaCodecDecoderException extends DecoderException {
   public MediaCodecDecoderException(Throwable cause, @Nullable MediaCodecInfo codecInfo) {
     super("Decoder failed: " + (codecInfo == null ? null : codecInfo.name), cause);
     this.codecInfo = codecInfo;
-    diagnosticInfo = Util.SDK_INT >= 21 ? getDiagnosticInfoV21(cause) : null;
+    diagnosticInfo =
+        cause instanceof MediaCodec.CodecException
+            ? ((MediaCodec.CodecException) cause).getDiagnosticInfo()
+            : null;
     errorCode =
         Util.SDK_INT >= 23
             ? getErrorCodeV23(cause)
             : Util.getErrorCodeFromPlatformDiagnosticsInfo(diagnosticInfo);
   }
 
-  @RequiresApi(21)
-  @Nullable
-  private static String getDiagnosticInfoV21(Throwable cause) {
-    if (cause instanceof MediaCodec.CodecException) {
-      return ((MediaCodec.CodecException) cause).getDiagnosticInfo();
-    }
-    return null;
-  }
-
   @RequiresApi(23)
   private static int getErrorCodeV23(Throwable cause) {
     if (cause instanceof MediaCodec.CodecException) {

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/mediacodec/MediaCodecInfo.java

@@ -258,22 +258,12 @@ public final class MediaCodecInfo {
       if (format.width <= 0 || format.height <= 0) {
         return true;
       }
-      if (Util.SDK_INT >= 21) {
+      return isVideoSizeAndRateSupportedV21(format.width, format.height, format.frameRate);
-        return isVideoSizeAndRateSupportedV21(format.width, format.height, format.frameRate);
-      } else {
-        boolean isFormatSupported =
-            format.width * format.height <= MediaCodecUtil.maxH264DecodableFrameSize();
-        if (!isFormatSupported) {
-          logNoSupport("legacyFrameSize, " + format.width + "x" + format.height);
-        }
-        return isFormatSupported;
-      }
     } else { // Audio
-      return Util.SDK_INT < 21
+      return (format.sampleRate == Format.NO_VALUE
-          || ((format.sampleRate == Format.NO_VALUE
+              || isAudioSampleRateSupportedV21(format.sampleRate))
-                  || isAudioSampleRateSupportedV21(format.sampleRate))
+          && (format.channelCount == Format.NO_VALUE
-              && (format.channelCount == Format.NO_VALUE
+              || isAudioChannelCountSupportedV21(format.channelCount));
-                  || isAudioChannelCountSupportedV21(format.channelCount)));
     }
   }
 
@@ -482,7 +472,6 @@ public final class MediaCodecInfo {
    *     Format#NO_VALUE} or any value less than or equal to 0.
    * @return Whether the decoder supports video with the given width, height and frame rate.
    */
-  @RequiresApi(21)
   public boolean isVideoSizeAndRateSupportedV21(int width, int height, double frameRate) {
     if (capabilities == null) {
       logNoSupport("sizeAndRate.caps");
@@ -506,13 +495,13 @@ public final class MediaCodecInfo {
         return false;
       }
       // If COVERAGE_RESULT_NO_PERFORMANCE_POINTS_UNSUPPORTED then logic falls through
-      // to API 21+ code below.
+      // to code below.
     }
 
-    if (!areSizeAndRateSupportedV21(videoCapabilities, width, height, frameRate)) {
+    if (!areSizeAndRateSupported(videoCapabilities, width, height, frameRate)) {
       if (width >= height
           || !needsRotatedVerticalResolutionWorkaround(name)
-          || !areSizeAndRateSupportedV21(videoCapabilities, height, width, frameRate)) {
+          || !areSizeAndRateSupported(videoCapabilities, height, width, frameRate)) {
         logNoSupport("sizeAndRate.support, " + width + "x" + height + "@" + frameRate);
         return false;
       }
@@ -525,8 +514,6 @@ public final class MediaCodecInfo {
    * Returns the smallest video size greater than or equal to a specified size that also satisfies
    * the {@link MediaCodec}'s width and height alignment requirements.
    *
-   * <p>Must not be called if the device SDK version is less than 21.
-   *
    * @param width Width in pixels.
    * @param height Height in pixels.
    * @return The smallest video size greater than or equal to the specified size that also satisfies
@@ -534,7 +521,6 @@ public final class MediaCodecInfo {
    *     codec.
    */
   @Nullable
-  @RequiresApi(21)
   public Point alignVideoSizeV21(int width, int height) {
     if (capabilities == null) {
       return null;
@@ -543,18 +529,15 @@ public final class MediaCodecInfo {
     if (videoCapabilities == null) {
       return null;
     }
-    return alignVideoSizeV21(videoCapabilities, width, height);
+    return alignVideoSize(videoCapabilities, width, height);
   }
 
   /**
    * Whether the decoder supports audio with a given sample rate.
    *
-   * <p>Must not be called if the device SDK version is less than 21.
-   *
    * @param sampleRate The sample rate in Hz.
    * @return Whether the decoder supports audio with the given sample rate.
    */
-  @RequiresApi(21)
   public boolean isAudioSampleRateSupportedV21(int sampleRate) {
     if (capabilities == null) {
       logNoSupport("sampleRate.caps");
@@ -575,12 +558,9 @@ public final class MediaCodecInfo {
   /**
    * Whether the decoder supports audio with a given channel count.
    *
-   * <p>Must not be called if the device SDK version is less than 21.
-   *
    * @param channelCount The channel count.
    * @return Whether the decoder supports audio with the given channel count.
    */
-  @RequiresApi(21)
   public boolean isAudioChannelCountSupportedV21(int channelCount) {
     if (capabilities == null) {
       logNoSupport("channelCount.caps");
@@ -674,28 +654,17 @@ public final class MediaCodecInfo {
   }
 
   private static boolean isTunneling(CodecCapabilities capabilities) {
-    return Util.SDK_INT >= 21 && isTunnelingV21(capabilities);
-  }
-
-  @RequiresApi(21)
-  private static boolean isTunnelingV21(CodecCapabilities capabilities) {
     return capabilities.isFeatureSupported(CodecCapabilities.FEATURE_TunneledPlayback);
   }
 
   private static boolean isSecure(CodecCapabilities capabilities) {
-    return Util.SDK_INT >= 21 && isSecureV21(capabilities);
-  }
-
-  @RequiresApi(21)
-  private static boolean isSecureV21(CodecCapabilities capabilities) {
     return capabilities.isFeatureSupported(CodecCapabilities.FEATURE_SecurePlayback);
   }
 
-  @RequiresApi(21)
+  private static boolean areSizeAndRateSupported(
-  private static boolean areSizeAndRateSupportedV21(
       VideoCapabilities capabilities, int width, int height, double frameRate) {
     // Don't ever fail due to alignment. See: https://github.com/google/ExoPlayer/issues/6551.
-    Point alignedSize = alignVideoSizeV21(capabilities, width, height);
+    Point alignedSize = alignVideoSize(capabilities, width, height);
     width = alignedSize.x;
     height = alignedSize.y;
 
@@ -712,8 +681,7 @@ public final class MediaCodecInfo {
     }
   }
 
-  @RequiresApi(21)
+  private static Point alignVideoSize(VideoCapabilities capabilities, int width, int height) {
-  private static Point alignVideoSizeV21(VideoCapabilities capabilities, int width, int height) {
     int widthAlignment = capabilities.getWidthAlignment();
     int heightAlignment = capabilities.getHeightAlignment();
     return new Point(

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/mediacodec/MediaCodecUtil.java

@@ -166,12 +166,9 @@ public final class MediaCodecUtil {
     if (cachedDecoderInfos != null) {
       return cachedDecoderInfos;
     }
-    MediaCodecListCompat mediaCodecList =
+    MediaCodecListCompat mediaCodecList = new MediaCodecListCompatV21(secure, tunneling);
-        Util.SDK_INT >= 21
-            ? new MediaCodecListCompatV21(secure, tunneling)
-            : new MediaCodecListCompatV16();
     ArrayList<MediaCodecInfo> decoderInfos = getDecoderInfosInternal(key, mediaCodecList);
-    if (secure && decoderInfos.isEmpty() && 21 <= Util.SDK_INT && Util.SDK_INT <= 23) {
+    if (secure && decoderInfos.isEmpty() && Util.SDK_INT <= 23) {
       // Some devices don't list secure decoders on API level 21 [Internal: b/18678462]. Try the
       // legacy path. We also try this path on API levels 22 and 23 as a defensive measure.
       mediaCodecList = new MediaCodecListCompatV16();
@@ -290,9 +287,8 @@ public final class MediaCodecUtil {
         for (CodecProfileLevel profileLevel : decoderInfo.getProfileLevels()) {
           result = max(avcLevelToMaxFrameSize(profileLevel.level), result);
         }
-        // We assume support for at least 480p (SDK_INT >= 21) or 360p (SDK_INT < 21), which are
+        // We assume support for at least 480p, which is the level mandated by the Android CDD.
-        // the levels mandated by the Android CDD.
+        result = max(result, 720 * 480);
-        result = max(result, Util.SDK_INT >= 21 ? (720 * 480) : (480 * 360));
       }
       maxH264DecodableFrameSize = result;
     }
@@ -562,17 +558,6 @@ public final class MediaCodecUtil {
       return false;
     }
 
-    // Work around broken audio decoders.
-    if (Util.SDK_INT < 21
-        && ("CIPAACDecoder".equals(name)
-            || "CIPMP3Decoder".equals(name)
-            || "CIPVorbisDecoder".equals(name)
-            || "CIPAMRNBDecoder".equals(name)
-            || "AACDecoder".equals(name)
-            || "MP3Decoder".equals(name))) {
-      return false;
-    }
-
     // Work around https://github.com/google/ExoPlayer/issues/3249.
     if (Util.SDK_INT < 24
         && ("OMX.SEC.aac.dec".equals(name) || "OMX.Exynos.AAC.Decoder".equals(name))
@@ -588,26 +573,6 @@ public final class MediaCodecUtil {
       return false;
     }
 
