Add context sharing capabilities to the default GlObjectsProvider

Creates a way for apps to provide their EGLContext to DefaultVideoFrameProcessor, so that we can attach their context to the one we create. See [the EGL docs for more information about how contexts are shared in GL](https://registry.khronos.org/EGL/sdk/docs/man/html/eglCreateContext.xhtml)

PiperOrigin-RevId: 525708652

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

@@ -31,16 +31,17 @@ import androidx.media3.common.util.UnstableApi;
 @UnstableApi
 public interface GlObjectsProvider {
   /**
-   * Provider for GL objects that configures a GL context with 8-bit RGB or 10-bit RGB attributes,
+   * @deprecated Please use {@code DefaultGlObjectsProvider} in {@code androidx.media3.effect}.
-   * and no depth buffer or render buffers.
    */
+  @Deprecated
   GlObjectsProvider DEFAULT =
       new GlObjectsProvider() {
         @Override
         @RequiresApi(17)
         public EGLContext createEglContext(
             EGLDisplay eglDisplay, int openGlVersion, int[] configAttributes) throws GlException {
-          return GlUtil.createEglContext(eglDisplay, openGlVersion, configAttributes);
+          return GlUtil.createEglContext(
+              EGL14.EGL_NO_CONTEXT, eglDisplay, openGlVersion, configAttributes);
         }
 
         @Override

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

@@ -249,12 +249,14 @@ public final class GlUtil {
    */
   @RequiresApi(17)
   public static EGLContext createEglContext(EGLDisplay eglDisplay) throws GlException {
-    return createEglContext(eglDisplay, /* openGlVersion= */ 2, EGL_CONFIG_ATTRIBUTES_RGBA_8888);
+    return createEglContext(
+        EGL14.EGL_NO_CONTEXT, eglDisplay, /* openGlVersion= */ 2, EGL_CONFIG_ATTRIBUTES_RGBA_8888);
   }
 
   /**
    * Creates a new {@link EGLContext} for the specified {@link EGLDisplay}.
    *
+   * @param sharedContext The {@link EGLContext} with which to share data.
    * @param eglDisplay The {@link EGLDisplay} to create an {@link EGLContext} for.
    * @param openGlVersion The version of OpenGL ES to configure. Accepts either {@code 2}, for
    *     OpenGL ES 2.0, or {@code 3}, for OpenGL ES 3.0.
@@ -263,13 +265,16 @@ public final class GlUtil {
    */
   @RequiresApi(17)
   public static EGLContext createEglContext(
-      EGLDisplay eglDisplay, @IntRange(from = 2, to = 3) int openGlVersion, int[] configAttributes)
+      EGLContext sharedContext,
+      EGLDisplay eglDisplay,
+      @IntRange(from = 2, to = 3) int openGlVersion,
+      int[] configAttributes)
       throws GlException {
     checkArgument(
         Arrays.equals(configAttributes, EGL_CONFIG_ATTRIBUTES_RGBA_8888)
             || Arrays.equals(configAttributes, EGL_CONFIG_ATTRIBUTES_RGBA_1010102));
     checkArgument(openGlVersion == 2 || openGlVersion == 3);
-    return Api17.createEglContext(eglDisplay, openGlVersion, configAttributes);
+    return Api17.createEglContext(sharedContext, eglDisplay, openGlVersion, configAttributes);
   }
 
   /**
@@ -691,13 +696,14 @@ public final class GlUtil {
 
     @DoNotInline
     public static EGLContext createEglContext(
-        EGLDisplay eglDisplay, int version, int[] configAttributes) throws GlException {
+        EGLContext sharedContext, EGLDisplay eglDisplay, int version, int[] configAttributes)
+        throws GlException {
       int[] contextAttributes = {EGL14.EGL_CONTEXT_CLIENT_VERSION, version, EGL14.EGL_NONE};
       EGLContext eglContext =
           EGL14.eglCreateContext(
               eglDisplay,
               getEglConfig(eglDisplay, configAttributes),
-              EGL14.EGL_NO_CONTEXT,
+              sharedContext,
               contextAttributes,
               /* offset= */ 0);
       if (eglContext == null) {

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

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package androidx.media3.effect;
+
+import android.opengl.EGL14;
+import android.opengl.EGLContext;
+import android.opengl.EGLDisplay;
+import android.opengl.EGLSurface;
+import androidx.annotation.Nullable;
+import androidx.media3.common.C;
+import androidx.media3.common.GlObjectsProvider;
+import androidx.media3.common.GlTextureInfo;
+import androidx.media3.common.util.GlUtil;
+import androidx.media3.common.util.UnstableApi;
+
+// TODO(b/261820382): Add tests for sharing context.
+/**
+ * Implementation of {@link GlObjectsProvider} that configures an {@link EGLContext} to share data
+ * with a preexisting {@code sharedEglContext}.
+ *
+ * <p>The created {@link EGLContext} is configured with 8-bit RGB or 10-bit RGB attributes and no
+ * depth buffer or render buffers.
+ */
+@UnstableApi
+public final class DefaultGlObjectsProvider implements GlObjectsProvider {
+
+  private final EGLContext sharedEglContext;
+
+  /**
+   * Creates an instance.
+   *
+   * @param sharedEglContext The {@link EGLContext} with which to share data.
+   */
+  public DefaultGlObjectsProvider(@Nullable EGLContext sharedEglContext) {
+    this.sharedEglContext = sharedEglContext != null ? sharedEglContext : EGL14.EGL_NO_CONTEXT;
+  }
+
+  @Override
+  public EGLContext createEglContext(
+      EGLDisplay eglDisplay, int openGlVersion, int[] configAttributes) throws GlUtil.GlException {
+    return GlUtil.createEglContext(sharedEglContext, eglDisplay, openGlVersion, configAttributes);
+  }
+
+  @Override
+  public EGLSurface createEglSurface(
+      EGLDisplay eglDisplay,
+      Object surface,
+      @C.ColorTransfer int colorTransfer,
+      boolean isEncoderInputSurface)
+      throws GlUtil.GlException {
+    return GlUtil.createEglSurface(eglDisplay, surface, colorTransfer, isEncoderInputSurface);
+  }
+
+  @Override
+  public EGLSurface createFocusedPlaceholderEglSurface(
+      EGLContext eglContext, EGLDisplay eglDisplay, int[] configAttributes)
+      throws GlUtil.GlException {
+    return GlUtil.createFocusedPlaceholderEglSurface(eglContext, eglDisplay, configAttributes);
+  }
+
+  @Override
+  public GlTextureInfo createBuffersForTexture(int texId, int width, int height)
+      throws GlUtil.GlException {
+    int fboId = GlUtil.createFboForTexture(texId);
+    return new GlTextureInfo(texId, fboId, /* rboId= */ C.INDEX_UNSET, width, height);
+  }
+}