Avoid memcpy in JavaToNativeEncodedImage

Followup to https://webrtc-review.googlesource.com/c/src/+/142160

Bug: webrtc:9378
Change-Id: If790cd628433046d6819a92449fcc68106535df4
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/154561
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29359}

sdk/android/src/jni/encoded_image.cc

@@ -11,14 +11,42 @@
 #include "sdk/android/src/jni/encoded_image.h"
 
 #include "api/video/encoded_image.h"
+#include "rtc_base/ref_counted_object.h"
 #include "rtc_base/time_utils.h"
 #include "sdk/android/generated_video_jni/EncodedImage_jni.h"
 #include "sdk/android/native_api/jni/java_types.h"
 #include "sdk/android/src/jni/jni_helpers.h"
+#include "sdk/android/src/jni/scoped_java_ref_counted.h"
 
 namespace webrtc {
 namespace jni {
 
+namespace {
+
+class JavaEncodedImageBuffer : public EncodedImageBufferInterface {
+ public:
+  JavaEncodedImageBuffer(JNIEnv* env,
+                         const JavaRef<jobject>& j_encoded_image,
+                         const uint8_t* payload,
+                         size_t size)
+      : j_encoded_image_(ScopedJavaRefCounted::Adopt(env, j_encoded_image)),
+        data_(const_cast<uint8_t*>(payload)),
+        size_(size) {}
+
+  const uint8_t* data() const override { return data_; }
+  uint8_t* data() override { return data_; }
+  size_t size() const override { return size_; }
+
+ private:
+  // The Java object owning the buffer.
+  const ScopedJavaRefCounted j_encoded_image_;
+
+  // TODO(bugs.webrtc.org/9378): Make const, and delete above const_cast.
+  uint8_t* const data_;
+  size_t const size_;
+};
+}  // namespace
+
 ScopedJavaLocalRef<jobject> NativeToJavaFrameType(JNIEnv* env,
                                                   VideoFrameType frame_type) {
   return Java_FrameType_fromNativeIndex(env, static_cast<int>(frame_type));
@@ -62,9 +90,14 @@ EncodedImage JavaToNativeEncodedImage(JNIEnv* env,
   const size_t buffer_size = env->GetDirectBufferCapacity(j_buffer.obj());
 
   EncodedImage frame;
-  frame.Allocate(buffer_size);
-  frame.set_size(buffer_size);
-  memcpy(frame.data(), buffer, buffer_size);
+  if (Java_EncodedImage_maybeRetain(env, j_encoded_image)) {
+    frame.SetEncodedData(new rtc::RefCountedObject<JavaEncodedImageBuffer>(
+        env, j_encoded_image, buffer, buffer_size));
+  } else {
+    // Encoder doesn't support retain/release, so make a copy.
+    frame.SetEncodedData(EncodedImageBuffer::Create(buffer, buffer_size));
+  }
+
   frame._encodedWidth = Java_EncodedImage_getEncodedWidth(env, j_encoded_image);
   frame._encodedHeight =
       Java_EncodedImage_getEncodedHeight(env, j_encoded_image);

sdk/android/src/jni/scoped_java_ref_counted.cc

@@ -0,0 +1,28 @@
+/*
+ *  Copyright 2019 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "sdk/android/src/jni/scoped_java_ref_counted.h"
+
+#include "sdk/android/generated_base_jni/RefCounted_jni.h"
+
+namespace webrtc {
+namespace jni {
+
+ScopedJavaRefCounted::~ScopedJavaRefCounted() {
+  if (!j_object_.is_null()) {
+    JNIEnv* jni = AttachCurrentThreadIfNeeded();
+    Java_RefCounted_release(jni, j_object_);
+    CHECK_EXCEPTION(jni)
+        << "Unexpected java exception from ScopedJavaRefCounted.release()";
+  }
+}
+
+}  // namespace jni
+}  // namespace webrtc

sdk/android/src/jni/scoped_java_ref_counted.h

@@ -31,14 +31,7 @@ class ScopedJavaRefCounted {
   ScopedJavaRefCounted(const ScopedJavaRefCounted& other) = delete;
   ScopedJavaRefCounted& operator=(const ScopedJavaRefCounted&) = delete;
 
-  ~ScopedJavaRefCounted() {
-    if (!j_object_.is_null()) {
-      JNIEnv* jni = AttachCurrentThreadIfNeeded();
-      Java_RefCounted_release(jni, j_object_);
-      CHECK_EXCEPTION(jni)
-          << "Unexpected java exception from ScopedJavaRefCounted.release()";
-    }
-  }
+  ~ScopedJavaRefCounted();
 
  private:
   // Adopts reference.