-    // Work around https://github.com/google/ExoPlayer/issues/548.
-    // VP8 decoder on Samsung Galaxy S3/S4/S4 Mini/Tab 3/Note 2 does not render video.
-    if (Util.SDK_INT == 19
-        && "OMX.SEC.vp8.dec".equals(name)
-        && "samsung".equals(Util.MANUFACTURER)
-        && (Util.DEVICE.startsWith("d2")
-            || Util.DEVICE.startsWith("serrano")
-            || Util.DEVICE.startsWith("jflte")
-            || Util.DEVICE.startsWith("santos")
-            || Util.DEVICE.startsWith("t0"))) {
-      return false;
-    }
-
-    // VP8 decoder on Samsung Galaxy S4 cannot be queried.
-    if (Util.SDK_INT == 19
-        && Util.DEVICE.startsWith("jflte")
-        && "OMX.qcom.video.decoder.vp8".equals(name)) {
-      return false;
-    }
-
     // MTK AC3 decoder doesn't support decoding JOC streams in 2-D. See [Internal: b/69400041].
     if (Util.SDK_INT <= 23
         && MimeTypes.AUDIO_E_AC3_JOC.equals(mimeType)
@@ -663,19 +628,6 @@ public final class MediaCodecUtil {
           });
     }
 
-    if (Util.SDK_INT < 21 && decoderInfos.size() > 1) {
-      String firstCodecName = decoderInfos.get(0).name;
-      if ("OMX.SEC.mp3.dec".equals(firstCodecName)
-          || "OMX.SEC.MP3.Decoder".equals(firstCodecName)
-          || "OMX.brcm.audio.mp3.decoder".equals(firstCodecName)) {
-        // Prefer OMX.google codecs over OMX.SEC.mp3.dec, OMX.SEC.MP3.Decoder and
-        // OMX.brcm.audio.mp3.decoder on older devices. See:
-        // https://github.com/google/ExoPlayer/issues/398 and
-        // https://github.com/google/ExoPlayer/issues/4519.
-        sortByScore(decoderInfos, decoderInfo -> decoderInfo.name.startsWith("OMX.google") ? 1 : 0);
-      }
-    }
-
     if (Util.SDK_INT < 32 && decoderInfos.size() > 1) {
       String firstCodecName = decoderInfos.get(0).name;
       // Prefer anything other than OMX.qti.audio.decoder.flac on older devices. See [Internal
@@ -1056,7 +1008,6 @@ public final class MediaCodecUtil {
     boolean isFeatureRequired(String feature, String mimeType, CodecCapabilities capabilities);
   }
 
-  @RequiresApi(21)
   private static final class MediaCodecListCompatV21 implements MediaCodecListCompat {
 
     private final int codecKind;

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/mediacodec/SynchronousMediaCodecAdapter.java

@@ -17,7 +17,6 @@
 package androidx.media3.exoplayer.mediacodec;
 
 import static androidx.media3.common.util.Assertions.checkNotNull;
-import static androidx.media3.common.util.Util.castNonNull;
 
 import android.media.MediaCodec;
 import android.media.MediaFormat;
@@ -80,15 +79,9 @@ public final class SynchronousMediaCodecAdapter implements MediaCodecAdapter {
   }
 
   private final MediaCodec codec;
-  @Nullable private ByteBuffer[] inputByteBuffers;
-  @Nullable private ByteBuffer[] outputByteBuffers;
 
   private SynchronousMediaCodecAdapter(MediaCodec mediaCodec) {
     this.codec = mediaCodec;
-    if (Util.SDK_INT < 21) {
-      inputByteBuffers = codec.getInputBuffers();
-      outputByteBuffers = codec.getOutputBuffers();
-    }
   }
 
   @Override
@@ -106,9 +99,6 @@ public final class SynchronousMediaCodecAdapter implements MediaCodecAdapter {
     int index;
     do {
       index = codec.dequeueOutputBuffer(bufferInfo, 0);
-      if (index == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED && Util.SDK_INT < 21) {
-        outputByteBuffers = codec.getOutputBuffers();
-      }
     } while (index == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED);
 
     return index;
@@ -122,21 +112,13 @@ public final class SynchronousMediaCodecAdapter implements MediaCodecAdapter {
   @Override
   @Nullable
   public ByteBuffer getInputBuffer(int index) {
-    if (Util.SDK_INT >= 21) {
+    return codec.getInputBuffer(index);
-      return codec.getInputBuffer(index);
-    } else {
-      return castNonNull(inputByteBuffers)[index];
-    }
   }
 
   @Override
   @Nullable
   public ByteBuffer getOutputBuffer(int index) {
-    if (Util.SDK_INT >= 21) {
+    return codec.getOutputBuffer(index);
-      return codec.getOutputBuffer(index);
-    } else {
-      return castNonNull(outputByteBuffers)[index];
-    }
   }
 
   @Override
@@ -158,7 +140,6 @@ public final class SynchronousMediaCodecAdapter implements MediaCodecAdapter {
   }
 
   @Override
-  @RequiresApi(21)
   public void releaseOutputBuffer(int index, long renderTimeStampNs) {
     codec.releaseOutputBuffer(index, renderTimeStampNs);
   }
@@ -170,8 +151,6 @@ public final class SynchronousMediaCodecAdapter implements MediaCodecAdapter {
 
   @Override
   public void release() {
-    inputByteBuffers = null;
-    outputByteBuffers = null;
     try {
       if (Util.SDK_INT >= 30 && Util.SDK_INT < 33) {
         // Stopping the codec before releasing it works around a bug on APIs 30, 31 and 32 where

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/scheduler/PlatformScheduler.java

@@ -25,7 +25,6 @@ import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
 import android.os.PersistableBundle;
-import androidx.annotation.RequiresApi;
 import androidx.annotation.RequiresPermission;
 import androidx.media3.common.util.Log;
 import androidx.media3.common.util.UnstableApi;
@@ -44,7 +43,6 @@ import androidx.media3.common.util.Util;
  *     android:exported="true"/>
  * }</pre>
  */
-@RequiresApi(21)
 @UnstableApi
 public final class PlatformScheduler implements Scheduler {
 

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/scheduler/Requirements.java

@@ -202,9 +202,7 @@ public final class Requirements implements Parcelable {
   private boolean isDeviceIdle(Context context) {
     PowerManager powerManager =
         (PowerManager) Assertions.checkNotNull(context.getSystemService(Context.POWER_SERVICE));
-    return Util.SDK_INT >= 23
+    return Util.SDK_INT >= 23 ? powerManager.isDeviceIdleMode() : !powerManager.isInteractive();
-        ? powerManager.isDeviceIdleMode()
-        : Util.SDK_INT >= 20 ? !powerManager.isInteractive() : !powerManager.isScreenOn();
   }
 
   private boolean isStorageNotLow(Context context) {

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

@@ -58,13 +58,10 @@ import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
-import java.lang.reflect.Constructor;
-import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArraySet;
 import java.util.concurrent.Executor;
-import org.checkerframework.checker.nullness.qual.EnsuresNonNull;
 import org.checkerframework.checker.nullness.qual.EnsuresNonNullIf;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
@@ -491,7 +488,6 @@ public final class CompositingVideoSinkProvider implements VideoSinkProvider, Vi
     private final VideoFrameReleaseControl.FrameReleaseInfo frameReleaseInfo;
 
     private @MonotonicNonNull VideoFrameProcessor videoFrameProcessor;
-    @Nullable private Effect rotationEffect;
     @Nullable private Format inputFormat;
     private @InputType int inputType;
     private long inputStreamStartPositionUs;
@@ -611,21 +607,6 @@ public final class CompositingVideoSinkProvider implements VideoSinkProvider, Vi
           throw new UnsupportedOperationException("Unsupported input type " + inputType);
       }
       videoFrameReleaseControl.setFrameRate(format.frameRate);
-      // MediaCodec applies rotation after API 21.
-      if (inputType == INPUT_TYPE_SURFACE
-          && Util.SDK_INT < 21
-          && format.rotationDegrees != Format.NO_VALUE
-          && format.rotationDegrees != 0) {
-        // We must apply a rotation effect.
-        if (rotationEffect == null
-            || this.inputFormat == null
-            || this.inputFormat.rotationDegrees != format.rotationDegrees) {
-          rotationEffect = ScaleAndRotateAccessor.createRotationEffect(format.rotationDegrees);
-        } // Else, the rotation effect matches the previous format's rotation degrees, keep the same
-        // instance.
-      } else {
-        rotationEffect = null;
-      }
       this.inputType = inputType;
       this.inputFormat = format;
 
@@ -884,9 +865,6 @@ public final class CompositingVideoSinkProvider implements VideoSinkProvider, Vi
       }
 
       ArrayList<Effect> effects = new ArrayList<>();
-      if (rotationEffect != null) {
-        effects.add(rotationEffect);
-      }
       effects.addAll(videoEffects);
       Format inputFormat = checkNotNull(this.inputFormat);
       checkStateNotNull(videoFrameProcessor)
@@ -1081,42 +1059,4 @@ public final class CompositingVideoSinkProvider implements VideoSinkProvider, Vi
               listener);
     }
   }
-
-  private static final class ScaleAndRotateAccessor {
-    private static @MonotonicNonNull Constructor<?> scaleAndRotateTransformationBuilderConstructor;
-    private static @MonotonicNonNull Method setRotationMethod;
-    private static @MonotonicNonNull Method buildScaleAndRotateTransformationMethod;
-
-    public static Effect createRotationEffect(float rotationDegrees) {
-      try {
-        prepare();
-        Object builder = scaleAndRotateTransformationBuilderConstructor.newInstance();
-        setRotationMethod.invoke(builder, rotationDegrees);
-        return (Effect) checkNotNull(buildScaleAndRotateTransformationMethod.invoke(builder));
-      } catch (Exception e) {
-        throw new IllegalStateException(e);
-      }
-    }
-
-    @EnsuresNonNull({
-      "scaleAndRotateTransformationBuilderConstructor",
-      "setRotationMethod",
-      "buildScaleAndRotateTransformationMethod"
-    })
-    private static void prepare() throws NoSuchMethodException, ClassNotFoundException {
-      if (scaleAndRotateTransformationBuilderConstructor == null
-          || setRotationMethod == null
-          || buildScaleAndRotateTransformationMethod == null) {
-        // TODO: b/284964524 - Add LINT and proguard checks for media3.effect reflection.
-        Class<?> scaleAndRotateTransformationBuilderClass =
-            Class.forName("androidx.media3.effect.ScaleAndRotateTransformation$Builder");
-        scaleAndRotateTransformationBuilderConstructor =
-            scaleAndRotateTransformationBuilderClass.getConstructor();
-        setRotationMethod =
-            scaleAndRotateTransformationBuilderClass.getMethod("setRotationDegrees", float.class);
-        buildScaleAndRotateTransformationMethod =
-            scaleAndRotateTransformationBuilderClass.getMethod("build");
-      }
-    }
-  }
 }

libraries/exoplayer/src/test/java/androidx/media3/exoplayer/audio/DecoderAudioRendererTest.java

