Effect: Avoid allocating bitmaps and textures in Overlays.

In `TextOverlay` and `DrawableOverlay`, treat `Bitmap` as a buffer, where we
allocate it rarely and reuse it as long as possible before making a new one.

In `BitmapOverlay`, avoid allocating GL textures too often as well.

Strongly reduces allocations and memory usage growth (saving ~100-150 MB on 4k60fps
at high end), at the cost of more code complexity and low-end using 70MB more, on
1/1 comparisons.

PiperOrigin-RevId: 585990602

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

@@ -571,20 +571,15 @@ public final class GlUtil {
   }
 
   /**
-   * Allocates a new texture, initialized with the {@link Bitmap bitmap} data.
-   *
-   * <p>The created texture will have the same size as the specified {@link Bitmap}.
+   * Allocates a new texture, initialized with the {@link Bitmap bitmap} data and size.
    *
    * @param bitmap The {@link Bitmap} for which the texture is created.
    * @return The texture identifier for the newly-allocated texture.
    * @throws GlException If the texture allocation fails.
    */
   public static int createTexture(Bitmap bitmap) throws GlException {
-    assertValidTextureSize(bitmap.getWidth(), bitmap.getHeight());
     int texId = generateTexture();
-    bindTexture(GLES20.GL_TEXTURE_2D, texId);
-    GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, /* level= */ 0, bitmap, /* border= */ 0);
-    checkGlError();
+    setTexture(texId, bitmap);
     return texId;
   }
 
@@ -642,14 +637,22 @@ public final class GlUtil {
     return texId;
   }
 
-  /** Returns a new GL texture identifier. */
-  private static int generateTexture() throws GlException {
+  /** Returns a new, unbound GL texture identifier. */
+  public static int generateTexture() throws GlException {
     int[] texId = new int[1];
     GLES20.glGenTextures(/* n= */ 1, texId, /* offset= */ 0);
     checkGlError();
     return texId[0];
   }
 
+  /** Sets the {@code texId} to contain the {@link Bitmap bitmap} data and size. */
+  public static void setTexture(int texId, Bitmap bitmap) throws GlException {
+    assertValidTextureSize(bitmap.getWidth(), bitmap.getHeight());
+    bindTexture(GLES20.GL_TEXTURE_2D, texId);
+    GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, /* level= */ 0, bitmap, /* border= */ 0);
+    checkGlError();
+  }
+
   /**
    * Binds the texture of the given type with default configuration of GL_LINEAR filtering and
    * GL_CLAMP_TO_EDGE wrapping.

libraries/effect/src/main/java/androidx/media3/effect/BitmapOverlay.java

@@ -44,6 +44,7 @@ public abstract class BitmapOverlay extends TextureOverlay {
   private final float[] flipVerticallyMatrix;
 
   private int lastTextureId;
+  private boolean hasUpdatedBitmapReference;
   private @Nullable Bitmap lastBitmap;
 
   /* package */ BitmapOverlay() {
@@ -74,16 +75,27 @@ public abstract class BitmapOverlay extends TextureOverlay {
     return new Size(checkNotNull(lastBitmap).getWidth(), checkNotNull(lastBitmap).getHeight());
   }
 
+  /**
+   * Returns whether the cached bitmap overlay should be updated using the latest {@linkplain
+   * #getBitmap bitmap}.
+   */
+  protected boolean shouldInvalidateCache() {
+    // Bitmap#sameAs() is documented as a slow method. Therefore, only use a reference comparison by
+    // default, instead of the deeper comparison done in sameAs.
+    return hasUpdatedBitmapReference;
+  }
+
   @Override
   public int getTextureId(long presentationTimeUs) throws VideoFrameProcessingException {
     Bitmap bitmap = getBitmap(presentationTimeUs);
-    if (bitmap != lastBitmap) {
-      try {
+    hasUpdatedBitmapReference = bitmap != lastBitmap;
+    if (shouldInvalidateCache()) {
       lastBitmap = bitmap;
-        if (lastTextureId != C.INDEX_UNSET) {
-          GlUtil.deleteTexture(lastTextureId);
+      try {
+        if (lastTextureId == C.INDEX_UNSET) {
+          lastTextureId = GlUtil.generateTexture();
         }
-        lastTextureId = GlUtil.createTexture(checkNotNull(lastBitmap));
+        GlUtil.setTexture(lastTextureId, bitmap);
       } catch (GlUtil.GlException e) {
         throw new VideoFrameProcessingException(e);
       }

libraries/effect/src/main/java/androidx/media3/effect/DrawableOverlay.java

@@ -19,6 +19,8 @@ import static androidx.media3.common.util.Assertions.checkNotNull;
 
