Add setPlaybackSpeed as a convenience method to change speed.

PiperOrigin-RevId: 359734928

library/common/src/main/java/com/google/android/exoplayer2/BasePlayer.java

@@ -138,6 +138,11 @@ public abstract class BasePlayer implements Player {
   }
 
   @Override
+  public final void setPlaybackSpeed(float speed) {
+    setPlaybackParameters(getPlaybackParameters().withSpeed(speed));
+  }
+
+  @Override
   public final void stop() {
     stop(/* reset= */ false);
   }

library/common/src/main/java/com/google/android/exoplayer2/Player.java

@@ -1305,6 +1305,18 @@ public interface Player {
   void setPlaybackParameters(@Nullable PlaybackParameters playbackParameters);
 
   /**
+   * Changes the rate at which playback occurs.
+   *
+   * <p>The pitch is not changed.
+   *
+   * <p>This is equivalent to {@code setPlaybackParameter(getPlaybackParameter().withSpeed(speed))}.
+   *
+   * @param speed The linear factor by which playback will be sped up. Must be higher than 0. 1 is
+   *     normal speed, 2 is twice as fast, 0.5 is half normal speed...
+   */
+  void setPlaybackSpeed(float speed);
+
+  /**
    * Returns the currently active playback parameters.
    *
    * @see EventListener#onPlaybackParametersChanged(PlaybackParameters)

library/core/src/test/java/com/google/android/exoplayer2/ExoPlayerTest.java

@@ -8606,6 +8606,20 @@ public final class ExoPlayerTest {
   }
 
   @Test
+  public void playerIdle_withSetPlaybackSpeed_usesPlaybackParameterSpeedWithPitchUnchanged() {
+    ExoPlayer player = new TestExoPlayerBuilder(context).build();
+    player.setPlaybackParameters(new PlaybackParameters(/* speed= */ 1, /* pitch= */ 2));
+    Player.EventListener mockListener = mock(Player.EventListener.class);
+    player.addListener(mockListener);
+    player.prepare();
+
+    player.setPlaybackSpeed(2);
+
+    verify(mockListener)
+        .onPlaybackParametersChanged(new PlaybackParameters(/* speed= */ 2, /* pitch= */ 2));
+  }
+
+  @Test
   public void targetLiveOffsetInMedia_withSetPlaybackParameters_usesPlaybackParameterSpeed()
       throws Exception {
     long windowStartUnixTimeMs = 987_654_321_000L;