@@ -18,7 +18,6 @@ package androidx.media3.exoplayer.audio;
 import static androidx.media3.common.C.FORMAT_HANDLED;
 import static androidx.media3.exoplayer.RendererCapabilities.ADAPTIVE_NOT_SEAMLESS;
 import static androidx.media3.exoplayer.RendererCapabilities.DECODER_SUPPORT_PRIMARY;
-import static androidx.media3.exoplayer.RendererCapabilities.TUNNELING_NOT_SUPPORTED;
 import static androidx.media3.exoplayer.RendererCapabilities.TUNNELING_SUPPORTED;
 import static androidx.media3.test.utils.FakeSampleStream.FakeSampleStreamItem.END_OF_STREAM_ITEM;
 import static androidx.media3.test.utils.FakeSampleStream.FakeSampleStreamItem.oneByteSample;
@@ -96,17 +95,6 @@ public class DecoderAudioRendererTest {
     audioRenderer.init(/* index= */ 0, PlayerId.UNSET, Clock.DEFAULT);
   }
 
-  @Config(sdk = 19)
-  @Test
-  public void supportsFormatAtApi19() {
-    assertThat(audioRenderer.supportsFormat(FORMAT))
-        .isEqualTo(
-            ADAPTIVE_NOT_SEAMLESS
-                | TUNNELING_NOT_SUPPORTED
-                | FORMAT_HANDLED
-                | DECODER_SUPPORT_PRIMARY);
-  }
-
   @Config(sdk = 21)
   @Test
   public void supportsFormatAtApi21() {

libraries/exoplayer/src/test/java/androidx/media3/exoplayer/audio/DefaultAudioSinkTest.java

@@ -315,20 +315,6 @@ public final class DefaultAudioSinkTest {
         .isEqualTo(SINK_FORMAT_SUPPORTED_WITH_TRANSCODING);
   }
 
-  @Config(maxSdk = 20)
-  @Test
-  public void floatPcmNeedsTranscodingIfFloatOutputEnabledBeforeApi21() {
-    defaultAudioSink = new DefaultAudioSink.Builder().setEnableFloatOutput(true).build();
-    Format floatFormat =
-        STEREO_44_1_FORMAT
-            .buildUpon()
-            .setSampleMimeType(MimeTypes.AUDIO_RAW)
-            .setPcmEncoding(C.ENCODING_PCM_FLOAT)
-            .build();
-    assertThat(defaultAudioSink.getFormatSupport(floatFormat))
-        .isEqualTo(SINK_FORMAT_SUPPORTED_WITH_TRANSCODING);
-  }
-
   @Config(minSdk = 21)
   @Test
   public void floatOutputSupportedIfFloatOutputEnabledFromApi21() {

libraries/muxer/src/main/java/androidx/media3/muxer/Mp4MoovStructure.java

@@ -21,7 +21,6 @@ import android.media.MediaCodec.BufferInfo;
 import androidx.media3.common.C;
 import androidx.media3.common.Format;
 import androidx.media3.common.MimeTypes;
-import androidx.media3.common.util.Util;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Lists;
 import java.nio.ByteBuffer;
@@ -218,8 +217,7 @@ import org.checkerframework.checker.nullness.qual.PolyNull;
       return null;
     }
 
-    Locale locale =
+    Locale locale = Locale.forLanguageTag(languageTag);
-        Util.SDK_INT >= 21 ? Locale.forLanguageTag(languageTag) : new Locale(languageTag);
 
     return locale.getISO3Language().isEmpty() ? languageTag : locale.getISO3Language();
   }

libraries/session/src/main/java/androidx/media3/session/DefaultMediaNotificationProvider.java

@@ -366,7 +366,7 @@ public class DefaultMediaNotificationProvider implements MediaNotification.Provi
       }
     }
 
-    if (player.isCommandAvailable(COMMAND_STOP) || Util.SDK_INT < 21) {
+    if (player.isCommandAvailable(COMMAND_STOP)) {
       // We must include a cancel intent for pre-L devices.
       mediaStyle.setCancelButtonIntent(
           actionFactory.createMediaActionPendingIntent(mediaSession, COMMAND_STOP));
@@ -639,9 +639,7 @@ public class DefaultMediaNotificationProvider implements MediaNotification.Provi
   }
 
   private static long getPlaybackStartTimeEpochMs(Player player) {
-    // Changing "showWhen" causes notification flicker if SDK_INT < 21.
+    if (player.isPlaying()
-    if (Util.SDK_INT >= 21
-        && player.isPlaying()
         && !player.isPlayingAd()
         && !player.isCurrentMediaItemDynamic()
         && player.getPlaybackParameters().speed == 1f) {

libraries/session/src/main/java/androidx/media3/session/MediaLibraryService.java

@@ -98,13 +98,8 @@ public abstract class MediaLibraryService extends MediaSessionService {
    *   <th>{@link ControllerInfo#getPackageName()}<br>for legacy browser</th>
    *   <th>{@link ControllerInfo#getUid()}<br>for legacy browser</th></tr>
    * <tr>
-   *   <td>{@code SDK_INT < 21}</td>
-   *   <td>Actual package name via {@link Context#getPackageName()}</td>
-   *   <td>Actual UID</td>
-   * </tr>
-   * <tr>
    *   <td>
-   *     {@code 21 <= SDK_INT < 28}<br>
+   *     {@code SDK_INT < 28}<br>
    *     for {@link Callback#onConnect onConnect}<br>
    *     and {@link Callback#onGetLibraryRoot onGetLibraryRoot}
    *   </td>
@@ -113,7 +108,7 @@ public abstract class MediaLibraryService extends MediaSessionService {
    * </tr>
    * <tr>
    *   <td>
-   *     {@code 21 <= SDK_INT < 28}<br>
+   *     {@code SDK_INT < 28}<br>
    *     for other {@link Callback callbacks}
    *   </td>
    *   <td>{@link ControllerInfo#LEGACY_CONTROLLER_PACKAGE_NAME}</td>

libraries/session/src/main/java/androidx/media3/session/MediaNotificationManager.java

@@ -210,14 +210,11 @@ import java.util.concurrent.TimeoutException;
       MediaSession session,
       MediaNotification mediaNotification,
       boolean startInForegroundRequired) {
-    if (Util.SDK_INT >= 21) {
+    // Call Notification.MediaStyle#setMediaSession() indirectly.
-      // Call Notification.MediaStyle#setMediaSession() indirectly.
+    android.media.session.MediaSession.Token fwkToken =
-      android.media.session.MediaSession.Token fwkToken =
+        (android.media.session.MediaSession.Token)
-          (android.media.session.MediaSession.Token)
+            session.getSessionCompat().getSessionToken().getToken();
-              session.getSessionCompat().getSessionToken().getToken();
+    mediaNotification.notification.extras.putParcelable(Notification.EXTRA_MEDIA_SESSION, fwkToken);
-      mediaNotification.notification.extras.putParcelable(
-          Notification.EXTRA_MEDIA_SESSION, fwkToken);
-    }
     this.mediaNotification = mediaNotification;
     if (startInForegroundRequired) {
       startForeground(mediaNotification);
@@ -379,9 +376,7 @@ import java.util.concurrent.TimeoutException;
     if (Util.SDK_INT >= 24) {
       Api24.stopForeground(mediaSessionService, removeNotifications);
     } else {
-      // For pre-L devices, we must call Service.stopForeground(true) anyway as a workaround
+      mediaSessionService.stopForeground(removeNotifications);
-      // that prevents the media notification from being undismissable.
-      mediaSessionService.stopForeground(removeNotifications || Util.SDK_INT < 21);
     }
     startedInForeground = false;
   }

libraries/session/src/main/java/androidx/media3/session/MediaSession.java

@@ -25,7 +25,6 @@ import static androidx.media3.session.SessionResult.RESULT_SUCCESS;
 import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
-import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.IBinder;
@@ -524,25 +523,7 @@ public class MediaSession {
       return interfaceVersion;
     }
 
