Implement AndroidVideoBuffer::ToI420.

webrtc/sdk/android/src/jni/native_handle_impl.cc

 /*
  *  Copyright 2015 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 "webrtc/sdk/android/src/jni/native_handle_impl.h"
 
 #include <memory>
 
 #include "webrtc/common_video/include/video_frame_buffer.h"
 #include "webrtc/rtc_base/bind.h"
 #include "webrtc/rtc_base/checks.h"
 #include "webrtc/rtc_base/keep_ref_until_done.h"
 #include "webrtc/rtc_base/logging.h"
 #include "webrtc/rtc_base/scoped_ref_ptr.h"
 #include "webrtc/rtc_base/timeutils.h"
 #include "webrtc/sdk/android/src/jni/classreferenceholder.h"
 #include "webrtc/sdk/android/src/jni/jni_helpers.h"
 #include "webrtc/system_wrappers/include/aligned_malloc.h"
 
 namespace webrtc_jni {
 
+namespace {
+
+class AndroidVideoI420Buffer : public webrtc::I420BufferInterface {
+ public:
+  AndroidVideoI420Buffer(JNIEnv* jni,
+                         jmethodID j_release_id,
+                         int width,
+                         int height,
+                         jobject j_video_frame_buffer);
+  ~AndroidVideoI420Buffer();
+
+ private:
+  const uint8_t* DataY() const override { return data_y_; }
+  const uint8_t* DataU() const override { return data_u_; }
+  const uint8_t* DataV() const override { return data_v_; }
+
+  int StrideY() const override { return stride_y_; }
+  int StrideU() const override { return stride_u_; }
+  int StrideV() const override { return stride_v_; }
+
+  int width() const override { return width_; }
+  int height() const override { return height_; }
+
+  const jmethodID j_release_id_;
+  const int width_;
+  const int height_;
+  // Holds a VideoFrame.I420Buffer.
+  const ScopedGlobalRef<jobject> j_video_frame_buffer_;
+
+  const uint8_t* data_y_;
+  const uint8_t* data_u_;
+  const uint8_t* data_v_;
+  int stride_y_;
+  int stride_u_;
+  int stride_v_;
+};
+
+AndroidVideoI420Buffer::AndroidVideoI420Buffer(JNIEnv* jni,
+                                               jmethodID j_release_id,
+                                               int width,
+                                               int height,
+                                               jobject j_video_frame_buffer)
+    : j_release_id_(j_release_id),
+      width_(width),
+      height_(height),
+      j_video_frame_buffer_(jni, j_video_frame_buffer) {
+  jclass j_video_frame_i420_buffer_class =
+      FindClass(jni, "org/webrtc/VideoFrame$I420Buffer");
+  jmethodID j_get_data_y_id = jni->GetMethodID(
+      j_video_frame_i420_buffer_class, "getDataY", "()Ljava/nio/ByteBuffer;");
+  jmethodID j_get_data_u_id = jni->GetMethodID(
+      j_video_frame_i420_buffer_class, "getDataU", "()Ljava/nio/ByteBuffer;");
+  jmethodID j_get_data_v_id = jni->GetMethodID(
+      j_video_frame_i420_buffer_class, "getDataV", "()Ljava/nio/ByteBuffer;");
+  jmethodID j_get_stride_y_id =
+      jni->GetMethodID(j_video_frame_i420_buffer_class, "getStrideY", "()I");
+  jmethodID j_get_stride_u_id =
+      jni->GetMethodID(j_video_frame_i420_buffer_class, "getStrideU", "()I");
+  jmethodID j_get_stride_v_id =
+      jni->GetMethodID(j_video_frame_i420_buffer_class, "getStrideV", "()I");
+
+  jobject j_data_y =
+      jni->CallObjectMethod(j_video_frame_buffer, j_get_data_y_id);
+  jobject j_data_u =
+      jni->CallObjectMethod(j_video_frame_buffer, j_get_data_u_id);
+  jobject j_data_v =
+      jni->CallObjectMethod(j_video_frame_buffer, j_get_data_v_id);
+
+  data_y_ = static_cast<const uint8_t*>(jni->GetDirectBufferAddress(j_data_y));
+  data_u_ = static_cast<const uint8_t*>(jni->GetDirectBufferAddress(j_data_u));
+  data_v_ = static_cast<const uint8_t*>(jni->GetDirectBufferAddress(j_data_v));
+
+  stride_y_ = jni->CallIntMethod(j_video_frame_buffer, j_get_stride_y_id);
+  stride_u_ = jni->CallIntMethod(j_video_frame_buffer, j_get_stride_u_id);
+  stride_v_ = jni->CallIntMethod(j_video_frame_buffer, j_get_stride_v_id);
+}
+
+AndroidVideoI420Buffer::~AndroidVideoI420Buffer() {
+  JNIEnv* jni = AttachCurrentThreadIfNeeded();
+  jni->CallVoidMethod(*j_video_frame_buffer_, j_release_id_);
+}
+
+}  // namespace
+
 Matrix::Matrix(JNIEnv* jni, jfloatArray a) {
   RTC_CHECK_EQ(16, jni->GetArrayLength(a));
   jfloat* ptr = jni->GetFloatArrayElements(a, nullptr);
   for (int i = 0; i < 16; ++i) {
     elem_[i] = ptr[i];
   }
   jni->ReleaseFloatArrayElements(a, ptr, 0);
 }
 