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.PorterDuff;
 import android.graphics.drawable.Drawable;
 import androidx.media3.common.util.UnstableApi;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
@@ -31,6 +33,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
  */
 @UnstableApi
 public abstract class DrawableOverlay extends BitmapOverlay {
+  private boolean hasUpdatedDrawable;
   private @MonotonicNonNull Bitmap lastBitmap;
   private @MonotonicNonNull Drawable lastDrawable;
 
@@ -44,19 +47,34 @@ public abstract class DrawableOverlay extends BitmapOverlay {
    */
   public abstract Drawable getDrawable(long presentationTimeUs);
 
+  /**
+   * Returns whether the cached drawable overlay should be updated using the latest {@linkplain
+   * #getDrawable drawable}
+   */
+  @Override
+  protected final boolean shouldInvalidateCache() {
+    return hasUpdatedDrawable;
+  }
+
   @Override
   public Bitmap getBitmap(long presentationTimeUs) {
     Drawable overlayDrawable = getDrawable(presentationTimeUs);
     // TODO(b/227625365): Drawable doesn't implement the equals method, so investigate other methods
     //   of detecting the need to redraw the bitmap.
-    if (!overlayDrawable.equals(lastDrawable)) {
+    hasUpdatedDrawable = !overlayDrawable.equals(lastDrawable);
+    if (shouldInvalidateCache()) {
       lastDrawable = overlayDrawable;
+      if (lastBitmap == null
+          || lastBitmap.getWidth() != lastDrawable.getIntrinsicWidth()
+          || lastBitmap.getHeight() != lastDrawable.getIntrinsicHeight()) {
         lastBitmap =
             Bitmap.createBitmap(
                 lastDrawable.getIntrinsicWidth(),
                 lastDrawable.getIntrinsicHeight(),
                 Bitmap.Config.ARGB_8888);
+      }
       Canvas canvas = new Canvas(lastBitmap);
+      canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
       lastDrawable.draw(canvas);
     }
     return checkNotNull(lastBitmap);

libraries/effect/src/main/java/androidx/media3/effect/TextOverlay.java

@@ -22,6 +22,8 @@ import static java.lang.Math.ceil;
 import android.annotation.SuppressLint;
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.PorterDuff;
 import android.text.Layout;
 import android.text.SpannableString;
 import android.text.StaticLayout;
@@ -78,6 +80,8 @@ public abstract class TextOverlay extends BitmapOverlay {
 
   public static final int TEXT_SIZE_PIXELS = 100;
 
+  private boolean hasUpdatedText;
+
   private @MonotonicNonNull Bitmap lastBitmap;
   private @MonotonicNonNull SpannableString lastText;
 
@@ -88,19 +92,34 @@ public abstract class TextOverlay extends BitmapOverlay {
    */
   public abstract SpannableString getText(long presentationTimeUs);
 
+  /**
+   * Returns whether the cached text overlay should be updated using the latest {@linkplain #getText
+   * text}
+   */
+  @Override
+  protected final boolean shouldInvalidateCache() {
+    return hasUpdatedText;
+  }
+
   @Override
   public Bitmap getBitmap(long presentationTimeUs) {
     SpannableString overlayText = getText(presentationTimeUs);
-    if (!overlayText.equals(lastText)) {
+    hasUpdatedText = !overlayText.equals(lastText);
+    if (shouldInvalidateCache()) {
       lastText = overlayText;
       TextPaint textPaint = new TextPaint();
       textPaint.setTextSize(TEXT_SIZE_PIXELS);
       StaticLayout staticLayout =
           createStaticLayout(overlayText, textPaint, getSpannedTextWidth(overlayText, textPaint));
+      if (lastBitmap == null
+          || lastBitmap.getWidth() != staticLayout.getWidth()
+          || lastBitmap.getHeight() != staticLayout.getHeight()) {
         lastBitmap =
             Bitmap.createBitmap(
                 staticLayout.getWidth(), staticLayout.getHeight(), Bitmap.Config.ARGB_8888);
+      }
       Canvas canvas = new Canvas(checkNotNull(lastBitmap));
+      canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
       staticLayout.draw(canvas);
     }
     return checkNotNull(lastBitmap);