-    /**
+    /** Returns the package name, or {@link #LEGACY_CONTROLLER_PACKAGE_NAME} on API ≤ 24. */
-     * Returns the package name. Can be {@link #LEGACY_CONTROLLER_PACKAGE_NAME} for
-     * interoperability.
-     *
-     * <p>Interoperability: Package name may not be precisely obtained for legacy controller API on
-     * older device. Here are details.
-     *
-     * <table>
-     * <caption>Summary when package name isn't precise</caption>
-     * <tr><th>SDK version when package name isn't precise</th>
-     *     <th>{@code ControllerInfo#getPackageName()} for legacy controller</th>
-     * <tr><td>{@code SDK_INT < 21}</td>
-     *     <td>Actual package name via {@link PackageManager#getNameForUid} with UID.<br>
-     *         It's sufficient for most cases, but doesn't precisely distinguish caller if it
-     *         uses shared user ID.</td>
-     * <tr><td>{@code 21 <= SDK_INT < 24}</td>
-     *     <td>{@link #LEGACY_CONTROLLER_PACKAGE_NAME}</td>
-     * </table>
-     */
     public String getPackageName() {
       return remoteUserInfo.getPackageName();
     }
@@ -550,8 +531,8 @@ public class MediaSession {
     /**
      * Returns the UID of the controller. Can be a negative value for interoperability.
      *
-     * <p>Interoperability: If {@code 21 <= SDK_INT < 28}, then UID would be a negative value
+     * <p>Interoperability: If {@code SDK_INT < 28}, then UID would be a negative value because it
-     * because it cannot be obtained.
+     * cannot be obtained.
      */
     public int getUid() {
       return remoteUserInfo.getUid();
@@ -1221,7 +1202,6 @@ public class MediaSession {
    * android.media.session.MediaSession} created internally by this session.
    */
   @SuppressWarnings("UnnecessarilyFullyQualified") // Avoiding clash with Media3 token.
-  @RequiresApi(21)
   @UnstableApi
   public final android.media.session.MediaSession.Token getPlatformToken() {
     return (android.media.session.MediaSession.Token)

libraries/session/src/main/java/androidx/media3/session/MediaSessionImpl.java

@@ -53,11 +53,9 @@ import android.os.SystemClock;
 import android.view.KeyEvent;
 import android.view.ViewConfiguration;
 import androidx.annotation.CheckResult;
-import androidx.annotation.DoNotInline;
 import androidx.annotation.FloatRange;
 import androidx.annotation.GuardedBy;
 import androidx.annotation.Nullable;
-import androidx.annotation.RequiresApi;
 import androidx.media3.common.AudioAttributes;
 import androidx.media3.common.DeviceInfo;
 import androidx.media3.common.MediaItem;
@@ -1213,7 +1211,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     }
     // Double tap detection.
     int keyCode = keyEvent.getKeyCode();
-    boolean isTvApp = Util.SDK_INT >= 21 && Api21.isTvApp(context);
+    boolean isTvApp = context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_LEANBACK);
     boolean doubleTapCompleted = false;
     switch (keyCode) {
       case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE:
@@ -1910,12 +1908,4 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
       }
     }
   }
-
-  @RequiresApi(21)
-  private static final class Api21 {
-    @DoNotInline
-    public static boolean isTvApp(Context context) {
-      return context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_LEANBACK);
-    }
-  }
 }

libraries/session/src/main/java/androidx/media3/session/MediaSessionLegacyStub.java

@@ -35,7 +35,6 @@ import static androidx.media3.common.util.Assertions.checkNotNull;
 import static androidx.media3.common.util.Assertions.checkStateNotNull;
 import static androidx.media3.common.util.Util.castNonNull;
 import static androidx.media3.common.util.Util.postOrRun;
-import static androidx.media3.session.MediaUtils.TRANSACTION_SIZE_LIMIT_IN_BYTES;
 import static androidx.media3.session.SessionCommand.COMMAND_CODE_CUSTOM;
 import static androidx.media3.session.SessionError.ERROR_UNKNOWN;
 import static androidx.media3.session.SessionResult.RESULT_INFO_SKIPPED;
@@ -1226,7 +1225,7 @@ import org.checkerframework.checker.initialization.qual.Initialized;
           () -> {
             int completedBitmapFutureCount = resultCount.incrementAndGet();
             if (completedBitmapFutureCount == mediaItemList.size()) {
-              handleBitmapFuturesAllCompletedAndSetQueue(bitmapFutures, timeline, mediaItemList);
+              handleBitmapFuturesAllCompletedAndSetQueue(bitmapFutures, mediaItemList);
             }
           };
 
@@ -1247,9 +1246,7 @@ import org.checkerframework.checker.initialization.qual.Initialized;
     }
 
     private void handleBitmapFuturesAllCompletedAndSetQueue(
-        List<@NullableType ListenableFuture<Bitmap>> bitmapFutures,
+        List<@NullableType ListenableFuture<Bitmap>> bitmapFutures, List<MediaItem> mediaItems) {
-        Timeline timeline,
-        List<MediaItem> mediaItems) {
       List<QueueItem> queueItemList = new ArrayList<>();
       for (int i = 0; i < bitmapFutures.size(); i++) {
         @Nullable ListenableFuture<Bitmap> future = bitmapFutures.get(i);
@@ -1264,22 +1261,9 @@ import org.checkerframework.checker.initialization.qual.Initialized;
         queueItemList.add(LegacyConversions.convertToQueueItem(mediaItems.get(i), i, bitmap));
       }
 
-      if (Util.SDK_INT < 21) {
+      // Framework MediaSession#setQueue() uses ParceledListSlice,
-        // In order to avoid TransactionTooLargeException for below API 21, we need to
+      // which means we can safely send long lists.
-        // cut the list so that it doesn't exceed the binder transaction limit.
+      setQueue(sessionCompat, queueItemList);
-        List<QueueItem> truncatedList =
-            MediaUtils.truncateListBySize(queueItemList, TRANSACTION_SIZE_LIMIT_IN_BYTES);
-        if (truncatedList.size() != timeline.getWindowCount()) {
-          Log.i(
-              TAG,
-              "Sending " + truncatedList.size() + " items out of " + timeline.getWindowCount());
-        }
-        setQueue(sessionCompat, truncatedList);
-      } else {
-        // Framework MediaSession#setQueue() uses ParceledListSlice,
-        // which means we can safely send long lists.
-        setQueue(sessionCompat, queueItemList);
-      }
     }
 
     @Override

libraries/session/src/main/java/androidx/media3/session/SessionToken.java

@@ -300,8 +300,7 @@ public final class SessionToken {
 
   private static MediaSessionCompat.Token createCompatToken(
       Parcelable platformOrLegacyCompatToken) {
-    if (Util.SDK_INT >= 21
+    if (platformOrLegacyCompatToken instanceof android.media.session.MediaSession.Token) {
-        && platformOrLegacyCompatToken instanceof android.media.session.MediaSession.Token) {
       return MediaSessionCompat.Token.fromToken(platformOrLegacyCompatToken);
     }
     // Assume this is an android.support.v4.media.session.MediaSessionCompat.Token.

libraries/test_exoplayer_playback/src/androidTest/java/androidx/media3/test/exoplayer/playback/gts/DashStreamingTest.java

@@ -666,7 +666,7 @@ public final class DashStreamingTest {
         MediaCodecUtil.getDecoderInfo(
             MimeTypes.VIDEO_H264, /* secure= */ false, /* tunneling= */ false);
     assertThat(decoderInfo).isNotNull();
-    assertThat(Util.SDK_INT < 21 || decoderInfo.adaptive).isTrue();
+    assertThat(decoderInfo.adaptive).isTrue();
   }
 
   @Test

libraries/test_exoplayer_playback/src/androidTest/java/androidx/media3/test/exoplayer/playback/gts/DebugRenderersFactory.java

@@ -17,13 +17,11 @@ package androidx.media3.test.exoplayer.playback.gts;
 
 import static java.lang.Math.max;
 
-import android.annotation.SuppressLint;
 import android.content.Context;
 import android.media.MediaCrypto;
 import android.media.MediaFormat;
 import android.os.Handler;
 import androidx.annotation.Nullable;
-import androidx.annotation.RequiresApi;
 import androidx.media3.common.C;
 import androidx.media3.common.Format;
 import androidx.media3.decoder.DecoderInputBuffer;
@@ -244,8 +242,6 @@ import java.util.ArrayList;
       super.renderOutputBuffer(codec, index, presentationTimeUs);
     }
 
-    @SuppressLint("UseSdkSuppress") // Not a test class or method.
-    @RequiresApi(21)
     @Override
     protected void renderOutputBufferV21(
         MediaCodecAdapter codec, int index, long presentationTimeUs, long releaseTimeNs) {

libraries/test_exoplayer_playback/src/androidTest/java/androidx/media3/test/exoplayer/playback/gts/EnumerateDecodersTest.java

@@ -115,9 +115,7 @@ public class EnumerateDecodersTest {
     boolean isAudio = MimeTypes.isAudio(requestedMimeType);
     StringBuilder result = new StringBuilder();
     result.append("[requestedMimeType=").append(requestedMimeType);
-    if (Util.SDK_INT >= 21) {
+    result.append(", mimeType=").append(codecCapabilities.getMimeType());
-      result.append(", mimeType=").append(codecCapabilities.getMimeType());
-    }
     result.append(", profileLevels=");
     appendProfileLevels(codecCapabilities.profileLevels, result);
     if (Util.SDK_INT >= 23) {
@@ -125,23 +123,19 @@ public class EnumerateDecodersTest {
           .append(", maxSupportedInstances=")
           .append(codecCapabilities.getMaxSupportedInstances());
     }
-    if (Util.SDK_INT >= 21) {
+    if (isVideo) {
-      if (isVideo) {
+      result.append(", videoCapabilities=");
-        result.append(", videoCapabilities=");
+      appendVideoCapabilities(codecCapabilities.getVideoCapabilities(), result);
-        appendVideoCapabilities(codecCapabilities.getVideoCapabilities(), result);
+      result.append(", colorFormats=").append(Arrays.toString(codecCapabilities.colorFormats));
-        result.append(", colorFormats=").append(Arrays.toString(codecCapabilities.colorFormats));
+    } else if (isAudio) {
-      } else if (isAudio) {
+      result.append(", audioCapabilities=");
-        result.append(", audioCapabilities=");
+      appendAudioCapabilities(codecCapabilities.getAudioCapabilities(), result);
-        appendAudioCapabilities(codecCapabilities.getAudioCapabilities(), result);
-      }
     }
     if (isVideo
         && codecCapabilities.isFeatureSupported(CodecCapabilities.FEATURE_AdaptivePlayback)) {
       result.append(", FEATURE_AdaptivePlayback");
     }
-    if (Util.SDK_INT >= 21
+    if (isVideo && codecCapabilities.isFeatureSupported(CodecCapabilities.FEATURE_SecurePlayback)) {
-        && isVideo
-        && codecCapabilities.isFeatureSupported(CodecCapabilities.FEATURE_SecurePlayback)) {
       result.append(", FEATURE_SecurePlayback");
     }
     if (Util.SDK_INT >= 26
@@ -149,8 +143,7 @@ public class EnumerateDecodersTest {
         && codecCapabilities.isFeatureSupported(CodecCapabilities.FEATURE_PartialFrame)) {
       result.append(", FEATURE_PartialFrame");
     }
-    if (Util.SDK_INT >= 21
+    if ((isVideo || isAudio)
-        && (isVideo || isAudio)
         && codecCapabilities.isFeatureSupported(CodecCapabilities.FEATURE_TunneledPlayback)) {
       result.append(", FEATURE_TunneledPlayback");
     }

libraries/test_session_current/src/androidTest/java/androidx/media3/session/MediaControllerCompatCallbackWithMediaSessionTest.java