 jfloatArray Matrix::ToJava(JNIEnv* jni) const {
@@ skipping 186 matching lines @@
 
 int AndroidVideoBuffer::width() const {
   return width_;
 }
 
 int AndroidVideoBuffer::height() const {
   return height_;
 }
 
 rtc::scoped_refptr<webrtc::I420BufferInterface> AndroidVideoBuffer::ToI420() {
-  // TODO(magjed): Implement using Java ToI420.
-  return nullptr;
+  JNIEnv* jni = AttachCurrentThreadIfNeeded();
+  ScopedLocalRefFrame local_ref_frame(jni);
+
+  jclass j_video_frame_buffer_class =
+      FindClass(jni, "org/webrtc/VideoFrame$Buffer");
+  jmethodID j_to_i420_id =
+      jni->GetMethodID(j_video_frame_buffer_class, "toI420",
+                       "()Lorg/webrtc/VideoFrame$I420Buffer;");
+
+  jobject j_i420_buffer =
+      jni->CallObjectMethod(*j_video_frame_buffer_, j_to_i420_id);

[magjed_webrtc, 2017/08/01 12:31:42]

I'm still worried about the asymmetry between where retain and release happens.
Move this into the ctor and comment that the retain happens in Java code.

[sakal, 2017/08/09 11:07:29]

I don't like having this in the constructor because it unnecessarily limits
where the frame can come from. I changed this to be a static method
AndroidVideoI420Buffer::WrapReference and added comments.

+
+  return new rtc::RefCountedObject<AndroidVideoI420Buffer>(
+      jni, j_release_id_, width_, height_, j_i420_buffer);
 }
 
 jobject AndroidVideoBuffer::ToJavaI420Frame(JNIEnv* jni,
                                             int rotation) {
   jclass j_byte_buffer_class = jni->FindClass("java/nio/ByteBuffer");
   jclass j_i420_frame_class =
       FindClass(jni, "org/webrtc/VideoRenderer$I420Frame");
   jmethodID j_i420_frame_ctor_id = GetMethodID(
       jni, j_i420_frame_class, "<init>", "(ILorg/webrtc/VideoFrame$Buffer;J)V");
   // Java code just uses the native frame to hold a reference to the buffer so
@@ skipping 46 matching lines @@
 rtc::scoped_refptr<AndroidVideoBuffer> AndroidVideoBufferFactory::CreateBuffer(
     jobject j_video_frame_buffer) const {
   JNIEnv* jni = AttachCurrentThreadIfNeeded();
   int width = jni->CallIntMethod(j_video_frame_buffer, j_get_width_id_);
   int height = jni->CallIntMethod(j_video_frame_buffer, j_get_height_id_);
   return new rtc::RefCountedObject<AndroidVideoBuffer>(
       jni, j_retain_id_, j_release_id_, width, height, j_video_frame_buffer);
 }
 
 }  // namespace webrtc_jni