@@ -610,7 +610,7 @@ public class MediaControllerCompatCallbackWithMediaSessionTest {
     session.setPlayer(playerConfigToUpdate);
 
     // In API 21 and 22, onAudioInfoChanged is not called when playback is changed to local.
-    if (Util.SDK_INT == 21 || Util.SDK_INT == 22) {
+    if (Util.SDK_INT <= 22) {
       PollingCheck.waitFor(
           TIMEOUT_MS,
           () -> {
@@ -657,21 +657,13 @@ public class MediaControllerCompatCallbackWithMediaSessionTest {
 
     session.setPlayer(playerConfig);
 
-    // In API 21+, onAudioInfoChanged() is not called when playbackType is not changed.
+    PollingCheck.waitFor(
-    if (Util.SDK_INT >= 21) {
+        TIMEOUT_MS,
-      PollingCheck.waitFor(
+        () -> {
-          TIMEOUT_MS,
+          MediaControllerCompat.PlaybackInfo info = controllerCompat.getPlaybackInfo();
-          () -> {
+          return info.getPlaybackType() == legacyPlaybackType
-            MediaControllerCompat.PlaybackInfo info = controllerCompat.getPlaybackInfo();
+              && info.getAudioAttributes().getLegacyStreamType() == legacyStream;
-            return info.getPlaybackType() == legacyPlaybackType
+        });
-                && info.getAudioAttributes().getLegacyStreamType() == legacyStream;
-          });
-    } else {
-      assertThat(playbackInfoNotified.await(TIMEOUT_MS, MILLISECONDS)).isTrue();
-      MediaControllerCompat.PlaybackInfo info = controllerCompat.getPlaybackInfo();
-      assertThat(info.getPlaybackType()).isEqualTo(legacyPlaybackType);
-      assertThat(info.getAudioAttributes().getLegacyStreamType()).isEqualTo(legacyStream);
-    }
   }
 
   @Test
@@ -709,23 +701,14 @@ public class MediaControllerCompatCallbackWithMediaSessionTest {
 
     session.setPlayer(playerConfigToUpdate);
 
-    // In API 21+, onAudioInfoChanged() is not called when playbackType is not changed.
+    PollingCheck.waitFor(
-    if (Util.SDK_INT >= 21) {
+        TIMEOUT_MS,
-      PollingCheck.waitFor(
+        () -> {
-          TIMEOUT_MS,
+          MediaControllerCompat.PlaybackInfo info = controllerCompat.getPlaybackInfo();
-          () -> {
+          return info.getPlaybackType() == legacyPlaybackTypeToUpdate
-            MediaControllerCompat.PlaybackInfo info = controllerCompat.getPlaybackInfo();
+              && info.getMaxVolume() == deviceInfoToUpdate.maxVolume
-            return info.getPlaybackType() == legacyPlaybackTypeToUpdate
+              && info.getCurrentVolume() == deviceVolumeToUpdate;
-                && info.getMaxVolume() == deviceInfoToUpdate.maxVolume
+        });
-                && info.getCurrentVolume() == deviceVolumeToUpdate;
-          });
-    } else {
-      assertThat(playbackInfoNotified.await(TIMEOUT_MS, MILLISECONDS)).isTrue();
-      MediaControllerCompat.PlaybackInfo info = controllerCompat.getPlaybackInfo();
-      assertThat(info.getPlaybackType()).isEqualTo(legacyPlaybackTypeToUpdate);
-      assertThat(info.getMaxVolume()).isEqualTo(deviceInfoToUpdate.maxVolume);
-      assertThat(info.getCurrentVolume()).isEqualTo(deviceVolumeToUpdate);
-    }
   }
 
   @Test
@@ -1555,15 +1538,8 @@ public class MediaControllerCompatCallbackWithMediaSessionTest {
     assertThat(latch.await(LONG_TIMEOUT_MS, MILLISECONDS)).isTrue();
     List<QueueItem> queueFromParam = queueRef.get();
     List<QueueItem> queueFromGetter = controllerCompat.getQueue();
-    if (Util.SDK_INT >= 21) {
+    assertThat(queueFromParam).hasSize(listSize);
-      assertThat(queueFromParam).hasSize(listSize);
+    assertThat(queueFromGetter).hasSize(listSize);
-      assertThat(queueFromGetter).hasSize(listSize);
-    } else {
-      // Below API 21, only the initial part of the playlist is sent to the
-      // MediaControllerCompat when the list is too long.
-      assertThat(queueFromParam.size() < listSize).isTrue();
-      assertThat(queueFromGetter).hasSize(queueFromParam.size());
-    }
     for (int i = 0; i < queueFromParam.size(); i++) {
       assertThat(queueFromParam.get(i).getDescription().getMediaId())
           .isEqualTo(TestUtils.getMediaIdInFakeTimeline(i));

libraries/test_session_current/src/androidTest/java/androidx/media3/session/MediaControllerListenerWithMediaSessionCompatTest.java

@@ -347,7 +347,7 @@ public class MediaControllerListenerWithMediaSessionCompatTest {
     // We need to trigger MediaControllerCompat.Callback.onAudioInfoChanged in order to raise the
     // onAudioAttributesChanged() callback. In API 21 and 22, onAudioInfoChanged is not called when
     // playback is changed to local.
-    assumeTrue(Util.SDK_INT != 21 && Util.SDK_INT != 22);
+    assumeTrue(Util.SDK_INT > 22);
 
     session.setPlaybackToRemote(
         /* volumeControl= */ VolumeProviderCompat.VOLUME_CONTROL_ABSOLUTE,

libraries/test_session_current/src/androidTest/java/androidx/media3/session/MediaControllerMediaSessionCompatCallbackAggregationTest.java

@@ -49,7 +49,6 @@ import androidx.media3.common.Player.PositionInfo;
 import androidx.media3.common.Timeline;
 import androidx.media3.common.Timeline.Window;
 import androidx.media3.common.util.BitmapLoader;
-import androidx.media3.common.util.Util;
 import androidx.media3.datasource.DataSourceBitmapLoader;
 import androidx.media3.test.session.common.HandlerThreadTestRule;
 import androidx.test.core.app.ApplicationProvider;
@@ -200,24 +199,6 @@ public class MediaControllerMediaSessionCompatCallbackAggregationTest {
       MediaItem mediaItem = timelineRef.get().getWindow(i, new Window()).mediaItem;
       MediaItem expectedMediaItem =
           (i == testMediaItemIndex) ? testCurrentMediaItem : testMediaItems.get(i);
-      if (Util.SDK_INT < 21) {
-        // Bitmap conversion and back gives not exactly the same byte array below API 21
-        MediaMetadata mediaMetadata =
-            mediaItem
-                .mediaMetadata
-                .buildUpon()
-                .setArtworkData(/* artworkData= */ null, /* artworkDataType= */ null)
-                .build();
-        MediaMetadata expectedMediaMetadata =
-            expectedMediaItem
-                .mediaMetadata
-                .buildUpon()
-                .setArtworkData(/* artworkData= */ null, /* artworkDataType= */ null)
-                .build();
-        mediaItem = mediaItem.buildUpon().setMediaMetadata(mediaMetadata).build();
-        expectedMediaItem =
-            expectedMediaItem.buildUpon().setMediaMetadata(expectedMediaMetadata).build();
-      }
       assertThat(mediaItem).isEqualTo(expectedMediaItem);
     }
     assertThat(timelineChangeReasonRef.get()).isEqualTo(TIMELINE_CHANGE_REASON_PLAYLIST_CHANGED);

libraries/test_session_current/src/androidTest/java/androidx/media3/session/MediaControllerWithFrameworkMediaSessionTest.java

@@ -27,7 +27,6 @@ import android.media.session.PlaybackState;
 import android.os.HandlerThread;
 import androidx.media3.common.Player;
 import androidx.media3.common.Player.State;
-import androidx.media3.common.util.Util;
 import androidx.media3.test.session.common.MainLooperTestRule;
 import androidx.media3.test.session.common.TestHandler;
 import androidx.test.core.app.ApplicationProvider;
@@ -37,7 +36,6 @@ import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import org.junit.After;
-import org.junit.Assume;
 import org.junit.Before;
 import org.junit.ClassRule;
 import org.junit.Test;
@@ -57,9 +55,6 @@ public class MediaControllerWithFrameworkMediaSessionTest {
 
   @Before
   public void setUp() {
-    if (Util.SDK_INT < 21) {
-      return;
-    }
     context = ApplicationProvider.getApplicationContext();
 
     HandlerThread handlerThread = new HandlerThread(TAG);
@@ -79,7 +74,6 @@ public class MediaControllerWithFrameworkMediaSessionTest {
   @SuppressWarnings("UnnecessarilyFullyQualified") // Intentionally fully qualified for fwk session.
   @Test
   public void createController() throws Exception {
-    Assume.assumeTrue(Util.SDK_INT >= 21); // For framework MediaSession.
     MediaSession fwkSession = new android.media.session.MediaSession(context, TAG);
     fwkSession.setActive(true);
     fwkSession.setFlags(
@@ -100,7 +94,6 @@ public class MediaControllerWithFrameworkMediaSessionTest {
   @SuppressWarnings("UnnecessarilyFullyQualified") // Intentionally fully qualified for fwk session.
   @Test
   public void onPlaybackStateChanged_isNotifiedByFwkSessionChanges() throws Exception {
-    Assume.assumeTrue(Util.SDK_INT >= 21); // For framework MediaSession.
     MediaSession fwkSession = new android.media.session.MediaSession(context, TAG);
     fwkSession.setActive(true);
     fwkSession.setFlags(

libraries/test_session_current/src/androidTest/java/androidx/media3/session/MediaControllerWithMediaSessionCompatTest.java

@@ -571,11 +571,8 @@ public class MediaControllerWithMediaSessionCompatTest {
     assertThat(TextUtils.equals(metadata.subtitle, testSubtitle)).isTrue();
     assertThat(TextUtils.equals(metadata.description, testDescription)).isTrue();
     assertThat(metadata.artworkUri).isEqualTo(testIconUri);
-    if (Util.SDK_INT >= 21) {
+    assertThat(metadata.artworkData).isEqualTo(testArtworkData);
-      // Bitmap conversion and back gives not exactly the same byte array below API 21
+    if (Util.SDK_INT >= 23) {
-      assertThat(metadata.artworkData).isEqualTo(testArtworkData);
-    }
-    if (Util.SDK_INT < 21 || Util.SDK_INT >= 23) {
       // TODO(b/199055952): Test mediaUri for all API levels once the bug is fixed.
       assertThat(mediaItem.requestMetadata.mediaUri).isEqualTo(testMediaUri);
     }
@@ -909,19 +906,6 @@ public class MediaControllerWithMediaSessionCompatTest {
         threadTestRule.getHandler().postAndSync(controller::getMediaMetadata);
 
     assertThat(mediaMetadata.artworkData).isNotNull();
-    if (Util.SDK_INT < 21) {
-      // Bitmap conversion and back gives not exactly the same byte array below API 21
-      mediaMetadata =
-          mediaMetadata
-              .buildUpon()
-              .setArtworkData(/* artworkData= */ null, /* artworkDataType= */ null)
-              .build();
-      testMediaMetadata =
-          testMediaMetadata
-              .buildUpon()
-              .setArtworkData(/* artworkData= */ null, /* artworkDataType= */ null)
-              .build();
-    }
     assertThat(mediaMetadata.artworkData).isEqualTo(testMediaMetadata.artworkData);
   }
 
@@ -1573,7 +1557,7 @@ public class MediaControllerWithMediaSessionCompatTest {
 
   @Test
   public void setPlaybackToLocal_notifiesDeviceInfoAndVolume() throws Exception {
-    if (Util.SDK_INT == 21 || Util.SDK_INT == 22) {
+    if (Util.SDK_INT <= 22) {
       // In API 21 and 22, onAudioInfoChanged is not called.
       return;
     }

libraries/test_session_current/src/androidTest/java/androidx/media3/session/MediaSessionCallbackWithMediaControllerCompatTest.java

@@ -91,7 +91,7 @@ public class MediaSessionCallbackWithMediaControllerCompatTest {
 
   private static final String TEST_URI = "http://test.test";
   private static final String EXPECTED_CONTROLLER_PACKAGE_NAME =
-      (Util.SDK_INT < 21 || Util.SDK_INT >= 24) ? SUPPORT_APP_PACKAGE_NAME : LEGACY_CONTROLLER;
+      Util.SDK_INT >= 24 ? SUPPORT_APP_PACKAGE_NAME : LEGACY_CONTROLLER;
 
   @ClassRule public static MainLooperTestRule mainLooperTestRule = new MainLooperTestRule();
 
@@ -1200,7 +1200,7 @@ public class MediaSessionCallbackWithMediaControllerCompatTest {
 
   @Test
   public void setVolumeWithLocalVolume() throws Exception {
-    if (Util.SDK_INT >= 21 && audioManager.isVolumeFixed()) {
+    if (audioManager.isVolumeFixed()) {
       // This test is not eligible for this device.
       return;
     }
@@ -1250,7 +1250,7 @@ public class MediaSessionCallbackWithMediaControllerCompatTest {
 
   @Test
   public void adjustVolumeWithLocalVolume() throws Exception {
-    if (Util.SDK_INT >= 21 && audioManager.isVolumeFixed()) {
+    if (audioManager.isVolumeFixed()) {
       // This test is not eligible for this device.
       return;
     }

libraries/test_session_current/src/androidTest/java/androidx/media3/session/MediaSessionCompatCallbackWithMediaControllerTest.java

@@ -541,7 +541,7 @@ public class MediaSessionCompatCallbackWithMediaControllerTest {
 
   @Test
   public void setDeviceVolume_forLocalPlayback_setsStreamVolume() throws Exception {
-    if (Util.SDK_INT >= 21 && audioManager.isVolumeFixed()) {
+    if (audioManager.isVolumeFixed()) {
       // This test is not eligible for this device.
       return;
     }
@@ -570,7 +570,7 @@ public class MediaSessionCompatCallbackWithMediaControllerTest {
 
   @Test
   public void increaseDeviceVolume_forLocalPlayback_increasesStreamVolume() throws Exception {
-    if (Util.SDK_INT >= 21 && audioManager.isVolumeFixed()) {
+    if (audioManager.isVolumeFixed()) {
       // This test is not eligible for this device.
       return;
     }
@@ -600,7 +600,7 @@ public class MediaSessionCompatCallbackWithMediaControllerTest {
 
   @Test
   public void decreaseDeviceVolume_forLocalPlayback_decreasesStreamVolume() throws Exception {
-    if (Util.SDK_INT >= 21 && audioManager.isVolumeFixed()) {
+    if (audioManager.isVolumeFixed()) {
       // This test is not eligible for this device.
       return;
     }

libraries/test_session_current/src/androidTest/java/androidx/media3/session/MediaSessionKeyEventTest.java

@@ -45,7 +45,6 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
 import org.junit.After;
-import org.junit.Assume;
 import org.junit.Before;
 import org.junit.ClassRule;
 import org.junit.Rule;
@@ -79,9 +78,6 @@ public class MediaSessionKeyEventTest {
 
   @Before
   public void setUp() throws Exception {
-    if (Util.SDK_INT < 21) {
-      return;
-    }
     Context context = ApplicationProvider.getApplicationContext();
     audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
     handler = threadTestRule.getHandler();
@@ -128,9 +124,6 @@ public class MediaSessionKeyEventTest {
 
   @After
   public void tearDown() throws Exception {
-    if (Util.SDK_INT < 21) {
-      return;
-    }
     handler.postAndSync(
         () -> {
           if (mediaPlayer != null) {
@@ -143,7 +136,6 @@ public class MediaSessionKeyEventTest {
 
   @Test
   public void playKeyEvent() throws Exception {
-    Assume.assumeTrue(Util.SDK_INT >= 21); // TODO: b/199064299 - Lower minSdk to 19.
     dispatchMediaKeyEvent(KeyEvent.KEYCODE_MEDIA_PLAY, false);
 
     player.awaitMethodCalled(MockPlayer.METHOD_PLAY, TIMEOUT_MS);
@@ -151,7 +143,6 @@ public class MediaSessionKeyEventTest {
 
   @Test
   public void pauseKeyEvent() throws Exception {
-    Assume.assumeTrue(Util.SDK_INT >= 21); // TODO: b/199064299 - Lower minSdk to 19.
     dispatchMediaKeyEvent(KeyEvent.KEYCODE_MEDIA_PAUSE, false);
 
     player.awaitMethodCalled(MockPlayer.METHOD_PAUSE, TIMEOUT_MS);
@@ -159,7 +150,6 @@ public class MediaSessionKeyEventTest {
 
   @Test
   public void nextKeyEvent() throws Exception {
-    Assume.assumeTrue(Util.SDK_INT >= 21); // TODO: b/199064299 - Lower minSdk to 19.
     dispatchMediaKeyEvent(KeyEvent.KEYCODE_MEDIA_NEXT, false);
 
     player.awaitMethodCalled(MockPlayer.METHOD_SEEK_TO_NEXT, TIMEOUT_MS);
@@ -167,7 +157,6 @@ public class MediaSessionKeyEventTest {
 
   @Test
   public void previousKeyEvent() throws Exception {
-    Assume.assumeTrue(Util.SDK_INT >= 21); // TODO: b/199064299 - Lower minSdk to 19.
     dispatchMediaKeyEvent(KeyEvent.KEYCODE_MEDIA_PREVIOUS, false);
 
     player.awaitMethodCalled(MockPlayer.METHOD_SEEK_TO_PREVIOUS, TIMEOUT_MS);
@@ -177,7 +166,6 @@ public class MediaSessionKeyEventTest {
   public void
       fastForwardKeyEvent_mediaNotificationControllerConnected_callFromNotificationController()
           throws Exception {
-    Assume.assumeTrue(Util.SDK_INT >= 21); // TODO: b/199064299 - Lower minSdk to 19.
     MediaController controller = connectMediaNotificationController();
     dispatchMediaKeyEvent(KeyEvent.KEYCODE_MEDIA_FAST_FORWARD, /* doubleTap= */ false);
 
@@ -204,8 +192,6 @@ public class MediaSessionKeyEventTest {
   public void
       fastForwardKeyEvent_mediaNotificationControllerNotConnected_callFromLegacyFallbackController()
           throws Exception {
-    Assume.assumeTrue(Util.SDK_INT >= 21); // TODO: b/199064299 - Lower minSdk to 19.
-
     dispatchMediaKeyEvent(KeyEvent.KEYCODE_MEDIA_FAST_FORWARD, false);
 
     player.awaitMethodCalled(MockPlayer.METHOD_SEEK_FORWARD, TIMEOUT_MS);
@@ -220,7 +206,6 @@ public class MediaSessionKeyEventTest {
   @Test
   public void rewindKeyEvent_mediaNotificationControllerConnected_callFromNotificationController()
       throws Exception {
-    Assume.assumeTrue(Util.SDK_INT >= 21); // TODO: b/199064299 - Lower minSdk to 19.
     MediaController controller = connectMediaNotificationController();
 
     dispatchMediaKeyEvent(KeyEvent.KEYCODE_MEDIA_REWIND, false);
@@ -246,8 +231,6 @@ public class MediaSessionKeyEventTest {
   public void
       rewindKeyEvent_mediaNotificationControllerNotConnected_callFromLegacyFallbackController()
           throws Exception {
-    Assume.assumeTrue(Util.SDK_INT >= 21); // TODO: b/199064299 - Lower minSdk to 19.
-
     dispatchMediaKeyEvent(KeyEvent.KEYCODE_MEDIA_REWIND, false);
 
     player.awaitMethodCalled(MockPlayer.METHOD_SEEK_BACK, TIMEOUT_MS);
@@ -261,7 +244,6 @@ public class MediaSessionKeyEventTest {
 
   @Test
   public void stopKeyEvent() throws Exception {
-    Assume.assumeTrue(Util.SDK_INT >= 21); // TODO: b/199064299 - Lower minSdk to 19.
     dispatchMediaKeyEvent(KeyEvent.KEYCODE_MEDIA_STOP, false);
 
     player.awaitMethodCalled(MockPlayer.METHOD_STOP, TIMEOUT_MS);
@@ -320,7 +302,6 @@ public class MediaSessionKeyEventTest {
 
   @Test
   public void playPauseKeyEvent_playing_pause() throws Exception {
-    Assume.assumeTrue(Util.SDK_INT >= 21); // TODO: b/199064299 - Lower minSdk to 19.
     handler.postAndSync(
         () -> {
           player.playWhenReady = true;
@@ -334,7 +315,6 @@ public class MediaSessionKeyEventTest {
 
   @Test
   public void playPauseKeyEvent_doubleTapOnPlayPause_seekNext() throws Exception {
-    Assume.assumeTrue(Util.SDK_INT >= 21); // TODO: b/199064299 - Lower minSdk to 19.
     handler.postAndSync(
         () -> {
           player.playWhenReady = true;
@@ -348,7 +328,6 @@ public class MediaSessionKeyEventTest {
 
   @Test
   public void playPauseKeyEvent_doubleTapOnHeadsetHook_seekNext() throws Exception {
-    Assume.assumeTrue(Util.SDK_INT >= 21); // TODO: b/199064299 - Lower minSdk to 19.
     handler.postAndSync(
         () -> {
           player.playWhenReady = true;
@@ -390,10 +369,8 @@ public class MediaSessionKeyEventTest {
       return SUPPORT_APP_PACKAGE_NAME;
     }
     // Legacy controllers
-    if (Util.SDK_INT < 21 || Util.SDK_INT >= 28) {
+    if (Util.SDK_INT >= 28) {
       // Above API 28: package of the app using AudioManager.
-      // Below 21: package of the owner of the session. Note: This is specific to this test setup
-      // where `ApplicationProvider.getContext().packageName == SUPPORT_APP_PACKAGE_NAME`.
       return SUPPORT_APP_PACKAGE_NAME;
     } else if (Util.SDK_INT >= 24) {
       // API 24 - 27: KeyEvent from system service has the package name "android".

libraries/test_session_current/src/androidTest/java/androidx/media3/session/MediaSessionTest.java

@@ -1014,8 +1014,7 @@ public class MediaSessionTest {
    * <p>Calling this method should only be required to test legacy behaviour.
    */
   private static String getControllerCallerPackageName(ControllerInfo controllerInfo) {
-    return (Util.SDK_INT < 21
+    return (Util.SDK_INT > 23
-            || Util.SDK_INT > 23
             || controllerInfo.getControllerVersion() != ControllerInfo.LEGACY_CONTROLLER_VERSION)
         ? ApplicationProvider.getApplicationContext().getPackageName()
         : MediaSessionManager.RemoteUserInfo.LEGACY_CONTROLLER;

libraries/test_session_current/src/androidTest/java/androidx/media3/session/SessionTokenTest.java

@@ -20,7 +20,6 @@ import static androidx.media3.test.session.common.CommonConstants.MOCK_MEDIA3_SE
 import static androidx.media3.test.session.common.CommonConstants.SUPPORT_APP_PACKAGE_NAME;
 import static androidx.media3.test.session.common.TestUtils.TIMEOUT_MS;
 import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assume.assumeTrue;
 
 import android.content.ComponentName;
 import android.content.Context;
@@ -28,7 +27,6 @@ import android.os.Bundle;
 import android.os.Process;
 import android.support.v4.media.session.MediaSessionCompat;
 import androidx.media3.common.MediaLibraryInfo;
-import androidx.media3.common.util.Util;
 import androidx.media3.test.session.common.HandlerThreadTestRule;
 import androidx.media3.test.session.common.MainLooperTestRule;
 import androidx.media3.test.session.common.TestUtils;
@@ -117,8 +115,6 @@ public class SessionTokenTest {
   @Test
   public void createSessionToken_withPlatformTokenFromMedia1Session_returnsTokenForLegacySession()
       throws Exception {
-    assumeTrue(Util.SDK_INT >= 21);
-
     MediaSessionCompat sessionCompat =
         sessionTestRule.ensureReleaseAfterTest(
             new MediaSessionCompat(context, "createSessionToken_withLegacyToken"));

libraries/test_utils/src/main/java/androidx/media3/test/utils/AssetContentProvider.java

@@ -29,7 +29,6 @@ import android.system.ErrnoException;
 import android.system.OsConstants;
 import androidx.annotation.Nullable;
 import androidx.media3.common.util.UnstableApi;
-import androidx.media3.common.util.Util;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
@@ -148,8 +147,7 @@ public final class AssetContentProvider extends ContentProvider
   }
 
   private static boolean isBrokenPipe(IOException e) {
-    return Util.SDK_INT >= 21
+    return e.getCause() instanceof ErrnoException
-        && e.getCause() instanceof ErrnoException
         && ((ErrnoException) e.getCause()).errno == OsConstants.EPIPE;
   }
 }

libraries/test_utils/src/main/java/androidx/media3/test/utils/CapturingRenderersFactory.java

@@ -331,7 +331,6 @@ public class CapturingRenderersFactory implements RenderersFactory, Dumper.Dumpa
       dequeuedOutputBuffers.delete(index);
     }
 
-    @RequiresApi(21)
     @Override
     public void releaseOutputBuffer(int index, long renderTimeStampNs) {
       MediaCodec.BufferInfo bufferInfo = checkNotNull(dequeuedOutputBuffers.get(index));

libraries/test_utils/src/main/java/androidx/media3/test/utils/DecodeOneFrameUtil.java

@@ -204,9 +204,6 @@ public final class DecodeOneFrameUtil {
    */
   @Nullable
   private static String getSupportedDecoderName(MediaFormat format) {
-    if (Util.SDK_INT < 21) {
-      throw new UnsupportedOperationException("Unable to detect decoder support under API 21.");
-    }
     // TODO(b/266923205): De-duplicate logic from EncoderUtil.java#findCodecForFormat().
     MediaCodecList mediaCodecList = new MediaCodecList(MediaCodecList.REGULAR_CODECS);
     // Format must not include KEY_FRAME_RATE on API21.

libraries/test_utils/src/main/java/androidx/media3/test/utils/SsimHelper.java

@@ -24,7 +24,6 @@ import android.content.Context;
 import android.media.Image;
 import android.media.MediaCodec;
 import androidx.annotation.Nullable;
-import androidx.annotation.RequiresApi;
 import androidx.media3.common.util.UnstableApi;
 import java.io.IOException;
 import java.nio.ByteBuffer;
@@ -43,7 +42,6 @@ import java.nio.ByteBuffer;
  * channel (Y') because the {@linkplain MediaCodec decoder} decodes to luma.
  */
 @UnstableApi
-@RequiresApi(21)
 public final class SsimHelper {
 
   /** The default comparison interval. */

libraries/test_utils/src/main/java/androidx/media3/test/utils/VideoDecodingWrapper.java

@@ -32,7 +32,6 @@ import android.media.MediaFormat;
 import android.net.Uri;
 import android.os.Handler;
 import androidx.annotation.Nullable;
-import androidx.annotation.RequiresApi;
 import androidx.media3.common.Format;
 import androidx.media3.common.MimeTypes;
 import androidx.media3.common.util.ConditionVariable;
@@ -55,7 +54,6 @@ import java.util.List;
  * ImageReader} for use in CPU test utility functions.
  */
 @UnstableApi
-@RequiresApi(21)
 public final class VideoDecodingWrapper implements AutoCloseable {
 
   private static final String TAG = "VideoDecodingWrapper";

libraries/test_utils_robolectric/src/main/java/androidx/media3/test/utils/robolectric/ShadowMediaCodecConfig.java

@@ -25,7 +25,6 @@ import android.media.MediaFormat;
 import androidx.media3.common.C;
 import androidx.media3.common.MimeTypes;
 import androidx.media3.common.util.UnstableApi;
-import androidx.media3.common.util.Util;
 import androidx.media3.exoplayer.mediacodec.MediaCodecUtil;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -77,10 +76,6 @@ public final class ShadowMediaCodecConfig extends ExternalResource {
 
   @Override
   protected void before() throws Throwable {
-    if (Util.SDK_INT == 19) {
-      // Codec config not supported with Robolectric on API == 19. Skip rule set up step.
-      return;
-    }
     configureCodecs(supportedMimeTypes);
   }
 
@@ -88,10 +83,6 @@ public final class ShadowMediaCodecConfig extends ExternalResource {
   protected void after() {
     supportedMimeTypes.clear();
     MediaCodecUtil.clearDecoderInfoCache();
-    if (Util.SDK_INT == 19) {
-      // Codec config not supported with Robolectric on API == 19. Skip rule tear down step.
-      return;
-    }
     ShadowMediaCodecList.reset();
     ShadowMediaCodec.clearCodecs();
   }

libraries/ui/src/main/java/androidx/media3/ui/CaptionStyleCompat.java

@@ -23,9 +23,7 @@ import android.view.accessibility.CaptioningManager;
 import android.view.accessibility.CaptioningManager.CaptionStyle;
 import androidx.annotation.IntDef;
 import androidx.annotation.Nullable;
-import androidx.annotation.RequiresApi;
 import androidx.media3.common.util.UnstableApi;
-import androidx.media3.common.util.Util;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -116,17 +114,13 @@ public final class CaptionStyleCompat {
    */
   public static CaptionStyleCompat createFromCaptionStyle(
       CaptioningManager.CaptionStyle captionStyle) {
-    if (Util.SDK_INT >= 21) {
+    return new CaptionStyleCompat(
-      return createFromCaptionStyleV21(captionStyle);
+        captionStyle.hasForegroundColor() ? captionStyle.foregroundColor : DEFAULT.foregroundColor,
-    } else {
+        captionStyle.hasBackgroundColor() ? captionStyle.backgroundColor : DEFAULT.backgroundColor,
-      return new CaptionStyleCompat(
+        captionStyle.hasWindowColor() ? captionStyle.windowColor : DEFAULT.windowColor,
-          captionStyle.foregroundColor,
+        captionStyle.hasEdgeType() ? captionStyle.edgeType : DEFAULT.edgeType,
-          captionStyle.backgroundColor,
+        captionStyle.hasEdgeColor() ? captionStyle.edgeColor : DEFAULT.edgeColor,
-          Color.TRANSPARENT,
+        captionStyle.getTypeface());
-          captionStyle.edgeType,
-          captionStyle.edgeColor,
-          captionStyle.getTypeface());
-    }
   }
 
   /**
@@ -151,17 +145,4 @@ public final class CaptionStyleCompat {
     this.edgeColor = edgeColor;
     this.typeface = typeface;
   }
-
-  @RequiresApi(21)
-  @SuppressWarnings("ResourceType")
-  private static CaptionStyleCompat createFromCaptionStyleV21(
-      CaptioningManager.CaptionStyle captionStyle) {
-    return new CaptionStyleCompat(
-        captionStyle.hasForegroundColor() ? captionStyle.foregroundColor : DEFAULT.foregroundColor,
-        captionStyle.hasBackgroundColor() ? captionStyle.backgroundColor : DEFAULT.backgroundColor,
-        captionStyle.hasWindowColor() ? captionStyle.windowColor : DEFAULT.windowColor,
-        captionStyle.hasEdgeType() ? captionStyle.edgeType : DEFAULT.edgeType,
-        captionStyle.hasEdgeColor() ? captionStyle.edgeColor : DEFAULT.edgeColor,
-        captionStyle.getTypeface());
-  }
 }

libraries/ui/src/main/java/androidx/media3/ui/DefaultTimeBar.java

@@ -759,13 +759,8 @@ public class DefaultTimeBar extends View implements TimeBar {
     if (duration <= 0) {
       return;
     }
-    if (Util.SDK_INT >= 21) {
+    info.addAction(AccessibilityAction.ACTION_SCROLL_FORWARD);
-      info.addAction(AccessibilityAction.ACTION_SCROLL_FORWARD);
+    info.addAction(AccessibilityAction.ACTION_SCROLL_BACKWARD);
-      info.addAction(AccessibilityAction.ACTION_SCROLL_BACKWARD);
-    } else {
-      info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_FORWARD);
-      info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD);
-    }
   }
 
   @Override

libraries/ui/src/main/java/androidx/media3/ui/DefaultTrackNameProvider.java

@@ -115,8 +115,7 @@ public class DefaultTrackNameProvider implements TrackNameProvider {
     if (TextUtils.isEmpty(language) || C.LANGUAGE_UNDETERMINED.equals(language)) {
       return "";
     }
-    Locale languageLocale =
+    Locale languageLocale = Locale.forLanguageTag(language);
-        Util.SDK_INT >= 21 ? Locale.forLanguageTag(language) : new Locale(language);
     Locale displayLocale = Util.getDefaultDisplayLocale();
     String languageName = languageLocale.getDisplayName(displayLocale);
     if (TextUtils.isEmpty(languageName)) {

libraries/ui/src/main/java/androidx/media3/ui/LegacyPlayerControlView.java

@@ -47,9 +47,7 @@ import android.view.accessibility.AccessibilityEvent;
 import android.widget.FrameLayout;
 import android.widget.ImageView;
 import android.widget.TextView;
-import androidx.annotation.DoNotInline;
 import androidx.annotation.Nullable;
-import androidx.annotation.RequiresApi;
 import androidx.media3.common.C;
 import androidx.media3.common.MediaLibraryInfo;
 import androidx.media3.common.Player;
@@ -857,19 +855,15 @@ public class LegacyPlayerControlView extends FrameLayout {
     boolean requestPlayPauseAccessibilityFocus = false;
     boolean shouldShowPlayButton = Util.shouldShowPlayButton(player, showPlayButtonIfSuppressed);
     if (playButton != null) {
-      requestPlayPauseFocus |= !shouldShowPlayButton && playButton.isFocused();
+      requestPlayPauseFocus = !shouldShowPlayButton && playButton.isFocused();
-      requestPlayPauseAccessibilityFocus |=
+      requestPlayPauseAccessibilityFocus =
-          Util.SDK_INT < 21
+          (!shouldShowPlayButton && playButton.isAccessibilityFocused());
-              ? requestPlayPauseFocus
-              : (!shouldShowPlayButton && Api21.isAccessibilityFocused(playButton));
       playButton.setVisibility(shouldShowPlayButton ? VISIBLE : GONE);
     }
     if (pauseButton != null) {
       requestPlayPauseFocus |= shouldShowPlayButton && pauseButton.isFocused();
       requestPlayPauseAccessibilityFocus |=
-          Util.SDK_INT < 21
+          shouldShowPlayButton && pauseButton.isAccessibilityFocused();
-              ? requestPlayPauseFocus
-              : (shouldShowPlayButton && Api21.isAccessibilityFocused(pauseButton));
       pauseButton.setVisibility(shouldShowPlayButton ? GONE : VISIBLE);
     }
     if (requestPlayPauseFocus) {
@@ -1357,12 +1351,4 @@ public class LegacyPlayerControlView extends FrameLayout {
       }
     }
   }
-
-  @RequiresApi(21)
-  private static final class Api21 {
-    @DoNotInline
-    public static boolean isAccessibilityFocused(View view) {
-      return view.isAccessibilityFocused();
-    }
-  }
 }

libraries/ui/src/main/java/androidx/media3/ui/PlayerNotificationManager.java

@@ -55,7 +55,6 @@ import androidx.annotation.DrawableRes;
 import androidx.annotation.IntDef;
 import androidx.annotation.IntRange;
 import androidx.annotation.Nullable;
-import androidx.annotation.RequiresApi;
 import androidx.core.app.NotificationBuilderWithBuilderAccessor;
 import androidx.core.app.NotificationCompat;
 import androidx.core.app.NotificationManagerCompat;
@@ -1013,11 +1012,10 @@ public class PlayerNotificationManager {
    * @deprecated Use {@link #setMediaSessionToken(MediaSession.Token)} and pass in {@code
    *     (MediaSession.Token) compatToken.getToken()}.
    */
+  // TODO: b/333355694 - Remove the dependency on androidx.media when this method is removed.
   @Deprecated
   public final void setMediaSessionToken(MediaSessionCompat.Token compatToken) {
-    if (Util.SDK_INT >= 21) {
+    setMediaSessionToken((MediaSession.Token) compatToken.getToken());
-      setMediaSessionToken((MediaSession.Token) compatToken.getToken());
-    }
   }
 
   /**
@@ -1028,7 +1026,6 @@ public class PlayerNotificationManager {
    *
    * @param token The {@link MediaSession.Token}.
    */
-  @RequiresApi(21)
   public final void setMediaSessionToken(MediaSession.Token token) {
     if (!Util.areEqual(this.mediaSessionToken, token)) {
       mediaSessionToken = token;
@@ -1247,8 +1244,7 @@ public class PlayerNotificationManager {
    * Creates the notification given the current player state.
    *
    * @param player The player for which state to build a notification.
-   * @param builder The builder used to build the last notification, or {@code null}. Re-using the
+   * @param builder The builder used to build the last notification, or {@code null}.
-   *     builder when possible can prevent notification flicker when {@code Util#SDK_INT} < 21.
    * @param ongoing Whether the notification should be ongoing.
    * @param largeIcon The large icon to be used.
    * @return The {@link NotificationCompat.Builder} on which to call {@link
@@ -1291,17 +1287,7 @@ public class PlayerNotificationManager {
     }
 
     int[] actionIndicesForCompactView = getActionIndicesForCompactView(actionNames, player);
-    if (Util.SDK_INT >= 21) {
+    builder.setStyle(new MediaStyle(mediaSessionToken, actionIndicesForCompactView));
-      builder.setStyle(new MediaStyle(mediaSessionToken, actionIndicesForCompactView));
-    } else {
-      // TODO: b/333355694 - Remove dependency on androidx.media once this logic is gone.
-      androidx.media.app.NotificationCompat.MediaStyle mediaStyle =
-          new androidx.media.app.NotificationCompat.MediaStyle();
-      mediaStyle.setShowActionsInCompactView(actionIndicesForCompactView);
-      mediaStyle.setShowCancelButton(!ongoing);
-      mediaStyle.setCancelButtonIntent(dismissPendingIntent);
-      builder.setStyle(mediaStyle);
-    }
 
     // Set intent which is sent if the user selects 'clear all'
     builder.setDeleteIntent(dismissPendingIntent);
@@ -1317,9 +1303,7 @@ public class PlayerNotificationManager {
         .setPriority(priority)
         .setDefaults(defaults);
 
-    // Changing "showWhen" causes notification flicker if SDK_INT < 21.
+    if (useChronometer
-    if (Util.SDK_INT >= 21
-        && useChronometer
         && player.isCommandAvailable(COMMAND_GET_CURRENT_MEDIA_ITEM)
         && player.isPlaying()
         && !player.isPlayingAd()
@@ -1628,7 +1612,6 @@ public class PlayerNotificationManager {
     }
   }
 
-  @RequiresApi(21)
   private static final class MediaStyle extends androidx.core.app.NotificationCompat.Style {
 
     private final int[] actionsToShowInCompact;